Abstract: This study aimed to explore the effects of glycyrrhizic acid (GA) on allergic reactions by using sensitized BALB/c female mice model, passive cutaneous anaphylaxis reaction and atopic dermatitis model and rat basophil leukemia RBL-2H3 cells and to explore the underlying mechanism. The results showed that GA could effectively inhibit vascular permeability and histamine level in serum of passive skin allergic mice. The serum tumor necrosis factor receptor-α level in mice with allergic dermatitis, as determined by enzyme-linked immunosorbent assay, was significantly decreased after GA administration at 10 mg/kg mb or above. Experiments with RBL-2H3 cells showed that GA could significantly reduce the release rate of β-hexosaminidase, thereby inhibiting the degranulation of mast cells. The fluorescent calcium probe Fluo-3 AM was used to analyze RBL-2H3 cells sensitized by IgE. It turned out that GA could inhibit the increase of intracellular Ca2+ level induced by antigen. Quantitative real-time polymerase chain reaction and Western blot analysis showed that GA significantly decreased the mRNA transcription and protein expression of calcium channel regulatory proteins STIM1 and TRPC1. These results suggest that GA can inhibit degranulation by regulating the expression of calcium release and transporter factors and decreasing intracellular calcium concentration after antigen stimulation.

Key words: glycyrrhizic acid, anti-allergic activity, passive cutaneous anaphylaxis