‘ICPCR’ hosted by Faculty of Pharmacy, University of Sumatera Utara, Medan, Sumatera Utara, Indonesia 03 November 2017 Vol 11, Special issue 1, 2018 Online - 2455-3891 Print - 0974-2441 IN VITRO ANTIBACTERIAL ACTIVITY OF THE ETHANOLIC EXTRACT OF JALOH (SALIX TETRASPERMA ROXB.) LEAVES AGAINST STAPHYLOCOCCUS AUREUS AND PSEUDOMONAS AERUGINOSA FITRAH WAHYUNI 1,2 *, URIP HARAHAP 3 , MASFRIA 4 1 Master Programme in Pharmacy, Faculty of Pharmacy, University of Sumatera Utara, Jalan Tri Dharma No. 5, Padang Bulan, Medan, Indonesia. 2 Loka Litbang Biomedis Aceh, Jalan Bandara SIM Lorong Teungku Dilangga No. 9 Lambaro, Aceh Besar 23371, Indonesia. 3 Department of Pharmacology, Faculty of Pharmacy, University of Sumatera Utara, Jalan Tri Dharma No. 5, Padang Bulan, Medan, Indonesia. 4 Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Sumatera Utara, Jalan Tri Dharma No. 5, Padang Bulan, Medan, Indonesia. Email: wahyunifitrah@gmail.com Received: 06 December 2017, Revised and Accepted: 06 April 2018 ABSTRACT Objective: This study aims to determine antibacterial activity of ethanolic extract of jaloh (Salix tetrasperma Roxb.) leaves against Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA). Methods: Extract was obtained by maceration method of jaloh (S. tetrasperma Roxb.) leaves dried powder with 96% ethanol as solvent. The antibacterial activities of extract were tested by Kirby–Bauer method against SA and PA. Data were analyzed statistically using Kruskal–Wallis test for significant difference level p<0.05. Results: Based on the regression test, the equation of regression curve of extract antibacterial activity on SA and PA, respectively, was y=350.456x-229.579 and y=331.866x-272.069. The minimum inhibitory concentrations (MICs) of SA and PA from the equation of regression curve, respectively, were 4.5193 and 6.6039 mg/mL. Conclusion: Based on the MIC value, ethanolic jaloh leaves extract had a weak antibacterial activity against SA and PA. Keywords: Antibacterial, Salix tetrasperma Roxb., Jaloh, Staphylococcus aureus, Pseudomonas aeruginosa. INTRODUCTION Commonly to treat infectious diseases use antibiotics. The improper usage of antibiotics arise bacterial resistant to one or some type of antibiotic (multiple drug resistance) [1]. For this reason, the effort to search and develop new antibacterials still have been done. New antibacterial sources can be obtained and developed from plants because of the content of secondary metabolites such as saponins, tannins, alkaloids, flavonoids, and terpenoid efficacious as antibacterial [2,3]. There are plant species that grow in Aceh, by people called jaloh or sijaloh (Salix tetrasperma Roxb.), from the Salicaceae family. Utilization of this plant in some areas of Aceh is used as a febrifuge (antipyretic) [4]. Salicaceae family plant contains the main compounds of phenols such as flavonoids and tannins [5]. Based on that, jaloh plants have potential as antibacterial. This study aims to determine the antibacterial activity of jaloh plants. METHODS Chemical and reagents Ethanol 96% (Merck), dimethyl sulfoxide (DMSO) (Merck), medium nutrient agar (oxoid), nutrient broth (oxoid), Mueller-Hinton agar (oxoid), aqua bidestilata sterile (Ikapharmindo Putramas), and NaCl 0.9% (Widatra Bhakti) were used. Bacterial strains Bacteria test culture was Gram-positive Staphylococcus aureus (SA) ATCC 6538 and Gram-negative Pseudomonas aeruginosa (PA) ATCC 9027 obtained from Microbiology Laboratory of Faculty of Pharmacy USU, Medan, Indonesia. Plant materials Jaloh plant (S. tetrasperma Roxb.) was collected from Lambaro Angan village, Aceh Besar, Aceh Province, Indonesia. Preparation of extracts A total of 600 g of jaloh leaves dried powder was macerated with 6 L ethanol 96% [6]. The macerate was then distilled and evaporated under reduced pressure at a temperature of not more than 50°C using a rotary evaporator to obtain a viscous extract [7]. Antibacterial activity assay The antibacterial activity test was performed by Kirby-Bauer method by as much as 0.1 mL inoculum of each bacterium SA and PA 10 6 CFU/mL mixed homogeneously with 15 mL Mueller-Hinton Agar in a petri dish, then left until medium solidified. Thereafter, paper disc was impregnated by 10 µL of each extract solution in DMSO concentration of 500, 250, 125. 62.5, 31.25, 15.625, and 7.8125 mg/mL implantation to the medium for 10 min to diffuse and then incubated at 36–37°C for 24 h. Furthermore, each Petri was measured the diameter of the transparent zone (inhibition zone) around the disc using the sliding term [7,8]. The test was conducted 5 times. The minimum inhibitory concentration (MIC) of the extract was determined using the regression equation from the graph of square inhibition zone diameter (mm) to the concentration log and the intersection on the X-axis recorded as MIC [9,10]. Statistical analysis Data were analyzed statistically using Kruskal–Wallis test with significant different level p<0.05. This statistical analysis was performed using the Statistical Product and Service Solution program version 18. Research Article © 2018 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4. 0/) DOI: http://dx.doi.org/10.22159/ajpcr.2018.v11s1.26580