SOD1 and diabetic kidney disease: So we examined the related indexes of antioxidant defense, and the data showed that GSH and SOD levels were significantly decreased, and MDA levels were significantly increased in the kidneys of DKD rats compared with the control group, whereas GSPE Fer-1 significantly inhibited the depletion of GSH and SOD levels and the increase of MDA content (Fig 1F-H), which indicated that GSPE could inhibit the oxidative stress damage in the kidneys of DKD rats (S1 Fig-S5 Fig).