ovalbumin and protocatechuic-acid

To clarify the effects of dietary supplementation of protocatechuic acid (PCA) and in-depth mechanisms on allergic asthma in ovalbumin (OVA)-induced mice.. 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.. Dietary supplementation of PCA was achieved by adding 50 mg/kg PCA to AIN 93G diet for 25 days.. 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.. 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.. 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.

Topics: Allergens; Animals; Asthma; Bronchoalveolar Lavage Fluid; Cytokines; Dietary Supplements; Female; Functional Food; Hydroxybenzoates; Jagged-1 Protein; Jagged-2 Protein; Leukocyte Count; Lung; Mice, Inbred BALB C; Ovalbumin; Receptor, Notch1; Receptor, Notch2; Receptors, Cell Surface; Signal Transduction; STAT6 Transcription Factor

Protocatechuic acid (PCA) has been isolated from the leaves of ilex chinenses and has numerous pharmacologic effects, including anti-inflammatory and antitumoral activities. This study aims to evaluate the antiasthma activity of PCA and investigate its possible molecular mechanisms. BALB/c mice were sensitized and challenged to ovalbumin (OVA).Then mice were intraperitoneally (i.p.) injected with PCA 1h before OVA challenge. We found that PCA treatment at 15 or 30 mg/kg significantly decreased OVA-induced airway hyper-responsiveness (AHR) to inhaled methacholine. Type 2 helper T cell (Th2) cytokines in bronchoalveolar lavage (BAL) fluid, such as interleukin-4 (IL-4), interleukin 5 (IL-5) and interleukin-13 (IL-13), and serum OVA-specific immunoglobulin E (IgE) levels, were also reduced by PCA. Moreover treatment with PCA markedly decreased the number of inflammatory cells in BALF and attenuated OVA-induced mRNA expression of CCl11, CCR3, Muc5ac, acidic mammalian chitinase (AMCase), chitinase 3-like protein 4 (Ym2) and E-selectin in lung tissues, lung histopathological studies showed that PCA inhibited inflammatory cell infiltration and mucus hypersecretion compared with the OVA-induced mice group. We then investigated the possible molecular mechanisms which might be implicated in PCA activity. Our results suggested that the protective effect of PCA might be mediated by the inhibition of the extracellular signal-regulated protein kinase (ERK), p38 Mitogen-activated protein kinase (MAPK) phosphorylation and the nuclear factor-κB (NF-κB) activation.

Topics: Administration, Inhalation; Animals; Anti-Asthmatic Agents; Asthma; Blotting, Western; Bronchoalveolar Lavage Fluid; Cytokines; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Female; Hydroxybenzoates; Immunoglobulin E; Lung; Methacholine Chloride; Mice; Mice, Inbred BALB C; Ovalbumin; Respiratory Hypersensitivity