Punicalagin Alleviates Aged Bronchial Asthma by Inhibiting Th2 Differentiation through IL-4/STAT6 and Jagged1/Notch Pathways

OBJECTIVE: To explore the therapeutic effect and mechanism of punicalagin on bronchial asthma in the elderly. METHODS: Peripheral venous blood was collected from healthy people and elderly patients with bronchial asthma. Peripheral blood mononuclear cells (PBMCs) were isolated and cultured. PBMCs in the patient group were treated with different concentrations (0, 50, 100, and 200 mg/L) of punicalagin (PUN). MTT assay was used to detect cell activity, ELISA was used to detect the levels of IFN-γ, IL-2, IL-4, and IL-5, and Western blotting was used to detect the protein levels of p-STAT6, Jagged1, and GATA3. RESULT: MTT results showed that 50–200 mg/L PUN had no cytotoxicity to PBMCs within 24 h. ELISA results showed that the levels of IFN-γ and IL-2 in the serum of the patients were significantly lower than those of healthy people, and the levels of IL-4 and IL-5 were significantly higher than those of the healthy people. PUN treatment significantly increased the levels of IFN-γ and IL-2 in the supernatant of PBMCs culture, while significantly decreased the levels of IL-4 and IL-5, and the change was proportional to the concentration of PUN. Western blotting results showed that the levels of p-STAT6, Jagged1, and GATA3 protein in PBMCs of patients were significantly higher than those of the healthy people. PUN treatment could significantly reduce the expression of p-STAT6, Jagged1, and GATA3 protein in PBMCs of patients, and the reduction level was proportional to PUN concentration. CONCLUSION: PUN can inhibit Th2 differentiation and regulate Th1/Th2 balance by regulating IL-4/STAT6 and Jagged1/Notch pathways to alleviate the progress of bronchial asthma in the elderly.