Assessment of antioxidant capacity, proximate composition and inhibitory activity of unripe plantain (Musa paradisiaca) products on Fe2+ and sodium nitroprusside -induced oxidative stress in vitro

Abstract

This study sought to assess the proximate composition, antioxidant and inhibitory effect of unripe false horn plantain (Musa paradisiaca) products on Fe2+ and sodium nitroprusside (SNP) induced lipid peroxidation in rat’s pancreas. The EC50 of Fe2+ chelating, 2,2-diphenyl-1picrylhydrazyl (DPPH) and OH free radical scavenging ability were also determined. A portion of the unripe false horn plantain pulps were roasted to form a local meal called ‘boli’ while the other was boiled in water. Thereafter, each portion was sundried and milled into flour. The aqueous extracts of roasted flour (Rf) and boiled flour (Bf) samples were prepared (1 g/20 mL). Proximate composition showed that the Rf had higher ash and fibre content while the Bf had higher carbohydrate, fat, protein and moisture content. The Bf had higher phenolic contents, reducing power, DPPH and OH free radical scavenging ability. The Rf flour had higher vitamin C content, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and Fe2+ chelating ability. Bf had higher inhibitory effect on both the Fe2+and SNP induced lipid peroxidation in pancreas at the concentration tested (1.25 to 6.25 mg/mL). Their strong inhibitory activities, coupled with the antioxidant properties suggest that they could be a cheap source of natural antioxidants and also a means of restoring antioxidant status. Key words: Antioxidant capacity, Musa paradisiaca, lipid peroxidation, oxidative stress, 2,2-diphenyl-1picrylhydrazyl (DPPH).