Research - Citrus Fruits
In vitro effect of bergamot (Citrus bergamia) juice againstcagA-positive and-negative clinical isolates of Helicobacter pylori
Angela Filocamo1, Carlo Bisignano2, Nadia Ferlazzo1, Santa Cirmi1, Giuseppina Mandalari1* and Michele Navarra1*
Helicobacter pylori infection has been associated with chronic gastritis, peptic ulcer and gastric carcinoma as over half of the world's population is colonized with this gram-negative bacterium. Due to the increasing antibiotic resistance, its eradication rates fails in a great portion of patients. A number of studies showed that molecules largely distributed in commonly consumed fruits and vegetables may have antimicrobial activity. The aim of the present study was to investigate the effect of bergamot juice (BJ) against Helicobacter pylori in vitro. The potential therapeutic combination between BJ and the antibiotics amoxicillin (AMX), clarithromycin (CLA) and metronidazole (MTZ) has also been evaluated.
MethodsThe minimum inhibitory concentration (MIC) of BJ, AMX, CLA and MTZ against 2 ATCC and 32 clinical isolates of H. pylori was assayed according to CLSI. The checkerboard method was used to determine the efficacy of the association BJ with the three reference antibiotics.
Killing curves were performed on the two cagA-positive ATCC strains of H. pylori (ATCC 43504 and ATCC 49503), on the clinical isolate cagA-positive HP6 strain of H. pylori and on the clinical isolatecagA-negative HP61 strain of H. pylori.
ResultsBJ (2.5 %, v/v) inhibited the growth of 50 % of the H. pylori clinical isolates, whereas 5 % (v/v) inhibited 90 %. AMX was the most effective antibiotic against the reference strains and the clinical isolates, followed by CLA and MTZ. In the combination assays, synergism was observed between BJ and AMX and between BJ and MTZ against both the reference strains and the clinical isolates. Indifference was observed between BJ and CLA.
Conclusions BJ was effective in vitro against H. pylori and the genotype status of the clinical strains may have an impact on its susceptibility. The synergistic combination of BJ and antibiotics could be used to prevent or treat resistance.
Source : BMC Complementary and Alternative Medicine
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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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An Orange a Day Keeps Stroke Away.
A compound found in oranges, grapefruit, and other citrus fruit may modestly reduce stroke risk among women, an observational study determined.
Women with the highest levels of flavanone in their diet were 19% less likely to have an ischemic stroke during 14 years of follow-up than those with the least flavanone intake (P=0.04), Aedín Cassidy, PhD, of the University of East Anglia in Norwich, England, and colleagues found.
As the main source of these antioxidants, citrus fruit and juice showed a similar trend (relative risk 0.90, 95% CI 0.77 to 1.05), they reported in the April issue of Stroke: Journal of the American Heart Association.
Vitamin C has gotten most of the praise for the protective effect of citrus found in prior stroke studies, but in Cassidy's analysis of the Nurses' Health Study, the vitamin didn't correlate with total or ischemic stroke or attenuate the link to flavanones.
Most of the flavanones consumed by women in the study came from orange and grapefruit juice (63%). But eating the whole fruit would likely be a better way to boost intake, the researchers suggested.
"Given the higher flavanone content of citrus fruits and the sugar content of commercial fruit juices, public health recommendations should focus on increasing citrus fruit intake," they recommended in the paper.
Flavanones are one of six types of commonly consumed flavonoids, which various studies have linked individually to different benefits -- hypertension risk reduction with anthocyanins, lower stroke risk in some studies of flavonols -- but never looked at all simultaneously.
Cassidy's group broke down food frequency data from nearly 70,000 women participating in the Nurses' Health Study for total flavonoid intake and for each component.
With dietary reports every four years over a total 14 years of follow-up, the researchers found big variations in total flavonoid intake, ranging from an average 761 mg per day in the top quintile to 97 mg per day in the bottom quintile.
Tea was the biggest contributor to those levels, followed by apples and oranges or orange juice.
However, total flavonoid intake didn't predict ischemic stroke risk in the multivariate-adjusted model (P=0.36 for trend).
These results suggested "that flavanones may be another important cardioprotective constituent of citrus fruits," Cassidy's group wrote. "However, in a population-based study like ours, it is impossible to disentangle the relative influence of all the constituents of citrus fruits."
An impact from flavanones is plausible, they noted, pointing to experimental evidence that two flavanones, naringenin and hesperetin, act on neuroprotective pathways with effects on nitric oxide release. Naringenin was the strongest anti-inflammatory of all the flavonoids tested in one study.
A trend appeared for the flavones at the highest intake level of more than 3 mg per day compared with the lowest at less than 1 mg per day, but the difference wasn't statistically significant (adjusted relative risk 0.88, 95% CI 0.72 to 1.08).
The same was true for anthocyanins (blueberries were the main source) and flavan-3-ols (predominantly consumed from tea).
None of the compounds impacted hemorrhagic stroke risk.
Individual flavonoids are likely to differ in benefits because of different mechanisms through their specific structural characteristics, the researchers noted.
They cautioned that residual or unmeasured confounding was possible despite the detailed adjustment used in the study.
Another limitation is that the actual flavonoid content in foods consumed may have differed from levels recorded because of wide variability based on where the food was grown and during what season and how it was cultivated and processed.
Randomized trials are needed to test flavanone and citrus foods for reduction of ischemic stroke risk, the group concluded.
Source : Medpage Today
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