Phytochemical screening and evaluation of antimicrobial and cytotoxic activities of native medicinal plants from west region of Paraná state.

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Many plants do not present its proven therapeutic potentialities through scientific studies. Thus, the aim of this work was to accomplish a phytochemical, antimicrobial and cytotoxic study of the vegetal species Eupatorium serratum (Asteraceae), Myrcianthes pungens (Myrtaceae), Urera nitida (Urticaceae), Campomanesia xanthocarpa (Myrtaceae) and two varieties of Psidium cattleyanum (Myrtaceae). The plants were dried and extracted with different solvents (hexane, methanol and ethyl acetate) resulting in 18 crude extracts. Specific methods had been used for identification of alkaloids, saponnins, flavonoids, tannins and steroids. To determine the minimum inhibitory (MIC) and bactericidal (MBC) concentrations were used Gram-positive (Staphylococcus aureus and Micrococcus luteus) and Gram negative (Escherichia coli and Salmonella typhi) bacteria. The method of disc diffusion was used against yeasts (Candida albicans and Saccharomyces cerevisiae). C. xanthocarpa, M. pungens (ethyl acetate and hexane extracts) and a variety of P. cattleyanum (ethyl acetate extract), presented MIC ≤ 62.5 μg/ml against Gram-positive bacteria, which may be related to tannins in the leaves of these plants. The hexanic extract of M. pungens showed the strongest inhibition, presenting MBC of equal concentration. The methanolic extracts of C. xanthocarpa and M. pungens showed good antifungal activity. The cytotoxic assay verified the hemolytic effect and the hexanic extract of a variety of P. cattleyanum presented high citotoxicity at the concentrations tested.