Lipoxin A4 methyl ester (LXA4 methyl ester) is a more lipid soluble, prodrug formulation of the transcellular metabolite LXA4. LXA4 is a trihydroxy fatty acid containing a conjugated tetraene, produced by the metabolism of 15-HETE or 15-HpETE with human leukocytes.[1] LXA4 is equipotent to leukotriene B4 (LTB4) in inducing superoxide generation in human neutrophils at 0.1 μM.[2] LXA4 is associated with several other biological functions including leukocyte activation, chemotaxis effects, natural killer cell inhibition, and monocyte migration and adhesion.[2],[3],[4]

Leukotriene C4 (LTC4) is the parent cysteinyl-leukotriene produced by the LTC4 synthase-catalyzed conjugation of glutathione to LTA4. LTC4 is produced by neutrophils, macrophages, and mast cells, and by transcellular metabolism in platelets. It is one of the constituents of slow-reacting substance of anaphylaxis (SRS-A) and exhibits potent smooth muscle contracting activity. LTC4-induced bronchoconstriction and enhanced vascular permeability contribute to the pathogenesis of asthma and acute allergic hypersensitivity. The concentration of LTC4 required to produce marked contractions of lung parenchymal strips and isolated tracheal rings is about 1 nM. LTC4 methyl ester is a more lipid soluble form of LTC4. The biological activity of LTC4 methyl ester has not been reported.

Lipoxin B4 (LXB4) methyl ester is a lipid soluble prodrug form of the transcellular metabolite LXB4 . LXB4 is a positional isomer of LXA4 produced by the metabolism of 15-HETE or 15-HpETE by human leukocytes. At a concentration of 100 nM, LXB4 inhibits polymorphonuclear leukocyte (PMN) migration stimulated by leukotriene B4 and inhibits LTB4-induced adhesion of PMNs with an IC50 value of 0.3 nM.

Produced by neutrophils, macrophages, mast cells, and by transcellular metabolism in platelets, leukotriene C4 (LTC4) is the parent cysteinyl leukotriene formed by the LTC4 synthase-catalyzed conjugation of glutathione to LTA4. It is one of the constituents of slow-reacting substance of anaphylaxis (SRS-A) and exhibits potent smooth muscle contracting activity. LTC4, however, is rapidly metabolized to LTD4 and LTE4, which makes the characterization of LTC4 pharmacology difficult. N-methyl Leukotriene C4 (N-methyl LTC4) is a synthetic analog of LTC4 that is not readily metabolized to LTD4 and LTE4.It acts as a potent and selective CysLT2 receptor agonist exhibiting EC50 values of 122 and > 2,000 nM at the human CysLT2 and CysLT1 receptors, respectively. It has essentially the same potency as LTC4 at both the human and murine receptors CysLT2 receptors. N-methyl LTC4 is potent and active in vivo, causing vascular leak in mice overexpressing the human CysLT2 receptor but not in CysLT2 receptor knockout mice.

Salcaprozate sodium (SNAC), an oral absorption promoter, serves as a potent delivery agent for oral heparin and insulin by enhancing passive transcellular permeation through small intestinal epithelia. This is achieved through its capability to increase lipophilicity via non-covalent macromolecule complexation.

Resolvin E4 (RvE4) is a member of the specialized pro-resolving mediator (SPM) family of bioactive lipids.1It is produced from eicosapentaenoic acid by 15-lipoxygenase (15-LO)via15(S)-HpEPE and 15S-hydroxy, 5S-HpEPE intermediatesin vitroand by isolated human M2 macrophages or polymorphonuclear (PMN) neutrophils under normoxic or hypoxic conditions. RvE4 synthesis is enhanced in M2 macrophage and neutrophil co-cultures, indicating transcellular biosynthesis by a potential 15-LO and 5-LO mechanism. It has been found in mouse inflammatory exudates. RvE4 (10 nM) increases efferocytosis of apoptotic neutrophils or senescent red blood cells (sRBCs) by human M2 macrophages under hypoxic conditionsin vitro. Intraperitoneal administration of RvE4 (100 ng/animal) inhibits increases in inflammatory exudate neutrophil infiltration in a mouse model of hemorrhagic peritonitis induced by zymosan A and thrombin. It also increases inflammatory exudate macrophage infiltration and efferocytosis of apoptotic neutrophils and/or RBCs in the same model. 1.Norris, P.C., Libreros, S., and Serhan, C.N.Resolution metabolomes activated by hypoxic environmentSci. Adv.5(10)eaax4895(2019)

PBT434 methanesulfonate is an orally active, potent α-synuclein aggregation inhibitor with the ability to cross the blood-brain barrier. Acting as an iron chelator, it modulates transcellular iron trafficking, inhibits iron-mediated redox activity, and prevents iron-mediated aggregation of α-synuclein. PBT434 methanesulfonate also safeguards against the loss of substantia nigra pars compacta neurons (SNpc), showing promise for Parkinson’s disease (PD) research.

15(R)-HETE, a monohydroxy fatty acid, is synthesized from arachidonic acid via aspirin-acetylated COX-2, leading to the formation of specialized pro-resolving mediators 15(R)-lipoxin A4 and B4 through a transcellular mechanism involving 5-lipoxygenase (5-LO). Additionally, this compound is produced by the cytochrome P450 (CYP) isoform CYP2C9 and can be generated from arachidonic acid by COX-1 in human mast cells, where it accumulates due to its resistance to conversion into 15-KETE by 15-hydroxyprostaglandin dehydrogenase (15-PGDH). As an agonist of PPARβ/δ, 15(R)-HETE induces the expression of a target gene in NIH3T3 cells, demonstrating its biological significance.

VSWRAPTA is a promoter of neuronal branching via transcellular activation of the focal adhesion kinase (FAK) and the ERK1/2 signaling pathway in vitro.

Cyclic Phosphatidic Acids (cPAs) are naturally occurring lysophosphatidic acid (LPA) analogs, characterized by a 5-membered ring formed between the sn-2 hydroxy group and the sn-3 phosphate. Carba-derivatives of cPA (ccPA) modify the sn-2 (2-ccPA) or sn-3 (3-ccPA) linkage, hindering the conversion of cPA into LPA. Oleoyl 3-Carbacyclic Phosphatidic Acid (3-ccPA 18:1) incorporates the 18:1 fatty acid oleate at the sn-1 position on the glycerol backbone, acting as a cyclic LPA analog. This compound, at a concentration of 25 μM, blocks MM1 cells' transcellular migration through mesothelial cell monolayers induced by fetal bovine serum (by 90.1%) or LPA (by 99.9%), without impeding cell proliferation. Additionally, 3-ccPA 18:1, in the 0.1-1.0 μM range, notably suppresses autotaxin, which plays a vital role in various cancer cell behaviors including survival, growth, migration, invasion, and metastasis.

pTH-Related Protein (1-40) (human, mouse, rat) enhances calcium absorption in rat intestinal cells by activating the PTHR1 receptor and the PKCα/β signaling pathways. This compound also increases the expression of the parathyroid hormone 1 receptor (PTHR1) and four key proteins involved in transcellular calcium transport: potential vanillin member 6 (TRPV6), calcium-binding protein-D9K (CaBP-D9k), sodium-calcium Exchanger 1 (NCX1), and plasma membrane calcium ATPase 1 (PMCA1) [1].