Synergistic effects of sinapic acid and ellagic acid ameliorate streptozotocin-induced diabetic nephropathy by inhibiting apoptosis, DNA damage, and structural deterioration in rats.

Introduction: Diabetic nephropathy (DN), a global problem that threatens human health, is an important reason for chronic kidney disease and kidney failure. In our study, it was aimed to investigate the individual and combined effects of SA and EA in streptozotocin (STZ)-induced rats.
Methods: The groups are as follows: Control, untreated diabetic, diabetic treated with Sinapic acid (SA), diabetic treated with Ellagic acid (EA), diabetic treated with SA and EA, treated with SA, treated with EA, and treated with SA and EA. Total kidney volume, total glomerulus volume, total filtration space volume, caspase-3, and 8-OHdG immunoreactivity, Malondialdehyde (MDA), Glutathione (GSH), Catalase (CAT), serum urea, and creatinine levels were evaluated by stereological, immunohistochemical, and biochemical methods.
Results: The findings of the study showed that total kidney volume, total glomerulus volume, total filtration gap volume, caspase-3, and 8-OHdG immunoreactivity, MDA, serum urea, and creatinine levels significantly increased in the untreated diabetic group compared to the control group. Also, severe mesangial and glomerular enlargement, extracellular matrix accumulation, and glomerular and tubular basal membrane thickness were observed in the tubulointerstitial and glomerular of the diabetic rats. However, individual and combined treatments of SA and EA ameliorated these histological changes. Additionally, decreased GSH and CAT in the untreated diabetic group increased by SA and EA treatment.
Conclusions: The findings suggest that treatment of SA and EA prevent apoptosis and DNA damage and structural changes in STZ-induced DN. However, the combined treatment of SA and EA were more effective than their individual treatments in all parameters except serum urea and creatinine.