ABX-1431

ABX-1431 is a potent human MGLL inhibitor (average IC50 = 0.014 μM) with >100-fold selectivity against ABHD6 and >200-fold selectivity against PLA2G7. Treatment of intact human PC3 cells with ABX-1431 following a 30 min inhibitor incubation time causes concentration dependent inhibition of MGLL activity with an IC50 value of 0.0022 μM, which is ∼6-fold more potent than that observed in vitro. ABX-1431 inhibits MGLL via carbamoylation of the catalytic nucleophile Ser122^[1].

Human prostate cancer PC3 cells are grown in F-12K medium supplemented with 10% fetal bovine serum at 37 °C with 5% CO2 to ∼80% confluency in 100 mm dishes. ABX-1431 is added to cells to give final concentration of 0.1-10 μM compound in serum free media. Cells are incubated with compound for 30 min at 37°C with 5% CO2. Cells are washed, harvested, and lysed by probe sonication. Cell lysates (2 mg/mL) are treated with JW912 (1 μM) and analyzed by SDS-PAGE and in-gel fluorescence scanning.

Pharmacokinetic analysis in rats and dogs of ABX-1431 indicate low to moderate systemic clearance, moderate volume of distribution, and high oral bioavailability (64% in rat, 57% in dog). While ABX-1431 is stable in human and dog plasma, it is not stable in rat plasma. ABX-1431 is a potent and selective inhibitor of MGLL in mouse and rat brain in vivo^[1]. ABX-1431 inhibits MGLL activity with an ED50 of 0.5-1.4 mg/kg (po) and dose-dependently increases brain 2-AG levels in mouse brain. A rat inflammatory pain model is used to assess the pharmacodynamics effect. ABX-1431 demonstrates potent antinociceptive effects in a formalin paw test at a dose that produced near complete MGLL inhibition and maximal elevation of 2-AG^[2].