Antibacterial, cytotoxic and phytochemical screening of some traditional medicinal plants in Brazil

Abstract

As part of a program oriented towards the discovery of bioactive natural products, 44 methanol extracts from 37 Brazilian traditional medicinal plants, most of them commonly used for treating conditions likely to be associated with microorganisms, were evaluated for their antibacterial activity and toxicity to brine shrimp. The agar-well diffusion method was used against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium, Shigella sonnei, Klebsiella pneumoniae, Escherichia coli, and Bacillus cereus. The active extracts were subjected to serial dilution assay for determination of the minimal inhibitory concentration. Phytochemical analysis of the extracts for their major groups of phytoconstituents is also reported. Extracts of Baccharis dracunculifolia, Cajanus cajan, Eugenia uniflora, Solanum palinacanthum and Solanum concinnum presented strong antibacterial activity with MIC values below 10 μg/mL for some bacterial strains. The extracts of Mikania glomerata and Leonurus sibiricus showed significant toxicity against brine shrimp with LC₅₀ values of 63 and 86 μg/mL, respectively.

Keywords::

• Antibacterial
• Artemia salina
• cytotoxicity
• medicinal plants

Acknowledgements

The authors are grateful to Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) and Universidade Federal de Juiz de Fora (UFJF)/Brazil for financial support and to Dr. Fatima Regina Salimena for the botanical identification of some species.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.