Study on the underlying mechanism of Poria in intervention of arrhythmia zebrafish by integrating metabolomics and network pharmacology.

BACKGROUND: Poria is an herb with both medicinal and dietary application. It has been used in various traditional Chinese patent medicines and medicinal decoctions for the treatment of arrhythmia. However, the specific mechanisms involved in the antiarrhythmic effects of Poria have, until now, remained unknown.

PURPOSE: This present study sought to explore the potential compounds and mechanisms by which Poria ameliorates BaCl2 -induced arrhythmia.

METHOD: We initiated by using network pharmacology to predict probable components, targets, and associated signaling pathways before optimizing the extraction process of Poria. We then applied Poria extract to a zebrafish model of BaCl2 -induced arrhythmia. We combined network pharmacology and untargeted metabolomic analysis to predict the likely signaling and metabolic pathways governed by Poria. Finally, we verified putative mRNA and metabolite targets of Poria involved in the intervention of arrhythmia by PCR, molecular docking, enzymatic inhibition and targeted metabolomics.

RESULTS: We found that triterpenoids may be the main components of Poria responsible for its effects on arrhythmia, and that the optimal extraction process for its water extract is 9 volumes of water with the 7.5 h first extraction period, and the second extraction period of 1.5 h. Through experimentation, we have found that the water extract of Poria can interfere with BaCl2 induced arrhythmia in zebrafish by significantly increasing the heart rate, reducing the SV-BA distance, and pericardial area, and the degree of cardiomyocyte apoptosis in zebrafish. In addition, PCR validation revealed that Poria can regulate the calcium signaling pathway by upregulating the gene expression levels of ADRB1, HTR7, CALMB1, and PPP3CA. Meanwhile, through molecular docking and enzyme activity inhibition, it was found that the compounds in Poria can bind to ADRB1, HTR7, CALMB1, and PPP3CA, respectively. Targeted metabolism confirmed that Poria can downregulate the synthesis of cAMP in the calcium signaling pathway, as well as the synthesis of valine and isoleucine in valine, leucine, and isoleucine biosynthesis.

CONCLUSION: Overall, our study indicates that Poria exerts its antiarrhythmic effect through regulating the calcium signaling pathway and valine, leucine, and isoleucine biosynthesis. Our findings not only establish a mechanistic framework for elucidating the antiarrhythmic effects of Chinese patent medicine containing Poria, but also provide a medicinal basis for the study of its dual use as medicine and food.