In silico and in vitro analysis of quorum quenching active phytochemicals from the ethanolic extract of medicinal plants against quorum sensing mediated virulence factors of Acinetobacter baumannii

Abstract

Inhibition of quorum sensing called quorum quenching (QQ) is now extensively utilized in the prevention of bacterial infections. In the present study, in silico and in vitro analysis of quorum quenching (QQ) or anti-Quorum sensing (QS) activity of ethanolic extract of medicinal plants against QS mediated virulence factors of human pathogenic bacteria Acinetobacter baumannii has been investigated. The effect of plant extracts on QS by acyl homoserine lactone (AHL) has been carried out by quantification of secreted AHL by high-pressure liquid chromatography (HPLC). Measurement of QQ activity was determined by maximum inhibition of virulence factors and AHL production which was recorded in E. globules and A. indica extracts.
In silico analysis was studied with possible bioactive compounds in the ethanolic extract of respective plant material that were characterized by gas chromatography equipped with mass spectroscopy (GCMS) against the enzyme responsible for the production of signaling molecule which mediates QS AHL synthase. Distinct reduction of all the
QS-mediated virulence factors was recorded in the E. globules and A. indica. Among the different bioactive compounds, the ethanolic leaf extract of E. globules of GCMS analyzed compound, Hexadeconoic acid, 1-(hydroxymethyl), 1, 2-ethannediyl ester interacted with 1KZF protein (AHL synthase) and showed binding energy of −11.2 kcal/mol to MET 42 and TYR 54. Phytochemicals mediated inhibition of AHL synthase activity which was responsible for AHL production would suggest the possible utilization of plant extracts as an antibacterial agent to fight against disease-causing pathogenic bacteria.