Effects of Long-term High-Ergosterol Intake on the Cholesterol and Vitamin D Biosynthetic Pathways of Rats Fed a High-Fat and High-Sucrose Diet.

Dyslipidemia is a lifestyle-related (physical inactivity or obesity) disease; therefore, dietary foods that can easily be consumed in daily life is important to prevent dyslipidemia. Ergosterol, a precursor of vitamin D2 , is a fungal sterol present in the membranes of edible mushrooms and other fungi. Ergosterol is converted to brassicasterol by 7-dehydrocholesterol reductase (DHCR7), a cholesterol biosynthesis enzyme that converts 7-dehydrocholesterol (a precursor of vitamin D3 ) into cholesterol. Previously, we reported that ergosterol increases 7-dehydrocholesterol, decreases cholesterol levels by competitive effect of DHCR7, and reduces DHCR7 mRNA and protein levels in human HepG2 hepatoma cells. Here, we investigated the effects of long-term high ergosterol intake on the cholesterol, vitamin D2 , and D3 biosynthetic pathways of rats fed a high-fat and high-sucrose (HFHS) diet using gas chromatography-mass spectrometry and liquid chromatography with tandem mass spectrometry. In HFHS rats, oral ergosterol administration for 14 weeks significantly decreased plasma low-density lipoprotein cholesterol, total bile acid, and cholesterol precursor (squalene and desmosterol) levels and increased 7-dehydrocholesterol levels compared to HFHS rats without ergosterol. Ergosterol, brassicasterol, and vitamin D2 were detected, cholesterol levels were slightly decreased, and levels of vitamin D3 and its metabolites were slightly increased in rats fed HFHS with ergosterol. These results showed that ergosterol increased vitamin D2 levels, inhibited the cholesterol biosynthetic pathway, and possibly promoted vitamin D3 biosynthesis in vivo. Therefore, daily ergosterol intake may aid in the prevention of dyslipidemia.