Glycemic indices and effect of bitter leaf (Vernonia amygdalina) flavored non-alcoholic wheat beer (NAWB) on key carbohydrate metabolizing enzymes in high fat diet fed (HFD)/STZ-induced diabetic Wistar rats

In a bid to make the use of functional food easier in the management and prevention of diseases, product development and fortification from/with functional foods have become the recent focus of research. This study, therefore, sought to exploit the recent trend in the brewing industry on the production of non-alcoholic beers by investigating the possibility of having a non-alcoholic beer flavored with bitter leaf, a known plant widely reported to have a strong hypoglycemic effect, as against the traditional use of hops, and the effect of the produced beer on the glycemic indices and various diabetic biochemical parameters that serve as biomarkers for type-2 diabetes (T2D). The glycemic indices, as well as the inhibitory potentials of bitter leaf-flavored Non-alcoholic wheat beer (NAWB) in ratios of 100%HP, 100%BL, 75:25BL, 50:50BL, and 25:75BL, on enzymes linked to a high-fat diet/streptozocin (HFD/STZ)-induced T2D albino Wistar rats were investigated. There were no significant difference (p > .05) between the starch (1.72-1.77 mg/100 mL), amylose (0.22-0.24 mg/100 mL), and amylopectin (1.49-1.53 mg/100 mL) contents of the various samples. The Glycemic Index (GI) of the samples ranged from 36 to 73 with 75:25Bl and 50:50BL have the lowest (36) values. The samples reduced blood glucose levels and inhibited pancreatic alpha-amylase, lipase, and intestinal alpha-glucosidase activity. The inhibitory potentials of these beer samples on alpha-amylase and alpha-glucosidase as well as their ability to reduce blood glucose levels in diabetic rats thus making the bitter leaf flavored NAWB a suitable healthy beverage for better glycemic control in diabetics. Practical applications This study revealed the potential of producing non-alcoholic wheat beer flavored with bitter leaves as a possible substitute for hops. The potential inherent in bitter leaf in the management of type 2 diabetes can thus be made available through a far-reaching beverage medium such as non-alcoholic beer to help in the treatment/management of T2D. The results of this research could be an eye-opener to the possible utilization of bitter leaf and by extension other plants that have been reported in the management of T2D. The use of the bitter leaf as a substitute for hops in the production of non-alcoholic beer in the brewing industry could help in a health-oriented campaign for safe drinks that could be helpful in the control of blood glucose levels of diabetic patients.