Isolation of Alkaloids from Sinomenium acutum by Centrifugal Partition Chromatography and Their Ameliorating Effects on Dexamethasone-Induced Atrophy in C2C12 Myotubes

Abstract

Bioactivity-guided isolation was conducted using centrifugal partition chromatography (CPC) from an extract of Sinomenium acutum rhizome, which has shown promising preventive effects in a dexamethasone-induced C2C12 myotube atrophy model. CPC was operated with a solvent system of n-butanol–acetonitrile–water (10:2:8, v/v/v, containing 0.5% triethylamine) in dual mode (ascending to descending), which provided a high recovery rate (>99%) with a high resolution. Then, the preventive effects of the obtained CPC fractions were examined against dexamethasone-induced atrophy in C2C12 myotubes according to the weight ratios of the obtained fractions. The active fractions were further purified by semi-preparative HPLC that led to obtaining five alkaloids, one lignan glycoside, and one phenylpropanoid glycoside. Among these, at a concentration of 1 nM, sinomenine, magnoflorine, and acutumine could ameliorate dexamethasone-induced myotube atrophy in C2C12 myotubes by 9.3%, 13.8%, and 11.3%, respectively.