Effect of diallyldisulphide on an antioxidant enzyme system in Candida species

This study was carried out to show the effect of diallyldisulphide (DADS), an important organosulphur compound found in garlic (Allium sativum), on antioxidant systems in Candida species. Changes in antioxidant metabolites and antioxidant activity in the presence of DADS were found in Candida albicans and Candida tropicalis. Candida cells were treated with sublethal concentrations of DADS. DADS caused a decrease in the activity of all antioxidant enzymes except catalase, resulting in oxidative stress and damaged cells. The amount of oxidative stress generated by DADS was found to be a function of its concentration. A significant decrease in superoxide dismutase, glutathione-S-transferase, and glutathione peroxidase activities but an increase in catalase activity were observed. Increased levels of lipid peroxidation and decreased levels of glutathione were observed in treated cells. Activity of glucose-6-phosphate dehydrogenase decreased significantly following DADS treatment and could be correlated with a decrease in glutathione concentration in both Candida species. These results indicate that diallyl disulphide acts as a pro-oxidant to Candida species and hence may act as a potent antifungal in the management of candidiasis.