Pirinixic Acid Aminothiazole is a dual inhibitor of 5-lipoxygenase (5-LO) and microsomal prostaglandin E2 synthase 1 (mPGES-1) with IC50 values of 0.3 and 0.4 μM, respectively [1].

5-lipoxygenase (5-LO) and microsomal prostaglandin E2 synthase-1 (mPGES-1) are critical enzymes involved in the metabolism of arachidonic acid (AA). They are key enzymes in the synthesis of leukotrienes (LTs) and PGE2, respectively [1][2][3]. Dual inhibition of 5-LO and mPGES-1 is currently pursued as potential pharmacological strategy for treatment of inflammation and cancer [1].

Pirinixic Acid Aminothiazole is a dual inhibitor of 5-LO and mPGES-1. Pirinixic Acid Aminothiazole hardly inhibited cyclooxygenase (COX)-1/2 activities and failed to inhibit 12/15-LOs. In cell-free assay, Pirinixic Acid Aminothiazole was highly potent against both 5-LO and mPGES-1 with IC50 values of 0.3 and 0.4 μM, respectively. In the cell-based assay, Pirinixic Acid Aminothiazole inhibited 5-LO directly with IC50 value of 0.2 μM [1].

In zymosan-induced peritonitis in mice, Pirinixic Acid Aminothiazole (10 mg/kg) reduced vascular permeability by 57% and inhibited neutrophil infiltration by 45%, accompanied by significantly impaired levels of cysLTs (84% reduction) and PGE2 (46% reduction). These results suggested that Pirinixic Acid Aminothiazole dually inhibited LT and PGE2 synthesis in vivo connected to anti-inflammatory effectiveness [1].

References:
[1].  Hanke T, Dehm F, Liening S, et al. Aminothiazole-featured pirinixic acid derivatives as dual 5-lipoxygenase and microsomal prostaglandin E2 synthase-1 inhibitors with improved potency and efficiency in vivo. J Med Chem. 2013 Nov 27;56(22):9031-44.
[2].  Funk CD. Prostaglandins and leukotrienes: advances in eicosanoid biology. Science. 2001 Nov 30;294(5548):1871-5.
[3].  Samuelsson B, Morgenstern R, Jakobsson PJ. Membrane prostaglandin E synthase-1: a novel therapeutic target. Pharmacol Rev. 2007 Sep;59(3):207-24.