Anti-Streptococcal activity of Brazilian Amazon Rain Forest plant extracts presents potential for preventive strategies against dental caries

Caries is a global public health problem, whose control requires the introduction oflow-cost treatments, such as strong prevention strategies, minimally invasivetechniques and chemical prevention agents. Nature plays an important role as a sourceof new antibacterial substances that can be used in the prevention of caries, andBrazil is the richest country in terms of biodiversity.

Objective

In this study, the disk diffusion method (DDM) was used to screen over 2,000Brazilian Amazon plant extracts against Streptococcus mutans.

Material and Methods

Seventeen active plant extracts were identified and fractionated. Extracts andtheir fractions, obtained by liquid-liquid partition, were tested in the DDM assayand in the microdilution broth assay (MBA) to determine their minimal inhibitoryconcentrations (MICs) and minimal bactericidal concentrations (MBCs). The extractswere also subjected to antioxidant analysis by thin layer chromatography.

Results

EB271, obtained from Casearia spruceana, showed significantactivity against the bacterium in the DDM assay (20.67±0.52 mm), as did EB1129,obtained from Psychotria sp. (Rubiaceae) (15.04±2.29 mm). EB1493,obtained from Ipomoea alba, was the only extract to show strongactivity against Streptococcus mutans (0.08 mg/mLConclusions The active extracts, discovered in the Amazon rain forest, show potential assources of new antibacterial agents for use as chemical coadjuvants in preventionstrategies to treat caries.