Effect of tomato extract supplementation against high-fat diet-induced hepatic lesions

Higher intake of tomatoes or tomato-based products has been associated with lower risk forliver cancer. In this study, we investigated the effects of supplementing tomato extract (TE), which containsmainly lycopene (LY) and less amounts of its precursors, phytoene (PT) and phytofluene (PTF) against highfat-diet related hepatic inflammation and lipid profiles, and carcinogenesis. Four groups of rats were injectedwith a hepatic carcinogen, diethylnitrosamine (DEN) and then fed either Lieber-DeCarli control diet (35%fat, CD) or high fat diet (71% fat, HFD) with or without TE supplementation for 6 weeks. Results showedthat the supplementation of TE significantly decreased the multiplicity of both inflammatory foci and alteredhepatic foci (AHF) expressing placental form glutathione-S transferase (p-GST) in the liver of HFD-fedrats. High-performance liquid chromatography (HPLC) analysis showed that TE supplementation resultsin a significantly higher accumulation of both PT and PTF than LY in livers of rats. In addition, the TEsupplementation led to a decrease of plasma cholesterol levels but an overall increase in hepatic lipids whichis associated with changes in the genes on lipid metabolism, including the peroxisome proliferator-activatedreceptor gamma (PPARγ) and the sterol-regulatory element binding protein (SREBP-1). These data suggest that TE supplementation decreases hepatic inflammation and plasma total cholesterol associated with highdietary fat intake. Moreover, TE supplementation results in an accumulation of hepatic PT and PTF as wellas increased lipogenesis suggesting further investigation into their biological function(s).