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
Himanshi Tomar, Avneesh Rawat, Kirti Nagarkoti, Om Prakash, Ravendra Kumar, Ravi Mohan Srivastava, Shilpi Rawat, Deepa Rawat
Abstract
The aim of present study was to investigate the phytochemical analysis and biological activities of the essential oils of Ocimum gratissimum L. and Ocimum sanctum L. The GC-MS analysis of Ocimum gratissimum essential 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 constituents 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 IC 50 = 65.69±0.99 µg/mL and IC 50 = 115.30±0.29 µg/mL, respectively, to reduce Fe 3+ complex to Fe 2+ with RP 50 = 36.59±0.14 µg/mL and RP 50 = 46.24±1.49 µg/mL and to chelate metals with IC 50 = 17.83±0.17 µg/mL and IC 50 = 82.57±0.10 µg/mL, respectively compared with standard antioxidants, namely BHT, ascorbic acid, and Na 2 EDTA. Compared with diclofenac sodium, the standard anti-inflammatory drug, both OGEO and OSEO showed inhibition of protein denaturation with IC 50 = 52.10±0.14 µg/mL and IC 50 = 39.83±0.32 µg/mL, respectively. Inhibition of α-amylase was also observed in both OGEO and OSEO with IC 50 = 58.54±0.04 µg/mL and IC 50 = 42.14±0.57 µg/mL, respectively, compared with acarbose (IC 50 = 16.04±0.01 µg/mL). The oils showed strong antifeedant activity (90%) against Spilosoma obliqua 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. • Two species of Ocimum were chemically profiled in the study. • Eugenol was the major phenylpropanoid constituent in both species. • The species were bio-evaluated for certain biological and pesticidal activities. • Quantitative structure-activity relationships have been studied. • O. gratissimum exhibited significantly high biological activities compared to O. sanctum .