The Role of Berberine in the Prevention of HIF-1α Activation to Alleviate Adipose Tissue Fibrosis in High-Fat-Diet-Induced Obese Mice

Berberine (BBR) is the main active ingredient of a traditional Chinese herb Coptis chinensis. It has been reported to exhibit beneficial effects in treating diabetes and obesity. However, the underlying mechanism has not been fully elucidated. Adipose tissue fibrosis is a hallmark of obesity-associated adipose tissue dysfunction. HIF-1α plays a key role in adipose tissue fibrosis, which closely linked to metabolic dysfunction in obese state. We hypothesized that BBR may alleviate obesity-induced adipose tissue fibrosis and associated metabolic dysfunction through inhibition of HIF-1α. To test this hypothesis, we treated high fat diet (HFD) feeding mice with different dose of BBR (100 mg/kg, 200 mg/kg, and 300 mg/kg) for 8 weeks. We found that BBR treatment greatly decreased the body weight gain and reduced insulin resistance induced by HFD. Data also revealed that BBR improved histologic fibrous of epididymal white adipose tissue (eWAT) and was accompanied with inhibition of the abnormal synthesis and deposition of extracellular matrix (ECM) proteins, such as collagen and fibronectin. We also found that BBR treatment suppressed the expression of HIF-1α and decreased the mRNA expression of LOX in epididymal adipose tissue, which plays a key role in fibrosis development. Taken together, these results suggest that BBR can regulate metabolic homeostasis and suppress adipose tissue fibrosis through inhibiting the expression of HIF-1α.