The flower of the chrysanthemum plant Shiranui Himekiku has been used as a folk medicine for a variety of diseases including cancer, and cytotoxic effects in some cancer lines have been reported. However, little is known about the anti-cancer activity of the leaf extract and its active compounds. Therefore, to clarify the anti-cancer activity of Shiranui Himekiku leaf and flower, the anti-proliferative effects of the extracts on human cancer cells were examined. Both leaf and flower water extracts dose-dependently suppressed the proliferation of the human breast cancer cell line MCF-7 at concentrations >25 µg/ml. Furthermore, the anti-proliferative effect in MCF-7 is more than four times that in normal human dermal fibroblast cells. When heated at 100℃ for 30 minutes, the proliferation inhibitory activity of the flower extract was unchanged. In contrast, under identical conditions, the activity of the leaf extract was lost. The extracts were separated into two fractions ; one with a molecular weight (MW) >10 000 (high molecular weight fraction) (HMW) and the other with a MW<10 000 (low molecular weight fraction) (LMW). A significant proliferation inhibitory effect can be seen in the LMW fraction of both extracts, but the HMW fraction of the leaf extract also slightly inhibits cell growth. Both polyphenols and non-polyphenols are candidate active compounds because the anti-cancer effect was seen in the polyphenol-and non-polyphenol-fractions. These results suggest that the extracts contain several types of anti-cancer components and that both leaves and flowers can be useful.

To clarify the immunoregulatory activity of the chrysanthemum plant Shiranui himekiku, the effects of its flower and leaf extracts on proliferation and histamine release of rat and human basophilic leukemia cells were examined. Water extracts of flower and leaf suppressed proliferation and histamine release of rat RBL-2H3 cells dose-dependently at concentrations over 10 µg/mL. The histamine release-suppressive effect of the leaf extract was as strong as that of the flower extract. The effects of these extracts on proliferation and histamine release of human KU812 cells were much weaker than those on RBL-2H3 cells. When these extracts were heated at 100℃ for 30 min, the histamine release-inhibitory activity was unchanged, but the proliferation-inhibitory activity decreased slightly. Histamine release-inhibitory activity was detected in water extract of a commercial dried flower extract prepared with a stainless kettle as well as that prepared with an earthen pot as recommended by the manufacturer. These results suggest that these extracts contain anti-allergic components, that leaves are useful as well as flowers, and that the extracts can be prepared using stainless pots, which are useful in IH cooking.

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