ML-193 (Synonyms: CID-1261822)

IC50: 221 nM

ML-193 is a GPR55 antagonist.

GPR55 is a class A G protein-coupled receptor (GPCR) that has been implicated in inflammatory pain, neuropathic pain, metabolic disorder, bone development, and cancer. Initially deorphanized as a cannabinoid receptor, GPR55 has been shown to be activated by non-cannabinoid ligands such as l-α-lysophosphatidylinositol (LPI).

In vitro: Previous study found that for antagonist activity in the β-arrestin trafficking assay, ML193 and its two close analogs (ML191 and ML192) could inhibit trafficking induced by 10 μM LPI with IC50 values of 0.22 ± 0.03, 1.08 ± 0.03 and 0.70 ± 0.05μM, respectively.In addition, it was also found that ML193, ML191 and ML192 was able to inhibit trafficking induced by 1 μM ML186 with IC50 values of 0.12 ±0.02, 1.03 ± 0.03 and 0.29 ± 0.09 μM, respectively [1].

In vivo: Animal study showd that ML-193 was able to block the increases in intracellular calcium levels that was induced by lysophosphatidylinositol (LPI) in dissociated rat periaqueductal gray neurons and could also modulate pain perception in LPI-treated rats, suggesting that interfering with GPR55 signaling in the PAG might promote analgesia [2].

Clinical trial: So far, no clinical study has been conducted.

References:
[1] Kotsikorou, E. ,Sharir, H.,Shore, D.M., et al. Identification of the GPR55 antagonist binding site using a novel set of high-potency GPR55 selective ligands. Biochemistry 52(52), 9456-9469 (2013).
[2] Deliu, E. ,Sperow, M.,Console-Bram, L., et al. The lysophosphatidylinositol receptor GPR55 modulates pain perception in the periaqueductal gray. Mol.Pharmacol. 88(2), 265-272 (2015).