Antibacterial activity of leaf extract of caricature plant (Graptophyllum pictum L.) against Staphylococcus aureus and Pseudomonas aeruginosa

Caricature plants (Graptophyllum pictum L.) contained bioactive compounds that are known to have antibacterial properties, such as alkaloids, flavonoids, saponins and tannins. However the antibacterial activity study of this plant extract is still limited. Current study aims to investigate the effects of ethanol-soluble fraction of leaf extract of the caricature plant on Staphylococcus aureus and Pseudomonas aeruginosa strains. The ethanol-fractions of 20%, 40 %, 60%, 80%, and 100% (v/v) screened for their antibacterial activity using well-diffusion agar method. Growth inhibition of the extract was compared with distilled water as the negative control and the standard antibiotic, ampicillin, as the positive control. The caricature plant extract significantly inhibits the growth of both tested bacterial strains in a concentration-dependent manner. At the concentration of 100%, the extract caused growth zone of inhibitions of 20.54 mm in S. aureus and 19.8 mm in P. aeruginosa. The minimal inhibit concentration of the extracts against those bacteria consecutively are 13% and 17%. Sub culturing the bacteria taken from the media with negative growth on the solid NA agar showed that the growth of S. aureus still detected, but not for P aeruginosa. The ethanol-soluble fractions of the caricature plant leaves extract possess antibacterial activity and depict a bacteriostatic property against S. aureus and a bactericidal against P. aeruginosa.