The antimicrobial activity of two crude plant extracts– Solanum paniculatum L. (jurubeba) and Bixa orellana L. (annatto) against Enterococcus faecalis was tested in vitro, and their efficacy was compared with that of a chemical agent with known antibacterial activity – chlorhexidine digluconate at 0.12% concentration. Extracts were prepared from jurubeba roots and annatto seeds after selection by phytochemical screening. Microorganisms were divided into two groups: E. faecalis (ATCC 292012) and E. faecalis (44 - AB). The minimum inhibitory concentration (MIC) and the minimum inhibitory concentration of adherence (MICA) of the extract and the control were determined, and the cytotoxic potential and lethal dose (LD) of jurubeba extract were assessed because it was the only extract to exhibit inhibitory activity against bacteria. Only the S. paniculatum Linn (jurubeba) extract exhibited activity against the two bacterial strains– MIC: up to 1:64 against E. faecalis ATCC 292012, up to 1:32 against E. faecalis of the oral environment (44-AB); MICA: up to 1:512 against the two strains, exhibiting cytotoxicity at the 1:2 dilution (250 mg/mL) and LD = 0. The B. orellana Linn extract exhibited no inhibitory activity in any of the experiments; thus, it was not assayed in the cytotoxicity experiments, nor was its LD determined. The low toxicity of S. paniculatum L. extract (cytotoxicity only at the 1:2 dilution, or 250 mg/mL) in addition to its LD = 0 and good antibacterial performance in the tests suggest the potential use of this product for the treatment of endodontic and periodontal oral infections; however, further experiments strengthening these results should be performed. The B. orellana L. extract exhibited no antimicrobial activity.
Key words: Antimicrobial activity, plant extracts, phytotherapeutics, Enterococcus faecalis, endodontic infections, Bixa orellana L., Solanum paniculatum L.
Copyright © 2022 Author(s) retain the copyright of this article.
This article is published under the terms of the Creative Commons Attribution License 4.0