Unripe <i>Musa paradisiacal</i> fruit diet ameliorates impaired glucose regulation caused by Iron-induced oxidative stress

Abstract

Excess iron impairs glucose regulatory mechanisms through an increase in  oxidative stress. Unripe Musa paradisiaca fruit (UMP) diets have been reported to alleviate diabetes and exert antioxidant effects. In this study, some glucose  regulatory indices were investigated in Wistar rats with iron-induced oxidative  stress and maintained on UMP-diet. Thirty-rats were divided into five equal groups. Group 1 (control) received standard rat chow only. Oxidative stress was induced  with ferrous-sulphate (3mg/kg, i.p.) in groups 2–5 and animals were simultaneously maintained on standard rat chow (group2), 20%UMP-diet (group3), 40%UMP-diet (group4) and 80%UMP-diet (group5) respectively, for 28days. Phytochemical,  mineral and proximate analysis of UMP were evaluated. Blood glucose was  monitored on days 0,7,14,21 and 28 respectively using the tail tipping method. At  day28 post-treatment, blood samples were obtained from each animal; serum was extracted and assayed for iron, total iron binding capacity (TIBC), insulin and interleukin-6 levels. Muscle glycogen was determined using the anthrone method;  insulin resistance, pancreatic beta cell function and transferrin saturation levels were mathematically calculated. Pancreatic samples were histologically evaluated using H and E stains. Phytochemical screening showed the presence of flavonoids, saponins, phenols, tannins, coumarins, steroids and alkaloid. Mineral and proximate analysis indicate the presence of proteins, fibre, sodium, iron, zinc and potassium. Blood glucose on day28 was unchanged in control, increased in group2 and decreased in groups 3-5 respectively compared to day 0. Beta cell function, insulin and TIBC were decreased while transferrin saturation was increased in group2 compared to all other groups. Serum iron and interleukin-6 was increased while muscle glycogen was reduced in group2 compared to groups4 and 5 respectively. Group2 animals had pancreas with necrotic acinar cells and ill-defined islet of Langerhans. These pathologies were not observed in normal and UMP treatment groups. This study suggests that unripe Musa paradisiaca fruit diet may reduce the deleterious effects of iron-induced oxidative stress on glucose regulatory indices.

Keywords: Unripe Musa paradisiaca, glucose, iron, iron-induced oxidative stress