In vitro antimicrobial activity of an extract from anacardium occidentale Linn. on Streptococcus mitis, Streptococcus mutans and Streptococcus sanguis

ABSTRACT

The antimicrobial activity of an extract from stems of the cashew tree, Anacardium occidentale Linn, was evaluated on three cultures of bacteria, Streptococcus mitis, Streptococcus mutans, Streptococcus sanguis, found in dental plaque. The antimicrobial activity was carried out on solid media plates by a diffusion method for the screening and determination of Minimum Inhibitory Concentration (MIC) and Concentration of Minimum Inhibitory Adherence (CIMA). Chlorexidine gluconate (0.12%) was used as a positive control. The results showed effective inhibitory action of the extract when compared with Chlorexidine gluconate. Chlorexidine gluconate (0.12%) and the extract showed inhibitory action. Inhibition halos (MIC) were observed at a concentration of 12.5muL for S. mutans and 6.25 mg/L for S. mitis and S. sanguis. The results suggest that the extract from Anacardium occidentale Linn was also effective for CIMA (adherence) at concentrations of 0.3lmg/L for L for S. mutans and S. mitis and 0.15 mg/L for S. sanguis. the extract from the cashew tree systems showed a potential inhibitory action on the synthesis of glucan measured as the adherence to glass in sub inhibitory conditions. The results suggest that the cashew trees may have some therapeutic uses in dentistry and could be used as an oral antibacterial agent