The present study was carried out to evaluate the effect of N-acetyl cysteine and vitamin C on a lung carcinoma cell line. We studied the trypan blue exclusion pattern of a malignant lung cell line, NCI-H82, with and without supplementation of the drugs added alone or in combination. The levels of lipid peroxidation and glutathione were estimated in addition to the estimation of antioxidant enzymes. The results suggested the antiproliferative nature of the drugs, the effect being more when the drugs were added in combination. Both of the drugs could elevate the level of glutathione in lung cancer cells and the activities of antioxidant enzymes, thus minimizing the cancer-promoting, peroxidative damage to the cells.
The chemoprotective effects of neem (Azadirachta indica A. Juss.) on hepatic and circulatory lipid peroxidation and on antioxidant and detoxifying enzyme status during 7, 12-dimethylbenz [a] anthracene (DMBA)-induced buccal pouch carcinogenesis was investigated in Syrian male hamsters. Enhanced lipid peroxidation in the liver and circulation of tumor-bearing animals was accompanied by a significant decrease in reduced glutathione (GSH) concentration and activities of the detoxifying enzymes glutathione peroxidase (GPx) and glutathione-S-transferase (GST). Administration of neem leaf extract significantly decreased the formation of lipid peroxides and enhanced the levels of antioxidants and detoxifying enzymes. We speculate that neem leaf extract exerts its effects by modulating lipid peroxidation and enhancing antioxidant and detoxification systems.
The effect of Giardia lamblia infection on D-glucose uptake and brush-border enzymes was studied in chronically ethanol-fed rats. Giardia lamblia trophozoites counts were significantly lower in the intestine of ethanol-fed rats than in the controls. Also, the Na+-dependent uptake of D-glucose and brush-border enzymes was significantly reduced (p<0.0001, p<0.01, respectively) in the G. lamblia-infected rat intestine. There was no change in Na+-independent glucose uptake under these conditions. Levels of mRNA encoding Na+-dependent D-glucose transporter (SGLT1) and brush-border sucrase and lactase were reduced in G. lamblia-infected animals compared with those of the controls. However, the mRNA levels encoding these proteins in ethanol-fed and control animals were similar in rat intestine. These findings suggest that down-regulation of SGLT1 and disaccharidases could be responsible for the observed D-glucose malabsorption and decrease in the activity of disaccharidases in G. lamblia infection.
We studied the anti-hepatotoxic potential of Liv.100, a herbal formulation, on anti-tubercular (anti-TB) drugs [isoniazid (INH), rifampicin (RMP), and pyrazinamide (PZA)]-induced mitochondrial damage in rat liver. Liv.100 (400mg/kg body wt./day, orally) was administered simultaneously with anti-TB drugs for 6 weeks. Activities of TCA cycle enzymes (succinate dehydrogenase, isocitrate dehydrogenase, malate dehydrogenase, and α-ketoglutarate dehydrogenase) and respiratory marker enzymes (cytochrome c oxidase, NADH dehydrogenase) and levels of mitochondrial lipid peroxidation in liver were determined. Activities of TCA cycle enzymes and respiratory marker enzymes were significantly lower upon anti-TB drug treatment than those of normal controls. Mitochondrial lipid peroxidation was found to be increased when compared with the normal control value. This indicates impaired function of hepatic mitochondria in anti-TB drug-induced hepatocellular damage. In our present study, Liv.100 co-administration significantly reduced the anti-TB drug-induced alterations in the level of lipid peroxide and activities of TCA cycle enzymes and respiratory marker enzymes in liver mitochondria. The mechanism of action of Liv.100 is probably due to its antioxidant nature against anti-TB drug-induced lipid peroxidation, which is mainly responsible for the inhibition of these enzyme activities.
To assess the appropriate content of vitamin E (VE) in fish oil capsules, we determined lipid peroxide and VE levels in human blood after hyperlipidemic female volunteers had heed given purified eicosapentaenoic acid (EPA) ethyl ester (90% purity) in capsules along with a controlled basal diet. A two consecutive 7-day menu cycle was used, and the capsules were taken with the second 7-day menu. The basal diet was based on the recommended dietary allowances for female Japanese with light physical activities. The fat energy density of the diet was 25%, and the cholesterol intake was less than 300mg per day. Each volunteer ingested nine capsules (2.43g of EPA ethyl ester in total) daily in three divided doses, and a daily total of 5.4mg of all-rac-α-tocopherol (4mg RRR-α-tocopherol equivalent) from the capsules. Blood was collected before and after 1 and 2 weeks of the basal diet periods. Triacylglycerol and total cholesterol concentrations in plasma were determined, and plasma lipid peroxide levels as estimated by thiobarbituric acid reactive substances (TBARS) and water-soluble fluorescent substances (WSF) were also measured. In addition, α-tocopherol levels in plasma, red blood cells (RBC), and platelets were analyzed. The plasma total cholesterol concentration decreased significantly after supplementation with the capsules, but that of triacylglycerol did not change significantly. The TBARS values expressed as plasma concentration and in terms of plasma lipid levels did not change significantly in each case. An amelioration of plasma lipid levels effectively lowered the plasma concentration of WSF. The plasma α-tocopherol concentration did not change significantly with the treatment with the capsules, although the concentration decreased significantly on the controlled basal diet with lower energy but without the supplementation. Neither the α-tocopherol content in RBC nor that in platelets changed significantly during the test period. In conclusion, the VE content in the EPA capsules appears to be sufficient to provide adequate antioxidant protection during the short period of the experiment. An assessment of appropriate VE content in fish oil capsules is discussed by comparing the current data with those reported elsewhere.