Saikosaponin A inhibits compound 48/80-induced pseudo-allergy via the Mrgprx2 pathway in vitro and in vivo

Nan Wang, Delu Che, Tao Zhang, Rui Liu, Jiao Cao, Jue Wang, Tingting Zhao, Pengyu Ma, Xinzhong Dong, Langchong He

Research output: Contribution to journalArticlepeer-review


Pseudo-allergic reactions-adverse, non-immunologic, anaphylaxis-like sudden onset reactions mediated through an IgE-independent pathway—are activated by various basic compounds and occur at least as frequently as IgE-mediated reactions to drugs. A large family of G protein coupled receptors (Mas-related genes; Mrgprs) is closely related to pseudo-allergies. However, few therapies can directly target pseudo-allergies and related Mrgprs. Saikosaponin A (SSA) is effective in the treatment of passive cutaneous anaphylaxis (PCA), adjuvant arthritis, and delayed hypersensitiveness. In this study, we investigated the anti-pseudo-allergy effect of SSA and its underlying mechanism. We examined the effect of SSA on both IgE-independent and IgE-dependent responses using PCA and active systemic anaphylaxis models, as well as in vitro-cultured mast cells. We also evaluated whether the anti-allergy effect is related to Mrgprs by using in vitro Mrgprx2-expressing HEK293 cells. SSA dose dependently suppressed compound 48/80 (C48/80)-induced PCA and mast cell degranulation in mice. When SSA and C48/80 were administered together through the vein, C48/80-induced systemic anaphylaxis did not occur, and C48/80-induced shock ratio decreased dose-dependently upon SSA treatment. However, SSA did not affect IgE-dependent allergy. When administered topically 24 h before antigen challenge, Evans blue leakage and paw swelling were induced in the SSA-treated group and the vehicle group. Our in vitro studies revealed that SSA reduced C48/80-induced calcium flux and suppressed degranulation in LAD2 cells. SSA could also dose-dependently inhibit C48/80-induced Mrgprx2-expressing HEK293 cell activation. As a conclusion, SSA could inhibits IgE-independent allergy, but not IgE-dependent allergy, and this effect involves the Mrgprx2 pathway. This study provided a new sight on pseudo-allergy and its therapy.

Original languageEnglish (US)
Pages (from-to)147-154
Number of pages8
JournalBiochemical Pharmacology
StatePublished - Feb 2018


  • IgE-independent
  • Mast cells
  • Mrgprx2
  • Pseudo-allergy
  • Saikosaponin A

ASJC Scopus subject areas

  • Biochemistry
  • Pharmacology


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