Effect of quercetin on nicotine-induced biochemical changes and DNA damage in rat peripheral blood lymphocytes.

We elucidated the protective effect of quercetin, a polyphenolic flavonoid, on lipid peroxidation, endogenous antioxidant status and DNA damage during nicotine-induced toxicity in cultured rat peripheral blood lymphocytes as compared to N-acetylcysteine (NAC), a well-known antioxidant. Lymphocytes were exposed to nicotine (3 mM) with and without quercetin and NAC (1 mM) in RPMI-1640 medium for 1 h. In preliminary experiments to fix the effective dose of quercetin, different doses of quercetin (25, 50, 75, 100 and 200 microM) were administered to lymphocytes with nicotine, and lipid peroxidation markers (thiobarbituric acid reactive substances and hydroperoxides) were analysed. A 75 microM dose of quercetin was found to be effective as evidenced by decreased lipid peroxidation. To evaluate the protective potential of quercetin against genotoxic effects of nicotine we used comet and micronucleus assays, which are valid parameters to assess genetic damage. In addition, biochemical changes including lipid peroxidation and antioxidant status were assessed. There were significant increases in the levels of lipid peroxidation, comet parameters and micronuclei frequencies, followed by decrease in the endogenous antioxidant status, in nicotine-treated lymphocytes, which were brought back to near normal by quercetin or NAC treatment. The protective effect of quercetin against nicotine toxicity was comparable to that of NAC. These findings suggest that quercetin can be as effective as NAC in protecting rat peripheral lymphocytes against nicotine-induced cellular and DNA damage.

Caffeic acid protects human peripheral blood lymphocytes against gamma radiation-induced cellular damage.

In the present study, we investigated in vitro radioprotective potential of caffeic acid (CA), a naturally occurring catecholic acid against gamma radiation-induced cellular changes. Different concentrations of CA (5.5, 11, 22, 44, 66, and 88 microM) were incubated with lymphocytes for 30 min prior to gamma-irradiation, and micronuclei (MN) scoring and comet assay were performed to fix the effective concentration of CA against gamma-irradiation. Among all concentrations, 66 microM of CA showed the optimum protection by effectively decreasing the MN frequencies and comet attributes. From the above-mentioned results, 66 microM of CA was selected as the effective concentration and was further used to investigate its radioprotective efficacy. For that purpose, a separate experiment was carried out on the lymphocytes in which lymphocytes were preincubated with CA (66 microM) and were exposed to different doses of radiation (1, 2, 3, and 4 Gy). Genetic damage (MN, dicentric aberration, and comet attributes) and biochemical changes were measured. Gamma-irradiated lymphocytes showed a dose-dependent increase in the genetic damage and thiobarbituric acid reactive substances, accompanied by the significant decrease in the antioxidant status, whereas CA pretreatment positively modulated all the radiation-induced changes through its antioxidant potential. The current study demonstrates that CA is effective in protecting lymphocytes against radiation-induced toxicity and encourages further in vivo study to evaluate radioprotective efficacy of CA.

Quercetin ameliorates gamma radiation-induced DNA damage and biochemical changes in human peripheral blood lymphocytes.

We investigated the radioprotective efficacy of quercetin (QN), a naturally occurring flavonoid against gamma radiation-induced damage in human peripheral blood lymphocytes and plasmid DNA. In plasmid study, QN at different concentrations (3, 6, 12, 24 and 48 microM) were pre-incubated with plasmid DNA for 1h followed by exposure of 6 Gy radiation. Among all concentrations of QN used, 24 microM showed optimum radioprotective potential. To establish the most effective protective concentration of QN in lymphocytes, the cells were pre-incubated with 3, 6, 12, 24 and 48 microM of QN for 30 min and then exposed to 4 Gy gamma-radiation. The concentration-dependent effects of QN were evaluated by scoring micronuclei (MN) frequencies. The results showed that QN decreased the MN frequencies dose dependently, but the effect was more pronounced at 24 microM. Thus, 24 microM of QN was selected as the optimum concentration and was further used to evaluate its radioprotective effect in lymphocytes. For that a separate experiment was carried out, in which lymphocytes were incubated with QN (24 microM) for 30 min and exposed to different doses of radiation (1, 2, 3 and 4 Gy). Genetic damage (MN, dicentric aberration and comet attributes) and biochemical changes were measured to evaluate the effect of QN on gamma-radiations (1-4 Gy). Radiation exposed showed significant increases in the genetic damage and thiobarbituric acid reactive substances (TBARS) accompanied by a significant decrease in the antioxidant status. QN pretreatment significantly decreased the genetic damage and TBARS and improved antioxidant status through its antioxidant potential. Altogether, our findings encourage further mechanistic and in vivo studies to investigate radioprotective efficacy of QN.

Modulatory potential of ellagic acid, a natural plant polyphenol on altered lipid profile and lipid peroxidation status during alcohol-induced toxicity: a pathohistological study.

Polyphenol-rich dietary foodstuffs, consumed as an integral part of vegetables, fruits, and beverages have attracted attention due to their antioxidant and anticancer properties. Ellagic acid (EA), a polyphenolic compound widely distributed in fruits and nuts, has been reported to scavenge free radicals and inhibit lipid peroxidation. Chronic consumption of alcohol potentially results in serious illness including hepatitis, fatty liver, hypertriglyceridemia, and cirrhosis. A little is known about the influence of EA on alcohol toxicity in vivo. Accordingly, in the present study, we have evaluated the protective effects of EA on lipid peroxidation and lipid levels during alcohol-induced toxicity in experimental rats. Forty female albino Wistar rats, which were weighing between 150-170 g were used for the study. The toxicity was induced by administration of 20% alcohol orally (7.9 g/kg body wt.) for 45 days. Rats were treated with EA at three different doses (30, 60, and 90 mg/kg body wt.) via intragastric intubations together with alcohol. At the end of experimental duration, liver marker enzymes (i.e., aspartate transaminase, alanine transaminase), lipid peroxidative indices (i.e., thiobarbituriacid reactive substances and hydroperoxides) in plasma, and lipid levels (i.e., cholesterol, free fatty acids, triglycerides and phospholipids) in tissues were analyzed to evaluate the antiperoxidative and antilipidemic effects of EA. Liver marker enzymes, lipid peroxidative indices, and lipid levels, i.e., cholesterol, triglycerides and free fatty acids, were significantly increased whereas phospholipid levels were significantly decreased in the alcohol-administered group. EA treatment resulted in positive modulation of marker enzymes, peroxidative indices, and lipid levels. EA at the dose of 60 mg/kg body wt. was found to be more effective when compared to the other two doses. Histological changes observed were also inconsistent with the biochemical parameters. Our study suggests that EA exerts beneficial effects at the dosage of 60 mg/kg body wt. against alcohol-induced damage, and it can be used as a potential drug for the treatment of alcohol-abuse ailments in the near future.

Influence of ferulic acid on nicotine-induced lipid peroxidation, DNA damage and inflammation in experimental rats as compared to N-acetylcysteine.

We examined the effect of ferulic acid (FA), a naturally occurring phenolic compound on lipid peroxidation and endogenous antioxidant status, DNA damage and inflammation in nicotine-administered Wistar rats. The effect of FA against nicotine toxicity was compared with N-acetylcysteine (NAC), a well-known antioxidant. Lung toxicity was induced by subcutaneous injection of nicotine at a dose of 2.5mg/kg body weight (5 days a week, for 22 weeks) and FA and NAC were given simultaneously by intragastric intubation for 22 weeks. Seventy two Wistar rats were divided into six groups: (i) control, (ii) nicotine, (iii) nicotine+FA (iv), nicotine+NAC, (v) FA and (vi) NAC. At the end of the experimental period, cellular damage was assessed by measuring the activities of lactate dehydrogenase and alkaline phosphatase in plasma, which were significantly elevated in nicotine-administered rats when compared with control group. Enhanced lipid peroxidation (evaluated by measuring the thiobarbituric acid reactive substances and hydroperoxides) was accompanied by a significant decrease in the endogenous antioxidant status viz., superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione in circulation, lung and liver of nicotine-treated rats when compared with control group. DNA single strand breaks (evaluated by comet assay) and frequency of micronuclei were significantly increased in peripheral blood of nicotine-treated rats when compared with control. Our Western blot analysis showed a significant increase in the expression of cyclooxygenase-2 and NF-kappaB in lung and liver of nicotine-treated rats. FA and NAC co-treated rats showed a significant decrease in the activities of circulatory lactate dehydrogenase and alkaline phosphatase, the levels of lipid peroxidative markers (in circulation, lung and liver), DNA single stranded breaks (comet parameters), micronuclei frequency (in the whole blood) and expression of cyclooxygenase-2 and Nf-kappaB (in lung and liver tissues), and significant increase in antioxidant status (in circulation, lung and liver). The protection of FA against nicotine-induced toxicity was merely equal to the effect of NAC. FA and NAC treatment alone did not produce any damage to control rats. Thus, we propose that FA exerts protective effect against nicotine toxicity by modulating the lipid peroxidation, inflammation, DNA damage and endogenous antioxidant status.

Protective effect of quercetin on nicotine-induced prooxidant and antioxidant imbalance and DNA damage in Wistar rats.

We have investigated the protective effect of quercetin (QN) against nicotine-induced prooxidant and antioxidant imbalance in circulation, lung, liver and kidney of experimental rats. The protective effect of QN was compared with N-acetylcysteine (NAC), a well-known antioxidant. Male albino rats of Wistar stain were used for the experimental study. Lung toxicity was induced by subcutaneous injection of nicotine at a dose of 2.5mg/kg body weight (5 days a week, for 22 weeks) and QN was given simultaneously by intragastric intubations for 22 weeks. The body weight gain of rats during experimental period was significantly decreased in nicotine treated group, whereas QN co-treated rats significantly increased in their body weight. The levels of lipid peroxidative indices viz., thiobarbituric acid reactive substances and hydroperoxides, and nitric oxide in circulation, lung, liver and kidney of nicotine-treated rats were increased significantly when compared to normal, which were brought down to near normal in QN co-treated group. Endogenous antioxidant status viz., superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione were found to be significantly decreased in circulation, lung, liver and kidney of nicotine-treated group, which were significantly increased in QN-administered groups. The extent of DNA damage (evaluated by comet assay) was significantly increased in circulatory blood of nicotine-treated rats, which was effectively brought down by QN treatment. The protective effect of QN against nicotine toxicity was comparable to that of NAC. Our data suggest that QN exerts its protective effect by modulating the extent of lipid peroxidation and augmenting antioxidant defense system and thus protects the DNA in experimental animals.

Dose-response effect of ellagic acid on circulatory antioxidants and lipids during alcohol-induced toxicity in experimental rats.

Ellagic acid (EA) is a naturally occurring polyphenolic compound that exhibits antioxidative, anti-inflammatory, anti-hyperlipidaemic and anticarcinogenic activities in a wide range of assays both in vitro and in vivo. It occurs in various foods such as strawberries, grapes, walnuts, etc. The aim of this study was to assess the effect of ellagic acid on alcohol-induced changes in the circulatory antioxidative status, micronutrients and lipid levels in a dose-dependent fashion. Female albino Wistar rats weighing 150-170 g were used to assess the effects of EA against alcohol-induced damage. Three different concentrations of EA (30, 60 and 90 mg/kg body weight) were tested against 20% alcohol via intragastric administration. At the end of the experimental duration of 45 days, we evaluated endogenous antioxidants: both enzymatic (superoxide dismutase, catalase and glutathione peroxidase) and non-enzymatic (vitamin C and E, and reduced glutathione) status, micronutrients, viz. copper and zinc, and lipids: cholesterol, triglycerides, free fatty acids and phospholipids in the circulation. The body weight gain of both alcohol-fed rats and EA-treated rats were also inferred. EA significantly inhibits alcohol-induced toxicity by improving body weight, restoring antioxidant status, modulating micronutrients and attenuating the lipid levels in the circulation. The greatest inhibitory effect was observed with 60 mg/kg body weight of EA in all the biochemical assessments. The results support the hypothesis that EA at the concentration of 60 mg/kg body weight decreases the intensity of alcohol-induced toxicity and could be developed as a potential drug for alcohol abuse in the near future.

Antioxidant and anti-inflammatory properties of curcumin.

Curcumin, a yellow pigment from Curcuma longa, is a major component of turmeric and is commonly used as a spice and food-coloring agent. It is also used as a cosmetic and in some medical preparations. The desirable preventive or putative therapeutic properties of curcumin have also been considered to be associated with its antioxidant and anti-inflammatory properties. Because free-radical-mediated peroxidation of membrane lipids and oxidative damage of DNA and proteins are believed to be associated with a variety of chronic pathological complications such as cancer, atherosclerosis, and neurodegenerative diseases, curcumin is thought to play a vital role against these pathological conditions. The anti-inflammatory effect of curcumin is most likely mediated through its ability to inhibit cyclooxygenase-2 (COX-2), lipoxygenase (LOX), and inducible nitric oxide synthase (iNOS). COX-2, LOX, and iNOS are important enzymes that mediate inflammatory processes. Improper upregulation of COX-2 and/or iNOS has been associated with the pathophysiology of certain types of human cancer as well as inflammatory disorders. Because inflammation is closely linked to tumor promotion, curcumin with its potent anti-inflammatory property is anticipated to exert chemopreventive effects on carcinogenesis. Hence, the past few decades have witnessed intense research devoted to the antioxidant and anti-inflammatory properties of curcumin. In this review, we describe both antioxidant and anti-inflammatory properties of curcumin, the mode of action of curcumin, and its therapeutic usage against different pathological conditions.

Protective effect of ferulic acid on nicotine-induced DNA damage and cellular changes in cultured rat peripheral blood lymphocytes: a comparison with N-acetylcysteine.

Nicotine is the major pharmacologically active substance in cigarette smoke and plays an important etiological role in the development of lung cancer. Incidence of cancer may be related to oxidative damage to host genome by nicotine. These oxidative actions may be modified by the phytochemicals present in food. The present study describes the protective effect of ferulic acid (FA), a naturally occurring nutritional compound on nicotine-induced DNA damage and cellular changes in cultured rat peripheral blood lymphocytes in comparison with N-acetylcysteine (NAC), a well-known antioxidant. One-hour exposure of lymphocytes to nicotine at the doses of 0.125, 0.25, 0.5, 1, 2, 3 and 4 mM induced a statistically significant dose-dependent increase in the levels of thiobarbituric acid reactive substances (TBARS), a lipid peroxidative marker and decrease in the levels of reduced glutathione (GSH), an important endogenous antioxidant. The lowest concentration eliciting significant damage was 1 mM nicotine and maximum damage was observed with 3 mM concentration. Hence, the test concentration was fixed at 3 mM nicotine. We have used 5 different doses of FA (10, 50, 100, 150 and 300 microM) and NAC (0.25, 0.5, 1, 2 and 4 mM) to test their protective effects. In all the groups, FA and NAC showed a dose-dependent inhibitory effect. Maximum protection was observed at the dose of 150 microM FA and 1mM NAC. So, 150 microM FA and 1mM NAC were used for further studies. There was a significant increase in the levels of lipid peroxidative index (TBARS and hydroperoxides (HP)), severity of DNA damage (evaluated by comet assay) in nicotine-treated group, which were significantly decreased in FA and NAC-treated groups. Nicotine treatment significantly decreased the endogenous antioxidant status viz., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), GSH, vitamin A, E and C. Co-administration of FA and NAC to nicotine-treated lymphocytes showed a significant increase in the antioxidant status. The protective effect of FA was merely equal to that of NAC effect. FA and NAC treatment alone did not produce any toxicity to the normal lymphocytes at their effective doses. On the whole, there is overwhelming evidence that FA has the ability to modulate DNA damage and a variety of cellular changes that occur during nicotine-induced toxicity in rat peripheral blood lymphocytes.

Ellagic acid, a natural polyphenol protects rat peripheral blood lymphocytes against nicotine-induced cellular and DNA damage in vitro: with the comparison of N-acetylcysteine.

The present work is aimed at evaluating the protective effect of ellagic acid (EA), a natural polyphenolic compound that is widely distributed in fruits and nuts against nicotine-induced toxicity in rat peripheral blood lymphocytes. The effect of EA against nicotine toxicity was compared with N-acetylcysteine (NAC), a well-known antioxidant. Lymphocytes were exposed to nicotine at the doses of 0.125, 0.25, 0.5, 1, 2, 3 and 4 mM for 1h in culture media. Thiobarbituric acid reactive substances (TBARS), a lipid peroxidative marker and reduced glutathione (GSH), as indicative of endogenous antioxidant status were analyzed to fix the optimum dose. The lowest concentration eliciting significant damage was 1 mM nicotine and maximum damage was observed with 3 mM concentration, as evidenced by increased levels of TBARS and decreased levels of GSH. Hence, the test concentration was fixed at 3 mM nicotine. To establish most effective protective support we used five different concentrations of EA (10, 50, 100, 150 and 300 microM) against 3 mM nicotine. A dose-dependent inhibitory effect was observed with all doses of EA. Maximum protection was observed at the dose of 100 microM EA. So, 100 microM dose was used for further studies. We have tested five different concentrations of NAC-0.25, 0.5, 1, 2 and 4 mM to elucidate the optimum protective dose against nicotine toxicity. One millimolar NAC showed a significant protection against nicotine toxicity. Protective effect of EA against nicotine toxicity was elucidated by analyzing the lipid peroxidative index, viz., TBARS, hydroperoxides (HP) and endogenous antioxidant status, viz., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), Vitamins A, E and C. DNA damage and repair were assessed by using alkaline single-cell microgel electrophoresis (Comet assay) and micronucleus assay. There was a significant increase in the levels of lipid peroxidative index, severity in DNA damage and micronuclei number in nicotine-treated group, which was positively modulated by EA treatment. Antioxidant status was significantly depleted in nicotine-treated group, which was effectively restored by EA treatment. The protection of EA against nicotine toxicity was equally effective to that of NAC. EA and NAC treatment alone did not produce any damage to the normal lymphocytes at their effective doses. These findings suggest the potential use and benefit of EA as a modifier of nicotine-induced genotoxicity.

Ferulic Acid modulates altered lipid profiles and prooxidant/antioxidant status in circulation during nicotine-induced toxicity: a dose-dependent study.

Nicotine, an active ingredient of tobacco smoke, is known to induce hyperlipidemia and disturb the prooxidant-antioxidant status. In our study, ferulic acid, a naturally occurring nutritional compound, was tested for its antioxidant and antihyperlipidemic property in a dose-dependent manner against nicotine-induced toxicity in female Wistar rats. We tested three different doses of ferulic acid-10 mg, 20 mg, and 40 mg/kg body weight-for their protective effects. The activities of biochemical marker enzymes lactate dehydrogenase and alkaline phosphatase, levels of peroxidative indices (thiobarbituric acid reactive substances and hydroperoxides), nitric oxide, and circulatory lipids (cholesterol, triglycerides, free fatty acids, and phospholipids) were increased significantly in the nicotine-treated group when compared to normal, which were brought down in ferulic acid-treated groups. The antioxidant status (superoxide dismutase, catalase, glutathione peroxidase, vitamin E, and reduced glutathione) was found to be decreased in the nicotine-treated group, and was significantly increased in ferulic acid-administered groups. Further, ferulic acid also positively modulated the nicotine-induced changes in the micronutrients (zinc and copper) level. The dose 20 mg/kg body weight was found to be more effective than the other two doses. Our data suggest that FA exerts its preventive effects by modulating the degree of lipid peroxidation, antioxidant status, lipid profiles, and trace element levels during nicotine-induced toxicity.