Research - Skin
A new topical treatment of atopic dermatitis in pediatric patients based on Ficus carica L. (Fig): A randomized, placebo-controlled clinical trial
.Abbasi S1, Kamalinejad M2, Babaie D3, Shams S4, Sadr Z5, Gheysari M6, Askari VR7, Rakhshandeh H8.
BACKGROUND:Atopic dermatitis (AD) is a common, chronic, relapsing and inflammatory skin disease characterized by pruritus and xerosis (dry skin). Its prevalence is on the increase worldwide, particularly in children. As the pathogenesis of AD involves a complex interaction of genetic, environmental and immunological factors, its definitive treatment is difficult.
OBJECTIVE:This clinical trial was designed as equivalence study to investigate the effect of aqueous extract of edible dried fig fruit on the severity of AD as measured with scoring atopic dermatitis (SCORAD), in comparison with Hydrocortisone 1.0% as the routine treatment of AD and base cream as a placebo.
METHOD:Forty five children aged 4 months to 14 years with mild to moderate AD (SCORAD <50) were randomly assigned, in a double blind manner, to three treatment groups in order to perform a randomised, double blinded, placebo-controlled clinical trial. The patients were instructed to apply their allocated creams twice a day for two weeks.
RESULTS:The randomised, placebo-controlled trial indicates that the new treatment had significantly increased efficacy in terms of reducing the SCORAD index, pruritus and intensity scores in comparison with Hydrocortisone 1.0% (p<0.05) and the placebo failed to ameliorate the symptoms.
CONCLUSION:Safety, efficacy, tolerability, and symptom relief were considerable in fig fruit extract in comparison with hydrocortisone 1.0%. This clinical trial suggests that fig fruit extract can be used instead of low potent corticosteroid in mild to moderate cases of AD
Source : Journal Complementary Therapies in Medicine
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Cellulite Reduction by Modified Thai Herbal Compresses: A Randomized Double-Blind Trial
Ngamrayu Ngamdokmai, MSc1 , Neti Waranuch, PhD2 , Krongkarn Chootip, PhD3 , Katechan Jampachaisri, PhD4 , C. Norman Scholfield, PhD5 , and Kornkanok Ingkaninan, PhD1
Cellulite remains an obstinate clinical and cosmetic problem. In this study, we adapted the Thai traditional noninvasive treatment formulated with 5 additional herbals to improve blood flow, edema, and lipolysis, thereby augmenting cellulite treatment. This was a double-blind, randomized placebo-controlled paired trial. Twenty-one women (20-55 years) having cellulite (grade ≥2) were treated with steamed placebo or herbal compresses randomly assigned to one or other thigh twice weekly for 8 weeks with 2 weeks washout. Cellulite reduction was assessed from standardized photographs by 3 blinded evaluators at baseline and every 2 weeks; also assessed were thigh circumferences and cutaneous skin-fold thicknesses, trial diaries, and participant feedback. After 8 weeks, herbal compress treatment reduced Nürnberger-Müller cellulite scores from 12.6 ± 2.0 to 9.9 ± 2.4 compared with 12.5 ± 2.1 to 12.1 ± 2.0 (means ± SEM) for contralateral placebo-treated thighs (P < .0001; effect size [ES] = 1.16, confidence interval [CI] = 0.48-1.83). Thigh circumferences diminished by 2.2 ± 0.9 cm (herbal) and 1.4 ± 0.7 cm (placebo) (ES = 0.96, CI = 0.30-1.61) and correspondingly skin-folds by 5.6 ± 2.2 and 2.4 ± 1.3 mm (ES = 1.72, CI = 0.99-2.45). No adverse actions were reported, and there were no dropouts, no missing data, and 100% adherence. Herbal compresses were efficacious against cellulite and thigh sizes. The herbal formula might be adapted to other delivery options, and rationally added herbals may increase effectiveness of traditional therapies and more sustainable actions.
Source : Journal Evidence Based Integrative Medicine
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Dietary Foeniculum vulgare Mill extract attenuated UVB irradiation-induced skin photoaging by activating of Nrf2 and inhibiting MAPK pathways
- Zhengwang Sun1,
- Sang Yong Park1,
- Eunson Hwang,
- Bom Park,
- Seul A Seo,
- Jin-Gyeong Cho,
- Mengyang Zhang,
- Tae-Hoo Yi
Background Foeniculum vulgare Mill (FV) has long been prescribed in traditional medicine due to its antioxidant anti-inflammatory properties. However, little research has been done on the use of FV to alleviate changes in UVB-induced photoaging
Purpose This study was to investigate the photoprotective effects and mechanism of FV in vitro and in vivo.
Methods The anti-photoaging effect of FV was assessed in normal human dermal fibroblasts (NHDFs) in vitro. The secretion of reactive oxygen species (ROS), lactate dehydrogenase (LDH), GSH, matrix metalloproteinases (MMPs), procollagen type I, IL-6 and transforming growth factor-β1 (TGF-β1) were measured by kits. Additionally, the level of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), p-ERK and p38 were evaluated by western blotting. In vivo, H&E and Masson's trichrome staining were employed. The expression of MMP-1, procollagen type I, TGF-β1 and elastin were measured by western blot.
Results FV significantly increased the production of collagen, elastin and TGF-β1 levels, while blocked matrix metalloproteinases (MMPs) production in UVB irradiation induced hairless mice, which were consistent with the result in NHDFs. Furthermore, FV dose-dependently decreased the production of ROS and LDH by promoting the nuclear amount of Nrf2 and enhancing the expression of cytoprotective antioxidants such as GSH. FV also significantly quenched UVB-induced phosphorylation of ERK and p38 in NHDFs.
Conclusion Our results indicate that FV is a potential botanical agent for the treatment of skin damage induced by UV irradiation.
Source : Journal Phytomedicine
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Antimicrobial and antioxidant efficacy of Citrus limon L. peel extracts used for skin diseases by Xhosa tribe of Amathole District, Eastern Cape, South Africa
W.M. Otang, A.J. Afolayan
Skin diseases such as dermatitis, prurigo, and scabies present a major health concern in the Eastern Cape, South Africa, where there is a scarcity of dermatologists, compounded by the fact that most dermatologists are centered near urban areas and are not accessible to 70% of the rural population. Hence, many people still depend to a large extent on traditional herbs such as Citrus limon for the treatment of skin diseases. The aim of this study was therefore to screen the acetone and ethanol extracts of C. limon for its antioxidant potential and antimicrobial efficacy agents against a panel of microbes implicated in skin diseases. The highest antibacterial activity was obtained with the acetone extract of C. limon against Enterococcus faecalis and Bacillus subtilis, and the most susceptible bacteria based on the overall mean inhibition diameters were the gram-negative Salmonella typhimurium, Shigella sonnei and the gram-positive E. faecalis and B. subtilis. Both extracts were active against Candida glabrata. The DPPH scavenging activity of the acetone extract was not significantly different from those of vitamin C and rutin. Nitric oxide scavenging activity was lowest in the ethanol extract of C. limon. The reducing ability of both plant extracts was significantly lower than that of vitamin C and rutin. The fact that both extracts of C. limon exhibited a broad spectrum of antibacterial activity and comparable efficacy to the synthetic antioxidants highlights the medicinal value of C. limon as a potential source for drug development amidst the obvious dearth of effective and safe antibacterial drugs, and also validates the ethnotherapeutic claim of the plant.
Source : South African Journal of Botany
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Acupoint stimulation for chronic urticaria: a systematic review of randomized controlled trials
Introduction Standard treatments are often unsatisfactory on chronic urticaria (CU). Acupoint stimulation, including acupuncture, electroacupuncture, acupoint catgut embedding, acupoint injection, has shown benefit about alleviating itching, reducing amount and range of the lesions. However, the methodological quality of these trials is unknown. Thus, the objective of this review is to evaluate the quality and effectiveness of acupoint stimulation for chronic urticaria.
Methods We searched PubMed, Embase, the Cochrane Central Register of Controlled Trials, CNKI, CBM, VIP, Wanfang databases from January 1966 to June 2015. Randomized controlled trials (RCTs) on acupoint stimulation for CU were included. The Cochrane risk of bias tool was used to evaluate methodological quality.
Results Eight RCTs met the inclusion criteria, which were all low quality. Acupuncture plus other treatment was significantly superior to western medicine alone and autologous blood injection plus herbal medicine was better than herbal medicine alone in increasing the number of cured patients.
Conclusions Acupoint stimulation may provide benefit in CU; however, more large scale, high quality studies are needed for assessing the effects before it is recommended.
Source : European Journal of Integrative Medicine
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Cocoa Flavanol Consumption Improves Facial Wrinkles and Skin Elasticity in Women with Photo-aged Facial Skin
Yoon H-S, Kim JR, Park GY, et al. Cocoa flavanol supplementation influences skin conditions of photo-aged women: a 24-week double-blind, randomized, controlled trial. J Nutr. 2016;146(1):46-50.
Cocoa products, derived from the dried, fermented fatty seeds of the cocoa (Theobroma cacao, Malvaceae) tree, reportedly have many health benefits. They are rich in polyphenolic antioxidants and flavanols such as epicatechin, catechin, and procyanidins. Clinical trials conducted for 12 weeks that investigated the effects of consuming high-flavanol cocoa products on skin photo-aging have shown conflicting results. Since finding an adequate daily dose and duration of cocoa flavanol supplementation might provide significant antioxidant photoprotection, these authors conducted a 24-week, double-blind, randomized, clinical trial to investigate whether high-flavanol cocoa supplementation would improve the moderately photo-aged facial skin of female subjects.
The subjects were healthy females aged between 40 and 86 years (mean age, 61.7 ± 13.1 years) with visible wrinkles. The study was conducted between February 2014 and March 2015 at Seoul National University Hospital in Seoul, Korea. Sixty-four subjects were randomly assigned to either the cocoa group or placebo group, with 32 subjects in each group. Of those subjects, 1 from each group did not follow the protocol and did not complete the study.
The beverage consumed daily by the cocoa group contained 4 g fat-reduced cocoa powder (Barry Callebaut Belgium N.V.; Lebbeke-Wieze, Belgium) that was processed in a manner to preserve a high amount (320 mg) of cacao bean flavanols. A nutrient-matched cocoa-flavored beverage that did not contain cocoa flavanols was consumed by the placebo group. The beverage powders were dissolved in 150-200 mL hot water.
Wrinkles were measured in the crow's feet area on the outer corner of the eye by using a Skin-Visiometer® SV 600 (Courage+Khazaka electronic GmbH; Cologne, Germany) to assess the following 5 roughness variables: skin roughness, maximum roughness, average roughness, smoothness depth, and arithmetic average roughness. As wrinkles diminish in depth, those values decrease. A Cutometer® MPA580 (Courage+Khazaka electronic GmbH) was used to measure skin elasticity on the cheek in terms of gross elasticity, net elasticity, and biological elasticity. The closer the value is to 1 on the cutometer, the more elastic the skin. Using a Corneometer® and a Tewameter® (both, Courage+Khazaka electronic GmbH), the authors evaluated skin hydration on each subject's cheek.
The facial skin of each subject was evaluated at baseline and during the study at 12 and 24 weeks. Ten subjects in each group agreed to undergo ultraviolet (UV)-B irradiation. The minimal erythema dose (MED), or the minimal UV dose causing erythema on all edges of an irradiated square of skin on the buttock, was assessed at baseline and at 24 weeks in those subjects.
Adverse effects were evaluated at 12 and 24 weeks. Blood samples were drawn at baseline and at 24 weeks to measure aspartate aminotransferase, alanine transaminase, glucose, blood urea nitrogen, creatinine, and hemoglobin and hematocrit concentrations.
The authors report no significant between-group differences in visiometer measurements after 12 weeks of supplementation. After 24 weeks, however, the mean percentage changes in average roughness (P=0.023) and maximum roughness (P=0.030) were significantly lower in the cocoa group than in the placebo group. "Because visiometer values decrease as wrinkle diminish, these results suggest that the cocoa group showed improvement in wrinkle severity compared with the placebo group." Changes in the other visiometer variables were not significant at 24 weeks.
The only significant between-group difference in skin elasticity after 12 weeks was in the mean percentage change in gross elasticity of the skin, which was significantly greater in the cocoa group than in the placebo group (P=0.020). After 24 weeks, significant between-group differences were observed in gross elasticity (P=0.027), net elasticity (P=0.027), and biological elasticity (P=0.032), which were all greater for the cocoa group than for the placebo group. No significant between-group differences were seen in epidermal hydration variables after 12 or 24 weeks of supplementation.
No adverse effects were reported, and no abnormal laboratory values were observed. Body weight changes were minimal; the placebo group gained more than the cocoa group after 24 weeks (P=0.021). Although cocoa flavanols have been reported to have beneficial effects on obesity, in this study, the subjects' diet and physical activity were not controlled, so this finding "can only be interpreted as indirect evidence and was an unintended outcome," write the authors.
Overall adherence rates were 97.6% at 12 weeks and 98.4% at 24 weeks.
The MED of those in the placebo group undergoing UV irradiation did not change significantly during the study. In the cocoa group, however, a significantly increased MED was observed at 24 weeks (P=0.022). Changes in MED at 24 weeks were significantly higher in the cocoa group than in the placebo group (P=0.035).
Although this study showed that cocoa flavanols can improve facial wrinkles and elasticity, the effects were not as great as those reported for direct curative therapies such as topical tretinoin, laser resurfacing, and chemical peeling. "Therefore, the main effect of cocoa flavanols on photo-aging might be preventive rather than curative," the authors state.
The authors note that their findings of changes in wrinkle severity and skin elasticity are consistent with those of previous trials.1,2 Conflicting results remain regarding changes in MED after cocoa flavanol consumption, possibly because of the variations in age, skin phototype, and race of subjects used in the trials.
The authors conclude that "in moderately photo-aged women, regular cocoa flavanol consumption had positive effects on facial wrinkles and elasticity," and that "regular cocoa flavanol consumption may be a good strategy for prevention of the progression of skin photo-aging."
Source : American Botanical Council - HerbClip
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Wenyang Huazhuo Tongluo formula, a Chinese herbal decoction, improves skin fibrosis by promoting apoptosis and inhibiting proliferation through down-regulation of survivin and cyclin D1 in systemic sclerosis
- Li Han,
- Hua Bian
- Jingfeng Ouyang,
- Yuefeng Bi,
- Lei Yang and
- Songshan Ye
Fibrosis is a major contributor to systemic sclerosis (SSc)-related morbidity, and rapid, progressive skin involvement predicts later mortality. Western medicine therapies for SSc cannot produce satisfactory effects currently, while Traditional Chinese Medicine (TCM), such as the Wenyang Huazhuo Tongluo (WYHZTL) formula, a Chinese herbal decoction, has shown amazing anti-fibrosis efficacy on SSc in clinical applications. This study is aiming to investigate the anti-fibrotic mechanism of WYHZTL formula for the treatment of SSc.
Fibroblasts from primary culture of skin lesions of SSc patients were exposed to rat medicated sera containing WYHZTL or XAV939, a small-molecule inhibitor of both tankyrase 1/2 and Wnt/β-catenin pathway. Cell counting kit-8 assay and Annexin V FITC/PI apoptosis kit were used to analyze cell proliferation and apoptosis in fibroblasts, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) and western blotting were used to detect the mRNA and protein levels of cyclin D1 and survivin.
After 28, 48 and 72 h of incubation, the proliferative ability of the fibroblasts cells was obviously reduced by the sera containing WYHZTL compared with that in the control group; the percentage of apoptotic cell population in the sera containing WYHZTL treated fibroblasts cells was significantly higher than that in those treated with the control sera, and was about similar to that in those treated with XAV939. The sera containing WYHZTL could down-regulate both mRNA and protein levels of cyclin D1 and survivin, compared with the control group.
The present study demonstrates the antiproliferative and pro-apoptotic actions of WYHZTL formula against fibroblasts and the effect may be related to the down-regulation of mRNA and protein levels of cyclin D1 and survivin in SSc.
Source : BMC Complementary and Alternative Medicine
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Topical Application of Turmeric Extract Reduces the Severity of Psoriasis Lesions
Sarafian G, Afshar M, Mansouri P, Asgarpanah J, Raoufinejad K, Rajabi M. Topical turmeric microemulgel in the management of plaque psoriasis; a clinical evaluation. Iran J Pharm Res. Summer 2015;14(3):865-876.
Plaque psoriasis is an autoimmune, inflammatory skin disorder that causes patches of inflamed, thickened skin lesions. Many patients with psoriasis have other inflammatory disorders, such as metabolic syndrome, Crohn's disease, and cardiovascular disease. Mildly to moderately severe psoriasis is often treated effectively with prescription topical and systemic medications. Topical medications may have undesirable side effects, which include burning, atrophy, and staining of skin and clothes. Turmeric (Curcuma longa, Zingiberaceae) has been used in traditional medicine and found to have anti-inflammatory, antimicrobial, and antioxidant properties. Turmeric extract can decrease the cytokine pro-inflammatory response by inactivating and decreasing the expression of key enzymes in the pro-inflammatory pathway in human cells. Several studies have shown that turmeric extract applied topically can reduce the severity of psoriasis lesions. The goal of this double-blind, placebo-controlled study was to measure the efficacy of turmeric extract microemulgel on the symptoms of psoriasis in patients with mild to moderate plaque psoriasis.
Forty patients between the ages of 18 and 60 years of age with mild to moderate psoriasis on their legs and arms were recruited for the study. Patients were included if the extent and severity of their psoriasis had been stable for at least 2 months. Patients could be taking systemic treatments for psoriasis but were excluded if they were using topical psoriasis treatments. Patients were also excluded if they were taking beta-blockers, had lymphoma, or were pregnant or lactating. Lesions were assessed on each patient. Lesions that were similar in appearance were chosen from the left and right arm and leg. Patients applied a placebo cream to either the left or right side and the turmeric treatment cream to the opposite side. The authors note that the side of the body chosen was randomized, but not whether randomization was done within each patient. The data presented suggest that the turmeric microemulgel was always applied to the right arm and leg and that the placebo was applied to the left side of each patient. The microemulgel was applied twice per day for 9 weeks. The placebo contained only the microemulgel, whereas the treatment contained the microemulgel plus 0.5% of turmeric extracted with water and alcohol (SOHA JISSA Co.; Salman Shahr, Mazandaran, Iran). Curcuminoid concentration of the extract was measured with high-performance liquid chromatography. The redness, thickness, scaling, and area of lesions in each body area were measured with the Psoriasis Area and Severity Index (PASI) every 3 weeks. In addition, patient quality of life was measured at the same time with the Dermatology Life Quality Index (DLQI). Compliance was checked weekly. Data were analyzed with t-tests and chi-squared tests.
Thirty-four patients completed the study. Reasons were not given for the loss of the other patients from the study. The patients noted that stress, changes in temperature, and sun exposure were the most important psoriasis triggers. Within this group of patients, 14.7% had metabolic syndrome, and another 11.8% had diabetes. The number of patients experiencing itching, pain, and social discomfort decreased over the course of the study (P values not given). The redness, thickness, and scaling of lesions on the arms decreased significantly with turmeric treatment over the course of the study (P < 0.05). The scaling of lesions on the legs also decreased significantly with turmeric treatment (P < 0.05). The mean PASI score with turmeric treatment decreased significantly from 3.6 to 1.4 over the course of the study (P < 0.05). The mean PASI score was also significantly lower with the turmeric treatment than with the placebo (P < 0.05). The placebo microemulgel did result in a decrease in the PASI score metrics over the first 3 weeks of the study, but this decrease was not significant. Adverse effects were similar between the turmeric and placebo microemulgels and included dryness and burning.
Turmeric microemulgel significantly reduced the symptoms of psoriasis over a 9-week course of treatment. This treatment also improved quality-of-life indices, although statistical analysis of these indices was not provided. In addition, the turmeric microemulgel was well tolerated with few adverse effects. Other studies have found that phosphorylase kinase (PK) expression is higher in patients with psoriasis and that curcuminoids inhibit PK activity. PK is integral to the pro-inflammatory response, and its inhibition should result in a decrease in inflammation. This study may have been limited by the small sample size and type of randomization used. The type of randomization is not adequately described, but the results suggest that the use of the turmeric microemulgel was randomized to the right side of the body for all patients. This may cause unwanted bias. The results of this study suggest that turmeric may be an effective topical treatment for psoriasis with few side effects.
--Cheryl McCutchan, PhD
Source : American Botanical Council - Herbclip
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Protective effects of citrus and rosemary extracts on UV-induced damagein skin cell model and human volunteers
A. Pérez-Sáncheza,1, E. Barrajón-Catalána,1, N. Caturlab, J. Castilloc,e, O. Benavente-Garcíac,e,M. Alcarazd,e, V. Micola,⇑
Ultraviolet radiation absorbed by the epidermis is the major cause of various cutaneous disorders, including photoaging and skin cancers. Although topical sunscreens may offer proper skin protection, dietar yplant compounds may significantly contribute to lifelong protection of skin health, especially when unconsciously sun UV exposed. A combination of rosemary and citrus bioflavonoids extracts was used to inhibit UV harmful effects on human HaCaT keratinocytes and in human volunteers after oral intake.Survival of HaCaT cells after UVB radiation was higher in treatments using the combination of extracts than in those performed with individual extracts, indicating potential synergic effects. The combination of extracts also decreased UVB-induced intracellular radical oxygen species (ROS) and prevented DNA damage in HaCaT cells by comet assay and decreased chromosomal aberrations in X-irradiated human lymphocytes. The oral daily consumption of 250 mg of the combination by human volunteers revealed a significant minimal erythema dose (MED) increase after eight weeks (34%,p< 0.05). Stronger protection was achieved after 12 weeks (56%,p< 0.01). The combination of citrus flavonoids and rosemary polyphenols and diterpenes may be considered as an ingredient for oral photo protection. Their mechanism of action may deserve further attention.
Source : Journal of Photochemistry and Photobiology B: Biology
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Gallic Acid Regulates Skin Photoaging in UVB-exposed Fibroblast and Hairless Mice
Eunson Hwang, Sang-Yong Park, Hyun Ji Lee, Tae Youp Lee, Zheng-wang Sun,
Ultraviolet (UV) radiation is the primary factor in skin photoaging, which is characterized by wrinkle formation, dryness, and thickening. The mechanisms underlying skin photoaging are closely associated with degradation of collagen via upregulation of matrix metalloproteinase (MMP) activity, which is induced by reactive oxygen species (ROS) production. Gallic acid (GA), a phenolic compound, possesses a variety of biological activities including antioxidant and antiinflammatory activities. We investigated the protective effects of GA against photoaging caused by UVB irradiation using normal human dermal fibroblasts (NHDFs) in vitro and hairless mice in vivo. The production levels of ROS, interlukin-6, and MMP-1 were significantly suppressed, and type I procollagen expression was stimulated in UVB-irradiated and GA-treated NHDFs. GA treatment inhibited the activity of transcription factor activation protein 1. The effects of GA following topical application and dietary administration were examined by measuring wrinkle formation, histological modification, protein expression, and physiological changes such as stratum corneum hydration, transepidermal water loss, and erythema index. We found that GA decreased dryness, skin thickness, and wrinkle formation via negative modulation of MMP-1 secretion and positive regulation of elastin, type I procollagen, and transforming growth factor-β1. Our data indicate that GA is a potential candidate for the prevention of UVB-induced premature skin aging.
Source :Phytotherapy Research
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(+)-Catechin protects dermal fibroblasts against oxidative stress-induced apoptosis
Tomoko Tanigawa, Shigeyuki Kanazawa, Ryoko Ichibori, Takashi Fujiwara, Takuya Magome, Kenta Shingaki, Shingo Miyata, Yuki Hata, Koichi Tomita, Ken Matsuda, Tateki Kubo, Masaya Tohyama, Kenji Yano and Ko Hosokawa
Oxidative stress has been suggested as a mechanism underlying skin aging, as it triggers apoptosis in various cell types, including fibroblasts, which play important roles in the preservation of healthy, youthful skin. Catechins, which are antioxidants contained in green tea, exert various actions such as anti-inflammatory, anti-bacterial, and anti-cancer actions. In this study, we investigated the effect of (+)-catechin on apoptosis induced by oxidative stress in fibroblasts.
Fibroblasts (NIH3T3) under oxidative stress induced by hydrogen peroxide (0.1 mM) were treated with either vehicle or (+)-catechin (0-100 muM). The effect of (+)-catechin on cell viability, apoptosis, phosphorylation of c-Jun terminal kinases (JNK) and p38, and activation of caspase-3 in fibroblasts under oxidative stress were evaluated.
Hydrogen peroxide induced apoptotic cell death in fibroblasts, accompanied by induction of phosphorylation of JNK and p38 and activation of caspase-3. Pretreatment of the fibroblasts with (+)-catechin inhibited hydrogen peroxide-induced apoptosis and reduced phosphorylation of JNK and p38 and activation of caspase-3.
(+)-Catechin protects against oxidative stress-induced cell death in fibroblasts, possibly by inhibiting phosphorylation of p38 and JNK. These results suggest that (+)-catechin has potential as a therapeutic agent for the prevention of skin aging.
Source : BMC Complementary and Alternative Medicine
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The Role of Phytonutrients in Skin Health
Julie A. Evans and Elizabeth J. Johnson*
Photodamage is known to occur in skin with exposure to sunlight, specifically ultraviolet (UV) radiation. Such damage includes inflammation, oxidative stress, breakdown of the extracellular matrix, and development of cancer in the skin. Sun exposure is considered to be one of the most important risk factors for both nonmelanoma and melanoma skin cancers. Many phytonutrients have shown promise as photoprotectants in clinical, animal and cell culture studies. In part, the actions of these phytonutrients are thought to be through their actions as antioxidants. In regard to skin health, phytonutrients of interest include vitamin E, certain flavonoids, and the carotenoids, β-carotene, lycopene and lutein.
Source : Journal Nutrients
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Dietary nutrient intakes and skin-aging appearance among middle-aged American women1,2,3,4
Background: Nutritional factors play a key role in normal dermatologic functioning. However, little is known about the effects of diet on skin-aging appearance.
Objective: We evaluated the associations between nutrient intakes and skin-aging appearance.
Design: Using data from the first National Health and Nutrition Examination Survey, we examined associations between nutrient intakes and skin aging in 4025 women (40–74 y). Nutrients were estimated from a 24-h recall. Clinical examinations of the skin were conducted by dermatologists. Skin-aging appearance was defined as having a wrinkled appearance, senile dryness, and skin atrophy.
Results: Higher vitamin C intakes were associated with a lower likelihood of a wrinkled appearance [odds ratio (OR) 0.89; 95% CI: 0.82, 0.96] and senile dryness (OR: 0.93; 95% CI: 0.87, 0.99). Higher linoleic acid intakes were associated with a lower likelihood of senile dryness (OR: 0.75; 95% CI: 0.64, 0.88) and skin atrophy (OR: 0.78; 95% CI 0.65, 0.95). A 17-g increase in fat and a 50-g increase in carbohydrate intakes increased the likelihood of a wrinkled appearance (OR: 1.28 and 1.36, respectively) and skin atrophy (OR: 1.37 and 1.33, respectively). These associations were independent of age, race, education, sunlight exposure, income, menopausal status, body mass index, supplement use, physical activity, and energy intake.
Conclusions: Higher intakes of vitamin C and linoleic acid and lower intakes of fats and carbohydrates are associated with better skin-aging appearance. Promoting healthy dietary behaviors may have additional benefit for skin appearance in addition to other health outcomes in the population.
Source : American Journal Clinical Nutrition
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Antitumor and Wound Healing Properties of Rubus ellipticus Smith.
Blassan Plackal George, Thangaraj Parimelazhaga, Yamini T. Kumar, Thankarajan Sajeesh
The present investigation has been undertaken to study the antioxidant, antitumor, and wound healing properties of Rubus ellipticus. The R. ellipticus leaves were extracted using organic solvents in Soxhlet and were subjected to in vitro antioxidant assays. R. ellipticus leaf methanol (RELM) extract, which showed higher in vitro antioxidant activity, was taken for the evaluation of in vivo antioxidant, antitumor, and wound healing properties. Acute oral and dermal toxicity studies showed the safety of RELM up to a dose of 2 g/kg. A significant wound healing property was observed in incision, excision, and Staphylococcus aureus-induced infected wound models in the treatment groups compared to the control group. A complete epithelialization period was noticed during the 13th day and the 19th day. A 250-mg/kg treatment was found to prolong the life span of mice with Ehrlich ascite carcinoma (EAC; 46.76%) and to reduce the volume of Dalton's lymphoma ascite (DLA) solid tumors (2.56 cm3). The present study suggests that R. ellipticus is a valuable natural antioxidant and that it is immensely effective for treating skin diseases, wounds, and tumors.
Source : Journal of Acupuncture and Meridian Studies
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Herbal Sunscreens and Ultraviolet Protectants
Eric Yarnell, ND, RH (AHG) and Kathy Abascal BS, JD, RH (AHG
Some herbal agents taken orally appear to be able to reduce local and systemic negative effects of excessive ultraviolet (UV ) light exposure. What is notable in this category is the well-researched Phlebodium aureum (golden serpent fern), frequently referred to in the literature by an old name Polypodium leucatomos. Sufficiently high oral doses of Camellia sinensis (green tea), as well as topical applications, also appear to be photoprotective.In addition, Panax ginseng (Asian ginseng) may be helpful as a systemic immunomodulator to prevent the harm done by ex-cessive UV light on local and general immune function. What is much less well-established is the potential of the immuno-modulating fungus Cordyceps sinensis to have this same benefit. Redox modulators such as propolis and proanthocyanidins (from Pinus maritima or Vitis vinifera) have also shown the ability topically to prevent sunburn and UV-related toxicities. More research is needed but natural products look promising as photoprotectives. Note: The next article related to this topic will discuss herbal photosensitizers, or agents that enhance the therapeutic properties of UV light
Numerous natural products show promise as photoprotec-tive agents. Unlike anything in conventional medicine, there are several herbal products that appear to be active, when taken orally, to prevent sunburn or other local negative effects of ex-cessive UV exposure, and also systemic negative effects. Some agents are also effective topically with good safety profiles, al-though these have generally not been as well-studied as systemic herbal extracts. More thorough and complete research including work on optimal dosing and preparations—with direct comparisons to existing synthetic agents in every case to prove equivalence or superiority in terms of efficacy and safety—are urgently needed. Studies are also needed to deter-mine optimal dose timing to ensure that vitamin D activation is not stopped by natural photoprotective agents, an area of study that has been nearly completely ignored.
Source : Alternative and Complementary Therapies
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Lower Risk of Photoaging Associated with Monounsaturated Fatty Acids from Olive Oil
As life expectancy increases in developed countries, concern with the condition and appearance of aging skin also rises. Chronological (intrinsic) skin aging due to genetically determined loss of cell function over time appears as fine wrinkles and dry, thin, pale skin. Concurrent aging due to environmental or lifestyle factors (extrinsic) causes solar elastosis, actinic keratosis, pigmentation, and vascular abnormalities. Extrinsic aging, especially exposure to ultraviolet (UV) rays (photoaging), can cause basal and squamous cell skin cancers. UV-B rays damage DNA directly. UV-A damage occurs through generation of reactive oxygen species (ROS) and their effects.
Skin is a major fat storage organ for humans, but there are few studies of lipid intake and skin physiology. Reduced fat intake has been proposed as protective against photoaging. Monounsaturated fatty acids (MUFAs) are reported to reduce oxidative stress, insulin resistance, and related inflammation. The authors explored associations between facial skin photoaging and MUFA intake by dietary source.
A cohort from the Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) study, a double-blind, placebo-controlled primary prevention trial evaluating antioxidant supplementation and incidence of ischemic heart failure in French adults, was used. The 13,017 SU.VI.MAX participants (7,876 women aged 35-60 years and 5,141 men aged 45-60 years at enrollment in 1994-1995) were followed for up to eight years. They completed 24-hour dietary records every two months, for six records/year/subject. The electronically administered record queried 900 items for three meals and up to four snacks daily. For each food or drink, participants selected a portion size. Types of oils and fats used were queried. Subjects who completed at least 10 records over 2.5 years were included in this study. Those who developed cancer or had a cardiovascular event during the same 2.5 years were excluded, as were women <45 years of age. Data from 1,264 women and 1,655 men from both placebo and intervention groups were used.
Separate analyses were undertaken for each gender. The SU.VI.MAX food composition table was used to determine total energy intake, total MUFA intake, and total intake of MUFAs from different dietary sources. Nutrient density was calculated by expressing MUFA intake as a percentage of total energy intake, then grouped into quartiles. Individual MUFA densities from major sources (vegetable oils, dairy products, meats, and processed meats) and the most frequently used oils containing MUFAs (olive [Olea europaea], sunflower [Helianthus annuus], and peanut [Arachis hypogaea] oils) were similarly grouped into quartiles. Results appear as estimated odds ratios (ORs) with 95% confidence intervals (CIs), with the first quartile as the reference in each case.
Photoaging was assessed at baseline by researchers on a 6-grade damage scale including slack tissue, wrinkles, and abnormal pigmentation. Because the cohort was middle-aged, those scored as grade 1 (least damage) or 6 (most damage) were scarce and were grouped, respectively, with grades 2 and 5, creating four grades of damage.
Covariates included age, geographical residence (postal code), tobacco (Nicotiana tabacum) use status, degree of physical activity, education, and, for women, hormonal status. Body mass index (BMI) was calculated from baseline height and weight. Residence was arbitrarily divided into North and South France. Subjects also rated the intensity of their lifetime sun exposure as none/mild, moderate, or severe.
Severe photoaging was strongly age-linked in both genders. Premenopausal women had less severe damage. In men, more severe skin aging was associated with less education, more sun exposure, and residence at higher (more northerly) latitudes. For men and women, those with the least MUFA intake had the worst skin aging. After adjusting for confounders, a significant association was found between severity of photoaging and higher total MUFAs in men (OR=0.76, 95% CI: 0.57-1.00, P=0.03). For both genders, higher intake of MUFAs from vegetable oils was associated with less risk of severe photoaging (women: OR=0.63, 95% CI: 0.44-0.90, P=0.01; men: OR=0.55, 95% CI: 0.40-0.76, P=0.0004). For olive oil only, a significant association for MUFA with less risk of skin aging was found (women: OR=0.69, 95% CI: 0.50-0.95, P=0.03; men: OR=0.58, 95% CI: 0.43-0.77, P=0.0002). Olive oil was the main vegetable oil for 59% of women and 51% of men in this study. No association was found with skin aging and MUFAs from dairy products, meats, or meat products.
These findings comport with those from studies examining aspects of the relationship between MUFA intake and skin aging. One reported a negative association between total MUFAs, olive oil intake, and skin aging. Another found a positive association between MUFA intake and skin elasticity. A third found no association between oleic acid intake and wrinkling, but reported greater risk of skin dryness with higher intake. The latter two studies did not consider specific MUFA sources. Olive oil's benefits against photoaging may be due to its having a higher ratio of MUFA and less omega-6 and omega-3 polyunsaturated fatty acids (PUFAs). MUFAs are less susceptible to peroxidation. Also, squalene and polyphenols in olive oil may be involved. Squalene, largely sequestered in skin, is thought to be a major protectant against free radical damage and dryness. Squalene and polyphenols seem to be important in benefits of the Mediterranean diet. In this study, higher intake of olive oil was positively correlated with higher intake of fruits, vegetables, fish, and tea, and negatively associated with sweets, butter, and milk.
Source : American Botanical Council via Latreille J, Kesse-Guyot E, Malvy D, et al. Dietary monounsaturated fatty acids intake and risk of skin photoaging. PLoS One. September 6, 2012;7(9):e44490. doi: 10.1371/journal.pone.0044490.
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Human skin, aging and antioxidants
Barkat Ali Khan 1 *, Naveed Akhtar 1 , Akhtar Rasul 1 , Haroon Khan 2 , Ghulam Murtaza 3 , Atif Ali 1 ,Kamran Ahmad Khan 4 , Shahiq-uz-Zaman 1 , Adnan Jameel 1 , Khalid Waseem 1 andTariq Mahmood 1
1 Department of Pharmacy, Faculty of Pharmacy and Alternative Medicine, The Islamia University of Bahawalpur,Pakistan .
2 Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Gomal University Dera Ismail Khan, Pakistan .
3 Department of Pharmaceutical Sciences, COMSATS Institute of Information Technology, Abbottabad, Pakistan.
4 Department of Pharmaceutics, Faculty of Pharmacy, Gomal University Dera Ismail Khan, Pakistan .
All health care professionals should have basic information about the structure and function of human skin inorder to be able to determine any type of change in normal skin, diagnose present skin problems and prescribe possible treatment for risk factors. Skin is also called the cutaneous membrane or the integumentry system as it has several accessory organs. In adults the skin has a surface area ranging from 1.2 to 2.2 m² and weighs about 5 kg. The skin is about 7% of the total body weight with a thickness of 0.02 ″ to 0.16 ″ range in the average adult. This review of literature covers all the aspects of human skin. Moreover, mechanisms of skin aging are discussed as well as the role of various natural and synthetic antioxidants in protecting skin are covered in this review with sagacity of understanding
Understanding of human skin, skin aging and anti-oxidants lead to a basic knowledge of preventing various skin disorders. Sustained disclosure to UV irradiations may contribute to photoaging. From this review we concluded that it refreshes the importance of anti-oxidants in skin aging and presents new information such as human skin and vitamins especially topical Vitamin C as antioxidant in skin aging. Moreover, mechanisms of skin aging are discussed as well as role of various natural and synthetic antioxidants in protecting skin are covered with sagacity of understanding
Source : Journal of Medicinal Plants Research Vol. 6(1), pp. 1-6, 9 January, 2012
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Skin Can Show First Signs of Some Internal Disease
Dermatologists find that the skin offers a window to what is going on inside the body and changes to the skin may signal a more serious health problem. The key is knowing how to spot these early warning signs so the internal disease can be successfully treated and before it becomes a bigger problem.
AMERICAN ACADEMY OF DERMATOLOGY EXPERT
Information provided by Cindy Owen, MD, FAAD, a board-certified dermatologist and assistant professor of dermatology at the University of Louisville in Louisville, Ky.
COMMON SIGNS SPELL INTERNAL TROUBLE
In some cases, the skin can show signs of an internal disease before the disease advances and becomes more serious; in other cases, a symptom is noticeable on the skin long after the disease begins causing damage internally. While there are hundreds of nuances of the skin that could spell trouble, a handful of general skin changes commonly signal an internal disease.
• Unusual rash, or a rash that does not respond to treatment or is accompanied by fever, joint pain, muscle aches, or other symptoms could indicate an internal problem or infection.
A rash occurring on the tops of the feet and lower legs that does not respond to topical steroids or antifungals can be a sign of hepatitis C infection (necrolytic acral erythema).
• Occasionally, people will develop a rash from an allergy to a new medicine. However, it is important to monitor the rash carefully, as it could be a sign of a more serious condition known as DRESS syndrome – which stands for Drug Reaction (or Rash) with Eosinophilia and Systemic Symptoms.
This condition can occur weeks to months after the start of a new medication, making it very difficult to diagnose. Dr. Owen explained that this is a potentially serious medical condition that could involve inflammation of the liver, heart, lungs or thyroid. She stressed that it is important to see a dermatologist for proper diagnosis if a rash is accompanied by swelling of the face or lymph nodes, fever and/or feeling of illness.
• Dermatomyositis is an inflammatory muscle disease with notable skin changes and is associated, in up to 20 percent of cases, with a wide variety of internal cancers (ovarian cancer being the most common in women). Signs on the skin include a violet-colored rash on the upper eyelids and in areas that are exposed to sunlight, and raised, scaly bumps on the knuckles. Other skin changes can be seen on the nail folds with visible blood vessels and ragged-looking cuticles that appear thicker and separate from the nail. Dr. Owen noted that in one case with only subtle changes of the nail fold and cuticles, a patient was diagnosed with dermatomyositis before being diagnosed with an early stage, treatable kidney cancer.
• Any new growths should be checked thoroughly by a board-certified dermatologist, as they could be skin cancer. Rarely, new growths can represent a metastasis or spread of an internal cancer to the skin. Also, certain tumors of the skin can be a sign of internal disease, or a genetic syndrome.
• In one example, yellow or waxy looking bumps on the arms, legs or trunk (eruptive xanthomas) could indicate high triglyceride levels, often as a sign of uncontrolled diabetes. In these instances, a biopsy in conjunction with laboratory testing can lead to diagnosis and treatment, hopefully reducing the cardiovascular risk from these conditions.
• Skin color changes can be a sign of internal disease. In the most common example, yellowing of the skin can indicate liver disease. However, other skin color changes can be important signs as well, including darkening of the skin.
• Noticeable darkening of creases in the skin, sun-exposed areas, joints, and old scars could be a sign of adrenal disease, such as Addison’s disease.
• Bronzing of the skin in a patient with diabetes can be a sign of an inherited defect in iron metabolism that leads to liver failure known as hemochromatosis.
Change in Texture
• Any unusual softening or hardening of the skin could indicate an underlying medical problem.
• Systemic sclerosis is an autoimmune disease in which one of the early signs is swelling, followed by hardening of the skin. In more severe cases, it could result in hardening of internal organs, such as the lungs or heart.
• Acanthosis nigricans is a common condition seen in overweight patients that results in darkened, velvety skin occurring in skin folds and most commonly on the back of the neck. The appearance of this textural change in the skin could indicate the presence of early diabetes. In some cases this skin change may be a sign of a cancerous tumor in an internal organ.
• Acquired cutis laxa is a rare connective tissue disease marked by very loose or doughy feeling skin that is silky to the touch. This disease could be a sign of lymphoma or multiple myeloma, and it could advance to involve loss of elasticity of other internal organs. Dr. Owen noted that with proper diagnosis, it is possible to slow the progression of the disease.
DR. OWEN’S TIPS
People can be their own best detective in noticing unusual changes in their skin, and Dr. Owen recommended seeing a dermatologist as soon as possible in these instances:
• If you notice an unusual rash that can’t be attributed to a specific cause.
• If a rash is diagnosed and not responding to the prescribed treatment.
• If a rash is accompanied by fever, muscle aches or other unusual symptoms.
AMERICAN ACADEMY OF DERMATOLOGY EXPERT ADVICE:
“When examining a patient’s skin for signs of skin cancer or any type of skin condition, dermatologists are always mindful of unusual markings on the skin that could indicate another medical problem,” said Dr. Owen. “Dermatologists have expertise to know when signs on the skin are more than a skin problem, which is why it is important to see a board-certified dermatologist if you notice any skin changes. Doing so can ensure proper diagnosis – and in some cases stop the progression of a more serious medical condition.”
Source : Newswise
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Silibinin found in Milk Thistle Protects Against UV Induced Skin cancer
A pair of University of Colorado Cancer Center studies published this month show that the milk thistle extract, silibinin, kills skin cells mutated by UVA radiation and protects against damage by UVB radiation - thus protecting against UV-induced skin cancer and photo-aging."When you have a cell affected by UV radiation, you either want to repair it or kill it so that it cannot go on to cause cancer. We show that silibinin does both," says Rajesh Agarwal, PhD, co-program leader of Cancer Prevention and Control at the CU Cancer Center and professor at the Skaggs School of Pharmacy and Pharmaceutical Sciences.
The first study, published in the journal Photochemistry and Photobiology worked with human skin cells subjected to UVA radiation, which makes up about 95 percent of the sun's radiation that reaches Earth. The Agarwal Lab treated these UVA-affected cells with silibinin. With silibinin, the rate at which these damaged cells died increased dramatically.
"When you take human skin cells - keratinocytes - and treat them with silibinin, nothing happens. It's not toxic. But when you damage these cells with UVA radiation, treatment with silibinin kills the cells," Agarwal says, thus removing the mutated cells that can cause skin cancer and photo-aging.
Specifically, the study shows that pretreatment with silibinin resulted in higher release of reactive oxygen species (ROS) within the UVA-exposed cells, leading to higher rates of cell death.
The second study, published this month by the same authors in the journal Molecular Carcinogenesis shows that instead of beneficially killing cells damaged by UVA radiation, treatment with silibinin protects human skill cells from damage by UVB radiation, which makes up about 5 percent of the sun's radiation reaching Earth.
Again, remember Agarwal's suggestion that the prevention of UV-induced skin cancer can happen in two ways: by protecting against DNA damage or by killing cells with damaged DNA. With UVA, silibinin kills; with UVB, it protects, in this case by increasing cells' expression of the protein interleukin-12, which works to quickly repair damaged cells.
"It has been 20 years of work with this compound, silibinin," Agarwal says. "We first noticed its effectiveness in treating both skin and solid cancers, and we now have a much more complete picture of the mechanisms that allow this compound to work."
Agarwal and colleagues continue to test the effectiveness of silibinin in cancer prevention and treatment in cell lines and mouse models, and are working toward human trials of silibinin-based therapeutics.
Source : Newswise
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Strawberry Extract Protects Against UVA Rays
An experiment has shown that strawberry extract added to skin cell cultures acts as a protector against ultraviolet radiation as well as increasing its viability and reducing damage to DNA. Developed by a team of Italian and Spanish researchers, the study opens the door to the creation of photoprotective cream made from strawberries.
"We have verified the protecting effect of strawberry extract against damage to skins cells caused by UVA rays," as explained by Maurizio Battino, researcher at the Università Politecnica delle Marche in Italy and lead author of the jointly Spanish and Italian study. The results are published in the 'Journal of Agricultural Food Chemistry'.
The team prepared human skin cell cultures (fibroblasts) and added strawberry extract in different concentrations (0.05, 0.25 and 0.5 mg/ml), the only exception being the control extract. Using ultraviolet light, the samples were then exposed to a dose "equivalent to 90 minutes of midday summer sun in the French Riviera."
Data confirm that the strawberry extract, especially at a concentration of 0.5 mg/ml, displays photoprotective properties in those fibroblasts exposed to UVA radiation, it increases cell survival and viability and decreases damage in the DNA when compared with control cells.
"These aspects are of great importance as they provide protection for cell lines subject to conditions that can provoke cancer and other skin-related inflammatory and degenerative illnesses," outlines Battino.
The researcher recognises that this is the "first step in determining the beneficial effects of strawberries in our diet or as a possible compound source for 'food integrators' or cosmetics for instance."
The redness of anthocyanins
But what molecules give strawberries their photoprotective properties? Scientists suspect that it could be the anthocyanins, which are pigments that give leaves, flowers and fruits their red colour. Analyses have confirmed that extracts are rich in such substances.
"These compounds have important anti-inflammatory, antioxidant and anti-tumour properties and are capable of modulating enzymatic processes," explains another of the authors, Sara Tulipani from the University of Barcelona. She adds that "we have not yet found a direct relationship between their presence and photoprotective properties."
"At the moment the results act as the basis for future studies evaluating the 'bioavailability' and 'bioactivity' of anthocyanins in the dermis and epidermis layers of the human skin, whether by adding them to formulations for external use or by ingesting the fruit itself," states Tulipani.
Also made up of researchers from the Universities of Salamanca and Granada, in its previous works the team had already demonstrated that strawberries (Fragaria x ananassa) strengthen the red bloods cells and protect the stomach from the effects of alcohol.
Source : Science Daily
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Pomegranate and berry extracts were shown to protect the skin from the harmful effects of UV exposure
In a new study published in Experimental Dermatology - Pomegranate and berry extracts were shown to protect the skin from the harmful effects of UV exposure
Ellagic acid is a phytochemical, or plant chemical, found in raspberries, strawberries, cranberries, walnuts, pecans, pomegranates, and other plant foods
and Korean scientists involved in the study state that this phytochemical may prevent, in human skin cells, the degradation of collagen, which would slow wrinkle formation and maintain skin structure.
Other studies showed that the phytochemical also prevented thickening of the skin when exposed to UV radiation. Topical application of ellagic acid was associated with a decrease in levels of pro-inflammatory compounds in the skin of the animals, report researchers from the Department of Food and Nutrition at Hallym University in Korea.
Below is the conclusion from the study and to see the full study please press the link below
"In conclusion, the present results demonstrate the photoprotective effects of anti-oxidant ellagic acid on skin wrinkle formation resulting from collagen breakdown through increasing MMP production. The mechanism by which ellagic acid alleviated UV-B-initiated photoageing should be further clarified in terms of cellular signalling components such as mitogen-activated protein kinase and nuclear transcriptional factors. Topical ellagic acid alleviated UV-Binduced dermal roughening and thickening leading to skin wrinkle. In addition, ellagic acid mitigated cutaneous accumulation of inflammatory cytokines and adhesion molecule ICAM-1, and inflammatory infiltrates of macrophages in hairless mice skin. Therefore, topical or dietary interventions
with berries and pomegranate rich in ellagic acid and ellagitannins are promising strategies in curtailing skin wrinkling and cutaneous inflammation associated with chronic UV exposure leading to photoageing.
Source: Experimental Dermatology
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Caffeine May Lower Risk of Common Skin Cancer
Relatively modest caffeine consumption was associated with a significantly lower relative risk of basal cell carcinoma (BCC), data from two large cohort studies showed.
People who consumed more than three cups of coffee a month had a 17% reduction in the relative risk of BCC versus individuals who drank less than one cup per month.
The association pertained to men and women and to sources of caffeine other than coffee.
Investigators found no association between caffeine consumption and squamous-cell carcinoma (SCC) or melanoma, as reported in the July 1 issue of Cancer Research.
"Given that nearly one million new cases [of BCC] are diagnosed each year in the U.S., modification in daily dietary factors with even small protective effects may have great public health impact," Jilali Han, PhD, of Harvard and Brigham and Women's Hospital in Boston, and co-authors wrote in conclusion.
Skin cancers are the most common malignancy among white people in the U.S. White Americans have an estimated 1 in 5 lifetime risk of developing skin cancer.
Laboratory studies have consistently shown that oral and topical caffeine prevents SCC in mice exposed to ultraviolet (UV) light, the authors wrote in their introduction. Other preclinical studies have suggested a potential mechanistic explanation, as topical caffeine has been shown to induce apoptosis in UV-damaged keratinocytes in mice.
Observational data have been less convincing, as studies have shown inconsistent associations between caffeine and skin cancer, including melanoma and nonmelanoma. None of these studies distinguished between caffeinated and decaffeinated coffee or tea, a key piece of evidence that might show whether other components of coffee or tea have anticancer activity.
To address limitations of current information, Han and co-authors reviewed data from the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS). The NHS included 121,700 women ages 30 to 55 at enrollment in 1976. HPFS enrolled 51,529 men ages 40 to 75 when the study began in 1976.
NHS participants provided information on caffeine intake on several occasions from 1984 to 2006, as did the HPFS participants from 1986 to 2006.
Han and co-authors analyzed data for 112,897 participants from the two studies (72,921 women and 39,976 men). During 24 and 22 years of follow-up in the NHS and HPFS, respectively, 22,786 participants developed BCC, 1,953 developed SCC, and 741 developed melanoma.
Using U.S. Department of Agriculture data, Han and co-authors estimated caffeine content 137 mg per cup of caffeinated coffee, 47 mg per cup of tea, 46 mg per 12-oz container of caffeinated soda, and 7 mg per 1-oz serving of chocolate.
Investigators stratified the study participants into quintiles of daily caffeine consumption, which range from 31 to 604 mg in NHS and 8 to 584 mg in the HPFS. The analysis showed an inverse association between caffeine consumption from all sources combined and the risk of BCC.
Comparison of the highest and lowest quintile of caffeine consumption resulted in a relative risk of 0.82 for BCC in women and 0.87 in men (P<0.0001 for trend in both groups). The relative risk was 0.84 for men and women combined.
Coffee accounted for 78.5% of all caffeine consumption. A separate comparison of skin cancer risk by coffee consumption produced a relative risk of 0.83 for the highest versus lowest quintile (95% CI 0.77 to 0.87). Investigators found a dose-response relationship between caffeine and BCC risk in women (P<0.0001 for trend) and men (P=0.003 for trend).
Caffeine from sources other than coffee tended to have an inverse association with BCC (0.88 in women, 0.93 in men), although the effect did not achieve statistical significance.
The authors noted a number of limitations including the reliance on self-report of BCC without confirmation from histology. Also, they noted that statistical power to calculate any relationship between caffeine and melanoma or SCC was lacking because the number of those cancers in the population was much lower than BCC.
Finally, they said they were "not able to rule out other differences between caffeinated and decaffeinated coffee that could also be etiologically relevant."
Primary source: Cancer Research
Song F, et al "Increased caffeine intake is associated with reduced risk of basal cell carcinoma of the skin" Cancer Res 2012; 72: 3282-3289.
Source : Medpage Today
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