Chemical compositions and different biological activity of leaf essential oil of Ocimum americanum L. grown in acidic soil conditions

Abstract

s Ocimum americanum L. is a highly valued aromatic plant whose leaves are used not only in traditional cuisine but also in the food, cosmetic, and pharmaceutical industries. This study aimed to identify the chemical profile of essential oil extracted from the leaves of Ocimum americanum by GC-FID and GC/MS grown in acidic soil conditions in the NE region of India. Furthermore, the biological activities like antioxidant, anti-diabetic, anti-inflammatory, and anti-tyrosinase activity were analyzed, as per standard methods. GC and GC/MS analysis identified 16 compounds in which citral-a (48.25%) was found as a major compound, followed by carveol (41.64%). The antioxidant activity was performed using DPPH and ABTS methods; and IC50 value obtained was 8.85 μL/mL and 28.82 μL/mL, respectively. The leaf essential oil of O. americanum exhibited strong anti-diabetic and anti-inflammatory activities, whereas moderate anti-tyrosinase activities with IC50 values of 40.84, 12.81, and 182.74 μL/mL, respectively. Furthermore, the ant-microbial activity was evaluated for four bacterial and four fungal strains, revealing that O. americanum essential oil expresses antifungal activity against S. cereviaceae only with a MIC value of 5±0.47 μg/mL. These evidences clearly indicates that essential oil obtained from the leaf of O. americanum showed potential anti-inflammatory and anti-diabetic activity that can be used as an alternative in pharmaceuticals and food industries as a natural source.