Volatiles, phenolic compounds and bioactive properties of essential oil and aqueous extract of purple basil (Ocimum basilicum L.) and antidiabetic activity in streptozotocin-induced diabetic Wistar rats

Abstract

Diabetes represents a significant global health concern, and researchers are actively exploring innovative approaches to managing this disease. In this study, we investigated the bioactive properties and anti-diabetic activity of the aqueous extract (BAE) and essential oil (BEO) derived from purple basil (Ocimum basilicum L.). The antioxidant activity of BAE was found to be higher than that of the essential oil extract from purple basil. Among the phenolic compounds identified, t-caffeic acid was the most abundant, followed by caftaric acid, kaempferol-3-glucoside, and quercetin-3-glucoside. In total, 49 volatile constituents were identified in cold- and hot-brewed basil, with methyl cinnamate, linalool, and eugenol were the major compounds. Both BAE and BEO showed inhibitory effect on the α-glucosidase and α-amylase enzymes. Furthermore, the administration of BAE led to a 37% reduction in blood glucose levels at day 14 and a 25.5% reduction at day 28. Similarly, BEO exhibited a 26.3% decrease in fasting blood glucose levels on the 28th day in rats. These findings highlight the potential of BAE and BEO in reducing blood glucose levels and their consequent antidiabetic activity. Based on the results obtained, we suggest that basil can be utilized in the formulation of functional and dietary foods within the food and beverage industry, owing to its demonstrated antidiabetic properties.

Keywords

• Purple basil
• Essential oil
• Anti-diabetic activity
• Antioxidant activity
• Phenolic compounds