pmnl

Olsalazine (Dipentium), an anti-inflammatory drug, is used in the treatment of inflammatory bowel disease. It is also a novel DNA hypomethylating agent.

LY255283 is a specific antagonit of leukotriene B4 (LTB4) receptor. It inhibits the production of LTB(4) in human peripheral blood polymorphonuclear leukocytes (PMNL) and in monocytes activated by calcium ionophore A23187.

15(S)-HETrE is the hydroxy-trienoic acid resulting from 15-lipoxygenation of dihomo-γ-linolenic acid. It inhibits 5-LO in human PMNL with an IC50 value of 4.6 μM. In RBL cells, 15(S)-HETrE also inhibits 5-LO, but is approximately 1/20 as potent as 15(S)-HpETE.

LTB4 dimethyl amide is a moderate inhibitor of LTB4-induced degranulation of human neutrophils (Ki = 130 nM) and lysozyme release from rat PMNL. LTB4 dimethyl amide appears to be an antagonist of the LTB4 receptor on guinea pig lung membranes.

5(S),12(S)-DiHETE is a natural bioactive lipid derived from arachidonic acid . It is synthesized by glycogen-induced rabbit peritoneal polymorphonuclear leukocytes (PMNLs) incubated with AA. 5(S),12(S)-DiHETE can be produced by successive oxygenation of AA by 5-lipoxygenase (5-LO) in platelets and 12-LO in leukocytes. It can also be synthesized from 12(S)-HETE by 5-LO, in the presence of 5-LO activating protein (FLAP), activated with calcium ionophore. 5(S),12(S)-DiHETE is an epimer of leukotriene B4 that is weakly chemotactic for PMNL.

5(S),15(S)-DiHETE is synthesized by 15-LO from 5(S)-HETE. It potentiates the degranulation of human PMNL in response to PAF, but not fMLP, calcium ionophore A23187, or LTB4. 5(S),15(S)-DiHETE is chemotactic for eosinophils with an ED50 value of 0.3 μM.

20-hydroxy LTB4 is a metabolite of LTB4 in human neutrophils. In human leukocytes, LTB4 is inactivated by the enzyme LTB4 20-hydroxylase. 20-hydroxy LTB4 is not only much less active (~5%) compared to LTB4 in causing degranulation of PMNL, but actually inhibits LTB4-induced degranulation of human neutrophils (Ki = 13.3 nM). However, 20-hydroxy LTB4 is as active as LTB4 in contracting parenchymal strips from guinea pig lung. 20-hydroxy LTB4 retains considerable ligand binding affinity at the BLT2 receptor, but does not appear to function as an agonist.

Diffractaic Acid (NSC 685595) can inhibit LTB4 biosynthesis in A-23187-stimulated bovine PMNL cells with activity value of 8 μM.

1CAY10649, a thiazolinone compound, directly inhibits 5-lipoxygenase (5-LO) product formation in intact polymorphonuclear leukocytes (PMNL) with an IC50 value of 0.28 μM and in a soluble fraction of an S100 PMNL cell lysate with an IC50 value of 0.09 μM, following stimulation by calcium and arachidonic acid. This activity highlights its potential in mitigating inflammatory responses by targeting the biosynthesis of leukotrienes, substances implicated in various inflammatory processes such as neutrophil chemotaxis, increased vascular permeability, and smooth muscle contraction.

Thromboxane B3 (TXB3), the stable hydrolysis product of TXA3, is synthesized from eicosapentaenoic acid (EPA) through the action of COX and thromboxane synthase enzymes. This compound is biosynthesized in several tissues, including seminal vesicles, lungs, polymorphonuclear leukocytes (PMNL), and ocular tissues.

Hexacyclinol exhibits moderate activity against Gram-positive bacteria and can inhibit oxidant production in yeast polysaccharide-stimulated polymorphonuclear leukocytes (PMNL) at concentrations of 4–40 μg/mL. It suppresses the growth of L-930 and K562 cells with IC50 values of 1.4 μg/mL and 0.4 μg/mL, respectively, and has an IC50 of 10 μg/mL for HeLa cells. Additionally, Hexacyclinol shows antimalarial activity, with an IC50 of 2.4 μg/mL against Plasmodium falciparum.