Antibacterial Activities in Watercress(Oenanthe javanica D.C.) Cultivated with Different Culture Methods

재배방법이 다른 미나리의 항세균 활성

Antibacterial activities in each part of watercress(Oenanthe javanica D.C.) grown under different culture conditions were measured to determine the possibility to use watercress as a resource to develop the antibacterial substance. The leaves of watercress were extracted with methanol and the methanol extract was further fractionated with various organic solvents. Antibacterial activities against Shigella dysenteriae ATCC 9361 in all fractions were determined according to the agar diffusion method using paper disc. Methanol extract of watercress leaves was more effectively inhibited the growth of the tested bacteria than the extracts of roots or stems at the concentration of 0.5 g eq./disc, and the extract of watercress from Hwasoon was the most effective one as compared to others. Phenolic and neutral fractions fractionated from methanol extract of watercress had a considerable inhibiting activity on the growth of the bacteria, but acidic and basic fractions did not show any inhibitory effect. Minimum inhibitory concentrations of phenolic and neutral fractions against Shigella dysenteriae ATCC 9361 were $400\;{\mu}g/disc$ and $550\;{\mu}g/disc$, respectively.