Antimicrobial activity of Terminalia catappa brown leaf extracts against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853

Abstract

The aim of this study was to determine the effects of various concentration ofTerminalia catappabrown leaves extract which can inhibit the growth ofStaphylococcus aureusATCC 25923 andPseudomonas aeruginosaATCC 27853. The crushed-brown leaves ofTerminalia catappawas extracted using 95% ethanol, filtered, and evaporated. The driedT. catappaextract was used to identify phytochemical content qualitatively. Total phenolic and flavonoid contents were also measured quantitatively from dried extract. The dried extracts were also dissolved in sterile aquadest and serial dilutions were prepared to final concentration of 30, 60 and 90%. A disc diffusion method was used to evaluate the antibacterial activity of various concentrations of ethanol extract of brown leaves ofT. catappa. Inhibition zone diameter was measured to determine antibacterial activity. Gentamycin sulfate and distilled water were used as positive and negative controls, respectively. Dried ethanolic extract of brownT. catappaleaves contained flavonoid, quinon, phenolic, triterpenoid, and tannin. A total of 208.722 mg gallic acid equivalent/g extract of total phenolic and 35.7671 mg quercetin equivalent/g extract of total flavonoid were also found in the dried extract. The inhibition zone diameters of ethanolic extracts ranged from 1.73 to 9.06 mm (S. aureus) and from 1.83 to 6.5 mm (P. aeruginosa). The higher concentration of extract, the wider the inhibition zone diameters for both bacteria.P. aeruginosawas more resistant to high concentrations of extract (90%) thanS. aureus. Ethanolic extracts of the brown leaves ofT. catappahad different antibacterial effects againstS. aureusandP. aeruginosa. The higher the concentration of extract, the wider the inhibition zone diameter for both bacteria.P. aeruginosawas more resistant to high concentrations of ethanolic extracts of the brown leaves ofT. catappa.