TIARA DINI HARLITA, Magister Biology, Faculty of Biology, University of Jenderal Soedirman. Antibacterial Activity of Bawang Dayak (Eleutherine palmifolia (L.) Merr) Bulb Extract to The Pathogenic Bacteria. Supervisors: Dr. Drs. Oedjijono, M.Sc. and Ari Asnani, S.Si., M.Sc., Ph.D.
The utilization of natural medicines made from herbs began to be developed again as an alternative to avoid the side effects of antibiotics. One of the medicinal plants used as an alternative treatment by the people of Kalimantan is the bulbs of dayak onions (Eleutherine palmifolia (L.) Merr). The plant is endemic to Central Kalimantan which empirically has the properties to cure various diseases. The bulbs of dayak onions have been known for its potential as a medicinal plant, and therefore its utilization as a modern medicine needs to be improved. The compounds contained in dayak onion bulbs are suspected to contain active compounds which are efficacious.
This research aims to: (1) test the antibacterial activity of dayak onion bulbs extracts of n-hexane fraction, ethyl acetate fraction and the ethanol 96% fraction against the bacterium of Methicillin-Resistant Staphylococcus Aureus (MRSA), Bacillus cereus, Shigella sp., and Pseudomonas aeruginosa, (2) determine the minimal concentration of dayak onions bulbs extracts of n-hexane fraction, ethyl acetate fraction and the ethanol 96% fraction which can inhibit the growth of MRSA, B. cereus, Shigella sp., and P. aeruginosa, (3) determine the type of secondary metabolites of dayak onions bulbs extracts of n-hexane fraction, ethyl acetate fraction and the ethanol 96% fraction, and (4) obtain the characteristics of secondary metabolites of dayak onion bulbs extract which has the best antibacterial activity through TLC-Bioautography techniques based on its Rf value, stability to heating temperature and pH.
This research was conducted in the Laboratory of Microbiology, Faculty of Biology and in the Laboratory of Biochemistry, Faculty of Mathematics and Natural Science, University of Jenderal Soedirman, Purwokerto. The research was an experimental research which employed completely randomized design with factorial design on two factors: the type of solvents (n-hexane, ethyl acetate, and ethanol 96%) and extract concentration (2, 4, 6, 8, and 10 mg/mL). The positive control was cefadroxil 30 µg/mL in sterile aquadest and the negative control was sterile aquadest. The multiple stage extraction was performed by maceration method and the rendement value of each fraction of extract was calculated. The test of antibacterial activity against test bacteria was in vitro by using agar diffusion method. The determination of the minimum inhibitory concentration was based on the smallest concentration of dayak onion bulb extract which still able to inhibit or kill the growth of test bacteria. Chemical compound component test was done qualitatively by observing the color change. The characterization of antibacterial compounds was done with the test of thin layer chromatography, the bioautography test, and also stability test to heating temperature and pH using the extract with the best antibacterial activity. Data analysis that was done is the analysis of variance (ANOVA) with Duncan Multiple Range Test (DMRT) on confidence level of 95%.
The test results of the antibacterial activity indicate that n-hexane fraction, ethyl acetate fraction and ethanol 96% fraction of dayak onion bulbs extract has antibacterial activity against the growth of pathogenic bacteria MRSA, B. cereus, Shigella sp., and P. aeruginosa with the best inhibitory activity at concentrations of 10 mg/mL. The minimum inhibitory concentration of dayak onion bulbs extract on the growth of the four bacteria was 2 mg/mL.
The results of chemical compound component test shows that there are different secondary metabolites on each fraction. Steroid is found in n-hexane, alkaloid and steroid are found in ethyl acetate, and flavonoid, triterpenoid and tannin are found in ethanol fraction.
Characterizatic of antibacterial compounds of ethyl acetate fraction of dayak onion bulbs extract based on TLC test obtained the Rf values of 0.24; 0.31; 0.40; 0.67 at 254 nm UV light and Rf 0.10; 0.26; 0.45; 0.85 at 366 nm UV light. Bioautography test results indicate that the ethyl acetate fraction of dayak onion bulbs extract has contains four types of active compunds and compounds with Rf values of 0.37 and 0.56 has a bacterial inhibition higher than the compound with Rf values of 0.13 and 0.18. The active compund fraction of the ethyl acetat extract of dayak onion bulbs resistant to heating temperature and has a pH optimum of 5-8 in inhibiting the growth of B. cereus.
Keywords: antibacterial, bioautografi, dayak onion bulbs, minimum inhibitory concentration