GPT and diabetes mellitus: However, since STZ-diabetic animals have severe diabetes with very high blood glucose levels, the antihyperglycemic effects of curcumin were probably subtle; this could also be true for the other effects of curcumin on the early markers of glycation, body weight gain, food intake, lipid profile, and biomarkers of hepatic (ALT, AST, and ALP) and renal (proteinuria) damage.