Antimicrobial and cytotoxic activities of some crude drug extracts from Mexican medicinal plants.

31 crude extracts derived from 28 plants highly valued as anti-infective agents in Mexican folk medicine have been screened for antimicrobial activity against four bacteria, a yeast and two molds. The results of the quantitative study indicated that the extracts derived from five species (Malmea depressa, Heliopsis longipes, Datura lanosa, Cnidosculus tehuacanensis and Helianthella quinquenervis) possessed significant antiseptic properties, therefore supporting the ethnomedical uses of these species. The cytotoxic activity was assayed against three cell lines HT-29 (Colon adenocarcinoma), MCF-7 (Breast carcinoma), A-549 (Lung carcinoma) and only the extract of Helianthella quinquenervis possessed significant activity against the MCF-7 cell line.