Antimicrobial Activity, Cytotoxicity and Phytochemical Analyses of Rhus aromatica, Rhus glabra and Sanguinaria canadensis Native to South Dakota

A total of twenty five South Dakota native medicinal plants were screened against enterotoxigenic Escherichia coli using a disk diffusion assay. Out of these 25 plants, three plants Rhus aromatica, Rhus glabra and Sanguinaria canadensis demonstrated the highest bacterial inhibition. The minimum inhibitory concentrations (MIC) of these plant extracts were determined using a bacterial enumeration assay. Alamar Blue in vitro cytotoxicity test showed that all extracts have some toxic effect to porcine intestinal epithelial cell lines. Phytochemical analysis of these plant extracts indicated the presence high concentration of flavonoids and condensed tannins in R. aromatica and that R. glabra contained higher amount of simple phenolic compounds. As R. aromatica showed antibacterial, anthelminthic and anticancer activity in our study, it was further studied for its essential oil components using gas chromatography and mass spectrometry. The major volatile compounds of its essential oils were identified as limonene, caryophyllene and cubebene consisting of 82% of the total essential oils. The total alkaloids content of S. canadensis was 1.24% of the fresh weight. HPLC analysis for sanguinarine quantification showed that it has 43% of sanguinarine out of total alkaloids