Puerarin-Tanshinone IIA Suppresses atherosclerosis inflammatory plaque via targeting succinate/HIF-1α/IL-1β axis

Abstract

Ethnopharmacological relevance: Inflammatory injury is an important pathological factor for the formation of atherosclerotic plaque. It is well known that Puerarin and Tanshinone IIA (Pue-Tan) can significantly reduce interleukin-1β (IL-1β) levels and delay the atherosclerosis (AS) process clinically in China. Previous evidence has shown that the Succinate/HIF-1α/IL-1β inflammatory signaling axis (Succinate axis) promotes the progression of atherosclerotic inflammatory plaques. It is not clear whether Pue-Tan inhibits inflammatory plaques by reducing the level of IL-1β through the succinate signaling axis.

Aim of study: Find out the interaction between Pue-Tan targets and the succinate axis by means of network pharmacology and bioinformatics analysis and to further confirm whether Pue-Tan can inhibit vascular inflammation and delay the formation of atherosclerotic inflammatory plaques by targeting the succinate signaling axis.

Materials and methods: Firstly, animal experiments were conducted to verify the changing relationship between Succinate and IL-1β under Pue-Tan intervention. Secondly, network pharmacology approach was employed to uncover the specific targets of Pue-Tan in the intervention of AS from multiple levels of components, proteins, and pathways, and at the same time, the target must be a key factor of the succinate signaling axis. Autodock vina1.5.6 was applied to molecular docking for Pue-Tan and target protein. Subsequently, cells experiment and animal experiment were performed to verify Pue-Tan inhibiting the inflammatory progression of atherosclerosis by targeting succinate signaling axis.

Results: Firstly, we first found that the reduction of IL-1β was positively correlated with succinate in the serum of Pue-Tan-treated mice. Secondly, network pharmacology compared with molecular docking showed that hypoxia-induced factor-1α (HIF-1α) was the key target of Pue-Tan and the key node of succinate singling axis. Finally, in vitro study, Pue-Tan significantly reduced the factors of succinate axis just as HIF-1α siRNA; in vivo study, we confirmed a decreased expression of succinate axis and ICAM-1 in the aorta of ApoE^-/- mice under Pue-Tan intervention, which was consistent with the in vitro results.

Conclusion: This study confirmed that Pue-Tan blocked the succinate axis by targeting HIF-1α to prevent the formation of atherosclerotic inflammatory plaques and delay the pathological process of AS. Network Pharmacology, Bioinformatics of Molecular Docking, and Molecular Biology Validation can be used as a effective way to discover and verify the pharmacological mechanism of TCM.

Keywords: Atherosclerosis; Inflammatory plaque; Macrophages; Network pharmacology; Puerarin and tanshinone IIA (Pue-tan); Succinate/HIF-1α/IL-1β axis.