Active components, derived from Kai-xin-san, a herbal formula, increase the expressions of neurotrophic factor NGF and BDNF on mouse astrocyte primary cultures via cAMP-dependent signaling pathway

Abstract

Ethnopharmacological relevanceKai-Xin-San (KXS), an ancient formula composed of Ginseng Radix et Rhizoma, Polygalae Radix, Acori Tatarinowii Rhizoma and Poria, was frequently applied for Alzheimer's disease and major depression disorders for thousands of years. However, its active components and molecular mechanism have not clearly been investigated. Aim of the studyWe aimed to reveal the active components of KXS on regulating neurotrophic factor NGF and BDNF expressions and its mechanisms on mouse astrocyte primary cultures. Materials and methodsExtracts of KXS had been prepared by water reflux and chemical standardization was carried out by HPLC-MS/MS. Various ethanol elution components were prepared by eluting ethanol on macro pore resin column and compound identification was carried out by high-resolution mass spectrometry. KXS extract, elution components and identified chemicals were applied on mouse astrocytes and expressions of NGF and BDNF and related metabolic enzymes were analyzed by qPCR and western blotting analysis. ResultsOne compatible ratio of KXS named D-652 exerted the best effect on stimulation of NGF and BDNF expressions on mouse astrocytes. 70% ethanol elution fraction of D-652 exerted the highest increase tendency on expressions of NGF and BDNF by activating cAMP-dependent signaling pathway as well as stimulating enzymes accounting for neurotrophic factor synthesis. Combined with compound identification by high-resolution mass spectrometry, ginsenoside Rg1 and Rb1 might be the active compounds of this fraction on increasing NGF and BDNF expressions. ConclusionsThe active compounds of KXS on increasing NGF and BDNF expressions might be the ginsenosides via activating cAMP-dependent signaling pathway as well as stimulating enzymes accounting for neurotrophic factor synthesis, which partly reveal the target of this formulae supported the clinically usage of this decoction.