Leong PK, Ko KM
 Division of Life Science, Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong, China
Shengmai San (SMS, transliterally meaning “the decoction for restoring the pulse” in Chinese) is an herbal formulation for the treatment of conditions of body Qi-Yin deficiency, such as the depletion of Qi and body fluids under conditions of heat-stroke. SMS is comprised of Ginseng Radix (GR, a Qi-invigorating herb), Ophiopogonis Radix (OR, a Yin-nourishing herb) and Schisandrae Fructus (SF, an “astringent” herb). Recent pharmacological studies have revealed the biochemical basis of the Qi-invigorating and Yin-nourishing actions of the component herbs of SMS in relation to the pathological condition of heat-stroke. The pathogenesis of heat-stroke indicates that its major complications include brain ischemic injury, myocardial and respiratory dysfunction. In this regard, GR possesses a Qi-invigorating action which is related to the induction of a glutathione-dependent antioxidant response and the preservation of mitochondrial function, with the resultant protection against ischemia/reperfusion injury in the brain and heart during heat-stroke. OR is a Yin-nourishing herb, which produces immunomodulatory effects. OR can reduce the extent of pulmonary hypertension, edema and inflammation under heat-stress conditions. Although the mechanism underlying the “astringent” action of SF is as yet unknown, we hypothesize that SF may retain body water, with a resultant cooling effect. Recent studies have shown that SF also possesses antioxidant and anti-inflammatory actions, which are likely to synergize the actions of GR and OR. The elucidation of the biochemical basis underlying the pharmacological actions of SMS (and its component herbs) can serve as a paradigm for the modernization of traditional Chinese herbal formulations used in treating disease.