Inhibitory effects of a flavonoid-rich extract of Pistacia vera hull on growth and acid production of bacteria involved in dental plaque

Abstract

The aim of present study was to investigate the antibacterial and the in vivo efficacy of aqueous, chloroformic and ethanolic extracts from Pistacia vera on bacteria involved in dental plaque. The growth inhibitory activity of the extracts were tested against Strep. mutans, Strep. salivarious, Strep. sobrinus and Strep. Sanguis. The bioautography and TLC analysis were used to provide relevant information on the chemical properties of extracts. Antimicrobial activity determined by agar well diffusion and determination of MIC values was measured by the liquid serial dilution culture method. Bactericidal and bacteriostatic, inhibition of glycolysis and sucrose-dependent adherence to smooth glass surface were tested using standard methods. The subjects used the mouthrinse and saliva samples were collected after 10 min, 1 and 3 h post-rinsing. The total streptococcal counts were measured before and after mouthrinsing. Aqueous, chloroformic and ethanolic extracts of P. vera hull inhibited the growth and acid production of tested bacteria. The result revealed that the ethanolic extract of P. vera hull displayed the most potent antimicrobial activity. In vitro studies had shown that ethanolic extract of P. vera, at concentrations of 2, 6 and 10% w/v, could inhibit the growth as well as the acid-producing ability of Strep. mutans. In in vivo study which was tested on three subjects shows that mouthrinse prepared by suspending 10% of ethanolic extract in PEG 300 (w/v) could reduced salivary bacterial count more than 55%, about 75% inhibition of adherence and inhibition of salivary glycolysis up to 3 h post rinsing. © 2007 Asian Network for Scientific Information.