Table 1.

Pro- and anti-inflammatory effects of different GPR55 ligands.

Compound	Observed effects
Agonists	Upregulated	Unchanged	Downregulated	Study
O-1602	Neurogenesis, neuronal formation	microglial activation		[68]
	IL-4, IL-10		Inflammasome activation, IL-1β, IL-6, TNFα	[70]
			Anxiety-like behavior	[42, 70]
			Depression-like behavior	[41, 70]
		PGE2		[71]
	hippocampal & frontal GPR55 expression		RhoA/ROCK2, IL-1β, TNFα, neuronal apoptosis, cognitive impairment	[84]
			IL-1β, IL-6, TNFα, Acetylcholinesterase (AChE) activity, microglial activation	[85]
			NF-κB signaling, IL-1β, IL-6, TNFα, GPR55 downregulation, neuronal apoptosis, cognitive impairment	[86]
LPI		IL-1β, IL-2, IL-10, IL-12, IFNγ	IL-6, TNFα	[69]
CID1792197	Cell growth	Cell growth in CB1-GPR55 heterodimer cells		[88]
Antagonists
ML 193	Anxiety-like behavior			[42]
			PGE2	[71]
CID16020046			IL-6, COX-2	[72]
Coumarin derivates			PGE2, COX-2, (IL-6)	[60, 71, 79]
CBD	Antipsychotic effects			[81]