SEASONAL CHANGES IN THE MAJOR FLAVONOIDS AND ANTI-TUMOR CAPACITY OF THE METHANOL EXTRACTS OF CARPINUS

摘要

Plants have long been used for treating cancer and are known to produce secondary metabolites. Plants of the genus Carpinus (Betulaceae) are the most widely distributed in the European landscape and have been used to treat various diseases, including tumors. This study aimed to determine the content of four flavonoids (rutin, quercetin, kaempferol and isorhamnetin) in the methanol extract of the leaf and stem of C. turczaninowii, C. betulus, and its four cultivars and evaluate the anti-tumor activity of the methanol extract with the highest flavonoid content. Our high-performance liquid chromatography analysis results showed that the highest flavonoid content (expressed as mg flavonoid/g of extract dry weight) was found in C. betulus 'Fastigiata' leaf in summer. Further, the methanol extract of C. betulus leaf showed the highest anti-tumor effect on BIU87 cancer cells among the four cancer cells investigated with inhibition ratios of 50.35 % and 42.75 after 48 and 24 h of treatment, respectively. These results suggest that the C. betulus 'Fastigiata' leaf methanol extract has the potential to be used as a natural anti-tumor agent, and C. betulus 'Fastigiata' can be a valuable source of flavonoid compounds.