PSB 603

PSB-603 is a potent and selective adenosine A2B receptor antagonist exhibiting a Ki value of 0.553 nM at the human A2B receptor and virtually no affinity for the human and rat A1 and A2A and the human A3 receptors up to a concentration of 10 μM[1].

Research Areas >> Inflammation/Immunology

Signaling Pathways >> GPCR/G Protein >> Adenosine Receptor

PSB-603 inhibits human A2B receptor in Jurkat T cells with an IC50 of 1.13 nM[1]. PSB-603 inhibits human, rat, and mouse A2B receptors with Ki values of 0.553, 0.355, and 0.265 nM, respectively[2]. PSB-603 (100 nM; 24 hours) antagonizes NECA (an adenosine receptor agonist; 1µM) inhibited interferon-γ and stimulated interleukin-6 production[3]. Cell Viability Assay[3] Cell Line: Peripheral T cells Concentration: 100 nM Incubation Time: 24 hours Result: Significantly inhibited NECA stimulated IL-6 release ≈3-fold.

PSB-603 shows anti-inflammatory effect in local and systemic inflammation models. PSB-603 (5 mg/kg b.w. ip) significantly reduces inflammation in two mice models of inflammation (local and systemic). PSB-603 significantly decreases levels of the inflammatory cytokines IL-6, TNF-α and of ROS in the inflamed paw and reduces inflammation of the peritoneum by significantly decreasing the infiltration of leukocytes[4]. PSB-603 is administered as suspensions in 1 % Tween 80[4]. Animal Model: Adult male Albino Swiss mice, CD-1, weighing 25-30 g[4] Dosage: 1, 5 or 10 mg/kg Administration: Administered intraperitoneally (ip), prior to carrageenan injection Result: Carrageenan-induced edema model. The increase in paw oedema was significantly inhibited in all groups receiving PSB-603. The dose of 5 mg/kg turned out to be the most active.

[1]. Thomas Borrmann, et al. 1-alkyl-8-(piperazine-1-sulfonyl)phenylxanthines: development and characterization of adenosine A_2B receptor antagonists and a new radioligand with subnanomolar affinity and subtype specificity. J Med Chem. 2009 Jul 9;52(13):3994-4006.

[2]. Mohamad Wessam Alnouri, et al. Selectivity is species-dependent: Characterization of standard agonists and antagonists at human, rat, and mouse adenosine receptors. Purinergic Signal. 2015 Sep;11(3):389-407.

[3]. Nadine Borg, et al. CD73 on T Cells Orchestrates Cardiac Wound Healing After Myocardial Infarction by Purinergic Metabolic Reprogramming. Circulation. 2017 Jul 18;136(3):297-313.

[4]. Magdalena Kotańska, et al. PSB 603 - a known selective adenosine A_2B receptor antagonist-has anti-inflammatory activity in mice. Biomed Pharmacother. 2021 Mar;135:111164.