Ameliorative effects of eugenol and silymarin on lead acetate induced renal damage in Wistar rats

Abstract

Lead (Pb) is a pervasive environmental toxicant known to induce severe nephrotoxicity primarily through oxidative stress-mediated mechanisms. Eugenol (EUG), a phenolic compound, and Silymarin (SM), a flavonolignan complex, possess potent antioxidant and renoprotective properties. The present study evaluated the protective efficacy of EUG and SM, individually and in combination, against Pb-induced renal toxicity in male Wistar rats. Thirty rats were randomly allocated into five groups (n = 6). Group I served as the control, while Groups II-V received lead acetate (500 ppm) in drinking water for 28 days. From day 15 to day 28, Groups III and IV were treated with EUG (5 mg/kg) and SM (50 mg/kg), respectively, and Group V received a combination of EUG and SM via the oro-gastric route. Renal function markers, oxidative stress parameters, and histopathological changes in kidney tissue were assessed. Pb exposure resulted in marked renal dysfunction, evidenced by significant elevation of serum urea, blood urea nitrogen (BUN), creatinine, and uric acid levels, enhanced lipid peroxidation and superoxide radical generation, and pronounced depletion of renal antioxidant defenses, including reduced glutathione, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. Histopathological examination revealed severe degenerative and necrotic alterations in renal tissues. Treatment with EUG or SM significantly attenuated Pb-induced renal damage by restoring antioxidant status, suppressing oxidative stress, and improving renal histoarchitecture. Notably, combined EUG + SM therapy exerted the most pronounced renoprotective effect, with near normalization of biochemical, oxidative, and histopathological parameters. These findings demonstrate that Pb induces significant nephrotoxicity via oxidative mechanisms, while EUG and SM, particularly in combination, effectively mitigate Pb-induced renal injury, highlighting their potential as natural therapeutic agents against heavy metal-induced kidney damage.