Antiproliferation of Hepatoma Cell and Progression of Cell Cycle as Affected by Isoflavone Extracts from Soybean Cake

Abstract: The objectives of this study were to isolate various isoflavone fractions andextracts from soybean cake by preparative column chromatography and compare themwith isoflavone standards with regards to inhibition of HepG2 cancer cell proliferation.Four fractions, including malonylglucoside, glucoside, acetylglucoside and aglycone, andtwo isoflavone extracts, ISO-1 and ISO-2, were collected for evaluation. MTT test resultsshowed that most treatments were slightly protective against HepG2 cell growth at a lowdose of isoflavone (5 and 10 μg/mL). However, at elevated concentration of isoflavone(20-50 μg/mL), both aglycone and acetylglucoside fractions as well as a mixture ofisoflavone standards were the most effective in inhibition, demonstrating a possiblesynergistic phenomenon. Genistein showed a better retardation effect than daidzein. Forcell cycle analysis, both aglycone and acetylglucoside fractions and a mixture ofisoflavone standards exhibited a high G2/M ratio, correlating well with the result of MTTtest. The presence of some other functional components in soybean cake like saponinsand phenolic compounds may also play a vital role in inhibiting HepG2 cell growth.