. 2021 Apr 27;10(5):1033. doi: 10.3390/cells10051033

Table 2.

Summary of the MRGPRX2/MRGPRB2 antagonists (peptides, small compounds and natural compounds).

S.N.	Antagonist	Major findings	References
1	Pertussis Toxin (PTx)	Decreased HDP-induced MC degranulation No effect on Ca²⁺ mobilization HDPs induced expression of IL-31 via the PI3K-MAP kinase pathway	[50,97]
2	Peptide QWF	Inhibited C48/80-, atracurium-, and ciprofloxacin-induced MC degranulation Inhibited SP-induced itch response	[70]
3	Small compounds (compound 1 and 2)	In vitro inhibition of SP- and Icatibant-induced MC degranulation and Ca²⁺ mobilization	[80]
Natural compounds
4	Resveratrol	Inhibited C48/80-induced Ca²⁺ mobilization and MC degranulation via Nrf2 pathway In vivo inhibition of local and systemic anaphylaxis	[98]
5	Genistein	Inhibited MC degranulation, MRGPRX2 activation and Ca²⁺ mobilization In vivo inhibition of local anaphylaxis in mice	[77]
6	Shikonin	Inhibited MC degranulation and Ca²⁺ mobilization Inhibited C48/80-induced pseudo-allergic reactions and systemic anaphylaxis	[174]
7	Osthole	Inhibited SP-, C48/80- and LL-37-induced MC degranulation and Ca²⁺ mobilization Inhibited in vivo MC degranulation	[170]
8	Kaempferol	Inhibited C48/80-induced hind paw swelling, Evans blue extravasation and MC degranulation Inhibited the release of histamine and cytokines	[175]
9	Paeoniflorin	Inhibited MC degranulation, MRGPRX2 activation and Ca²⁺ mobilization Downregulated PLCγ and MAPK/ERK	[176]
10	Piperine	Inhibited MC degranulation, and Ca²⁺ mobilization Showed binding affinity with MRGPRX2 via chromatography	[177]
12	Quercetin	Inhibited MC degranulation, MRGPRX2 activation and Ca²⁺ mobilization Inhibited cytokine release Inhibited C48/80 induced pseudo-allergic reactions and systemic anaphylaxis	[178]
12	Saikosaponin A	Inhibited MC degranulation and Ca²⁺ mobilization Inhibited C48/80-induced skin inflammation	[179]
13	Hydroxysafflor yellow A	Inhibited C48/80-, LL-37- and ciprofloxacin-induced MC degranulation Inhibited C48/80-induced hind paw swelling and Evans blue extravasation	[180]
14	Isoliquiritigenin	Inhibited C48/80-induced Ca²⁺ mobilization, MC degranulation, histamine and cytokines release. Attenuated hind paw swelling, and Evan blue extravasation	[181]
15	Others (DNA aptamer, cytokines, and stem cell factor)	DNA aptamer inhibited C48/80- and SP-induced histamine release and MC degranulation. Dual effect of IL-33 on MC degranulation and MRGPRX2 activation Acute exposure of stem cell factor inhibited MRGPRX2 activation and MC degranulation	[182,183,184]