Dietary Oyster-Extract Decreases Cholesterol Content by Suppressing hepatic HMG-CoA Reductase mRNA Expression Level and Enhancing Fecal Steroids Excretions in Rats Fed High-Fat Diet

Abstract

This study demonstrated the effect of oyster-extract on hepatic lipid accumulation and cholesterol metabolism in rats fed high-fat diet. Male Wistar rats were divided into two groups and fed an AIN-93G modified high-fat diet (control diet) and 5% (w/w) oyster-extract containing diet (OE diet) for four weeks. Cholesterol metabolism was measured through serum and liver cholesterol contents, fecal neutral and acidic steroids excretions, and hepatic mRNA expression levels of enzymes and nuclear receptors involved in cholesterol homeostasis. Dietary oyster-extract decreased hepatic cholesterol contents, perhaps through increasing fecal neutral and acidic steroids excretions and decreasing hepatic 3-hydroxy-3methylglutaryl-coenzyme A reductase (HMGCR) and acyl-coenzyme A:cholesterol acyltransferase-1 expression levels. In addition, the suppression of HMGCR expression in the liver could be through the reduction of sterol regulatory element binding factor-2 pathway due to oyster-extract intake. This study found that dietary administration of oyster-extract has hypocholesterolemic effects that may help prevent nonalcoholic fatty liver disease.