SCREENING OF MEDICINAL PLANTS FOR ANTILEISHMANIAL AND ANTIMICROBIAL ACTIVITY

Extracts of six plants with known antimicrobial activity were screened for inhibition to Leishmania mexicana, a protozoal parasite responsible for a disfiguring disease affecting millions worldwide. Toxic effects were also tested on two mammalian cell lines, CEM T4 and HeLa. Ethanol, dimethylsulfoxide (DMSO), and aqueous extracts of Medicago sativa, Matricaria chamomilla, Rosmarinus officinalis, Thymus vulgaris, Gaultheria procumbens, and Rumex crispus exhibited varying degrees of inhibition to the cell lines. Inhibition of LM227 was determined by using a microplate assay, measuring absorbance at 660 m-n after 24, 48, and 72 h with a microplate reader. Inhibition of the mammalian cell lines was determined by using a test tube assay, measuring absorbance at 660 nm. Ethanol and DMSO extracts exhibited varying degrees of inhibition against L. mexicana, while the aqueous extracts did not significantly inhibit growth. Extract inhibition of the growth of mammalian cell lines was also found. The protein concentration of each extract was tested in order to determine percent inhibition per mg protein. The ethanol and DMSO extracts also caused growth inhibition of several food-borne pathogens and bacteria using a disc assay method.