benzofurans and cholesteryl-ester-hydroperoxide

4,6-Di-tert-butyl-2,3-dihydro-2,2-dipentyl-5-benzofuranol (BO-653) is a novel antioxidant synthesized by theoretical findings and considerations. Here we report on the aqueous peroxyl radical-induced oxidation of human plasma in the presence of BO-653. When BO-653 was given to healthy human subjects at 400 mg twice daily for 28 days, lipids in the resulting plasma were protected from oxidation compared with lipids present in plasma from subjects receiving placebo. Similarly, BO-653 added in vitro at 50 muM inhibited the peroxyl radical-induced accumulation of cholesteryl ester hydroperoxides that occurred in the presence of alpha-tocopherol, although BO-653 did not decrease the rate of consumption of ascorbate, albumin-bound bilirubin, and uric acid. The antioxidant action of in vivo and in vitro added BO-653 was associated with the formation of two major reaction products of BO-653, the structures of which were elucidated by mass spectrometry and nuclear magnetic resonance analyses. The products were identified as stereoisomers of dioxybis(4,6-di-tert.-butyl-2,3,5,7a-tetrahydro-2,2-dipentylbenzofuran-5-one). These dialkylperoxides of BO-653 might be useful markers to assess the antioxidant function of BO-653 in biological systems in vivo.

Topics: Albumins; alpha-Tocopherol; Antioxidants; Ascorbic Acid; Benzofurans; Bilirubin; Cholesterol Esters; Humans; Lipid Metabolism; Lipid Peroxidation; Oxidation-Reduction; Peroxides; Plasma; Stereoisomerism; Uric Acid

The effects of salvianolic acid B (Sal B) decoction on antioxidative activities were evaluated. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, Fe(2+)-chelating activity, reducing power, and total phenolic content of the Sal B-decocted solutions did not change significantly after decoction in an aqueous solution. However, the formation of cholesteryl ester hydroperoxide (CE-OOH) in rat blood plasma containing the Sal B-decocted solutions was more effectively inhibited than that of plasma containing the Sal B solution, regardless of the decoction time. In addition, the accumulation of CE-OOH in rat plasma after oral administration of the Sal B-decocted solutions was more effectively suppressed than when the Sal B solution was administered, considering the lag time. It is likely that the decoction was partly responsible for the increased antioxidant activity in blood plasma. Therefore, the Sal B-decocted solution may contribute more to antioxidant defense in blood than a Sal B solution that is not decocted.

Topics: Administration, Oral; Animals; Antioxidants; Benzofurans; Biphenyl Compounds; Chelating Agents; Cholesterol Esters; Copper; Ions; Male; Oxidation-Reduction; Phenols; Picrates; Plant Extracts; Plant Preparations; Rats; Rats, Sprague-Dawley; Salvia