ABSTRACT
Objective: To evaluate in vitro the pH, Brix and antibacterial activity of herbal tinctures of calendula (Calendula officinalis L.) and cashew tree (Anacardium occidentale L.) against the following bacterial strains: Streptococcus mutans (ATCC 25175), Streptococcus oralis (ATCC 10557), Streptococcus salivarius (ATCC 9758), Enterococcus faecalis (ATCC 29212) and Eikenella corrodens (ATCC 23834). Material and Method: The strains were reactivated in agar Brain Heart Infusion (BHI) and seeded in blood agar with BHI. Susceptibility tests were performed and the strains were incubated in microaerophilia (37 °C) for 48 h. Chlorhexidine at 0.12% was used as a positive control and distilled water as a negative control. Dilution of the tinctures was carried out from 1:1 (pure form) to 1:64 in alcohol 70%, which is found in their composition, in order to evaluate a possible influence of alcohol on the antibacterial activity of the tinctures. O Bx readings were made by refractometry using an Abbe refractometer and the pH was measured using a digital pH meter. Results: The calendula tincture had pH=5.43 and 18 °Brix and cashew tree tincture had pH=7.2 and 17 °Brix. The cashew tree tincture did not presentantibacterial activity against S. oralis, but it inhibited the growth of all other bacteria up to the 1:64 dilution. The calendula tincture presented antibacterial activity against S. oralis up to 1:16 dilution (6.5 mm halo diameter); against S. mutans and S. salivarius up to 1:32 dilution (7 and 7.5 mm halo diameter, respectively); and against E. faecalis and E. corrodens up to 1:64 dilution. Alcohol 70% did not show any antibacterial activity against the bacterial strains. Conclusion: The tinctures of calendula and cashew tree have soluble solids, have different pH values and present a significant antibacterial activity against several bacterial strains, except for the cashew tree tincture against S. oralis, which was ineffective...