TGFB1 and diabetic kidney disease: Oral treatment of CS can inhibit the development of diabetic nephropathy via inhibition of AGEs accumulation in STZ-induced diabetic rats The CS-treated group had significantly inhibited COX-2 mRNA and protein, which mediates the symptoms of inflammation in the renal cortex of diabetic rats. Histopathological studies of kidney tissue showed that in diabetic rats, AGEs, the receptor for AGEs, TGF-β1, and collagen IV were suppressed by CS treatment.