Eicosanoids oxygenated

Eicosanoids Oxygenated lipid signaling molecules containing 20 carbons derived from polyunsaturated fatty acids released from membrane phospholipids by the action of phospholipase A. These include the prostanoids produced by the cyclooxygenase pathway and the leukotrienes produced by the lipoxygenase pathway. 

Nitric oxide and peroxynitrite contribute to oxidative damage 569 Production of eicosanoids from polyunsaturated fatty acids such as arachidonic acid may generate reactive oxygen species 570 Brain antioxidant defenses modify ischemia-reperfusion injury 570 Reactive oxygen species may modify both the excitotoxic and the apoptotic components of ischemic brain damage 570... 

A variety of biochemical and molecular mechanisms have been described to explain how PUFAs can modulate immune cell fate and function. The primary mechanism of action of dietary n-3 PUFAs involves the replacement of AA in the lipid membrane of the cells with either EPA or DHA. This, in effect, competitively inhibits the oxygenation of AA by the COX enzymes. For example, the EPA-induced suppression in the production of AA-derived eicosanoids is followed by a subsequent increase in the production of those from EPA. Generally, the EPA-derived eicosanoids are considered to be much less potent than those from AA, thus explaining, at least partially, the anti-inflammatory effects of PUFAs. A similar mechanism of action can be demonstrated for DHA, either directly or by retroconversion to EPA. 

Lipopolysaccharide had no effect on the protein synthesis ([ HJleucine incorporation) of HC cultured alone. A number of studies concluded that this decrease in protein synthesis was not due to a single cytokine, eicosanoid, or oxygen radical (West et al., 1989). Also, the activity could not be transferred in conditioned supernatant for KC stimulated with LPS alone. However, when... 

In addition to bioactive eicosanoids, the inflammatory response involves the sequential activation of various signaling pathways, including reactive oxygen intermediates, cytokines, growth factors, enzymes,... 

In conclusion, the beneficial effects of flavonoids in experimental IBD are mostly related with a preservation of intestinal function and/or with their ability to interfere simultaneously with different steps in the inflammatory cascade i.e. eicosanoid generation, oxygen and nitrogen reactive metabolites production and pro inflammatory cytokine release. The interest of flavonoids as potential drugs in the treatment of IBD is growing, and recently the intestinal antiinflammatory effects of the derivate flavonoid DA-6034 (7-carboxymethyloxy-3, 4, 5-trimethoxy flavone) has been reported in three... 

Oxygenated eicosanoids appear to be unique to animal cells. The first oxygenated eicosanoids to be discovered, the prostaglandins, were extracted from human semen in the... 

Prostaglandin. An oxygenated eicosanoid that has a hormonal function. Prostaglandins are unusual hormones in that they usually have effects only in that region of the organism where they are synthesized. 

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