Reactive oxygen species

Mulberry anthocyanins, cyanidin 3-rutinoside and cyanidin 3-glucoside, exhibited an inhibitory effect on the migration and invasion of a human lung cancer cell line.

The purpose of this review is to discuss the recent developments related to the chemistry and medicinal properties of flavonoids. Major flavonoids that show well categorized structures and well defined structure functionrelationships are: flavans, flavanones, flavones, flavanonols, flavonols, catechins, anthocyanidins and isoflavone. The biological properties of flavonoids include antioxidant, anti-inflamatory, antitumoral, antiviral and antibacterial, as well as a direct cytoprotective effect on coronary and vascular systems, the pancreas and the liver. These characteristics place them among the most attractive natural substances available to enrich the current therapy options.

Flavonoids: Prospective Drug Candidates

Free radicals are molecules with one or more unpaired electron(s) commonly found in seminal plasma. Physiologically, free radicals control sperm maturation, capacitation and hyperactivation, the acrosome reaction, and sperm-oocyte fusion. Pathologically, free radicals induce lipid peroxidation, DNA damage and apoptosis of spermatozoa. The present review deals with both the beneficial and detrimental effects of free radicals on sperm function.

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Free radicals: Their beneficial and detrimental effects on sperm function.

Polyphenols with antiglycation activity and mechanisms of action: A review of recent findings.

Incidence of diabetes mellitus is dramatically growing in the world. Oxidative stress, advanced glycation end products (AGEs) and receptor for AGE (RAGE) play key role in the pathogenesis of diabetes. Little is known about resveratrol effects on the liver. We hypothesize that resveratrol may exert a hepatoprotective effect in diabetic rats. Male rats with diabetes were treated with or without resveratrol at 1, 5 and 10 mg/kg body weight for 30 days. Total AGEs and malondialdehyde (MDA) levels in liver tissues were determined by spectrofluorimetric methods. Total antioxidant capacity and total oxidant contents in the liver and glucose in plasma were measured by a colorimetric assay. Expression of RAGE was assayed in liver of all animals using quantitative polymerase chain reaction. In liver tissue extract of resveratrol-treated rats with diabetes, MDA levels, total oxidant, plasma glucose and expression of RAGE were significantly reduced compared to the untreated group. Moreover, total antioxidant levels were significantly increased in treated rats. There was no significant difference in AGE contents among all groups. These results revealed that resveratrol had beneficial effects on the liver by extenuating oxidative stress and down regulation of RAGE expression.

Effects of Resveratrol on Receptor for Advanced Glycation End Products (RAGE) Expression and Oxidative Stress in the Liver of Rats with Type 2 Diabetes.

Background: Millions of people in the world have diabetes mellitus and its prevalence is growing. Oxidative stress, advanced glycation end-products (AGEs) and receptor for advanced glycation end-products (RAGE) play key role in the pathogenesis of diabetes. New and safe strategies of remedy are needed for this disease. Objectives: We hypothesized that resveratrol may exert a renal protective effect on diabetic rats. Materials and Methods: Male rats with diabetes were treated with or without resveratrol as 1, 5, 10 mg/kg of body weight for 30 days. The total AGEs and malondialdehyde levels in kidney tissues were determined by spectrofluorimetric method and the insulin level was assayed using ELISA. The total antioxidant capacity contents in kidney and the glucose in plasma were measured by a colorimetric assay. The expression of RAGE was assayed in kidneys of all animals using quantitative PCR. Results: In resveratrol-treated rats with diabetes, malondialdehyde levels, plasma glucose and expression of RAGE were significantly reduced compared with the untreated group. Moreover, the total antioxidant and insulin levels significantly increased in treated rats. There was no significant difference in the AGEs contents among all the groups. Conclusions: These results revealed that resveratrol has beneficial effects on kidney by extenuating the oxidative stress and down- regulation of RAGE expression.

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Resveratrol-Dependent Down-regulation of Receptor for Advanced Glycation End-products and Oxidative Stress in Kidney of Rats With Diabetes.

Dietary flavonoid intake has been reported to be inversely associated with the incidence of coronary artery disease. To clarify the possible role of flavonoids in the prevention of atherosclerosis, we investigated the effects of some of these compounds on the susceptibility of low-density lipoprotein (LDL) to oxidative modification. In this study, six flavonoids, "apigenin, genistein, morin, naringin, pelargonidin and quercetin", were added to plasma and incubated for 3h at 37°C. Then, the LDL fraction was separated by ultracentrifugation. The oxidizability of LDL was estimated by measuring conjugated diene (CD), lipid peroxides and thiobarbituric acid-reactive substances (TBARS) after cupric sulfate solution was added. We showed that among flavonoids used, quercetin and morin significantly ( P morin>pelargonidin>genistein>naringin>apigenin. LDL exposed to flavonoids in vitro reduced oxidizability. These findings show that flavonoids may have a role in ameliorating atherosclerosis.

Effects of flavonoids on the susceptibility of low-density lipoprotein to oxidative modification

Background: It is established that sperm DNA integrity is essential in fertilization and normal embryo and fetal development. Routine semen analysis gives an approximate evaluation of the functional competence of spermatozoa, but does not always reflect the quality of sperm DNA. Therefore, the evaluation of sperm DNA integrity, in addition to routine sperm parameters, could add further information on the quality of spermatozoa and reproductive potential of males. Objective: The objective of this study was to determine the levels of sperm DNA damage in fertile and infertile males and its correlation with semen parameters. Materials and Methods: Semen samples were collected from 45 infertile men selected from couples attending the infertility clinic with a history of infertility of ≥1 years and 75 healthy volunteers of proven fertility (initiated a successful pregnancy) served as the control group. After routine sperm analysis, DNA damage was determined using single cell gel electrophoresis (comet) assay method. Results: The mean of DNA damage (comet value) in the sperms of infertile males was significantly higher than that of fertile males (12.9±7.59 vs. 48.77±24.42, p<0.001). A significant negative correlation was observed between DNA damage and sperm motility in fertile group (p<0.02, R=-0.263). In infertile males, significant negative correlations were observed between DNA damage with sperm motility (p<0.002, R=-0.45) and morphology (p<0.03, R=-0.317). There was no significant correlation between sperm concentration and sperm DNA damage in both groups. Conclusion: These results indicate that sperm DNA damages in infertile males is significantly higher than fertile males and sperms with abnormal morphology and low levels of motility has more abnormal DNA damages than motile and normal sperms.

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Correlation between sperm parameters and sperm DNA fragmentation in fertile and infertile men

Background: Evidence supports the involvement of nitric oxide (NO) in a Varity of male reproductive processes such as spermatogenesis, spermiogenesis, sperm motion, sperm metabolism and sperm capacitation. However, Low concentration of NO is essential in biology and physiology of spermatozoa, but high amounts of NO is toxic and has negative effects on sperm functions. On the other hand, it is established that high amounts of NO have detrimental effects on DNA. The integrity of sperm DNA is an important factor in successful fertility and embryo development. It is hypothesized that supra physiological concentrations of NO in seminal plasma cause sperm DNA damage. The aim of this study was to determine sperm DNA damage by comet assay and its correlation with NO level in seminal plasma of fertile and infertile men. Methods: Semen samples were collected from 45 patients and 70 healthy donors. The stable metabolites of NO (nitrite and nitrate) in seminal plasma were measured by Griess assay and DNA damage was determined using single cell gel electrophoresis (comet) assay method. Results: The NO concentration in the seminal plasma of infertile males was significantly higher than fertile males (5.74 ± 1.01 µM/L vs. 3.88 ± 0.53 µM/L). There was a significant positive correlation between the NO concentration and sperm DNA comet value in infertile males (P<0.01, R = 0.598). Conclusion: These results indicate that the overproduction of NO in genital tract of infertile males has a potential pathogenetic role in the reduction of sperm DNA integrity. Iran. Biomed. J. 11 (4): 259-264, 2007

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Nasrin Sheikh

Papers

Effects of Resveratrol on Receptor for Advanced Glycation End Products (RAGE) Expression and Oxidative Stress in the Liver of Rats with Type 2 Diabetes.

Resveratrol-Dependent Down-regulation of Receptor for Advanced Glycation End-products and Oxidative Stress in Kidney of Rats With Diabetes.

Effects of flavonoids on the susceptibility of low-density lipoprotein to oxidative modification

Correlation between sperm parameters and sperm DNA fragmentation in fertile and infertile men

Nitric oxide level in seminal plasma and its relation with sperm DNA damages.