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 of
Terminalia catappa brown leaves extract which can inhibit the growth of
Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC
27853. The crushed-brown leaves of Terminalia catappa was extracted using
95% ethanol, filtered, and evaporated. The dried T. catappa extract 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 of T. 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
brown T. catappa leaves 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. aeruginosa was more resistant to high
concentrations of extract (90%) than S. aureus. Ethanolic extracts of the brown
leaves of T. catappa had different antibacterial effects against S. aureus and P.
aeruginosa. The higher the concentration of extract, the wider the inhibition
zone diameter for both bacteria. P. aeruginosa was more resistant to high
concentrations of ethanolic extracts of the brown leaves of T. catappa.