cytellin and erucic-acid

Plant stanols lower intestinal cholesterol absorption. This causes a decrease in serum low-density lipoprotein (LDL)-cholesterol, despite a compensatory increase in cholesterol synthesis. We therefore hypothesized that plant stanols also change LDL-cholesterol-standardized concentrations of ubiquinol-10 (a side product of the cholesterol synthesis cascade) and of those fat-soluble antioxidants that are mainly carried by LDL. To examine this, 112 nonhypercholesterolemic subjects consumed low erucic acid rapeseed oil (LEAR)-based margarine and shortening for 4 weeks. For the next 8 weeks, 42 subjects consumed the same products, while the other subjects received products with vegetable oil-based stanols (2.6 g sitostanol plus 1.2 g campestanol daily, n = 36) or wood-based stanols (3.7 g sitostanol plus 0.3 g campestanol daily, n = 34). Consumption of both plant stanol ester mixtures increased cholesterol synthesis and lowered cholesterol absorption, as indicated by increased serum cholesterol-standardized lathosterol and decreased plant sterol concentrations, respectively. Compared with the control group, absolute plasma ubiquinol-10 concentrations were lowered by 12.3% +/- 18.9% (-0.14 microg/mL v. the control group; P =.004; 95% confidence interval [CI] for the difference in changes, -0.05 to -0.22 microg/mL) in the vegetable oil-based group and by 15.4% +/- 13.0% (-0.17 microg/mL v. the control group; P <.001; 95% CI for the difference, -0.08 to -0.27 microg/mL) in the wood-based group. Changes in LDL-cholesterol-standardized ubiquinol-10 concentrations were not significantly changed. The most lipophylic antioxidants, the hydrocarbon carotenoids (beta-carotene, alpha-carotene, and lycopene), decreased most, followed by the less lipophylic oxygenated carotenoids (lutein/zeaxanthin and beta-cryptoxanthin) and the tocopherols. These reductions were related to the reduction in LDL, which carry most of these antioxidants. The decrease in the hydrocarbon carotenoids, however, was also significantly associated with a decrease in cholesterol absorption. LDL-cholesterol-standardized antioxidant concentrations were not changed, except for beta-carotene, which was still, although not significantly, lowered by about 10%. We conclude that the increase in endogenous cholesterol synthesis during plant stanol ester consumption does not result in increased LDL-cholesterol-standardized concentrations of ubiquinol-10, a side product of the cholesterol synthesis cascade. Fur

Topics: Absorption; Adolescent; Adult; Antioxidants; Carotenoids; Cholesterol; Cholesterol, LDL; Diet; Erucic Acids; Fats; Fatty Acids, Monounsaturated; Female; Humans; Male; Margarine; Middle Aged; Phytosterols; Plant Oils; Plants, Edible; Rapeseed Oil; Sitosterols; Solubility; Ubiquinone; Vitamin A; Vitamin E; Wood

Studies on the whole herb of Urtica dioica L. grown in Nyingchi area, China's Tibet Autonomous Region, resulted in the isolated of nine compounds: beta-sitosterol, trans-ferulic acid, dotriacotane, erucic acid, ursolic acid, scopoletin, rutin, quercetin and p-hydroxylbenzalcohol. Dotriacotane, erucic acid, scopoletin, rutin and p-hydroxylbenzalcohol were obtained from Urtica L. for the first time. Their structures were confirmed by modem spectral analysis (NMR, MS, etc).

Topics: Erucic Acids; Molecular Structure; Plants, Medicinal; Quercetin; Rutin; Scopoletin; Sitosterols; Tibet; Triterpenes; Ursolic Acid; Urtica dioica