N-Acyl Homoserine Lactone-Mediated Quorum Sensing System Inhibition of Phenolic Strawberry Extract

Abstract

Phenolic compounds which have many bioactivities such as antioxidant, antimicrobial and also inhibition of quorum sensing-regulated violacein pigment production properties are one of the plant secondary metabolites. The objective of this study was to determine the antioxidant, antimicrobial activity and the inhibition of quorum sensing (QSI) activity by the phenolic extract obtained from strawberry fruits (Fragaria×ananassa cv. ‘Rubygem‘). The phenolic content of extract was determined as 3089 μg GAE g fw-1. The antioxidant activity determined through the ABTS+ and FRAP method was 28.4 and 26.2 mmol TE L-1 respectively. The phenolic extract was able to inhibit all the evaluated bacteria by the disc diffusion assay in the range of 3.12–18.36 mm and could inhibit the quorum sensing phenomena in bacteria. The strawberry phenolic extract exhibited high antioxidant capacity, antimicrobial and anti-quorum sensing properties. To our knowledge, this is the first report on the quorum sensing inhibition activity of strawberry fruit extract. The discovery of non-toxic novel compounds within antibacterial and QSI activity could lead to the development of antimicrobial therapeutic agents that can be alternative and complementary treatments against antibiotic resistant bacterial pathogens