A standardized fraction of Cajanus scarabaeoides attenuates diabetic nephropathy via antiglycation, anti-inflammatory, and anti-fibrotic mechanisms.

Diabetic nephropathy is the critical microvascular complication of diabetes and a leading cause of end-stage renal disease. Its pathophysiology incriminates complex and interconnected mechanisms driven by hemodynamic and metabolic alterations, accompanied with glycation, inflammation, oxidative stress, and fibrosis. Targeting these cues through natural interventions may preserve kidney functions. The study aimed to investigate the renoprotective potential of a standardized ethyl acetate fraction of C. scarabaeoides (EAFCS), enriched with flavonoids including isoorientin, orientin, vitexin, isovitexin, and genistin, in diabetic nephropathy. In vitro mechanistic studies were performed in NRK-52E rat kidney tubular epithelial cells exposed to high glucose, while in vivo efficacy was assessed in a streptozotocin-induced diabetic rats. EAFCS markedly prevented advanced glycation end product (AGE) formation at early and intermediate stages of the glycation process and also promoted the degradation of preformed AGEs. In vitro, EAFCS attenuated glucose-induced ROS generation, inflammatory response, and pro-fibrotic gene expression. In diabetic rats, EAFCS ameliorated classical diabetic manifestations, including polyphagia, polydipsia, polyuria, and impaired glucose tolerance. Also, EAFCS reduced albuminuria and proteinuria, and improved renal function markers. Histopathological and molecular analyses demonstrated that EAFCS alleviated diabetes-induced renal structural damage and fibrosis. Mechanistically, EAFCS curbed TGF-β/Smad signaling, prevented myofibroblast activation, and reduced fibronectin and collagen accumulation in renal tissue. Additionally, EAFCS downregulated RAGE expression and inhibited NF-κB- and MAPK-mediated inflammatory signaling cascades. Collectively, the findings suggest that EAFCS attenuates multiple manifestations of renal dysfunctions and may exert renoprotective effects through mechanisms associated with reduced glycation, oxidative stress, inflammation, and fibrosis. These results support EAFCS as a potential candidate for further investigation in the management of diabetic nephropathy.