Protective Effects of Walnut (Juglans regia L.) Septum Extract Against Isoniazid-Induced Pulmonary Inflammation in Rats

Aim: Isoniazid (INH) is a first-line antituberculosis drug that can induce oxidative stress and tissue damage. Walnut (Juglans regia L.) septum extract contains high levels of antioxidant compounds with potential therapeutic applications. This study aimed to investigate the protective effects of walnut septum methanolic extract against isoniazid (INH)-induced pulmonary inflammation in rats.Material and Methods: Thirty-two adult male Wistar-Albino rats (250-300 g) were randomly divided into four groups (n=8): Control (saline), INH (400 mg/kg), INH + walnut septum extract 100 mg/kg, and INH + walnut septum extract 250 mg/kg. All treatments were administered orally for 7 consecutive days. Lung tissues were analyzed for lipid peroxidation (LPO), glutathione (GSH), and catalase (CAT) levels, accompanied by comprehensive histopathological examination.Results: INH administration significantly increased LPO levels and decreased GSH content and CAT activity in lung tissue compared to controls (p<0.05). Walnut septum extract dose-dependently reduced LPO levels and restored GSH content and CAT activity. Histopathologically, INH induced interalveolar cellular infiltration and peribronchial lymphoid tissue hyperplasia. Walnut septum extract, particularly at 250 mg/kg, significantly preserved normal pulmonary architecture and attenuated inflammatory changes.Conclusion: Walnut septum methanol extract exhibited significant protective effects against INH-induced pulmonary inflammation likely through its antioxidant properties, suggesting potential therapeutic value in preventing INH-associated pulmonary toxicity.