Histamine release-suppressive effect of water extracts prepared from flower and leaf of chrysanthemum, Shiranui himekiku

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 10μg/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°C 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.