Effects of moxibustion to zusanli (ST36) on alteration of natural killer cell activity in rats

Moxibustion is one of the major healing techniques in Oriental medicine. It has been widely used in many diseases such as rheumatoid arthritis, Hashimoto disease, breech presentation, etc. However, till now, effects of moxibustion on natural killer (NK) cell activity and relations between sympathetic nerve system (SNS) and the immune alteration induced by moxibustion were not well studied. This study was designed to evaluate effects of moxibustion on NK cell activity and the intervention of SNS in the alteration of NK cell activity induced by moxibustion. Splenic NK cell cytotoxicity was measured in a standard 4-hour 51Cr release assay. We measured the NK cell cytotoxicity after moxibustion stimulation for 1, 3, 5 and 7 days, and also measured the NK cell cytotoxicity after 3 and 7 days burn stimulation with similar temperature. Interleukin (IL)-2, -4 and interferon (INF)-gamma in serum were measured by rat IL-2, -4 and INF-gamma ELISA test kit. To evaluate the effects of sympathectomy on alteration of NK cell cytotoxicity, 6-hydroxydopamine (6-OHDA: 50 mg/kg) was used. We showed that NK cell activity of moxibustion stimulation group increased at the 3rd day, and declined at the 7th day in comparison with that of the control group. In the moxibustion stimulation group, NK cell activity was significantly higher than the sham group at the 3rd day. On the contrary, in the burn stimulation group, NK cell activity was significantly higher than that of the sham groups at 3rd and 7th days. INF-gamma level after 3 days in the moxibustion stimulation group was significantly higher than that of the sham group. IL-2 level among groups were not different. IL-4 was not detected in serum with this method. Sympathectomy abolished the NK cell activity alteration induced by moxibustion. The results suggest that moxibustion modulates NK cell activity, along with INF-gamma, and SNS is mediating these effects.