The Inhibition of Pparα Protein Degradation Alleviates the Cardiotoxicity of Tiebangchui by Regulating Fatty Acid Metabolism

Abstract

Ethnopharmacological relevanceTiebangchui (TBC) is a traditional Tibetan medicine that is commonly used to relieve pain and inflammation in China. Nevertheless, the poisoning incidents of TBC have often been reported in clinical application, which severely limits the use of TBC. Therefore, the cardiotoxicity mechanism of TBC and the way of toxicity reduction need to be explored deeply, which are of great significance for clinical safety and reasonable medication.Aim of the studyThe aim of this study was to explore the cardiotoxicity mechanism of TBC.MethodsIn this study, the cardiotoxicity of TBC or its main components (aconitine, 3-deoxyaconitine) on zebrafish and H9c2 cells were evaluated. And potential cardiotoxicity mechanism was screened by transcriptomics technology. Lipid levels and ATP content was determined by biochemical kit or staining. Subsequently, qRT-PCR, Western blot and immunofluorescence were used to detect the expression level of relevant targets. Molecular docking and cell thermal shift assay (CETSA) were used to determine the molecular binding capability between drugs and PPAR-α. Furthermore, we investigated the protective effect of PPARα agonist (WY14643) on the cardiotoxicity induced by Deo and Aco in zebrafish and H9c2 cells.ResultsTBC and its main toxic components can cause cardiac function disorder and cardiac damage in zebrafish. Meantime, they can induce the apoptosis of cardiac cells, increase the accumulation of lipid and energy deficit in vivo and in vitro. Further mechanism studies showed that the main toxic components can promote fatty acid absorption and inhibit fatty acid oxidation, thus resulting in lipid toxicity and insufficient energy production. Moreover, we found that aconitine and 3-deoxyaconitine can directly bind with PPARα protein to accelerate its degradation, and the cardiotoxicity induced by aconitine and 3-deoxyaconitine was significantly alleviated under the co-treatment of PPARα agonist (WY14643) in zebrafish and H9c2 cells.ConclusionTBC can induce cardiotoxicity by impairing fatty acid metabolism through accelerating PPARα degradation.

Keywords: Tiebangchui, Cardiotoxicity, Fatty acid metabolism, PPARα