In the present study, the antibacterial activity of the crude extracts obtained from flowers, leaves and stems of HypericumcalycinumL.against Streptococcus mitis CNCTC 4/77, Streptococcus salivarius CNCTC 64/59, Streptococcus mutans CNCTC 8/77 andStaphylococcus epidermidis ATCC 12228 was determined in vitro. Dried powder of flower, leave and stem parts of this plant were kept in acetone and methanol for 3 days in dark place. Disc diffusion method was used to determine the antibacterial activity of Hypericumcalycinum L. Methanol-impregnated discs and acetone-impregnated discs were used as negative control. Also commercial antibiotic discs (Clindamycin (10 μg), Tetracycline (10 μg) and Amoxicillin-Clavulanic acid (30 μg)) were utilized as positive control.According to the results of the present study, the crude extracts ofHypericumcalycinum L. prepared in acetone and methanol have been found to have antibacterial activity against the test microorganisms. Extracts of Hypericumcalycinum L.flowershowed the largest inhibition zone (13 mm in diameter) againstS. mutans.The antibacterial activities of methanol and acetone extracts ofHypericumcalycinum L.(at the doses of 3200 μg/10μl, 1600 μg/10μl, 800 μg/10μl and 400 μg/10μl)against Streptococcus salivarius, Streptococcus mutans, Staphylococcus epidermidis andStreptococcus mitis have been reported in this study for the first time.
Antibacterial activity, Disc diffusion method, Hypericumcalycinum L.