cytosolic pla2

Fluticasone propionate (CCI-187881), derived from fluticasone used to remedy asthma and allergic rhinitis, is a high affinity, selective GR (glucocorticoid receptor) agonist.

The group IVA phospholipase A2 (PLA2), known as calcium-dependent cytosolic PLA2 (cPLA2), selectively releases arachidonic acid from membrane phospholipids, playing a central role in initiating the synthesis of prostaglandins and leukotrienes. AX 048 is a potent group IVA cPLA2 inhibitor that demonstrates 50% inhibition of the enzyme at a mole fraction (XI(50)) of 0.022. Pretreatment with AX 048 (ED50 = 1.2 mg/kg) dose-dependently reduces thermal hyperalgesia evoked by carrageenan injection of rat hind paw. At concentrations as high as 30 μM, AX 048 does not inhibit COX activity or interfere with central cannabinoid receptor signaling.

The group IVA phospholipase A2 (PLA2), known as calcium-dependent cytosolic PLA2 (cPLA2), selectively releases arachidonic acid (AA) from membrane phospholipids, playing a central role in initiating the synthesis of prostaglandins (PGs) and leukotrienes (LTs). Pyrrophenone inhibits cPLA2α with an IC50 of 4.2 nM in enzyme assays and potently blocks the release of AA and the production of PGE2 and LTC4 in cells (IC50 = 24, 25, and 14 nM, respectively). Its action is reversible and selective, as pyrrophenone inhibits the secretory type IB and IIA PLA2s with more than a hundred-fold less potency. Pyrrophenone has also been shown to inhibit calcium ionophore (A23187)-stimulated AA release from monocytic cells, interleukin-1-induced PGE2 synthesis in mesangial cells, and the production of PGE2, LTs, and platelet-activating factor by human neutrophils, always with maximal inhibition at concentrations below 1 μM.

Phospholipase A2 (PLA2) catalyzes the hydrolysis of phospholipids at the sn-2 position leading to the production of lysophospholipids and free fatty acids. Calcium-dependent cytosolic PLA2 (cPLA2α) is a 85 kDa enzyme that plays a key role in the arachidonic cascade and the inflammatory response associated with this metabolic pathway. CAY10502 is a potent inhibitor of calcium-dependent cytosolic PLA2α (cPLA2α) with an IC50 value of 4.3 nM for the purified enzyme from human platelets. It inhibits arachidonic acid mobilization from A23187-stimulated or TPA-stimulated human platelets with IC50 values of 570 and 0.9 nM, respectively.

Variabilin, a novel inhibitor of human platelet aggregation, it is a potent RGD (Arg-Gly-Asp)-containing antagonist of the fibrinogen receptor glycoprotein IIb-IIIa (GPIIb-IIIa; αIIbβ3) and the vitronectin receptor αvβ3.Variabilin is also an antimicrobial furanosesterterpene. Variabilin is an inhibitor of human secretory and cytosolic phospholipase A2 (PLA2) activities that controls eicosanoid production in vitro and in vivo, inhibits neutrophil degranulation and superoxide generation in vitro and shows anti-inflammatory activity after topical or p.o. administration to mice.