Among all extracts, only the fresh juices of Rhizoma Typhonium Flagelliforme and Epipremnum pinnatum leaves and stems possessed antimicrobial activities ( None of the extracts, however, inhibited Ps. aeruginosa. Both S. aureus and B. subtilis are Gram-positive, while Ps. aeruginosa is Gram-negative and has an outer lipid membrane [41] . The results suggest that the antimicrobial compounds in the extracts were unable to penetrate this lipid membrane to exert their effects inside a cell. This speculation will require further experiments to confirm.