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.
Highlights
Staphylococcus and Pseudomonas species have been identified as causative agents of disease and serious pathogens in many aquatic animals, including fish[1,2,3,4], resulting in high mortality rates in many commercially farmed fish
The use of antibiotics to prevent and cure common infectious diseases in fish is becoming increasingly limited due to environmental concern, and increasingly expensive and ineffective because of microbial resistance[7,8,9]. Various plant extracts, such as those of Boesenbergia pandurata, Zingiber zerumbet and Solanum ferox, have been tested and used as an alternative to antibiotics[10,11,12]. Another potential plant extract that can be used as an antimicrobial is that of Terminalia catappa, which is widely distributed in tropical and sub-tropical regions, including Indonesia[13,14]
P. aeruginosa was more resistant to high concentrations of extract (90%) than S. aureus (Table 1)
Summary
Staphylococcus and Pseudomonas species have been identified as causative agents of disease and serious pathogens in many aquatic animals, including fish[1,2,3,4], resulting in high mortality rates in many commercially farmed fish. To reduce high mortality rates in farmed fish, aquaculturists and researcher used chemical agents and antibiotics to promote growth or prevent S. aureus and P. aeruginosa infection[6]. Various plant extracts, such as those of Boesenbergia pandurata, Zingiber zerumbet and Solanum ferox, have been tested and used as an alternative to antibiotics[10,11,12]. Another potential plant extract that can be used as an antimicrobial is that of Terminalia catappa, which is widely distributed in tropical and sub-tropical regions, including Indonesia[13,14]
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