To elucidate whether oxidative stress was involved in the progression of renal dysfunction and morphological alterations in streptozotocin-induced DN rats and confirm the potential inhibitory effect of HACE on oxidative stress, the activity of superoxide dismutase (SOD), hydrogen peroxidase (CAT), and glutathione peroxidase (GSH-PX), whose main biological role was to protect the organism from oxidative damage, was detected in serum and glomeruli for analyzing systemic and local antioxidant activity, respectively. The gene discussed is CAT; the disease is liver dysplastic nodule.