Cytotoxic, antitumour-promoting and inhibition of protein denaturation effects of flavonoids, isolated from Potentilla evestita Th. Wolf.

This study was designed to evaluate the isolated flavonoids (chrysin 1, and umbelliferone 2) from Potentilla evestita for cytotoxic, antitumour-promoting and inhibition of protein denaturation activities. The results showed marked cytotoxic effect of compounds 1 and 2 in brine shrimp cytotoxic assay at various concentrations with LD50 of 34.5 and 31.8 mg/mL, respectively. In Epstein-Barr-virus early antigen activation assay, both compounds 1 and 2 illustrated significant antitumour-promoting effect with IC50 values of 462 and 308 mol ratio/32 pmol TPA, respectively. The cytotoxic and antitumour-promoting effects of compounds were strongly supported by inhibition of protein denaturation activity with IC50 of 119 and 112 μg/mL, respectively. In conclusion, both compounds possess strong cytotoxic, antitumour-promoting and inhibition of protein denaturation activities.