Phytochemical screening, toxicity and antimicrobial action of Solanum paniculatum Linn extract against dental biofilm bacteria

Abstract

The aims of study were to determine the phytochemical composition of hydroalcoholic extract of Solanum paniculatum Linn (jurubeba) root, to evaluate its in vitro antimicrobial action, as well as to determine the acute toxicity and potential cytotoxic effects of this extract. The extract was characterized by phytochemical screening and thin-layer chromatography. The following oral bacteria were used to determine the minimum inhibitory concentration (MIC): Streptococcus mitis, Streptococcus mutans, Streptococcus sanguinis, Streptococcus oralis, Streptococcus salivarius and Lactobacillus casei. Each assay was carried out in duplicate and the positive control (0.12% chlorhexidine digluconate) was subjected to the same procedure. Results were analyzed by Student t-test or Mann-Whitney test, with the level of significance set at 5%. Preclinical acute toxicity assays were performed using the median lethal dose of the extracts in animals. In addition, the cytotoxic effects of the extracts on human erythrocytes were evaluated. Solanum paniculatum showed MIC values of 7.81 mg/mL. The extract had no acute effects at concentrations of 0.97 to 500 mg/mL. The S. paniculatum extract was only cytotoxic at a concentration of 250 mg/mL. Phytochemical screening revealed predominance of phenolic compounds such as flavonoids and tannins. In conclusion, S. paniculatum Linn showed in vitro antimicrobial activity against bacterial monocultures. No toxicological effects were observed. The predominance of phenols may explain the pharmacological activity of this extract. However, randomized controlled clinical trials should be conducted to evaluate the effect of S. paniculatum added to mouthwash solution. Key words: Microbiology, phytotherapy, chromatography, toxicity, Solanum paniculatum Linn.