Denise Pimenta da Silva LEITÃO,a Ademar Alves da SILVA FILHO,b Ana Cristina Morseli POLIZELLO,a Jairo Kenupp BASTOS,b and Augusto César Cropanese SPADARO*,a
a Laboratório de Bioquímica, Faculdade de Ciências Farmacêuticas de Ribeirão Preto-Universidade de São Paulo; and b Laboratório de Farmacognosia, Faculdade de Ciências Farmacêuticas de Ribeirão Preto-Universidade de São Paulo; Av. do Café, s/n.:14040–903, Ribeirão Preto, SP, Brazil.
Streptococcus mutans triggers dental caries establishment by two major factors: synthesis of organic acids, which demineralize dental enamel, and synthesis of glucans, which mediate the attachment of bacteria to the tooth surface. Propolis is a natural product that may prevent dental caries. Baccharis dracunculifolia DC (Aster- aceae), a native plant from Brazil, is the most important botanical origin for the production of green propolis (Brazilian propolis) by honeybees. However, whether B. dracunculifolia (Bd) has an anticariogenic effect, like green propolis, remains unknown. Herein, we have made a comparative evaluation of the effects of extracts from green propolis and Bd on the glucan synthesis and acidogenic potential of S. mutans. The inhibitory effects of the extracts on bacterial acid production were evaluated through the potentiometric measurement of pH from bacte- rial suspensions treated with serial concentrations of both extracts. Besides presenting close inhibitory values at the same concentration range, Bd leaf rinse and green propolis extracts had similar IC50 values (0.41 and 0.34 mg/ml, respectively). Both extracts produced a bacteriostatic effect on S. mutans cultures at a concentration of 0.40 mg/ml. Estimated inhibitory values of green propolis and Bd leaf rinse extracts on the synthesis of insoluble glucans (IC50
* THESE STATEMENTS HAVE NOT BEEN EVALUATED BY THE FOOD AND DRUG ADMINISTRATION. THIS IS NOT INTENDED TO DIAGNOSE, TREAT CURE OR PREVENT ANY DISEASE.