The mechanism of moxibustion: ancient theory and modern research.

THE MOXIBUSTION HAS A DUAL EFFECT OF TONIFICATION AND PURGATION IN TCM THEORIES, WHICH ARE BASED ON TWO ASPECTS: the actions of the meridian system and the roles of moxa and fire. Modern research works of the moxibustion mechanism mainly relate to the thermal effects, radiation effects, and pharmacological actions of moxa and its combustion products. Experimental results showed that moxibustion thermal stimulation affects both shallow and deep tissues of the skin, and the warm-heat effects of moxibustion have a close relation to the warm receptors or/and the polymodal receptor. The burning moxa radiation spectrum ranges from 0.8 to 5.6  μ m; peak is nearby 1.5  μ m, lying within the near infrared portion. There is an amazing consistency in the infrared spectrums of three types of indirect moxibustion and the unified spectrum of acupoints; all have their peaks of radiation near 10  μ m. Lots of ingredients had been identified from mugwort leaves and moxa smoke, which have a variety of biological activities; they were considered to participate in the comprehensive effects of moxibustion. Although lots of research works have been carried out and made some progress, there is still a great distance from fully understanding the mechanism of moxibustion.