Combination of ramipril and rutin alleviate alloxan induced diabetic nephropathy targeting multiple stress pathways in vivo

Diabetic nephropathy (DN) is considered as one of the major microvascular complications of diabetes mellitus (DM) which leads to end stage renal disease (ESRD). Even though existing therapeutic options are effective in decreasing albuminuria, drugs targeting the preservation of GFR and prevention of ESRD may provide better strategy for the treatment. Since metabolic disorders are multifactorial, poly-herbal medications, and drug-herbal combination are in demand. Therefore, the present work is focused on the combinatorial renoprotective effect of rutin and ramipril on alloxan induced DN in experimental rats. Male Wistar rats were divided into five groups, group I-control, group II-diabetic rats, group III-diabetic rats treated with ramipril, group IV-diabetic rats treated with rutin, group V-diabetic rats treated with ramipril and rutin for a period of six weeks. Results revealed administration of alloxan induced hyperglycemia and alteration in antioxidant profile. However, combination of a bioflavonoid with an Angiotensin converting enzyme (ACE) inhibitor administration restored the antioxidant status in experimental DN rats. Over-expression of ACE, TGF-beta 1 and decreased podocin expression in diabetic rats was significantly reversed in rats administered with both ramipril and rutin. In addition to attentuating oxidative stress and fibrosis, combinatorial therapy significantly down-regulated endoplasmic reticulum stress markers GRP78 and CHOP. Notably, combination of both ramipril and rutin in low doses reduced the side effects than the administration of monotherapy alone. Histopathological results revealed that combinatorial therapy was associated with a reduction in tubulointerstitial injury. The current study contributes the understanding of the multifactorial nature of DN and implies combinatorial treatment of ACE inhibitor with an antioxidant will be a promising therapeutic strategy for DN by their mechanism of action targeting various pathophysiological changes and stress pathways.