Shexiang Baoxin Pill, a Formulated Chinese Herbal Mixture, Induces Neuronal Differentiation of PC12 Cells: A Signaling Triggered by Activation of Protein Kinase A.

Miranda Li Xu,Ran Duan,Etta Yun-Le Liu,Xiao-Hui Shang,Tina Ting-Xia Dong,Zhong-Yu Zheng,Ying-Jie Xia,Wei-Hui Hu,Chang-Sen Zhan,Stanley Ka-Ho Chan,Karl Wah-Keung Tsim

doi:10.3389/fphar.2019.01130

Abstract

Background: Shexiang Baoxin Pill (SBP) is a well-known composite formula of traditional Chinese medicine (TCM), which is commonly used today in treating cardiovascular diseases. SBP consists of seven materials thereof, including Moschus, extract of Ginseng Radix et Rhizoma, Bovis Calculus Artifactus, Cinnamomi Cortex, Styrax, Bufonis Venenum, and Borneolum Syntheticum. Here, we are investigating the potential roles of SBP in inducing neuron differentiation, i.e., seeking possible application in neurodegenerative diseases. Methods: Water and ethanol extracts of SBP, denoted as SBPwater and SBPEtOH, respectively, as well as its individual herbal materials, were standardized and applied onto cultured rat pheochromocytoma PC12 cells. The potential effect of SBP extracts in neuronal differentiation was suggested by following parameters: (i) induction of neurite outgrowth of PC12 cells, (ii) increase of neurofilament expression, and (iii) activation of transcription of neurofilament. Results: The treatments of SBPwater and SBPEtOH, or extracts from individual herbal materials, with or without low concentration of nerve growth factor (NGF), could potentiate the differentiation of cultured PC12 cells. The differentiation was indicated by increase of neurite outgrowth, as well as expression of neurofilaments. In addition, application of H89, a protein kinase A (PKA) inhibitor, suppressed the SBP-induced neurofilament expressions, as well as the phosphorylation of cAMP-responsive element binding protein (CREB) in cultures. Conclusion: SBP is proposed to possess trophic activity in modulating neuronal differentiation of PC12 cells, and this induction is shown to be mediated partly by a cAMP-PKA signaling pathway. These results indicate the neurite-promoting SBP could be useful in developing potential drug in treating or preventing neurodegenerative diseases.

Highlights

Progressive reduction of neuron is a pathologica#l hallmark of neurodegenerative diseases [e.g. Alzheimer’s disease (AD)]
Four batches of Shexiang Baoxin Pill (SBP) and seven medicinal materials or extracts, including Moschus, ginseng radix et rhizoma, Bovis Calculus Artifactus, Cinnamomi Cortex, styrax
HPLC chromatograms of SBPwater and SBPEtOH (95% ethanol extract of SBP) were obtained, in which there were mainly 12 eluted peaks being identified in SBPEtOH; but only 3 of them were identified in SBPwater (Supplementary Figure 1)

Summary

Introduction

Progressive reduction of neuron is a pathologica#l hallmark of neurodegenerative diseases [e.g. Alzheimer’s disease (AD)]. Several lines of evidence suggest an insufficient supply of neurotrophic factors is leading to deduction in neuron, and thereafter causing neurodegenerative disorders (Cai et al, 2014). Neurotrophic factors have been identified as one of the potential therapeutic options for neurodegenerative disorders for a number of years (Weissmiller and Wu, 2012; Cai et al, 2014). The development of new compounds or drugs mimicking neurotrophic-like activity appears to be one of the promising therapeutic approaches in treating neurodegenerative diseases. We are investigating the potential roles of SBP in inducing neuron differentiation, i.e., seeking possible application in neurodegenerative diseases

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