Antimicrobial activity of Rheedia brasiliensisand 7-epiclusianone against Streptococcus mutans.

Abstract

This in vitro study evaluated the antimicrobial activity of extracts obtained from Rheedia brasiliensis fruit (bacupari) and its bioactive compound against Streptococcus mutans. Hexane, ethyl-acet ate and ethanolic extracts obtained (concentrations ranging from 6.25 to 800mg/ml) were tested against S. mutans UA1 59 through MIC /MBC assays. S. mutans5-days -old biofilm s were treat ed with the active extra cts (100 MIC ) for 0, 1, 2, 3 an d 4 h (time-k ill) and plate d for colony counting (CFU/m l). Active extracts were submitted to exploratory chemical analyses so as to isolate and identify the bioactive compound using spectroscopic method s. The bioactive compo und (concentration s ranging from 0.625 to 80mg/ml) was then tested through MIC /MBC assays . Pee l and seed hexane extracts showed antimicrobial activity against planktonic cells at low concentrations and were thus selected for the time kill test. These hexane extracts reduced S. mutans biofilm viability after 4 h, certifying of the bioactive compo und presence. The bioactive compound identified was the polyprenylated benzophenone 7-epiclusianone, which showed a good antimicrobial activity at low concentrations (MIC : 1.25–2 .5 mg/ml; MBC: 10–20mg/ml). The results indicated that 7-epi clusian one may be used as a ne w agent to control S. mutans biofilms; however, more studies are needed to further elucidate the mechanisms of action and the anticariogenic potential of such compound found in R. brasiliensis.