This study was carried out to examine mechanisms by which Holotrichia (HTC) produces protective effect against renal cell injury. HTC extraction (5%) prevented $H_2O_2(50mM)$-induced LDH release and lipid peroxidation in renal cortical slices. When slices were treated with 5% HTC extraction, cellular glutathione content and the superoxide dismutase activity were not altered in control and $H_2O_2$-treated tissues. When slices were treated with 50 mM $H_2O_2$, the catalase activity was significantly inhibited, which was completely restored by addition of 5% HTC. Treatment of slices with 5% HTC extraction increased the glutation peroxidase activity in $H_2O_2$-treated tissues. These results suggest that HTC prevents oxidant-induced cell injury and lipid peroxidation by increasing the activities of catalase and glutathione peroxidase in renal cortical slices.