Cystone – An ayurvedic polyherbal formulation inhibits adherence of uropathogenic E. coli and modulates H(2)O(2)-induced toxicity in NRK-52E cells

Gentamicin is a widely used antibiotic for the treatment of adverse urinary tract infections (UTI), which in turn causes nephrotoxicity to uroepithelial cells and hence an alternative safe herbal remedy is much desired to compensate these toxic effects. The bacterial adhesion to the uroepithelial cells is the primary step in UTI and it induces various immunogenic reactions leading to the generation of reactive oxygen species (ROS), which are detrimental to the cells survival. Inhibition of bacterial adherence to urinary tract epithelial cells has been assumed to account for the beneficial action ascribed to cystone (an ayurvedic polyherbal formulation) in the prevention of UTI. In this study, we have examined the effect of cystone on the adherence of pathogenic [2-(14)C]-acetate labeled Escherichia coli (MTCC-729) to rat proximal renal tubular cells (NRK-52E cells). Further, the antioxidant property of cystone was studied using hydrogen peroxide (400 μM) as a pro-oxidant in NRK-52E cells. The results showed that cystone inhibited the adherence of E. coli to NRK-52E cells significantly. Additionally cystone effectively combats the toxicity induced by H(2)O(2) in NRK-52E cells. The cytoprotective effect of cystone is brought about by inhibiting lipid peroxidation by 36% in cells treated with cystone compared to H(2)O(2)-treated cells without cystone. The antioxidant enzymes catalase, glutathione were increased by 53% and 68% respectively and superoxide dismutase activity was increased 3-fold. The glutathione content was significantly increased by 2.4-fold in NRK-52E cells treated with cystone compared to H(2)O(2) control group. These results suggest that cystone effectively inhibits bacterial adherence to NRK-52E cells and attenuates H(2)O(2)-induced toxicity in NRK-52E cells by inhibiting lipid peroxidation and increasing the antioxidant defense mechanism.