Ocimum gratissimum L. and Ocimum sanctum L.: Comparative compositional analysis of essential oils and in-vitro biological activities with in-silico PASS prediction and ADME/Tox studies

The aim of present study was to investigate the phytochemical analysis and biological activities of the essen-tial oils of Ocimum gratissimum L. and Ocimum sanctum L. The GC-MS analysis of Ocimum gratissimum essen-tial oil (OGEO) and Ocimum sanctum essential oil (OSEO) comprised 97.3% and 95.9% of the total compositions respectively, with phenylpropanoid, eugenol (74.8% and 54.0% respectively) as the main con-stituents among other minor/trace constituents. Both OGEO and OSEO were screened for various biological activities. The antioxidant activity of OGEO and OSEO was evaluated based on their free radicals scavenging ability and was observed with IC50 = 65.69 +/- 0.99 mu g/mL and IC50 = 115.30 +/- 0.29 mu g/mL, respectively, to reduce Fe3+ complex to Fe2+with RP50 = 36.59 +/- 0.14 mu g/mL and RP50 = 46.24 +/- 1.49 mu g/mL and to chelate met-als with IC50 = 17.83 +/- 0.17 mu g/mL and IC50 = 82.57 +/- 0.10 mu g/mL, respectively compared with standard anti-oxidants, namely BHT, ascorbic acid, and Na2EDTA. Compared with diclofenac sodium, the standard anti-inflammatory drug, both OGEO and OSEO showed inhibition of protein denaturation with IC50= 52.10 +/- 0.14 mu g/mL and IC50 = 39.83 +/- 0.32 mu g/mL, respectively. Inhibition of a-amylase was also observed in both OGEO and OSEO with IC50 = 58.54 +/- 0.04 mu g/mL and IC50 = 42.14 +/- 0.57 mu g/mL, respectively, compared with acarbose (IC50 = 16.04 +/- 0.01 mu g/mL). The oils showed strong antifeedant activity (90%) against Spilosoma obli-qua at the highest concentration (5.0 ppm). In addition, ADME/T and in-silico PASS studies using a web-based online tool demonstrated drug similarity, expected safety for consumption, and potential pharmacological activity. The study provides scientific evidence for the various biological activities of OSEO and OGEO and their ethnomedicinal uses. (c) 2023 SAAB. Published by Elsevier B.V. All rights reserved.