E and Platelet Aggregation

VITAMIN E AND PLATELET AGGREGATION a-Tocopherol, a natural antioxidant, inhibits platelet aggregation and release. The effect of vitamin E is dne to a redaction in platelet cyclooxygenase activity and inhibition of lipid peroxide formation. It is believed that snpplementing the diet with vitamin E could play a role in the treatment of thromboembolic disease, especially if it is given in conjnnc-tion with an inhibitor of platelet aggregation. 

Huijgens P, Vandenberg C, Imandt L, Langenhuisen M. Vitamin E and platelet-aggregation. Acta Haemologica 1981 65(3) 217-18. 

In 1990, Isono et al. reported the isolation of RK-286C (318) from the culture filtrate and the mycelium extract of Streptomyces sp. RK-286 (303). In nature, this isolate was obtained in its optically active form [a]p -I- 45.3 (c 0.22, EtOAc). Based on similar CD curves, the absolute configuration of this isolate was assigned to be similar to that of (-E)-staurosporine (295) (see Scheme 2.74) (284). RK-286C has shown PKC inhibitory activity and platelet aggregation in vitro, as well as weak antifungal activity (303). 

Wang, H. E, X. D. Li, Y. M. Chen, L. B. Yuan, and W. O. Foye. 1991. Radiation-protective and platelet aggregation inhibitory effects of five traditional Chinese drugs and acetylsalicylic acid following high-dose gamma-irradiation. J. Ethnopharmacol. 34 2-3, 215-219. 

Rajapakse, N., Jung, W. K., Mendis, E., Moon, S. H., and Kim, S. K. (2005a). A novel anticoagulant purified from fish protein hydrolysate inhibits factor XHa and platelet aggregation. Life Sci. 76, 2607-2619. 

Prostacyclin (PGI2) has remarkable antihypertensive and platelet aggregation inhibiting properties. This important compound has been synthesized from the 5,6-djdehydro-PGF2a derivative as outlined in Scheme 8 10b). The unique 2-alkylidenetetrahydrofuran structure is constructed with excellent stereoselectivity (Z E > 33 1) by cyclization of the ace-... 

Garlic is used for a variety of reasons, and some of the attributes associated with it, e.g. for cancer prevention, or to reduce heart attacks, may not be substantiated. Other properties such as antimicrobial activity, effects on lipid metabolism, and platelet aggregation inhibitory action have been demonstrated. Ajoene has been shown to be a potent antithrombotic agent through inhibition of platelet aggregation. 

Aviram, M. et al., Pomegranate juice consumption reduces oxidative stress, atherogenic modifications to LDL, and platelet aggregation studies in humans and in atherosclerotic apolipoprotein E-deficient mice. Am. J. Clin. Nutr., 71, 1062-1076, 2000. 

Allman et al. (1995) noted that platelet EPA levels were more than double for individuals fed flaxseed oil compared to sunflower oil group. Platelet EPArarachidonic acid ratio (i.e., marker for thromboxane production and platelet aggregation potential) increased in the flaxseed group, thus a protective effect against cardiovascular disease, over LA-rich oils, would be expected. Their findings support the decreased platelet aggregation observed in hyperlipidemic subjects fed flaxseed (Bierenbaum et al., 1993). 

More recent studies have shown that vitamin E also has roles in cell signaling, by inhibition or inactivation of protein kinase C, and in modulation of gene expression, inhibition of cell proliferation, and platelet aggregation. These effects are specific for a-tocopherol and are independent of the antioxidant properties of the vitamin. 

Liischer, E. F., Immune Complexes and Platelet Aggregation, Acta Med. 

Peerschke. E.I, Zudcer. M.B, Grant R.A, Egan. J.J and Johnson. M.M, Correlation between fibrinogen binding to human platelets and platelet aggregability. Blood, 55,841-847 (1980). 

Mbikay, M., Tadros, H., Ishida, N., Lemer, C.P., De Lamirande, E., Chen, A., El-Alfy, M., Clermont, Y., Seidah, N.G., Chretien, M., Gagnon, C., and Simpson, E.M. (1997). Impaired fertility in mice deficient for the testicular germ-cell protease PC4. Proc. Natl. Acad. Sci. USA 94 6842-6846. McDowell, R.S., Dennis, M., Louie, A., Shuster, M., Mulkerrin, M.G., and Lazarus, R.A. (1992). Mambin, a potent glycoprotein Ilb-IIIa antagonist and platelet aggregation inhibitor. Biochemistry 37 4766-4772. 

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