Abstract

Ethanol extracts of leaves of Chromolaena odorata and ethyl acetate extracts of stem bark of Uncaria perrottetii were examined for their antimicrobial and cytotoxic properties. To determine these activities, C. odorata and U. perrottetiiwere tested against bacteria and fungus through disc diffusion and minimum inhibitory concentration (MIC) assays; protozoa through growth curve determination, antiprotozoal and cytotoxicity assays using in situ cell death detection kit (Roche Diagnostics). C. odorata extracts revealed antibacterial activities, inhibiting the growth of Bacillus subtilis, Staphylococcus aureus, andSalmonella typhimurium. Antibacterial and antifungal assays for U. perrottetiiextracts showed that it inhibited B. subtilis, S. aureus, and Candida albicans. Both plant extracts presented low MIC (0.1%). The antiprotozoal and cytotoxicity assays against Trichomonas vaginalis and Blastocystis hominis illustrated that both plant extracts can reduce the number of parasites. With the in situ cell death detection kit, the parasites exposed to the plant extract concentrations were observed to fluoresce in yellow-green and red simultaneously signifying apoptotic-like changes. Preliminary phytochemical screening revealed the chemical composition of C. odorata extracts containing flavonoids, saponins, tannins and steroids, while U. perrottetii possessing alkaloids, tannins and leucoanthocyanin. Thus, these plant extracts can possibly be used to produce alternative forms of antimicrobials.

Key words: Plant extract, antibacterial, antifungal, antiprotozoal, cytotoxic,Chromolaena odorata, Uncaria perrottetii.