Silibinin Reduces the Impact of Obesity on Invasive Liver Cancer

Obesity is associated with non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). Obesity and metabolic abnormalities resulting in low-grade inflammation can increase the risk of developing NASH and HCC. NASH, a risk factor for HCC, is characterized by increased inflammation, lipid accumulation, and liver injury. Obesogenic proteins modulate signaling pathways that induce physiological changes including lipogenesis, ROS, and inflammation. Silibinin, a polyphenol in milk thistle seed, has been shown to have anti-inflammatory properties. Studies have yet to determine whether silibinin can be used to dissect the obesity-cancer link to delay progression of liver cancer. Using an in vitro model, sera from obese (OB), overweight (OW), or normal weight (NW) males (based on BMI) were used to determine the efficacy of silibinin to reduce the pro-tumorigenic properties of obesity. HepG2 cells were exposed to OB, OW, NW ± silibinin and tested for growth, ROS, lipogenesis, MMP-9, invasion and protein expression. Silibinin suppressed obesity-induced growth, ROS, lipogenesis, MMP-9, and cell invasion. These physiological changes corresponded with decreased FASN, IL-6, IL-1B, and phosphorylated Erk. We describe the differential effect of sera from OB, OW, and NW males on characteristics relevant for liver cancer and the potential use of silibinin to mitigate these effects.