Antioxidant effect of unripe plantain (Musa paradisiacae) on oxidative stress in alloxan-induced diabetic rabbits

Abstract

Background: Diabetes mellitus results in complications that could be contributed by elevated levels of free radicals and oxidative stress and increased risk of cardiovascular disease. Aim: We investigated the effect of the antioxidant activity of unripe plantain on oxidative stress markers in alloxan induced diabetic rabbits. Materials and Method: Rats were randomized into three groups; control, diabetic, and unripe plantaintreated diabetic rats. The proximate, phytochemical and antioxidant activity of the unripe plantain were determined. The glutathionine, malonaldehyde, catalase and glucose levels of the animals were also determined using standard techniques. Result: The diabetic rabbits placed on unripe plantain diet had a decrease in their blood glucose (- 24.25±8.08%) and malonaldehyde levels with a corresponding increase in their weights (23.63±1.20%), glutathione and catalase levels after 3weeks of dieting compared with the control (p<0.05). Glutathione correlated negatively with malonaldehyde and glucose (r = -0.77 and -0.877), but positively with catalase and body weight (r = 0.60 and 0.70). Malonaldehyde correlated negatively with catalase and body weight (r = - 0.44 and -0.72) but positively with glucose (r = 0.86). Catalase correlated negatively with glucose(-0.69) but positively with body weight (1). The extract had a high scavenging activity on DPPH radical (78.57±0.12%) comparable to that of standard vitamin C (83.20±0.00%) in addition to a high total antioxidant activity (62±0.20%). The flour contained low amounts of protein, lipid, tannin, saponin, alkaloids, flavonoids and energy value but significant quantities of crude fibre, ash and carbohydrates. Conclusion: These findings suggest that raised blood glucose level in diabetics could deplete cells of their antioxidant status with resultant increase in oxidative stress. Finally, unripe plantain intake may exert a free radical scavenging activity by ameliorating the altered antioxidant status.

Keywords: Diabetes, rabbits, plantain, oxidative stress, antioxidant