morin and Arteriosclerosis

In vitro studies have demonstrated increased atherogenicity of oxidized low-density lipoprotein (ox-LDL) compared to native LDL. Oxidative modification of LDL alters its structure allowing LDL to be taken up by scavenger receptors on macrophage, endothelial, and smooth muscle cells, leading to the formation of lipid-laden foam cells, the hallmark of early atherosclerotic lesions. The susceptibility of LDL to in vitro oxidation was assessed essentially by the technique described by Esterbauer et al. LDL oxidation were monitored by change in 234-absorbance in the presence and absence of pure flavonoids. Morin, genistein, apigenin and biochanin A, naringin and quercetin were used at different concentration. These flavonoids significantly inhibit in vitro LDL oxidation, genistein, morin and naringin have stronger inhibitory activity against LDL oxidation than biochanin A or apigenin. This study show that flavonoids prevent in vitro LDL oxidation and probably would be important to prevent atherosclerosis.

Topics: Antioxidants; Apigenin; Arteriosclerosis; Flavonoids; Genistein; Humans; In Vitro Techniques; Lipoproteins, LDL; Oxidation-Reduction

Dietary flavonoid intake has been reported to be inversely associated with the incidence of coronary artery disease. To clarify the possible role of flavonoids in the prevention of atherosclerosis, we investigated the effects of some of these compounds on the susceptibility of low-density lipoprotein (LDL) to oxidative modification. In this study, six flavonoids, "apigenin, genistein, morin, naringin, pelargonidin and quercetin", were added to plasma and incubated for 3h at 37 degrees C. Then, the LDL fraction was separated by ultracentrifugation. The oxidizability of LDL was estimated by measuring conjugated diene (CD), lipid peroxides and thiobarbituric acid-reactive substances (TBARS) after cupric sulfate solution was added. We showed that among flavonoids used, quercetin and morin significantly (P<0.01 by ANOVA) and dose-dependently prolonged the lag time before initiation of oxidation reaction. Also, these two flavonoids suppressed the formation of lipid peroxides and TBARS more markedly than others. Their ability to prolong lag time and suppression of lipid peroxides and TBARS formation resulted to be in the following order: quercetin>morin>pelargonidin>genistein>naringin>apigenin. LDL exposed to flavonoids in vitro reduced oxidizability. These findings show that flavonoids may have a role in ameliorating atherosclerosis.

Topics: Anthocyanins; Apigenin; Arteriosclerosis; Catechin; Flavanones; Flavonoids; Genistein; Humans; Lipid Peroxides; Lipoproteins, LDL; Oxidation-Reduction; Quercetin; Thiobarbituric Acid Reactive Substances