objective: To investigate the effect of Jiaotai Pill (交泰丸, JTP) at different constitutional proportions on insulin signaling through phosphatidylinositol 3-kinase (PI3K) pathway in the skeletal muscle of diabetic rats. Methods: The rat model of type 2 diabetes mellitus (T2DM) was established by intravenous injection of a small dose of streptozotoein plus high fat diet feeding. JTP at the same dosage of cinnamon and the increasing dosage of Coptis chinensis was administered to diabetic rats for nine weeks respectively. Plasma glucose and insulin levels were assayed. The expressions of proteins were determined by Western blot method. Results: All the three formulations of JTP decreased plasma glucose and fasting insulin levels as well as increased the protein expressions of insulin receptor β (InsR β) subunit, insulin receptor substrate-1 (IRS-1), PI3K p85 subunit and glucose transporter 4 (GLUT4) in skeletal muscle. Meanwhile, JTP increased the tyrosine phosphorylation of InsRβ subunit and IRS-1, and reduced the serine phosphorylation of IRS-1 in skeletal muscle. Interestingly, the effect of JTP on improving insulin sensitivity was not dose-dependent. In contrast, JTP containing the least amount of Coptis chinensis exhibited the best effect. Conclusion: JTP at different constitutional proportions attenuates the development of diabetes in a rat model of T2DM. The mechanism might be associated with enhancing insulin signaling through PI3K pathway in the skeletal muscle.
Chinese herbal medicine has developed new therapies for nonalcoholic fatty liver disease (NAFLD) based on its unique theory system and substantial herb remedies. In this review, 21 traditional Chinese herbs were introduced for their potential benefit in the treatment of NAFLD. Majority of them are evaluated by experimental studies and few by multicenter clinical trials. Herbal monomers as berberine and resveratrol, extracts from Polygonum hypoleucum Ohwi, and Artemisia sacrorum Ledeb., and formulae including Yinchenhao Decoction (~.~.~, YCHD), Qushi Huayu Decoction (~'~. ~.~, QSHYD), and Danning Tablet ()~?)~) were discussed in detail on their therapeutic potentials. Most of these herbal medicines were proved to improve biochemical and histological changes of NAFLD both in vitro and in vivo. Also, their therapeutic activities were associated with inhibiting lipid accumulation through adenosine monophosphate-activated protein kinase activation or upregulating low-density lipoprotein receptor (LDLR) expression, alleviating lipid peroxidation, and reducing the production of inflammatory cytokines. Although the efficacy and safety of these herbal medicines needed to be evaluated in multicenter large-scale clinical trials, Chinese medicine is promising and effective for preventing and treating NAFLD disease.