Arachidonate 5-lipoxygenase activity

Inhibitory effects (IC30 SD, N=3, pmol/L) on arachidonate 5-lipoxygenase activity ... 

Kohyama, N., T. Nagata, S. I. Fuji-moto, and K. Sekiya. Inhibition of arachidonate lipoxygenase activities by 2-(3-4-dihydroxyphenyl) ethanol, a OE066 phenolic compounds from olives. Bio-sci Biotech Biochem 1997 61(2) ... 

NSAIDs usually do not inhibit lipoxygenase activity at concentrations that inhibit COX activity. In fact, by preventing arachidonic acid conversion via the COX pathway, NSAIDs may cause more substrate to be metabolized through the lipoxygenase pathways, leading to an increased formation of the inflammatory leukotrienes. Even among the COX-dependent pathways, inhibiting the... 

Shimizu T, Radmark O, Samuelsson B (1984) Enzyme with dual lipoxygenase activities catalyzes leukotriene A4 synthesis from arachidonic acid. Proc Natl Acad Sci USA... 

Leukotriene-synthesis inhibitors The formation of leukotrienes depends on lipoxygenation of arachidonic acid by 5-lipoxygenase. Zileuton is a potent and selective inhibitor of 5-lipoxygenase activity and thus inhibits the formation of all 5-lipoxygenase products. Thus, in addition to... 

The leukotrienes occur in a variety of inflammatory cells that are abundant in asthma, including eosinophils, mast cells, and macrophages. They are derived from arachidonic acid via a branch of the common pathway to the prostacyclins and thromboxanes. Arachidonic acid itself is produced by the action of phospholipase A2 on cell walls. Unlike the prostacyclins and thromboxanes, excess arachidonic acid does not activate the pathway. Instead, the first step in the conversion of arachidonic acid to produce the leukotrienes is controlled by an activating protein, 5-lipoxygenase-activating protein, which... 

Fig. 4. Regulatory targets for leukotriene (LT) inhibition. AA, arachidonic acid FLAP, 5-lipoxygenase activating protein 5-HPETE, 5-hydroperoxyeicosatetraenoic acid.

As part of the response to leukocyte cell activation, cysteinyl leukotrienes are generated de novo from arachidonic acid liberated from cell membrane phospholipid by cytosolic phospholipase A2 (Fig. 3.8). In concert with 5-lipoxygenase-activating protein (FLAP), the enzyme 5-lipoxygenase (5-LO) converts arachidonic... 

Cysteinyl leukotrienes are generated de novo from arachidonic acid by phospholipase A2 with the initial participation of 5-lipoxygenase-activating protein and the enzyme 5-lipoxygenase. 

Flavones and flavonols can exert the anti-inflammatory activity in many animal models and are useful in allograft rejection and rheumatic diseases as an immunosuppressive agent A number of reports have been published which demonstrate that flavones and flavonols, such as quercetin, myricetin, and fisetin, can modulate arachidonic acid metabolism via the inhibition of cyclooxygenase and lipoxygenase activity [130, 131], Quercetin prevents inunune cells and inhibits both the production and release of histamine and is useful in allergic conditions like asthma, hay fever, etc. [132],... 

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