Effect of Danshen on TLR2-triggered inflammation in macrophages

Tingting Ye; Difeifei Xiong; Libing Chen; Yufei Li; Shuqing Gong; Luquan Zhang; Bailing Li; Jianyang Pan; Jing Qian; Haibin Qu

doi:10.1016/j.phymed.2020.153228

Effect of Danshen on TLR2-triggered inflammation in macrophages

Phytomedicine. 2020 Apr 20:70:153228. doi: 10.1016/j.phymed.2020.153228. Online ahead of print.

Authors

Affiliations

¹ Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.
² Guizhou Baite Pharmaceutical co., Ltd., Guizhou, China.
³ Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China. Electronic address: jingqian@zju.edu.cn.

PMID: 32361291
DOI: 10.1016/j.phymed.2020.153228

Abstract

Background: Danshen (Salvia Miltiorrhiza Radix et Rhizoma) is a valued herbal plant widely used to treat cardiovascular diseases in Asian countries. In modern medicine, innate immunity-induced inflammation is considered a risk factor for cardiovascular diseases. However, little is known about the anti-inflammatory effects and molecular mechanism of Danshen.

Purpose: To evaluate the molecular mechanisms of Danshen on Toll-like receptor (TLR) 2-triggered inflammation in macrophages and identify its bioactive components.

Methods: Pam3CSK4-stimulated bone marrow-derived macrophages (BMMs) were treated with Danshen water extract (DSE), and the levels of proinflammatory cytokines (interleukin (IL)-6, IL-12 and tumor necrosis factor (TNF)-α) were measured by both real-time quantitative PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA). RNA sequencing (RNA-seq)-based bioinformatics analyses were applied to reveal the novel molecular mechanisms of DSE, followed by western blotting for verification. Additionally, HPLC-UV analysis along with bioassays was performed to identify the bioactive ingredients of DSE.

Results: The results of RT-qPCR and ELISA showed that DSE significantly inhibited proinflammatory cytokine expression in a dose-dependent manner. Transcriptome analyses revealed that a wider panel of inflammatory cytokines responded to the regulatory effect of DSE, and that the TNF signaling pathway might have played a vital role. Western blotting data confirmed the involvement of extracellular signal-regulated protein kinases (ERK) and Jun N-terminal Kinase (JNK) related singling pathway. Among the seven components identified in DSE, Danshensu (DSS) and protocatechuic aldehyde (PA) were confirmed as bioactive ones with anti-inflammatory effects.

Conclusion: DSE showed a promising effect against TLR2-triggered inflammation associated with the inhibition of the TNF cascade down-streamed mitogen-activated protein kinase (MAPK) signaling pathway, in which IL-6 acts as the key effective molecule, and ERK and JNK phosphorylation was inhibited. Notably, DSS and PA were considered bioactive components with anti-inflammatory bioactivity.

Keywords: Danshen; IL-6; Inflammation; RNA-SEQ; Tnf signaling pathway.