In silico and in vitro analysis of bioactive compounds extracted from Ocimum basilicum against vancomycin-resistant enterococci

Abstract

Ocimum basilicum is an important herbal medicinal plant that has not been previously investigated for its biological potential against multi-drug resistant (MDR) clinical pathogens. This study explored the efficiency of O. basilicum phytocompounds as potent inhibitors of vancomycin-resistant enterococci (VRE) via in vitro and in silico analysis. An ethanolic extract of O. basilicum showed antimicrobial activity against 12 strains of vancomycin-resistant Enterococcus faecalis at varying concentrations. A total of 19 phytochemicals were analysed for ADMET (Adsorption, Distribution, Metabolism, Excretion and Toxicity) using the Swiss ADME server (http://www.swissadme.ch) to assess the pharmacological characteristics, including lipophilicity, water solubility, drug-likeness, pharmacokinetics and medicinal chemistry.Among 19 compounds, 8 compounds (adipic acid, ethyl citrate, glutamic acid 5-ethyl ester, imidazole, palmitic acid, phthalic anhydride, 2-Propenoic acid 3-phenyl-methyl ester, & stearic acid) were selected as they fulfilled the Lipinski's rule of five. Autodock Vina was used to dock the selected phytocompounds into the target proteins (5ZHW, 4FUO, 1E4E, 4ECL, 6GED, 6ORI) of E. faecalis. Phthalic anhydride and the positive control antibiotic, linezolid showed stronger binding energy with all 6 target proteins revealing their therapeutic potential to treat VRE infections. These findings could be the baseline for the pharmaceutical sector to evaluate a chemical's safety profile and the in silico approaches to provide considerable advantages for both regulatory requirements and risk assessment criteria.

Keywords

• Phytocompounds
• Ocimum basilicum
• Lipinski's rule
• pharmacokinetics
• vancomycin-resistant enterococci