Comparison of antimicrobial activity between ethanol and ethyl acetate extracts of zingiber zerumbet rhizome against skin microogranisms / Nurul Nadia Mohd Jaafar

Zingiber zerumbet is another ginger species where its rhizome part plays the most important role in medicine. Rhizome of Zingiber zerumbet (ZZR) was known to have antimicrobial effect traditionally and pharmaceutically. Various researches had been done to discover the potential of this plant rhizome since decades ago. Recently, Triclosan was becoming a big issue where the compound was revealed not to bring extra benefits on health but rather might be a negative impact both on health and environment. Besides, Triclosan also caused microorganisms including skin microorganism to develop resistant against many antibacterial agent and antibiotics. In this research study, antibacterial activity of the plant rhizome was further studied against skin microorganisms. Solvent extraction with maceration technique was a method of choice. The plant rhizome was extracted by using two different solvents which are 95% Ethanol and Ethyl acetate. Both extracts were made into 1000mg/ml concentration and was tested for Antimicrobial Susceptibility Testing (AST) and Minimal Inhibitory Concentration (MIC) as well as preliminary phytochemical testing. This study was aimed to determine and to compare the antibacterial activity of Zingiber zerumbet rhizome from the two different extracts against selected skin microorganisms which are Staphylococcus aureus, Staphylococcus epidermidis, Proteus mirabilis and Pseudomonas aeruginosa. Results showed that both extracts have antimicrobial activity against both gram positive organisms tested. Gram negative organisms tested showed resistancy towards 1000mg/ml ethanol extract while Ethyl acetate extract could only inhibit Proteus mirabilis at ZOI = 7.3 mm diameter. Both of AST and MIC testing results in this study revealed that Ethyl acetate extract has a better inhibitory effect against selected skin microorganisms compared to Ethanol extract of ZZR. MIC of Ethanol extract showed higher range of concentration needed to inhibit the organisms [(62.5-125 µg/ml) compared to ethyl acetate extract (2.0 - 31.5 µg/ml)]. In conclusion, both extracts especially Ethyl acetate extract of ZZR have potential in replacing Triclosan as antibacterial agent in skin products and other consumer products. The rhizome of the plant should not be left out and ignored as it might have more potential in the microorganism inhibitory effects.