AKTIVITAS ANTIBAKTERI EKSTRAK DAUN BAKAU HITAM (Rhizophora mucronata) TERHADAP BAKTERI PENYEBAB DIARE

Abstract

Leaves of Rhizophora mucronata have been widely used by coastal people as traditional medicine for treating diarrhea. Th e aim of this study was to obtain Rhizophora mucronata leaf extracts and determine their antibacterial activity against diarrhea-causing bacteria. Th e antibacterial activity was determined by agar well diff usion method. Th e highest yield was obtained aft er methanol extraction. Bioactive compounds found on methanol and aqueous extracts consisted of tannin, saponin, fl avonoid, phenol hydroquinone, and triterpenoid, while alkaloid was only found in methanol extract. Methanol extract had the highest antibacterial activity with inhibition zone of 3-12 mm. Minimum inhibitory concentrations of the methanol extract were 0.4 mg/mL (against Escherichia coli and Pseudomonas aeruginosa), 0.2 mg/mL (against Staphylococcus aureus). Bioautography of leaves extract against E. coli showed the active fractions were found on Rf values of 0.11 and 0.72. Preliminary identifi cation using Dragendorff spray reagent detected that the active compound was alkaloid.