The African Walnut plant is a climber which grows mainly in Nigeria and Cameroun. It is a lesser-used oil plant with probable efficacy for treating proliferative diseases. This study investigated the antioxidant properties of African walnut seed oil (AWSO) on Dimethyl nitrosamine (DMN) induced liver injuries in Wistar rats. The AWSO was extracted with n-hexane using the Soxhlet apparatus. Sets of 30 Wistar rats in 6 groups of 5 animals each. We fed Groups A and E a diet containing 10% of AWSO while groups B, C, D and F with normal rat pellets. Group B and D were pretreated for seven days with curcumin (200mg/kg) and dimethyl sulfoxide (DMSO) 200mg kg-1, respectively. After 7-days of pre-treatment, Group B, C and E (20µg kg-1) intraperitoneally administered DMN 48hours before they sacrificed by cervical dislocation. Results showed that animals pretreated with the AWSO extract had significant (p<0.05) elevation in the glutathione peroxidase (GPx) activity, superoxide dismutase (SOD) activity, glutathione-s-transferase (GST) activity, Catalase (CAT) activity, and a significant (p<0.05) reduction in the lipid peroxidation (MDA) level. Pretreatment of animals with a diet containing 10% of AWSO for 7-days significantly lowered the activities of ALT, AST, and ALP induced by the action of the toxicant (DMN). Also, AWSO lowered the DMN, prompted a rise in MDA levels and down-regulated the decrease in glutathione content. We, therefore, conclude that AWSO contains chemical properties that serve as a hepatoprotective agent.

Keywords: African walnut, Curcumin, Hepatoprotective, Free radicals, Dimethyl nitrosamine, Dimethyl sulfoxide