Role of <i>Arctium lappa</i> L. Root (Burdock) Extract in CFA-induced Arthritis Rat Model: Impact on Antioxidant Activity and Inflammation

Background: Arctium lappa L. is a well-known medicinal herb recognized for its anti-inflammatory and antioxidant properties, which have been shown to be beneficial in the treatment of various diseases. Objectives: The present study aimed to explore the protective effects of the hydroalcoholic extract of A. lappa root in complete Freund’s adjuvant (CFA)-induced arthritis in rats. Methods: Arthritis was induced in Sprague-Dawley rats through a single subcutaneous CFA injection into the right hind paws. After induction, the animals were orally administered A. lappa at doses of 200 and 400 mg/kg, or prednisolone (as a reference drug), for a duration of 30 days. Blood and ankle joint samples were collected for analysis. The anti-arthritic effects were assessed through nociceptive behavioral tests, paw edema, body weight measurements, serum concentrations of tumor necrosis factor-α (TNF-α), nitric oxide (NO), glutathione (GSH), superoxide dismutase (SOD) activity, and histopathological evaluations. Results: The A. lappa root extract significantly improved body weight and reduced thermal hyperalgesia, as well as decreased paw edema in a dose-dependent manner (P < 0.001). Furthermore, A. lappa reduced inflammatory cytokines and increased antioxidant defenses in the serum of all treated rats (P < 0.05 to P < 0.001). Histologically, A. lappa notably restored the ankle joint architecture compared to untreated arthritic rats (P < 0.05 to P < 0.001). Conclusions: The results suggest that A. lappa has significant anti-arthritic potential by reducing inflammatory cytokines and enhancing serum antioxidant levels, which supports its traditional use in the management of joint diseases.