Research - Apples
Protective effects of Egyptian cloudy apple juice and apple peel extract on lipid peroxidation, antioxidant enzymes and inflammatory status in diabetic rat pancreas
- Samah M. FathyEmail author and
- Ehab A. Drees
Apples possess rich content of varied polyphenolic compounds showing a variety of biological activities that may ascribe to worthy effects against some chronic diseases. The present study was designed to assess the protective effects of the cloudy apple juice (CAJ) and apple peel extract (APE) of Egyptian Anna apple on the complications in experimental diabetes.
Materials and methods
Four groups were studied. Diabetes was induced by a single dose of streptozotocin (STZ) to only three groups of albino Wistar rats. Two of the diabetic groups received either CAJ or APE for 21 days. At the end of the study, lipid profile parameters were measured in serum while lipid peroxidation (LPO) level, antioxidant enzyme activities and inflammatory markers were evaluated in pancreas tissue samples. The gas chromatography–mass spectrometry (GC-MS) analysis of phenolic compounds found in CAJ and APE was carried out. Moreover, total phenolic content of CAJ and APE were measured.
The significant increase of blood glucose level, serum total cholesterol (TC), triglycerides (TG), low- density lipoprotein cholesterol (LDL-C), and very low-density lipoprotein (VLDL) levels, in addition to tissue malondialdehyde (MDA), nuclear factor kappa B (NF-kB), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), interleukin 8 (IL-8) levels, but a significant decrease in high-density lipoprotein cholesterol (HDL-C), and the activity of pancreatic antioxidant enzymes were the remarkably parameters observed in diabetic control rats. Dissimilarly, oral supplementation of 15 ml/kg CAJ and 1 g/kg APE for 21 days resulted in a significant decrease in fasting blood glucose, serum TC, TG, LDL-C, VLDL-C and tissue MDA, NF-kB, TNF-α, IL-6, IL-8 levels coupled with a significant elevation of HDL-C and antioxidant enzymes’ activity when compared with diabetic control animals.
The results indicate that Egyptian CAJ and APE supplementation may have protective effects against deleterious complications of diabetes mellitus.
Source : BMC Complementary and Alternative Medicine
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Keeping older muscles strong
University of Iowa scientists discover cause of and potential treatment for muscle weakness and loss due to aging
As we grow older, we lose strength and muscle mass. However, the cause of age-related muscle weakness and atrophy has remained a mystery.
Scientists at the University of Iowa have discovered the first example of a protein that causes muscle weakness and loss during aging. The protein, ATF4, is a transcription factor that alters gene expression in skeletal muscle, causing reduction of muscle protein synthesis, strength, and mass. The UI study also identifies two natural compounds, one found in apples and one found in green tomatoes, which reduce ATF4 activity in aged skeletal muscle. The findings, which were published online Sept. 3 in the Journal of Biological Chemistry, could lead to new therapies for age-related muscle weakness and atrophy.
"Many of us know from our own experiences that muscle weakness and atrophy are big problems as we become older," says Christopher Adams, M.D., Ph.D., professor of internal medicine in the UI Carver College of Medicine, and senior study author. "These problems have a major impact on our quality of life and health."
Previously, Adams and his team had identified ursolic acid, which is found in apple peel, and tomatidine, which comes from green tomatoes, as small molecules that can prevent acute muscle wasting caused by starvation and inactivity. Those studies set the stage for testing whether ursolic acid and tomatidine might be effective in blocking the largest cause of muscle weakness and atrophy: aging.
In their latest study, Adams' team found that ursolic acid and tomatidine dramatically reduce age-related muscle weakness and atrophy in mice. Elderly mice with age-related muscle weakness and atrophy were fed diets lacking or containing either 0.27 percent ursolic acid, or 0.05 percent tomatidine for two months. The scientists found that both compounds increased muscle mass by 10 percent, and more importantly, increased muscle quality, or strength, by 30 percent. The sizes of these effects suggest that the compounds largely restored muscle mass and strength to young adult levels.
"Based on these results, ursolic acid and tomatidine appear to have a lot of potential as tools for dealing with muscle weakness and atrophy during aging," Adams says. "We also thought we might be able to use ursolic acid and tomatidine as tools to find a root cause of muscle weakness and atrophy during aging."
Adams' team investigated the molecular effects of ursolic acid and tomatidine in aged skeletal muscle. They found that both compounds turn off a group of genes that are turned on by the transcription factor ATF4. This led them to engineer and study a new strain of mice that lack ATF4 in skeletal muscle. Like old muscles that were treated with ursolic acid and tomatidine, old muscles lacking ATF4 were resistant to the effects of aging.
"By reducing ATF4 activity, ursolic acid and tomatidine allow skeletal muscle to recover from effects of aging," says Adams, who also is a member of the Fraternal Order of Eagles Diabetes Research Center and the Pappajohn Biomedical Institute, and is a staff physician with the Iowa City Veterans Affairs Medical Center.
Source : University of Iowa
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2004 - Apple phytochemicals and their health benefits
Jeanelle Boyer and Rui Hai Liu*
Evidence suggests that a diet high in fruits and vegetables may decrease the risk of chronic diseases, such as cardiovascular disease and cancer, and phytochemicals including phenolics, flavonoids and carotenoids from fruits and vegetables may play a key role in reducing chronic disease risk. Apples are a widely consumed, rich source of phytochemicals, and epidemiological studies have linked the consumption of apples with reduced risk of some cancers, cardiovascular disease, asthma, and diabetes. In the laboratory, apples have been found to have very strong antioxidant activity, inhibit cancer cell proliferation, decrease lipid oxidation, and lower cholesterol. Apples contain a variety of phytochemicals, including quercetin, catechin, phloridzin and chlorogenic acid, all of which are strong antioxidants. The phytochemical composition of apples varies greatly between different varieties of apples, and there are also small changes in phytochemicals during the maturation and ripening of the fruit. Storage has little to no effect on apple phytochemicals, but processing can greatly affect apple phytochemicals. While extensive research exists, a literature review of the health benefits of apples and their phytochemicals has not been compiled to summarize this work. The purpose of this paper is to review the most recent literature regarding the health benefits of apples and their phytochemicals, phytochemical bioavailability and antioxidant behavior, and the effects of variety, ripening, storage and processing on apple phytochemicals.
Source : Nutrition Journal 2004
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Oral administration of apple condensed tannins delays rheumatoid arthritis development in mice via downregulation of T helper 17 (Th17) cell responses
- Kosuke Nakamura1,†,*,
- Hideki Matsuoka1,†,
- Syohei Nakashima2,
- Tomomasa Kanda2,
- Tomoko Nishimaki-Mogami1 and
- Hiroshi Akiyama1
Apples are known to contain high concentrations of phenolic compounds such as condensed tannins. Consumption of condensed tannins has been reported to reduce the risk of many types of chronic diseases including allergies. However, their therapeutic effectiveness and potential in treating autoimmune disease remain controversial. Here, the effect of oral administration of apple condensed tannins (ACT) prepared from apples (Malus pumila cv. Fuji) on bovine type II collagen (CII)-induced arthritis in DBA1/J mice, a well-established murine model of human rheumatoid arthritis (RA), was evaluated. As compared to the control (without ACT administration) group, RA development was delayed and a significant reduction in the RA clinical score was observed in the ACT-administered group. Using cultured splenocytes isolated from CII-immunized mice, ACT-administration was shown to decrease the CII-induced increases in IL-17 expression and production in vitro. We propose that downregulation of T helper (Th) 17 cells is responsible for the ACT-induced RA suppression.
Source : Molecular Nutrition and Food Research
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Daily Apple versus Dried Plum: Impact on Cardiovascular Disease Risk Factors in Postmenopausal Women.
Chai SC, Hooshmand S, Saadat RL, Payton ME, Brummel-Smith K, Arjmandi BH.
BACKGROUND: Evidence suggests that consumption of apple or its bioactive components modulate lipid metabolism and reduce the production of proinflammatory molecules. However, there is a paucity of such research in human beings.
OBJECTIVE: Women experience a lower rate of cardiovascular disease before menopause compared with men. However, after the onset of menopause, the risk of cardiovascular disease increases drastically due to ovarian hormone deficiency. Hence, we conducted a 1-year clinical trial to evaluate the effect of dried apple vs dried plum consumption in reducing cardiovascular disease risk factors in postmenopausal women.
DESIGN: One-hundred sixty qualified postmenopausal women were recruited from the greater Tallahassee, FL, area during 2007-2009 and were randomly assigned to one of two groups: dried apple (75 g/day) or dried plum (comparative control). Fasting blood samples were collected at baseline, 3, 6, and 12 months to measure various parameters. Physical activity recall and 7-day dietary recall were also obtained.
RESULTS: Neither of the dried fruit regimens significantly affected the participants' reported total energy intake throughout the study period. On the contrary, women who consumed dried apple lost 1.5 kg body weight by the end of the study, albeit not significantly different from the dried plum group. In terms of cholesterol, serum total cholesterol levels were significantly lower in the dried apple group compared with the dried plum group only at 6 months. Although dried plum consumption did not significantly reduce serum total cholesterol and low-density lipoprotein cholesterol levels, it lowered their levels numerically by 3.5% and 8%, respectively, at 12 months compared with baseline. This may explain the lack of significance observed between the groups. However, within the group, women who consumed dried apple had significantly lower serum levels of total cholesterol and low-density lipoprotein cholesterol by 9% and 16%, respectively, at 3 months compared with baseline. These serum values were further decreased to 13% and 24%, respectively, after 6 months but stayed constant thereafter. The within-group analysis also reported that daily apple consumption profoundly improved atherogenic risk ratios, whereas there were no significant changes in lipid profile or atherogenic risk ratios as a result of dried plum consumption. Both dried fruits were able to lower serum levels of lipid hydroperoxide and C-reactive protein. However, serum C-reactive protein levels were significantly lower in the dried plum group compared with the dried apple group at 3 months.
CONCLUSIONS: There were no significant differences between the dried apple and dried plum groups in altering serum levels of atherogenic cholesterols except total cholesterol at 6 months. However, when within treatment group comparisons are made, consumption of 75 g dried apple (about two medium-sized apples) can significantly lower atherogenic cholesterol levels as early as 3 months. Furthermore, consumption of dried apple and dried plum are beneficial to human health in terms of anti-inflammatory and antioxidative properties.
Source : J Acad Nutr Diet. 2012 Aug;112(8):1158-68.
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Ursolic Acid: Apple Peel Compound Reduces Obesity In Mice
A new study shows that ursolic acid, a natural substance found in apple peel, can partially protect mice from obesity and some of its harmful effects.
Obviously ursolic acid, a lipophilic pentacyclic triterpenoid that contributes to the waxy coats on fruits and various herbs, can't be a license to eat ice cream and pizza every day but it seems to increase the amount of muscle and brown fat, two tissues recognized for their calorie-burning properties. Until recently, it was believed that only infants had brown fat, which then disappeared during childhood, but improved imaging techniques have shown that adults do retain a very small amount of the substance - mostly in the neck and between the shoulder blades. Some studies have linked increased levels of brown fat with lower levels of obesity and healthier levels of blood sugar and blood lipid, leading to the suggestion that brown fat may be helpful in preventing obesity and diabetes.
The study had mice on a high-fat diet over a period of several weeks. Half of the animals also received ursolic acid in their high-fat food. Mice whose diet included ursolic acid actually ate more food than mice not getting the supplement and there was no difference in activity between the two groups. Despite this, the ursolic acid-treated mice gained less weight and their blood sugar level remained near normal. Ursolic acid-treated mice also failed to develop obesity-related fatty liver disease, a common and currently untreatable condition that affects about one in five American adults.
"From previous work, we knew that ursolic acid increases muscle mass and strength in healthy mice, which is important because it might suggest a potential therapy for muscle wasting," said Christopher Adams, M.D., Ph.D., UI associate professor of internal medicine at the University of Iowa. "In this study, we tested ursolic acid in mice on a high-fat diet -- a mouse model of obesity and metabolic syndrome. Once again, ursolic acid increased skeletal muscle. Interestingly, it also reduced obesity, pre-diabetes and fatty liver disease. Since muscle is very good at burning calories, the increased muscle in ursolic acid-treated mice may be sufficient to explain how ursolic acid reduces obesity. However, we were surprised to find that ursolic acid also increased brown fat, a fantastic calorie burner. This increase in brown fat may also help protect against obesity."
Further study showed that ursolic acid consumption increased skeletal muscle, increasing the animals' strength and endurance, and also boosted the amount of brown fat. Because both muscle and brown fat burn calories, the researchers investigated energy expenditure in the mice and showed that ursolic acid-fed mice burned more calories than mice that didn't get the supplement.
"Our study suggests that ursolic acid increases skeletal muscle and brown fat leading to increased calorie burning, which in turn protects against diet-induced obesity, pre-diabetes and fatty liver disease," Adams says. "Brown fat is beneficial and people are trying to figure out ways to increase it. At this point, we don't know how ursolic acid increases brown fat, or if it increases brown fat in healthy mice. And, most importantly, we don't know if ursolic acid will benefit people. Our next step is to determine if ursolic acid can help patients."
Citation: Kunkel SD, Elmore CJ, Bongers KS, Ebert SM, Fox DK, et al. (2012) Ursolic Acid Increases Skeletal Muscle and Brown Fat and Decreases Diet-Induced Obesity, Glucose Intolerance and Fatty Liver Disease. PLoS ONE 7(6): e39332. doi:10.1371/journal.pone.0039332
Source : Science 2.0
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