Cholesterol docosahexaenoic acid

Hashimoto M., Hossain S., Agdul H., and Shido O. (2005). Docosahexaenoic acid-induced amelioration on impairment of memory learning in amyloid /i-inluscd rats relates to the decreases of amyloid fi and cholesterol levels in detergent-insoluble membrane fractions. Biochim. Biophys. Acta Mol. Cell Biol. Lipids 1738 91-98. 

Fish is the most important source of the n-3-PUFAs Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and populations consuming fish have lower heart rates. Other important parameters reported were lower blood pressure and higher HDL cholesterol. The strongest evidence for an effect of n-3-fatty acids on disease is the inverse relationship between diet, blood, and tissue levels and coronary heart disease. n-3-PUFAs prevent heart disease by preventing arrhythmias, generating prostanoids and leukotrienes with anti-inflammatory actions, and inhibiting synthesis of cytokines and mitogens that provoke inflammation and promote plaque formation. ... 

Fish oil supplements (SEDA-13, 460) (SEDA-18, 3), rich in long-chain polyunsaturated ( -3 fatty acids (eicosa-pentaenoic acid, docosahexaenoic acid), can reduce plasma concentrations of triglycerides and VLDL cholesterol, reduce platelet aggregation, prolong bleeding time, reduce blood pressure, increase the fluidity of the blood, and affect leukotriene production. Reported adverse effects include fullness and epigastric discomfort, diarrhea, and a fishy taste after belching. In addition to these mild symptoms, certain areas have been identified in which problems of a more serious nature could arise ... 

Huster D, Ar nold K, Gawrisch K. Influence of docosahexaenoic acid and cholesterol on lateral Upid organization in phospholipid mixtures. Biochemistry 1998 37 17,299-17,308. 

Parks JS, Thuren TY, Schmitt JD. Inhibition of lecithin cholesterol acyltransferase activity by synthetic phosphatidylcholine species containing eicosapentaenoic acid or docosahexaenoic acid in the sn-2 position. J Lipid Res 1992 33 879-887. 

The mechanism by which n-3 fatly acids are able to reduce the cholesterol level is still unclear, although some hypotheses have been advanced. For example, Bourre (1991) claimed that a-linolenic acid controls the composition of nerve membranes. Salem (1995) proposed that docosahexaenoic acid [DHA or (22 6n-3)] controls the composition and functions of the neuronal membrane. We recently reviewed a number of studies that provided support for apreferred n-3/n-6 ratio of 1 4 (Yehuda, et al., 1993). Itis possible that such a ratio optimizes uptake into the brain and its eventual incorporation into the neuronal membranes. 

Dietary intake of n-6 fatty acids such as linoleic acid, and n-3 fatty acids, such as the fish oils eicosapentanoic acid and docosahexaenoic acid, lowers plasma cholesterol and antagonizes platelet activation, but the fish oils are much more potent in this regard [26]. In particular, n-3 fatty acids competitively inhibit thromboxane synthesis in platelets but not prostacyclin synthesis in endothelial cells. These fatty acids have also been shown to have other potentially anti-atherogenic effects, such as inhibition of monocyte cytokine synthesis, smooth muscle cell proliferation, and monocyte adhesion to endothelial cells. While dietary intake of n-3 fatty acid-rich fish oils appears to be atheroprotective, human and animal dietary studies with the n-6 fatty acid linoleic acid have yielded conflicting results in terms of effects on both plasma lipoproteins and atherosclerosis. Indeed, excess amounts of both n-3 and n-6 fatty acids may actually promote oxidation, inflammation, and possibly atherogenesis (M. Toberek, 1998). In this context, enzymatic and non-enzymatic oxidation of linoleic acid in the sn-2 position of LDL phospholipids to 9- and 13-hydroxy derivatives is a key event in LDL oxidation (Section 6.2). 

In fact, unlike saturated fatty acids and cholesterol, which have been implicated in atherogenesis, (n-3) PUFAs such as eicosapentaenoic acid and docosahexaenoic acid (DHA) are considered to be vasodilators and antihypertensive agents. DHA, a 22-carbon fatty acid with six double bonds, is one of the major n-3 highly PUFAs in fish oils, and it is highly enriched in mammalian brain phospholipids. 

During a study, there has been evaluated the effect of supplementation with a low dose of co-3, obtained by olive oil, on the oxidative modification of low density lipoprotein (LDL) in a group of healthy volunteers, for 16 weeks. Oxidative modification of LDL was assessed measuring the concentrations of free cholesterol, cholesteryl esters and cholesteryl linoleate hydroperoxide in LDL, following copper-induced lipid peroxidation for 0, 2, 3 and 4 h. LDL eicosapentaenoic acid and docosahexaenoic acid compositions were significantly lower in the group treated with )-3 olive oil than the group treated with w-3 fish oil. 

Hun, C.S., Hasegawa, K., Kawabata,T., Kato, M., Shimokawa, T., and Kagawa, Y. (1999) Increased Uncoupling Protein 2 mRNA in White Adipose Tissue, and Decrease in Leptin, Visceral Fat, Blood Glucose, and Cholesterol in KK-Ay Mice Fed with Eicosapentaenoic and Docosahexaenoic Acids in Addition to Linolenic Acid,Biochem. Biophys. Res. Commun. 259,85-90. 

Froyland, L., Vaagenes, H., Asiedu, D., Garras, A., Lie, 0. Beige, R.K. (1996). Lipidk 31 169-178. Chronic administration of eicosapentaenoic acid and docosahexaenoic acid as ethyl esters reduced plasma cholesterol and changed fatty acid composition in rat blood and organs. 

Total sterol or cholesterol Monoglyceride and diglyceride Phosphatidylcholine Docosahexaenoic acid (DHA) CO-1 fatty acids oxidation products oxidation products Z, conjugugated double bonds... 

The induction of formation of endoplasmic reticulum membranes by phenobarbital leads to a considerable change in Upid composition of the membranes. The molar ratio of cholesterol/total phospholipid in the membranes of the endoplasmic reticulum faUs to 73 % of the control and the proportion of Unoleic acid in phosphatidylchoUne and phosphati-dylethanolamine rises to 120-125% of the control, whereas the proportion of oleic acid, arachidonic acid docosahexaenoic acid decreases (Davison and Wills 1976). The capacity of reducing added hydroperoxides is increased in isolated microsomal fi actions from phenobarbital-pretreated rats as compared to controls (Sies and Summer 1975). 

Collection from animals (some via chemical conversion) Cholesterol and its derivatives Lactose Peptides (protein digests) Amino acids Animal triglycerides and fatty acids containing unsaturated bonds (e.g. fish oil, docosahexaenoic acid) ... 

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