Biochanin A

The purpose of this study was to investigate the protective effects of biochanin A (BCA) on cardiac hypertrophy and to elucidate the underlying molecular mechanisms. The research question was whether BCA can reverse heart dysfunction and attenuate cardiomyocyte hypertrophy induced by pressure overload and AngII, respectively, and how it interacts with the NLRP3 pyroptosis pathway to achieve these effects.

We employed an animal model of pressure overload-induced cardiac hypertrophy and an in vitro model of AngII-induced cardiomyocyte hypertrophy to assess the effects of BCA. The expression of NLRP3 and its related signaling molecules was analyzed by western blotting, and the activity of the NLRP3 pathway was measured using pyroptosis assays. The role of Cbl-b, an E3 ubiquitin ligase, in BCA-mediated NLRP3 inhibition was also investigated.

BCA was found to reverse heart dysfunction and attenuate cardiomyocyte hypertrophy induced by pressure overload and AngII. Mechanistically, BCA mitigated cardiac hypertrophy by targeting the NLRP3 pyroptosis pathway. The reduction in NLRP3 expression by BCA was predominantly mediated through the upregulation of Cbl-b, which enhanced the ubiquitination and subsequent degradation of NLRP3. Additionally, BCA facilitated the upregulation of Cbl-b expression by interacting with NF-κB, preventing NF-κB binding to the promoter region of Cbl-b and reversing its suppressive action on Cbl-b expression.

This study provides initial evidence that BCA can protect against cardiac hypertrophy. Its mechanism of action involves interacting with NF-κB to promote the expression of Cbl-b, which facilitates the ubiquitination and degradation of NLRP3, ultimately inhibiting pyroptosis. This finding suggests that BCA may be a potential therapeutic agent for the treatment of cardiac hypertrophy.

Renal fibrosis driven by TGF‐β/Smad3 signaling is a critical factor in the advancement of chronic kidney disease, and partial epithelial‐to‐mesenchymal transition (EMT) in tubular cells plays a significant role in this process. In this study, we explored the reno‐protective role of biochanin A (BCA), a natural isoflavone, in mice with unilateral ureter obstruction (UUO) and in cultured renal tubular TCMK1 cells stimulated with the profibrotic cytokine TGF‐β1. Our results demonstrated that BCA (20 and 50 mg/kg) dose‐dependently ameliorated structural damage in UUO kidneys with reduced extracellular matrix deposition and downregulated levels of fibrotic genes Col1a1 , fibronectin , and α‐SMA . In vitro , BCA (5 and 10 μg/mL) also exhibited a dose‐dependent anti‐fibrosis effect in TCMK1 cells induced by TGF‐β1. Moreover, BCA prevented tubular partial EMT by mitigating the upregulation of mesenchymal marker genes N‐cadherin and vimentin in UUO kidneys and TGF‐β1‐induced TCMK1 cells. BCA treatment also reversed the reduced staining of Lotus Tetragonolobus Lectin and peanut agglutinin, two markers of mature renal tubular epithelia, in UUO kidneys. Mechanistically, BCA inhibited Smad2 and Smad3 phosphorylation and specifically downregulated Smad3 protein expression, without affecting Smad2, in TGF‐β1‐stimulated TCMK1 cells. Most importantly, in TGF‐β1‐treated TCMK1 cells, Smad3 overexpression abolished the anti‐fibrosis and anti‐EMT effects of BCA. In conclusion, our findings demonstrate the potential of BCA as a therapeutic agent against renal fibrosis by inhibiting TGF‐β/Smad3 signaling‐mediated tubular partial EMT.