Research Article: Biochanin A attenuates myocardial ischemia/reperfusion injury through the TLR4/NF-κB/NLRP3 signaling pathway1

Date Published: December 20, 2019

Publisher: Sociedade Brasileira para o Desenvolvimento da Pesquisa em

Author(s): Yejun Bai, Zhigang Li, Weihao Liu, Dong Gao, Min Liu, Peiying Zhang.


Myocardial ischemia/reperfusion (Ml/R) injury is a leading cause of damage in
cardiac tissues, with high rates of mortality and disability. Biochanin A
(BCA) is a main constituent of Trifolium pratense L. This study was intended
to explore the effect of BCA on Ml/R injury and explore the potential

In vivo MI/R injury was established by transient coronary
ligation in Sprague-Dawley rats. Triphenyltetrazolium chloride staining
(TTC) was used to measure myocardial infarct size. ELISA assay was employed
to evaluate the levels of myocardial enzyme and inflammatory cytokines.
Western blot assay was conducted to detect related protein levels in
myocardial tissues.

BCA significantly ameliorated myocardial infarction area, reduced the release
of myocardial enzyme levels including aspartate transaminase (AST), creatine
kinase (CK-MB) and lactic dehydrogenase (LDH). It also decreased the
production of inflammatory cytokines (IL-1β, IL-18, IL-6 and TNF-α) in serum
of Ml/R rats. Further mechanism studies demonstrated that BCA inhibited
inflammatory reaction through blocking TLR4/NF-kB/NLRP3 signaling

The present study is the first evidence demonstrating that BCA attenuated
Ml/R injury through suppressing TLR4/NF-kB/NLRP3 signaling pathway-mediated
anti-inflammation pathway.

Partial Text

Myocardial ischemia-reperfusion (MI/R) injury refers to the aggravation of myocardial
tissue injury or even permanent irreversible injury after blood flow is resupplied
due to myocardial ischemia injury1. It has become one of the cardiovascular diseases with the highest morbidity
and mortality in developed and developing countries2. Since MI/R injury was firstly reported by Jennings, it has been a research
hotspot in cardiovascular diseases3. Despite the achievement in new treatments (thrombolysis, percutaneous
revascularization4, percutaneous coronary intervention, bypass, etc.), there is still no way to
completely prevent the additional damage caused by reperfusion itself. Basic studies
have found that the pathological mechanism of MI/R is aerobic free radical injury,
intracellular pH change, calcium overload, inflammatory factor infiltration, etc. In
addition, other factors include immune imbalance, endoplasmic reticulum stress,
apoptosis and autophagy, myocardial energy metabolism disorder, myocardial
microvascular endothelial cell injury and so on.

All procedures were performed in accordance with the Guide for the Care and Use of
Laboratory Animals published by the U.S. National Institutes of Health (NIH
publication NO. 85-23, revised in 1996). The protocol was reviewed and approved by
the Ethics Committee (Protocol number: SCXK (SU) 2016-0004).

With the development of social economy and improvement of living standards, the risk
factors of cardiovascular disease are increasing. Tissue damage caused by myocardial
ischemia is an important cause of fatal diseases and is common in clinical practice.
The pathophysiological process of myocardial I/R injury involves multiple
mechanisms: inflammation, reactive oxygen species production, apoptosis,
mitochondrial dysfunction, intracellular calcium overload, etc26–28. Therefore, exploring the complex pathological mechanism of reperfusion
injury is expected to provide a promising therapeutic strategy for the treatment of
MI/R injury.

Overall, the present study is the first evidence confirming the protective role of
BCA in MI/R injury. More importantly, the TLR4/NF-κB/NLRP3 mediated inflammatory
pathway might be served as the potential mechanism. Further detailed research is
needed to explore the clinical application of BCA.