Antioxidant Activity, Carbohydrate‐Hydrolysing Enzyme Inhibition, Antihyperglycaemic Effect and Associated Expression Changes of Bryophyllum pinnatum ‐Fortified Wheat‐Plantain Snack in Streptozotocin‐Induced Diabetic Rats

Abstract

Type 2 diabetes is a risk factor for cardiovascular morbidity and mortality. Sugar‐laden snacks have been implicated as one of the major contributors when consumed in excess. The development of new snack products enriched with value‐added bioactive properties can open up fresh opportunities for health‐conscious consumers. This study developed snacks from wheat and unripe plantain flour blends fortified with Bryophyllum pinnatum leaf extract. The total phenolic and flavonoid contents of the snacks, as well as their in vitro antioxidant activities, were determined using standard methods. The antioxidant activity was evaluated based on DPPH, ABTS and hydroxyl (OH) radical‐scavenging activities and Fe 2+ ‐chelating capacity. The snacks were fed to streptozotocin‐induced (45 mg/kg) diabetic rats for 21 days while measuring the blood glucose level. The addition of BPLE to the blends significantly ( p  < 0.05) increased the total phenolic and flavonoid contents of the snacks. The snack with the highest antioxidant activities contained 80% wheat flour and 20% unripe plantain flour with BPLE. Also, the α‐amylase and α‐glucosidase inhibition activities were highest in the same sample. The blood glucose of the diabetic rats was reduced by 62% (post‐STZ induction) when fed the same snack (5–8 g daily) after a 21‐day treatment. The pancreatic lipid peroxidation was 6.4 nmol MDA equivalent/mg protein in the untreated group, while the values declined by more than 2‐fold in the animals fed the formulated snacks. The catalase and GSH values ranged from 2.65 to 5.05 μmol H 2 O 2 consumed/mg protein and 77.57–258.60 nmol/mg protein, respectively, with the lower values in the untreated group. The expression of GLUT4 and insulin receptor genes was significantly ( p  < 0.05) increased, whereas the expression of pro‐inflammatory genes (IL‐6 and TNF‐α) was lowered in animals fed the formulated snack. The study showed that inclusion of BPLE and unripe plantain flour improved the antihyperglycaemic properties of the formulated snack in diabetic rats.