The Antimicrobe of Kaempferia galanga L. Rhizome against Microsporum canis and Staphylococcus epidermidis – In-vitro Study

. This study aims to determine the ability of ethanolic extract of Kaempferia galanga L. rhizome in inhibiting the growth of Microsporum canis and Staphylococcus epidermidis. Rhizome concentrations used were 40, 50, 60, and 70%. Each treatment was replicate 4 times. Results showed that extract of K. galanga rhizome up to 70% have not significantly differences against M. canis and S. epidermidis. Rhizome extract of 70% inhibit the growth of M. canis with the highest inhibition 5.88 mm (in compared to ketoconazole 10.35 mm). Whereas the extract of 70% inhibit S. epidermidis with the highest inhibition 3.16 mm (in compared to chloramphenicol 25.49 mm).


Introduction
Kaempferia galanga L. is one of herb plants (Family Zingiberaceae), native to India and common grow in China, Myanmar, Indonesia, Malaysia, and Thailand [1]. The herb commonly used as mixed for food flavoring, spice since its highly aromas, cosmetics or as a traditional medicine [2,3]. Rao and Kaladhar [4] reported that rhizome of K. galanga contain antioxidant and antimicrobial activity. The in vitro antimicrobial activity of the essential oil of K. galanga rhizome against Gram-positive and Gram-negative bacteria was reported by Tewtrakul et al. [5].
Whereas Belgis et al. [6] observed that essential oils of K. galanga rhizome contain ethyl pmethoxy cinnamate (23.65%) and ethyl cinnamate (5.98%) that potential as an antibacterial against Staphylococcus pyogenes and Staphylococcus aureus that can cause sore throat.
Previous study by Parvez et al. [7] stated that crude extract of the rhizome K. galanga with petroleum, ether, acetone, and methanol have antimicrobial activities against Gram-positive bacteria (Bacillus sp., Pseudomonas sp.) and Gram-negative pathogenic bacteria (Escherichia coli, Salmonella sp., Shigella sonnei) [3]. The in vitro antifungal activity of essential oil of K. galanga rhizome against dermatophyte, filamentous fungi and yeast was studied by Jantan et.al. [8], they found that the essential oil showed selective antifungal activity against dermatophytes Aspergillus fumigatus but ineffective against yeasts. Microsporum canis is the most common dermatophyte in domestic and wild animals [9,10]. The pathogen is easily transmitted to human, causing lesion on skin (tinea corporis) and to the head (tinea capitis).
Vuong and Otto [11] reported that Staphylococcus epidermidis is one of opportunistic bacteria on human that cause nosocomial infection and difficult to eradicate. Otto [12] also stated that S. epidermidis is more virulent than Staphylococcus aureus. Therefore, the objective of this current study is to determine the ability ethanolic extract of Kaempferia galanga rhizome in inhibiting the growth of Microsporum canis and Staphylococcus epidermidis.

Bacterial and fungal isolation
Microbes used in this experiment was culture collection of Microbiology Pharmacy Laboratory, Universitas Sumatera Utara.

Preparation of extract
A total of 3000 g fresh harvested K. galanga was purchased from local farmer at Tinokkah Village Sipispis Regency, Serdang Bedagai, North Sumatera. The process of extraction was conducted according to the procedures of Sasidharan et al. [13] with some modifications. The dried rhizome was ground into powder using blender. The powder in flask 1000 ml then were submerged in 95% (v/v) ethanol. The suspension was stirred at 28℃ at 100 rpm for 12 h and filtered. The residue obtained was re-extracted in 40 ml 95% of ethanol, stirred for 12 h and filtered. The filtrate obtained then was concentrated using a rotary evaporator and lyophilized in a freeze dryer.
The filtrate was dissolved in DMSO to make concentration 40, 50, 60 and 70%. Antifungal (ketoconazole) and antibacteria (chloramphenicol) used as positive control (K+) and sterilized distilled water were used as negative control (K-). Each treatment was repeated three times.

Antimicrobe activity
The antimicrobe activity was conducted based on zone method. The medium used was potato dextrose agar (PDA) and nutrient agar (NA).

Statistical analysis
We analyzed the observed data using analysis of variance (ANOVA) for statistically significant differences, followed by Duncan's multiple range test at the 5% probability level. We used the Statistical Analysis System (SAS) software (version 9.1 3) statistical package (SAS Institute Inc. North Carolina).

Results and Discussion
Ethanolic extract of K. galanga rhizome was potential inhibit the growth of M. canis and S. epidermidis. The growth inhibition was indicated as the presence of clear zone surrounding paper disc. In general, the extract on each concentration more inhibits S. epidermidis than M. canis ( Figure 1). However, Rao and Kaladhar et al. [4] observed that rhizome extract of K. galanga as good activity against Aspergillus niger and Candida albicans) 11 to 22 mm) when compared to gram positive bacteria (9.5 to 13 mm). Selective toxicity of the extract against M.
canis might occurred as reported by Jantan et al. [8].   3.16 a 5.88 b Note: Numbers followed by same letters at the same column not significantly different (P<0.05) K-= no extract; K+ = ketoconazole for M. canis and chloramphenicol for S. epidermidis

Conclusions
The ethanolic extract of Kaempferia galanga rhizome has shown antimicrobial activity against Microsporum canis and Staphylococcus epidermidis and hence the use of the rhizome extract is potential as an alternative antimicrobe.