Investigation of Protective Effect of Hydroalcoholic Extract of Walnut Tree Leaves (Juglans regia) on Gentamicin-Induced Nephrotoxicity in Male Wistar Rats

Objective/background: The main side effect of gentamicin, an aminoglycoside antibiotic, is kidney toxicity. This side effect leads to electrolyte disorders and retention of nitrogen waste products such as urea and creatinine. This study aimed to investigate the protective effect of the hydroalcoholic extract of the walnut tree (Juglans regia) on gentamicin-induced nephrotoxicity in male Wistar rats. Methods: The experiment involved five groups of rats: a control group, a gentamicin-treated group, and three groups treated with different doses of walnut leaf extract (100, 200, or 400 mg/kg) via intragastric gavage for 14 consecutive days (once per day). After 14 days, blood samples were collected and analyzed for various biochemical markers. Kidney tissue was also examined histopathologically. Results: Findings showed that gentamicin significantly increased levels of uric acid (P < .001), urea (P < .001), creatinine (P < .01), albumin (P < .001), and lipid profile while decreasing the activity of antioxidant enzymes SOD (P < .001) and CAT (P < .001) compared to the control group. It also caused kidney tissue damage. Treatment with walnut leaf extract could significantly reduce urea in all treatment groups. However, the reduction in creatinine levels after treatment with walnut leaf extract wasn't significant. Further, walnut leaf extract at doses of 200 and 400 mg/kg could significantly reduce albumin and uric acid levels (P < .001). Walnut leaf extract significantly improved lipid profile. Also, walnut leaf extract significantly increased SOD and CAT activity in all doses. Walnut leaf extract significantly reduced kidney tissue damage, including inflammation, necrosis, and tubular degeneration. Conclusion: The results of this study conclude that walnut tree leaf extract positively affects kidney function and histology in gentamicin-treated rats. This extract or similar compounds could be an antioxidant treatment for people with renal impairment or chronic kidney disease.