EVALUATION OF THE ATTENUATING EFFECT OF VITAMIN E ON ISONIAZIDINDUCED NEUROPATHIES IN RATS

ABSTRACT

Peripheral neuropathy(PN) is a well-documented side effect associated with the use of isoniazid (INH), a key drug in the therapy of tuberculosis. Oral antioxidant supplementation has been found to attenuate neuropathic condition. Vitamin B6 (pyridoxine) is currently the standard therapy for INH induced neuropathy. This study aimed at exploring the potential therapeutic benefits of vitamin E in mitigating the development and progression of INH-induced peripheral neuropathy (INH-PN). Using well-known animal models, the effects of alpha-tocopherol (a form of vitamin E) supplementation in mitigating the neuropathic symptoms induced by isoniazid was assessed. Male Wistar rats, assigned randomly to six groups including a control, isoniazid-treated (800 mg/kg), isoniazid with alpha-tocopherol in low (3.8 mg/kg), medium (7.5 mg/kg) and high (15 mg/kg) daily doses, and isoniazid with pyridoxine treated, were used. Treatment parameters evaluated include skin sensation, analgesia, motor function, anxiety, and convulsion. Low dose (3.8 mg/kg/day) significantly (P<0.05) increased skin sensation compared to INH alone. There was no significant change in algesia and motor coordination as a result of vitamin E administration. Behaviour and convulsion were not significantly improved by concurrent administration of vitamin E and INH. In conclusion, aside from the low dose of vitamin E that significantly increased skin sensation, higher doses of the vitamin did not significantly improve the neuropathic conditions induced by INH. There may be need for dosage adjustment in future studies.