Antimutagenic effects and isolation of flavonoids from Humulus japonicus extract

To investigate the physiological activities of Humulus japonicus, we examined the mutagenic and antimutagenic effects of the extract and isolated the flavonoid compounds. The water and methanol extracts of Humulus japonicus did not show the mutagenicity by Ames test in the 0.5-4 mg/plate. The methanol extract showed the antimutagenic effect aganinst Salmonella typhimurium TA98 and TA100 induced by 4-nitro-o-phenylenediamine(NPD) and 4-nitroquinoline-N-oxide(NQO). The hexane fraction showed comparatively higher antimutagenic effect than other solvent fractions from the methanol extract. The 50% inhibition concentration() of hexane fraction were 2.0 mg/plate, 0.5 mg/plate in TA98 and TA100 respectively. Quercitrin and luteolin were identified in the ethyl acetate fraction from methanol extract of Humulus japonicus by TLC and HPLC.