Comparative Antidiabetic and Reno Protective Effects of Ginger and Cinnamon Extracts in STZ-Induced Diabetic Rats

Diabetic nephropathy (DN) is one of the significant microvascular complications of diabetes that is caused by chronic hyperglycemia and oxidative stress. Although Zingiber officinale (ginger) and Cinnamomum verum (cinnamon) share the same properties in terms of antidiabetic, their relative efficacy in DN is not well clarified. This research paper involved a head to head comparison of the antidiabetic and renoprotective effect of ginger and cinnamon extracts in streptozotocin (STZ)-induced diabetic rats with particular interest in renal oxidative stress and histopathology. The male Wistar rats were divided into five groups (n=8): normal control, Diabetic control, Ginger-treated (500 mg/kg/day), Cinnamon-treated (500mg/kg/day, p.o.), Metformin-treated (150mg/kg/day, p.o.). A single intraperitoneal injection of STZ (55 mg/kg) induced diabetes after which the treatment was done over six weeks. We determined the FBG and final HbA1c levels at the end of the week, renal functioning (serum creatinine, blood urea nitrogen, urinary albumin-to-creatinine ratio), renal oxidative stress (malondialdehyde/MDA, reduced glutathione/GSH, superoxide dismutase/SOD, catalase), and kidney histology. Diabetic rats had high levels of hyperglycemia (FBG over 400mg/dL), high HbA1c, renal failure, and oxidative stress. There were both extracts that resulted in significant improvements. The strongest antihyperglycemic was cinnamon extract as it decreased FBG and HbA1c back to metformin levels. On the contrary, ginger extract was a better renoprotector, which was reflected in a much lower serum creatinine (0.681 ± 0.056 mg/dL vs. 0.891 ± 0.064mg/dl in cinnamon) and urinary albumin-creatinine ratio (25.10 ± 2.98mg/g vs. 38.75±3.57mg/g in cinnamon). This was supported by a stronger antioxidant effect where the level of renal MDA was normalised by ginger and GSH, SOD, and catalase activities were restored better compared to cinnamon. These findings were confirmed with the help of histopathological analysis which revealed that renal architecture was significantly preserved in the group of ginger-treated. The findings reveal a clear mechanistic separation: cinnamon can be efficiently utilized with regard to systemic glycemic regulation, whereas ginger is better with regard to direct renoprotection, which is mostly achieved due to its powerful antioxidant properties. This indicates that they can be used as complementary therapies with cinnamon focusing on hyperglycemia and ginger focusing on diabetic nephropathy development.