Atopaxar (E5555), a reversible PAR-1 thrombin receptor antagonist, interferes with platelet signaling. Atopaxar has been investigated for the treatment of Coronary Artery Disease and Acute Coronary Syndrome.

Vorapaxar (MK-5348) (SCH 530348) is an effective and orally active thrombin receptor (PAR-1) antagonist (Ki: 8.1 nM).

Atopaxar, a reversible PAR-1 thrombin receptor antagonist, interferes with platelet signaling. Atopaxar has been investigated for the treatment of Coronary Artery Disease and Acute Coronary Syndrome.

Parmodulin 2 (ML 161) is the inhibitor of protease-activated receptor 1 (PAR1)-mediated platelet activation (IC50: 0.26 μM for the inhibition of platelet P-selectin expression on human platelets). It also inhibits thrombin-induced platelet activation.

Thrombin Receptor Activator for Peptide 5 (TRAP-5), also known as Coagulation Factor II Receptor (1-5) or Proteinase Activated Receptor 1 (1-5), is employed in coronary heart disease (CHD) research.

RWJ-56110 dihydrochloride is a potent, selective, peptide-mimetic inhibitor of PAR-1 activation and internalization (binding IC50=0.44 uM) and shows no effect on PAR-2, PAR-3, or PAR-4. RWJ-56110 dihydrochloride inhibits the aggregation of human platelets induced by both SFLLRN-NH2 (IC50=0.16 μM) and thrombin (IC50=0.34 μM), quite selective relative to U46619 . RWJ-56110 dihydrochloride blocks angiogenesis and blocks the formation of new vessels in vivo. RWJ-56110 dihydrochloride induces cell apoptosis[1][2]. Proteinase-activated receptors (PARs) are a family of G protein-coupled receptors activated by the proteolytic cleavage of their N-terminal extracellular domain, exposing a new amino terminal sequence that functions as a tethered ligand to activate the receptors.RWJ56110 inhibits the aggregation of human platelets induced by both SFLLRN-NH2 (IC50=0.16 μM) and thrombin (IC50=0.34 μM) while being quite selective relative to collagen and the thromboxane mimetic U46619 [1].RWJ-56110 dihydrochloride is fully inhibits thrombin-induced RASMC proliferation with an IC50 value of 3.5 μM. RWJ-56110 dihydrochloride shows blockade of thrombin's action with RASMC calcium mobilization (IC50=0.12 μM), as well as with HMVEC (IC50=0.13 μM) and HASMC calcium mobilization (IC50=0.17 μM)[1].RWJ56110 (0.1-10 μM; 24-96 hours) inhibits endothelial cell growth dose-dependently, with half-maximal inhibitory concentration of RWJ56110 is approximately 10 μM[2].RWJ56110 (0.1-10 μM; 6 hours) inhibits DNA synthesis of endothelial cells in a thymidine incorporation assays. Endothelial cells are in fast-growing state (50-60% confluence), RWJ56110 inhibits cell DNA synthesis in a dose-dependent manner, but when cells that are in the quiescent state (100% confluent), the inhibitory effect of PAR-1 antagonists is much less pronounced[2].RWJ56110 (0.1-10 μM; pretreatment for 15 min) inhibits thrombin-induced Erk1/2 activation in a concentration-dependent manner. However, when endothelial cells are stimulated by FBS (final concentration 4%), it reduces partially the activated levels of Erk1/2[2].RWJ56110 (30 μM; 24 hours) has an inhibitory effect on endothelial cell cycle progression. It reduces the percentage of cells in the S phase, while alterations in the percentages of G1 and G2/M cells are less pronounced[2]. Western Blot Analysis[2] Cell Line: Endothelial cells [1]. Andrade-Gordon, et al.Design, synthesis, and biological characterization of a peptide-mimetic antagonist for a tethered-ligand receptor. oc Natl Acad Sci U S A. 1999 Oct 26;96(22):12257-62. [2]. Panagiota Zania, et al. Blockade of angiogenesis by small molecule antagonists to protease-activated receptor-1: association with endothelial cell growth suppression and induction of apoptosis. J Pharmacol Exp Ther. 2006 Jul;318(1):246-54.

TFLLR-NH2(2TFA) is an agonist of PAR1 (EC50 :1.9 μM).

PAR-4 Agonist Peptide, amide (AY-NH2) is an agonist of proteinase-activated receptor-4 (PAR-4).

AC-264613 is an agonist of the GPCR protease-activated receptor 2 (PAR2). AC-264613(AC264613) suppresses interferon regulatory factor 5 and decreases interleukin-12p40 production by lipopolysaccharide-stimulated macrophages. AC-264613(AC264613) activated PAR2 signaling in cellular proliferation assays, phosphatidylinositol hydrolysis assays, and Ca(2+) mobilization assays, with potencies ranging from 30 to 100 nM.

Psychotridine is an alkaloid that has been found inP. forsterianaand has diverse biological activities.1,2,3It inhibits ADP-, collagen-, or thrombin-induced aggregation of washed isolated human platelets with IC50values of 1.4, 1.4, and 3.9 μM, respectively.1Psychotridine (2.5 or 5 μM) is cytotoxic to HTC rat hepatocellular carcinoma cells.2It reduces paw licking induced by capsaicin in mice when administered at doses of 0.5, 2.5, or 5 mg/kg.3 1.Beretz, A., Roth-Georger, A., Corre, G., et al.Polyindolinic alkaloids from Psychotria forsteriana. Potent inhibitors of the aggregation of human plateletsPlanta Med.51(4)300-303(1985) 2.Roth, A., Kuballa, B., Bounthanh, C., et al.Cytotoxic activity of polyindoline alkaloids of Psychotria forsteriana (Rubiaceae) (1)Planta Med.6450-453(1986) 3.Amador, T.A., Verotta, L., Nunes, D.S., et al.Involvement of NMDA receptors in the analgesic properties of psychotridinePhytomedicine8(3)202-206(2001)

Ala-parafluoroPhe-Arg-Cha-Cit-Tyr-NH2 is a biologically active peptide functioning as a selective agonist for Protease Activated Receptor 1 (PAR-1), a subtype of G-protein coupled receptors involved in mediating thrombin's cellular effects. Exhibiting high specificity for PAR-1 over PAR-2, its selectivity was assessed via cell-based calcium signaling assays in HEK293 cells. As an agonist, it is instrumental for in vivo investigations of PAR-1 activation. PAR-1 also collaborates with PAR-4, influencing thrombin-induced hepatocellular carcinoma within 'coagulation type' tumor environments where thrombin generation occurs.

AC-55541 (AOB2796) is a novel PAR2 agonist; activated PAR2 signaling in cellular proliferation assays, phosphatidylinositol hydrolysis assays, and Ca(2+) mobilization assays, with potencies ranging from 200 to 1000 nM.

Protease-Activated Receptor-4 is the proteinase-activated receptor-4 (PAR4) agonist, with Antiplatelet Therapy

TRAP-6 (Thrombin Receptor Activator Peptide 6)(2TFA) is an agonist of protease-activated receptor 1 (PAR1).

SCH79797 dihydrochloride is an effective and selective antagonist of protease activated receptor 1 (PAR1) with an IC50 of 70 nM and a Ki of 35 nM. SCH79797 dihydrochloride has antiproliferative and pro-apoptotic effects.

PAR-2-IN-1 (IUN76750) is a PAR- 2 signaling pathway inhibitor with anti-inflammatory and anticancer effects.

PAR-4 Agonist Peptide, amide TFA (PAR-4-AP (TFA)), is a selective activator of the proteinase-activated receptor-4 (PAR-4), demonstrating specificity by not influencing PAR-1 or PAR-2, and its activity can be inhibited by a PAR-4 antagonist.

AZ3451 is an allosteric antagonist of protease-activated receptor-2 (PAR2, IC50: 23 nM).

Vorapaxar sulfate (Zontivity) is a potent and orally active thrombin receptor (PAR-1) antagonist.

I-191 is a potent antagonist of protease-activated receptor 2 (PAR2), inhibits multiple signaling functions in human cancer cells.

Protease-Activated Receptor-2, amide (SLIGKV-NH2) is an agonist of PAR2 (IC50 : 10.4 M)

SLIGRL-NH2 (Protease-Activated Receptor-2 Activating Peptide) is a protease-activated receptor-2 (PAR-2) agonist that induces non-histaminergic pruritus.