Cytotoxicity and antiproliferative effects of ethyl acetate fraction of padina australis against MCM-B2 and K562 cell lines

The antiproliferative of the brown algae Padina australis extracts against cell MCM-B2 (canine benign mammary gland mixed tumor) and cell K562 (human chronic myelogenous leukemia) in vitro was examined. The tested samples were water extract (n-hexane fraction, ethyl acetate fraction, and ethanol fraction) and ethanol extract (n-hexane fraction, ethyl acetate fraction, and ethanol fraction). Cytotoxicity was screened using brine shrimp lethality test. The antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl. The antiproliferative activity test was conducted using trypan blue dye method and cells were counted using hemocytometer. The results showed that ethyl acetate fraction from water extract exhibited significant cytotoxicity with lethal concentration 50 value of 200.53 ppm. The ethyl acetate fraction from water extract was then considered for further examination. Results of antioxidant activity test showed that concentration for inhibitory activity of 50% of the ethyl acetate fraction reached 113.37 ppm. This fraction at concentration of 400 ppm could inhibit the growth of MCM-B2 and K562 cancer cell lines in vitro reaching 56.90% and 61.54%, respectively. Therefore, the present study suggested that ethyl acetate fraction of P. australis extract demonstrated a potential natural anticancer activity.