Metabolism of Orally Adiministered Ergosterol and 7-Dehydrocholesterol in Rats and Lack of Evidence for Their Vitamin D Biological Activity.

Abstract

SummaryMetabolism of orally administered ergosterol (Erg) and 7 -dehydrocholesterol (7-DHC) in rats and their vitamin D biological ac tivity were investigated. Most of orally administered Erg and 7-DHC were excreted in feces and the remaining sterols were absorbed through intestine. The absorbed sterols were not transported in skin as the intact forms but metabolized into brassicasterol and cholesterol, respectively, within 25h. Neither increment of intestinal calcium absorption nor plasma calcium concentrations were observed by oral administration of Erg and 7-DHC to vitamin D-deficient rats. Therefore, we have con cluded that orally administered Erg and 7-DHC have no vitamin D biological activity. Key Words vitamin D2, vitamin D3, provitamin D2, provitamin D3, ergosterol, 7-dehydrocholesterol, intestinal calcium absorption, bone calcium rbsorption, gas chromatography-mass spectrometry It is well known that ultraviolet (UV) irradiation of ergosterol (Erg) and 7 -dehydrocholesterol (7-DHC) in a solution state gives the respective vitamins D, vitamins D2 (ergocalciferol) and D3 (cholecalciferol), via previtamins D2 and D3 by photochemical and thermal isomerization (1). Therefore, the sterols are designated as provitamins D2 and D3, respectively. On the other hand, significant amounts of 7-DHC exist as an intermediate of cholesterol biosynthesis from acetyl CoA in skin of mammals (2, 3) and the endogenous 7-DHC can be also coverted into vitamin D3 by UV exposure of the skin in the same manner as in a test tube (4, 5) . The vitamin D3 endogenously formed in the skin is absorbed in blood and metabolized to 25

Vitamin D3 and Its Metabolites Have No Role in Calcium and Phosphorus Metabolism in Tilapia mossambica.

“…Our earlier studies in Rora (Labeo rohita) have shown that fish deficient in vitamin D (vitamin D-deficiency was judged by the absence of any detectable vitamin D in the liver of fish, grown in darkness and fed a diet devoid of vitamin D for six months) showed no significant differences in the vitamin D-related (bone and carcass mineral stores) and growth (carcass protein and lipid, hepatosomatic index, feed efficiency, and mortality rates) parameters when compared with the controls fed vitamin D3, suggesting that this vitamin may not be an essential nutrient for fishes (27). This observation is contrary to similar studies in terrestrial verte brates, where decreased calcification of bone and hypocalcemia is the classical manifestation of vitamin D deficiency (28)(29)(30).…”

5.ALPHA.,8.ALPHA.-Epidioxy-22E-ergosta-6,9(11),22-trien-3.BETA.-ol from an Edible Mushroom Suppresses Growth of HL60 Leukemia and HT29 Colon Adenocarcinoma Cells

“…23) Therefore, orally consumed ergosterol derivative 9(11)-DHEP would most likely impact on colon cancer, which is known to be related to diet. Therefore, we investigated the effect of 9(11)-DHEP on the growth of HT29 human colon adenocarcinoma cells.…”

Transformation of Ergosterol Peroxide to Cytotoxic Substances by Rat Intestinal Bacteria

“…37) Kobori et al suggested that orally administered EPO in edible mushrooms might have a protective effect against colon cancer, and reported it possesses a suppressive effect against HT-29, CACO-2 human colorectal cancer cell lines, including the action mechanism.…”