The glutathione S-transferases (GSTs) are a family of multifunctional enzymes involved in cellular detoxification. The aim of this study was to evaluate the effect of albendazole - drug of choice for trichinellosis - on the total activity and kinetics of cytosolic GST in the mouse intestines during experimental trichinellosis. Our results showed a statistically significant decrease in the total GST activity both in the small and large intestines of the mice infected with the nematode Trichinella spiralis (Owen, 1835) and treated with albendazole, compared with the control mice that were infected but untreated with the drug. Furthermore, albendazole administration modified the kinetics of substrate saturation of GST in the intestines of the infected mice because the drug caused changes in Michaelis constant values of this enzyme. Based on our observations, we suggest that the quaternary structure of GST from the mouse intestines is impacted by this drug during trichinellosis.
A crop legume Vigna unguiculata L. (Walp.) and a wild legume Crotalaria juncea L. were evaluated for their relative responses to the oxidative stress injury induced by various doses of UV-B radiation (UV-B, 280-315 nm; 0, 1.0, 1.4, 4.7, and 6.0 kJ m-2 d-1). A dose-dependent damage in lipid peroxidation was determined as an index of membrane injury caused by UV-B. The impact was significantly higher in V. unguiculata than in C. juncea. The specific activities of superoxide dismutase, ascorbate peroxidase, monodehydroascorbate reductase, and dehydroascorbate reductase increased directly proportional to UV-B doses. However, the activities of these enzymes were significantly higher in V. unguiculata than in C. juncea indicating that V. unguiculata was inflicted with more severe oxidative stress injury under UV-B. In C. juncea the glutathione reductase and ascorbate oxidase activities were 35 and 40 % greater than in V. unguiculata, respectively. Further, the non-enzymatic antioxidants ascorbate and glutathione, and their reduced/oxidizes ratios in C. juncea were much greater than V. unguiculata indicating C. juncea has an inherently greater antioxidative potential than V. unguiculata. Thus C. juncea is better adapted to oxidative stress than V. unguiculata by means of efficient cellular antioxidant mechanisms helping to combat the photooxidative stress injury elicited by UV-B.