Evaluation of the biological potential of crude extracts of Brazilian medicinal plants in a social context and for safe use in human health.

ETHNOPHARMACOLOGICAL RELEVANCE: Herbal medicines are the primary healthcare source for many in developing countries, which justifies the need for their validation through scientific studies to confirm their efficacy and safety.

AIM: This study aimed to identify the most commonly used plants for treating gastrointestinal problems in a Brazilian city, Franca/SP. The study sought to identify the most commonly used plants and evaluated five selected extracts for antimicrobial, antioxidant, and gastroprotective potential, as well as their safe use for human health.

MATERIAL AND

METHODS

Five plants (Ageratum conyzoides L., Coutarea hexandra (Jacq.) K.Schum., Heteropterys aphrodisiaca O.Mach., Pterodon emarginatus Vogel, and Quassia amara L.) were selected for further evaluation, after interviewing 384 individuals. Extracts were tested for antimicrobial activity against 12 gastrointestinal bacteria (minimum inhibitory concentration), antioxidant capacity (DPPH assay), and ability to protect gastric and liver tissues against HCl-induced damage in mice. This included histological analysis, occult blood tests and liver enzyme function. Additionally, for prediction of potential human risks, the cytotoxicity and genotoxicity of the extracts were evaluated using XTT and in vitro micronucleus assays.

RESULTS

Information obtained from 384 interviews revealed extensive use of medicinal plants, with more than 60 plant species identified. Among the five species chosen, only Q. amara exhibited a bactericidal effect. All extracts demonstrated free radical scavenging activity. A. conyzoides, C. hexandra, and Q. amara, at dose 500 mg/kg, reduced gastric damage, with C. hexandra and Q. amara also showing no occult blood in feces. All extracts lessened liver damage based on both histological evaluation and liver enzyme markers.

CONCLUSIONS

The five extracts displayed gastro- and hepatoprotective activity, with C. hexandra and Q. amara showing the most promising results, in the absence of significant genotoxic risk.