Nagarajan Devipriya

Lycopene: an antioxidant and radioprotector against γ-radiation-induced cellular damages in cultured human lymphocytes.

The present study aimed to evaluate the radioprotective effect of lycopene, a naturally occurring dietary carotenoid on gamma-radiation-induced toxicity. The cellular changes were estimated by using lipid peroxidative indices like thiobarbituric acid reactive substances (TBARS), hydroperoxides (HP), the antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and reduced glutathione (GSH). The DNA damage was analyzed by cytokinesis blocked micronucleus assay (CBMN), dicentric aberration (DC) and translocation frequency. The gamma-radiation at different doses (1, 2 and 4Gy) resulted in a significant increase in the number of micronuclei (MN), DC, translocation frequency, TBARS and HP level, whereas the levels of GSH and antioxidant enzymes were significantly decreased when compared with normal control. The maximum damage to lymphocytes was observed at 4Gy irradiation. Lycopene pretreatment (1, 5 and 10microg/ml) significantly decreased the frequency of MN, DC and translocation when compared with gamma-radiation control. The levels of TBARS, HP were also decreased and activities of SOD, CAT and GPx were significantly increased along with GSH levels when compared with gamma-radiation control. The dose of 5microg/ml of lycopene was found to be more effective than the other two doses. Thus, our result shows that pretreatment with lycopene offers protection to normal lymphocytes against gamma-radiation-induced cellular damage.

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.

Investigation of the radioprotective efficacy of hesperidin against gamma-radiation induced cellular damage in cultured human peripheral blood lymphocytes.

The present study was aimed to evaluate the radioprotective efficacy of hesperidin (HN), a flavonone glycoside against gamma-radiation-induced cellular damage in cultured human peripheral blood lymphocytes. Different concentrations of HN (3.27, 6.55, 9.83, 13.10, 16.38 and 19.65 microM) were pre-incubated with lymphocytes for 30 min prior to gamma-irradiation [4 Gy] and the micronuclei (MN) scoring, dicentric aberration and comet assay were performed to fix the effective dose of HN against gamma-irradiation induced cellular damage. The results indicated that among all the concentrations, 16.38 microM concentration of HN showed optimum protection by effectively decreasing the MN frequencies, dicentric aberrations and comet attributes. Based on the above results, 16.38 microM concentration of HN was fixed as the effective dose to further investigate its radioprotective efficacy which was then carried out by pre-incubating lymphocytes with 16.38 microM concentration of HN, exposing the lymphocytes to different doses (1, 2, 3 and 4 Gy) of radiation and investigating radiation induced genetic damage (MN, dicentric aberration, comet assay, DNA fragmentation assay) and biochemical changes (changes in the level of enzymic and non-enzymic antioxidants, lipid peroxidation). The results indicated a dose dependent increase in both genetic damage and thiobarbituric acid reactive substances (TBARS), accompanied by a significant decrease in the antioxidant status compared to HN treated groups which modulated the toxic effects through its antioxidant potential. Thus the current study shows HN to be an effective radioprotector against gamma-radiation induced in-vitro cellular damage in lymphocytes.

Evaluating the radioprotective effect of hesperidin in the liver of Swiss albino mice

The present study was aimed to evaluate the radioprotective efficacy of hesperidin, a flavonone glycoside against X-ray radiation-induced cellular damage in the liver of Swiss albino mice. The first phase of the study was carried out to fix the effective concentration of hesperidin by performing a 30 days of survival studies using different graded doses [12.5, 25, 50 and 100mg/kg body weight] of hesperidin administered orally to mice via intragastric intubations for seven consecutive days prior to exposure of whole body radiation (10 Gy). Based on the results of survival studies, the effective dose of hesperidin was fixed which was then administered to animals orally via intragastric intubations for seven consecutive days prior to exposure of whole body radiation (4 Gy) to evaluate its radioprotective efficacy by performing various biochemical estimations, comet assay, DNA fragmentation assay and histopathological studies in the liver of Swiss albino mice. The results indicated that radiation-induced decrease in the levels of endogenous antioxidant enzymes and increase in lipid peroxidative index, DNA damage and comet parameters were altered by pre-administration with the effective dose of hesperidin [25mg/kg body weight] which restored the antioxidant status to near normal and decreased the levels of lipid peroxidative index, DNA damage and comet parameters. These results were further confirmed by histopathological examinations which indicated that pre-administration with the effective dose of hesperidin reduced the hepatic damage induced by radiation. Thus the current study shows hesperidin to be an effective radioprotector against radiation induced damage in the liver of mice.

Effect of Ellagic Acid, a Plant Polyphenol, on Fibrotic Markers (MMPs and TIMPs) during Alcohol-Induced Hepatotoxicity

ABSTRACT Alcoholic fibrosis and its end-stage cirrhosis occur when the rate of matrix synthesis exceeds matrix degradation. Hepatic fibroproliferation is associated with alterations of hepatic tissue inhibitors of matrix metalloproteinase (TIMPs) and matrix metalloproteinases (MMPs/matrixins) expressions. The alteration of hepatic matrixins and TIMPs expression to disease stage and inflammatory activity underlines their potential diagnostic markers in chronic liver disease. Ellagic acid (EA), a natural phenolic compound found in fruits and nuts, has potent antioxidant, anti-inflammatory, and anticancerous properties. The aim of our study was to gain further insight into the effect of EA on fibrotic markers (MMPs and TIMPs) during alcohol-induced tissue injury. To elucidate the effect on the MMPs/TIMPs balance by EA, gelatin zymography, multiwell zymography, succinylated gelatin assay, and ELISA technique (for TIMPs) were carried out. Coadministration of EA with alcohol decreased the expression of MMP-2 and -9 and TIMP-2 in a dose-dependent manner. These results suggest that EA at the dosage of 60 mg/kg body weight effectively decreased the expression pattern of fibrotic markers during alcohol-induced toxicity. Hence, it can be developed as an antifibrotic compound in near future.

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.

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.

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 µM) were incubated with lymphocytes for 30 min prior to γ‐irradiation, and micronuclei (MN) scoring and comet assay were performed to fix the effective concentration of CA against γ‐irradiation. Among all concentrations, 66 µM of CA showed the optimum protection by effectively decreasing the MN frequencies and comet attributes. From the above‐mentioned results, 66 µM 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 µM) 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.

Protection against X-ray radiation-induced cellular damage of human peripheral blood lymphocytes by an aminothiazole derivative of dendrodoine.

The present study was aimed to evaluate the radioprotective efficacy of dendrodoine analog (DA), an aminothiazole derivative against X-ray radiation-induced cellular damage in cultured human peripheral blood lymphocytes. Different concentrations of DA (2, 4, 6, 8, 10 microg/ml or 6.15, 12.29, 18.44, 24.59, 30.73 microM) were pre-incubated with lymphocytes for 30 min prior to irradiation [4 Gy] and the micronuclei (MN) scoring and comet assay were performed to fix the effective concentration of DA against 4 Gy irradiation-induced cellular damage. The results indicated that among all the concentrations, 6 microg/ml concentration of DA showed optimum protection by effectively decreasing the MN frequencies and comet attributes. Based on the above results, 6 microg/ml concentration of DA was fixed as the effective dose to further investigate its radioprotective efficacy. This was carried out by pre-incubating the lymphocytes with 6 microg/ml concentration of DA followed by exposure of the lymphocytes to different doses (1, 2, 3 and 4 Gy) of radiation and investigating the radiation-induced genetic damage (MN, comet assay, DNA fragmentation assay) and biochemical changes (changes in the level of enzymic and non-enzymic antioxidants, lipid peroxidation). The results indicated a dose-dependent increase in both genetic damage and thiobarbituric acid reactive substances (TBARS), accompanied by a significant decrease in the antioxidant status in the irradiated groups compared to DA treated groups which modulated the toxic effects through its antioxidant potential. Thus the current study shows DA to be an effective radioprotector against X-ray radiation induced in vitro cellular damage in lymphocytes.