Evaluation of phenolic bioactive-linked anti-hyperglycemic and Helicobacter pylori inhibitory activities of Asian Basil (Ocimum spp.) varieties

Basil (Ocimum spp.) is an important herb from the Lamiaceae family with a long history of use in traditional medicine and food applications. Thus, targeting basil varieties for developing herbal medicines against non-communicable chronic diseases (NCDs) such as type 2 diabetes has significant merit. The aim of this study was to screen Asian basil varieties with therapeutic potential for type 2 diabetes targeting relevant phenolic bioactive-linked antioxidant, anti-hyperglycemic, and antimicrobial properties and was compared with a high phenolic and high antioxidant mint species (Mentha arvensis). Aqueous and ethanol (12%) extracts of 8 different varieties of Asian basil were analyzed for total soluble phenolic (TSP) content, phenolic acid profiles, total antioxidant activity (TA), alpha-amylase, and alpha-glucosidase enzyme inhibitory activities and inhibition of ulcer-causing bacteria, Helicobacter pylori using in vitro assay models. The highest TSP content was observed in mint and all basil varieties were compared to this standard. High TA, and a-glucosidase enzyme inhibitory activity were observed in targeted varieties of Indian basils. Major phenolic acids found were rosmarinic, ellagic, benzoic, and gallic acids, which may potentially contribute to health benefits such as antioxidant and anti-hyperglycemic properties. Inhibitory activity against H. pylori was observed in response to high phenolic mint but not in Asian basil extracts. This in vitro study provides biochemical rationale on phenolic bioactive-linked antioxidant and antihyperglycemic potentials of Asian Basil varieties that need to be further validated with in vivo studies for therapeutic and herbal medicine related applications against type 2 diabetes and associated complications.