Effect of AKBA at different concentrations (8, 16 and 32 μg/ml) on the cell viabilty of S.mutans ATCC 25175. S. mutans cells without AKBA served as control. The effect of AKBA was observed bacteriostatic at all tested concentrations when compared with non treated control (P < 0.05) over a period of 24 h study. Each time point represents the mean log10 standard deviations (± SD) of three different experiments performed in duplicate. *, P < 0.05; (Student's t test).