Soy Protein Isolate Mediated the Wnt/ β‐Catenin Signaling Pathway and Alleviated Fat Accumulation in the Liver of Obese Zucker Rats

Abstract

Excessive fat accumulation in liver can lead to chronic liver diseases. Managing this situation in obese population is critical to the improvement of overall health. Dietary soy protein isolate (SPI) possess beneficial effects of anti‐obesity. Wnt/β‐Catenin pathway, a crucial mediator of adipogenesis, was repressed by obesity. However, the interaction between SPI and Wnt/β‐Catenin in the obese population is elusive. The current study aimed to investigate the dietary effects of SPI on Wnt/β‐Catenin in the liver of obese rats. Obese Zucker rats were fed with isocaloric diets containing SPI or casein for 17 weeks. Lean rats were included as the reference group. Histology analysis of the liver demonstrated structural change and difference in fat content by dietary treatments. Triglyceride (TAG) and non‐esterified fatty acid (NEFA) contents were significantly lower in the liver of SPI‐fed obese rats compared with casein‐fed obese rats. SREBP1‐c gene expression was also reduced by SPI treatment indicating reduced fat synthesis. β‐Catenin protein abundance in the liver was upregulated in obese rats by SPI comparing to casein. In vitro cell culture studies further confirmed the interaction between fat accumulation and Wnt/β‐Catenin signaling. Taken together, our results suggested that SPI restored the Wnt/β‐Catenin signaling pathway and alleviated the fat accumulation in the liver of obese rats.