Cytoprotective and antioxidative effects of crude drug preparation (E- kong-san)

In the previous report, E-kong-san, which is usually used for recovering health in traditional medicine, has been shown to decrease cisplatin induced nephrotoxicity in vivo and in vitro. The significant reduction of E-kong-san on the cisplatin induced nephrotoxicity led us to investigate whether the effect of this water extract was a result of triggering antioxidation. In monkey kidney Vero cells, E-kong-san at 5~10 mg/ml was able to attenuate 2 mM cisplatin-stimulated cell death by 46.8% and 31.8%, respectively. E-kong- san showed strong free radical scavengering activities on 1,1-diphenyl-2- picrylhydrazil (DPPH) radical and xanthine/ xanthine oxidase (XOD) generated superoxide anion radical (O₂/^-·). We further studied the effects of E- kong-san on lipid peroxidation in rat liver microsomes induced by enzymatic and nonenzymatic methods. Moreover, E-kong-san exhibited significant inhibition on both ascorbic acid/Fe²⁺ and ADP/NADPH/Fe³⁺ induced lipid peroxidation in rat liver microsomes. Based on these results, we suggest that E-kong-san protects the cisplatin induced cytotoxicity by its antioxidative mechanism.