Effect of Euonymus alatus and Ulmus clavidiana var japonica on the immune system

화살나무 및 느릅나무 추출물이 면역계세포의 활성에 미치는 영향

We have previously shown that crude water extract of Euonymus alatus (EA) had strong prophylactic effect against chemically induced-and tumor cell implanted-cancer, and that the mechanisms responsible for its antitumor effects were due to nonspecific enhancement of the NK cell activities and the cell mediated immunity. However, it was unknown that any components of crude extract did work so, since it consisted of several components. In this paper, we fractionated the crude watar EA-extract into several fraction such as hexane-, ethylether-, ethyl acetate-, n-butanol- and water soluble-fraction, and screened the immune regulating activities of each fraction by the evaluation of lymphokine production and activated lymphocyte proliferation. As a result of the component fraction of EA-extract, it was found that n-butanol fraction was a potent immunostimulator, and the remained water soluble fraction also contained some stimulator, But, other fraction did not showed any remarkable effect. It is therefore suggested that EA-glycosides in n-butanol fraction may be new one of the potent biological response modifiers. The present study was also undertaken in an efforts to investigate the effects of elm-bark(EB, Ulmus clavidiana var japonica), which has been used for curing ulcer and inflammation as a folk medicine without any kind of experimental evidence to support this, on the cellular- and humoral-immune responses, lymphocyte function and NK cell activities in mice. Regardless of time and duration of EB-treatment, Arthus reaction and antibody response to SRBC were not modified by EB, but delayed hypersensitivity to SRBC was significantly enhanced only when EB was treated prior to SRBC-sensitization. EB slightly inhibited the proliferation responses of splenocytes to PHA-stimulation, but it significantly augmented the responses of these cells to S aureus Cowan 1 and Con A-activation, and these effects were manifested only when EB was added at culture initiation. EB did not influence Ig secretion of spleen cells but it significantly augmented the Con A-induced 1L 2 and MIF production of splenocytes. NK cell activities of splenocytes were markedly riled when effector cells were pretreated with EB and this augmentation was dine to the increase of binding affinity of effector cells to target cells and the target cell lytic activities of effector cells. These results led to the conclusion that EB triggers increase of cellular immune responses, such as delayed hypersensitivitiy, lymphokine production and NK cell activities. Also these results suggested that EB contains potent immune stimulants, which may provide the rational basis for their therapeutic use as one of the new biological response modifiers.