Qin Li1,2,3, Yinfan Wu1,2,4, Xingyue Guo1,2,4, Ren Wang5, Yuheng Mao1,2,3, Yimin Zhao1,2,3, Jinchao Zou1,2,3, Chunwei Li6,7, Yanqiu Chen8, Yan Yang9,10,11. 1. Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-Sen University (Guangzhou Campus), Guangzhou, China. 2. Guangdong Engineering Technology Research Center of Nutrition Translation, Guangzhou, China. 3. School of Public Health (Shenzhen), Sun Yat-Sen University (Shenzhen Campus), Shenzhen, China. 4. School of Public Health, Sun Yat-Sen University, Guangzhou, China. 5. Agriculture Life and Environmental Science, University of Alberta, Edmonton, Canada. 6. Guangzhou Key Laboratory of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China. 7. Department of Otolaryngology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China. 8. Department of Otolaryngology, Guangzhou Women and Children Medical Centre, Guangzhou, China. chenyq2014@163.com. 9. Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-Sen University (Guangzhou Campus), Guangzhou, China. yangyan3@mail.sysu.edu.cn. 10. Guangdong Engineering Technology Research Center of Nutrition Translation, Guangzhou, China. yangyan3@mail.sysu.edu.cn. 11. School of Public Health (Shenzhen), Sun Yat-Sen University (Shenzhen Campus), Shenzhen, China. yangyan3@mail.sysu.edu.cn.
Abstract
OBJECTIVE AND DESIGN: To clarify the effects of dietary supplementation of protocatechuic acid (PCA) and in-depth mechanisms on allergic asthma in ovalbumin (OVA)-induced mice. MATERIALS: Female BALB/c mice were randomly divided into three groups (n = 10 in each group): control group, OVA-induced allergic asthma group, and OVA plus PCA group. TREATMENT: Dietary supplementation of PCA was achieved by adding 50 mg/kg PCA to AIN 93G diet for 25 days. METHODS: Peripheral blood cells, pulmonary inflammatory cell infiltration, the levels of IL-4, IL-5, and IL-13 in bronchoalveolar lavage fluid (BALF), the mRNA levels of Th2-related genes in the lungs, and the protein expressions of the IL-4Rα-STAT6 and the Jagged1/Jagged2-Notch1/Notch2 signaling pathways were measured. RESULTS: Significantly reduced inflammatory cells infiltration and mucosal hypersecretion in the lung tissues, repaired levels of interleukin IL-4, IL-5, and IL-13 in the BALF, and decreased mRNA expression of IL-4, IL-5, and GATA3 were observed in OVA plus PCA group. Moreover, PCA treatment down-regulated the protein levels of IL-4Rα-STAT6 and Jagged1/Jagged2-Notch1/Notch2 signaling pathways. CONCLUSIONS: Dietary supplement of PCA alleviated allergic asthma partly through suppressing the IL-4Rα-STAT6 and Jagged1/Jagged2-Notch1/Notch2 signaling pathways in mice. Our study provided the theoretic basis of PCA used as functional food in preventing allergic asthma.
OBJECTIVE AND DESIGN: To clarify the effects of dietary supplementation of protocatechuic acid (PCA) and in-depth mechanisms on allergic asthma in ovalbumin (OVA)-induced mice. MATERIALS: Female BALB/c mice were randomly divided into three groups (n = 10 in each group): control group, OVA-induced allergic asthma group, and OVA plus PCA group. TREATMENT: Dietary supplementation of PCA was achieved by adding 50 mg/kg PCA to AIN 93G diet for 25 days. METHODS: Peripheral blood cells, pulmonary inflammatory cell infiltration, the levels of IL-4, IL-5, and IL-13 in bronchoalveolar lavage fluid (BALF), the mRNA levels of Th2-related genes in the lungs, and the protein expressions of the IL-4Rα-STAT6 and the Jagged1/Jagged2-Notch1/Notch2 signaling pathways were measured. RESULTS: Significantly reduced inflammatory cells infiltration and mucosal hypersecretion in the lung tissues, repaired levels of interleukin IL-4, IL-5, and IL-13 in the BALF, and decreased mRNA expression of IL-4, IL-5, and GATA3 were observed in OVA plus PCA group. Moreover, PCA treatment down-regulated the protein levels of IL-4Rα-STAT6 and Jagged1/Jagged2-Notch1/Notch2 signaling pathways. CONCLUSIONS: Dietary supplement of PCA alleviated allergic asthma partly through suppressing the IL-4Rα-STAT6 and Jagged1/Jagged2-Notch1/Notch2 signaling pathways in mice. Our study provided the theoretic basis of PCA used as functional food in preventing allergic asthma.