Comparison between in vitro and in vivo antibacterial activity of Curcuma zedoaria from Malaysia

The antimicrobial activity of the extracts of Curcuma zedoaria from Malaysia was compared using in vitro and in vivo systems. The comparison was performed against four bacterial strains including two gram negative strains (Escherichia coli and Pseudomonas aeruginosa) and two gram positive strains (Bacillus cereus and Staphylococcus aureus) using the agar well diffusion method. Petroleum ether, chloroform and methanol were used as solvents for preparing the plant extracts. Growth hormones namely indole-3-butyric acid (IBA) and 6-Benzylaminopurine (BAP) were used in the in vitro system separately between the range of 0.25 and 3.5 mg/l for IBA and 0.5 and 4 mg/l for BAP and a mix formula containing both hormones using the best ranges after rapid tests. The results showed that the in vitro system was more capable of inhibiting S. aureus growth compared with in vivo system on the agar plate. P. aeruginosa and E. coli growth were only inhibited by the in vitro system on the agar plate, while B. cereus was the only strain in the in vivo system which produced higher inhibition zone on the agar plate against its growth compared with the in vitro system.