Although effect of SA on the biochemical markers (such as blood urea, serum creatinine, uric acid, and FBG) have been investigated previously (DeFronzo et al., 1992; Kanchana et al., 2011; Wilson et al., 2011; Nithya and Subramanian, 2015; Nithya et al., 2017), we here investigating the effect of SA on the gene expression of SOD, GPx, and catalase and the signaling pathway of Nrf2/HO-1 in the STZ-induced DN rats. The gene discussed is SOD1; the disease is liver dysplastic nodule.