This model is thought to induce pain by indirectly acting on the abdominal release of prostaglandins and lipooxygenase
Proanthocyanidins demonstrate their free-radical scavenger and antioxidant activity through vasodilator, anti-carcinogenic, anti-allergic, anti-inflammatory, antibacterial, cardio-protective, immune-stimulant, antiviral, estrogenic effects related to cyclooxygenase, phospholipase A2, and lipooxygenase
Natural antioxidants, such as phenolic compounds, inhibit lipid peroxidation and lipooxygenase
in vitro (SOARES, 2002).
The ligand-receptor complex is then internalized and degraded leading to (1) activation of phospholipase A2-release of arachidon- ic acid which via cyclooxygenase and lipooxygenase
activity leads to formation of prostaglandins and leu- cotriens; (2) activation of phospholipase-C through a G-protein with degradation of PIP2 and formation of IP3 and DAG; and (3) recruitment of substrate pro- teins to an oligomerized growth factor receptor with increased tyrosine kinase activity.
ROS can be produced by the action of NADPH oxidase, uncoupled nitric oxide synthase (NOS), mitochondrial electron transport, xanthine oxidase, cyclooxygenase, lipooxygenase
, heme oxygenase and cytochrome P450 monooxygenase.
Cyclooxygenase and lipooxygenase
inhibitors have been reported from onions (Bayer et al.
Curcumin, an atoxic antioxidant and natural NFkappaB, cyclooxygenase-2, lipooxygenase
, and inducible nitric oxide synthase inhibitor: a shield against acute and chronic diseases.
Nettle leaf has cyclooxygenase and lipooxygenase
that may slow the enzymes that trigger inflammation.
Studies have shown that they also inhibit lipid peroxidation, thrombocyte aggregation, capillary permeability, and various enzymatic systems including cyclooxygenase and lipooxygenase
The dexamethasone acts by inhibiting phospholipase enzyme, thereby blocking oxygenase and lipooxygenase
pathway and reduce the synthesis of prostaglandins thereby reducing edema and pain .
Lichochalone A is a COX as well as a lipooxygenase
inhibitor, also allowing for anti-inflammatory effects.
In addition to this, CAPE is a lipooxygenase
inhibitor with antioxidant properties (Natarajan et al.