Leukotriene inhibitory action

Whatever the mechanism of action for the inhibition of 5-lipoxygenase by flavonoids, it appears to be distinct from the antioxidant properties of these compounds. The results comparing antioxidant activity with leukotriene inhibitory activity clearly demonstrate this distinction. The profound effects of metabolic transformation on the anti-inflammation activity of dietary flavonoids such as quercetin must also be considered in relation to in vitro studies, and further highlights the need to use actual metabolic forms of flavonoids rather than the free aglycone or glycosides occurring in the diet. 

Arachidonic acid is stored mainly in phospholipids of cell walls, from which it is mobilised largely by the action of phospholipase. Glucocorticoids prevent the formation of arachidonic acid by inducing the synthesis of an inhibitory polypeptide called lipocortin-1 the capacity to inhibit the subsequent formation of both prostaglandins and leukotrienes, explains part of the powerful anti-inflammatory effect of glucocorticoids (for other actions, see p. 664). 

Shegansu B (453) had inhibitory effect on LTB4 and bisisorhapontigenin A (517) exhibited antagonistic action on leukotriene D4 receptor [260]. 

The anti-inflammatory actions are thought to involve phospholipase A inhibitory proteins. These, in turn, control many of the mediators of inflammation such as prostaglandins and leukotrienes by inhibiting the release of the precursor molecule arachidonic acid. This reduction in inflammation, edema, and tumor burden is especially beneficial in reducing bone pain, neuropathic pain from infiltration or compression of structures, spinal cord compression, pain from bowel obstruction or organ capsule distention, pain from lymphedema, and headache pain associated with increased intracranial pressure... 

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