ABSTRACT
Crude extracts of Asiatic Pennywort (Centella asiatica (Linn.) Urban) extracted with either ethanol
or water were tested for antibacterial activity against 30 isolates of S. aureus from milk samples of dairy
cows. The antibacterial sensitivity of crude extracts were tested by the disc diffusion test, and results
showed that ethanol extracts and water extracts had average inhibition zones ranged from 6.44-6.49 and
6.54-17.72 mm in diameter, respectively. The modified resazurin microtiter-plate was used to determine
the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) was
determined by touching the loop from each well of MIC plate and streaking it on a mannitol salt agar.
Results showed that the ethanol extracts had an MIC50 value of 8 mg/mL, the water extracts of leaf
powder had an MIC50 value of 32 mg/mL, and the water extracts of fresh leaves had an MIC value of 32-
256 mg/mL. The ethanol extracts had an MBC value of 16 mg/mL. The water extracts could not kill S.
aureus. In conclusion, the ethanol extracts had more potential antibacterial activity than the water
extracts.
ABSTRACTCrude extracts of Asiatic Pennywort (Centella asiatica (Linn.) Urban) extracted with either ethanolor water were tested for antibacterial activity against 30 isolates of S. aureus from milk samples of dairycows. The antibacterial sensitivity of crude extracts were tested by the disc diffusion test, and resultsshowed that ethanol extracts and water extracts had average inhibition zones ranged from 6.44-6.49 and6.54-17.72 mm in diameter, respectively. The modified resazurin microtiter-plate was used to determinethe minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) wasdetermined by touching the loop from each well of MIC plate and streaking it on a mannitol salt agar.Results showed that the ethanol extracts had an MIC50 value of 8 mg/mL, the water extracts of leafpowder had an MIC50 value of 32 mg/mL, and the water extracts of fresh leaves had an MIC value of 32-256 mg/mL. The ethanol extracts had an MBC value of 16 mg/mL. The water extracts could not kill S.aureus. In conclusion, the ethanol extracts had more potential antibacterial activity than the waterextracts.
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