Location: Processed Foods Research
Title: Plasma and hepatic cholesterol-lowering in hamsters by tomato pomace, tomato seed oil and defatted tomato seed supplemented in high fat diets Authors
Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 15, 2013
Publication Date: May 1, 2013
Citation: Shao, D., Yokoyama, W.H., Bartley, G.E., Pan, Z., Zhang, H., Zhang, A. 2013. Plasma and hepatic cholesterol-lowering in hamsters by tomato pomace, tomato seed oil and defatted tomato seed supplemented in high fat diets. Food Chemistry. 139:589-596. Interpretive Summary: Tomato seeds and peels are byproducts of tomatoes processed for canning. They are potential sources of nutritional, health promoting ingredients. We found that the defatted tomato seed lowered plasma total and ldl cholesterol. These are considered risk factors for cardiovascular disease. The defatted tomato seed also lowered liver cholesterol and increased excretion of cholesterol and bile acids in the feces. Genes related to cholesterol metabolism in the liver were also analyzed.
Technical Abstract: We determined the cholesterol-lowering effects of tomato pomace (TP), a byproduct of tomato processing, and its components such as tomato seed oil (TSO) and defatted tomato seed (DTS) in hamsters, a widely used animal model for cholesterol metabolism. Male Syrian Golden hamsters were fed high-fat diets containing 8% butterfat, 10% corn oil, and 2% fish oil for 3 weeks. Hamsters fed a diet containing 10% TSO or 18% DTS were compared to a diet containing 10% corn oil and 10% microcrystalline cellulose (control 1), and hamsters fed 42% TP were compared to a diet containing 25% microcrystalline cellulose (control 2). All the tomato pomace byproducts reduced hepatic cholesterol content, and DTS also lowered plasma total (TC) and low-density lipoprotein cholesterol (LDL-C) concentrations. Fecal lipid, bile acid and cholesterol excretion increased in hamsters fed the DTS diet compared to control 1. DTS-fed hamsters had higher levels of hepatic CYP7A1, CYP51, ABCB11, and ABCG5 gene expression compared to the control, suggesting both hepatic bile acid and cholesterol synthesis increased due to increased fecal excretion of bile acids and cholesterol. Other hepatic genes relating to lipid metabolism were also modulated by DTS supplementation. The results show that DTS reduces plasma cholesterol and the fecal lipid analysis and hepatic gene expression results suggest that protein, dietary fiber or phenolic compounds in DTS may be responsible for plasma cholesterol decrease in the high-fat fed hamsters.