ovalbumin and myricetin

Myricetin, a flavonoid isolated from many edible vegetables and fruits, has multiple biological effects, including anti-inflammatory and anti-tumor effects. Myricetin could inhibit mast cell degranulation in vitro, and it reduced the eosinophil content in bronchoalveolar lavage fluid (BALF) of ovalbumin (OVA)-sensitized mice. However, it remains unclear whether myricetin alleviates airway hyperresponsiveness (AHR), airway inflammation, and oxidative stress in asthma. Here, we investigated whether myricetin attenuated AHR, airway inflammation, and eosinophil infiltration in lungs of asthmatic mice. Mice were sensitized with OVA, then injected intraperitoneally with myricetin to investigate anti-inflammatory and antioxidant effects of myricetin. Moreover, we examined its effects on human bronchial epithelial BEAS-2B cells stimulated with TNF-α and IL-4, in vitro. Myricetin effectively mitigated eosinophil infiltration, AHR, and goblet cell hyperplasia in lung, and it reduced Th2 cytokine expression in BALF from asthmatic mice. Myricetin effectively promoted glutathione and superoxide dismutase productions and mitigated malondialdehyde expressions in mice by promoting Nrf2/HO-1 expression. Myricetin also reduced the production of proinflammatory cytokines, eotaxins, and reactive oxygen species in BEAS-2B cells. Myricetin effectively suppressed ICAM-1 expression in inflammatory BEAS-2B cells, which suppressed monocyte cell adherence. These results suggested that myricetin could effectively improve asthma symptoms, mainly through blocking Th2-cell activation, which reduced oxidative stress, AHR, and airway inflammation.

Topics: Animals; Anti-Inflammatory Agents; Asthma; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Flavonoids; Humans; Inflammation; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Oxidative Stress

The bee pollen is used in folk medicine to alleviate allergic reactions. The bee pollen phenolic extract (BPPE) consists in phenolic compounds (flavonoids) from plants picked by Apis mellifera bee.. Here we evaluated the anti-allergic property of the BPPE and the flavonoid myricetin (MYR) in murine model of ovalbumin (OVA)-induced allergy.. The study focused on the BPPE or myricetin treatment of OVA-sensitized BALB/c mice and their effects on the IgE and IgG1 production, pulmonary cell migration, eosinophil peroxidase (EPO) activity and anaphylactic shock reaction.. The BPPE treatment (200mg/kg) showed inhibition of the paw edema, IgE and IgG(1) OVA-specific production, leukocyte migration to the bronchoalveolar lavage (BAL) and EPO activity in lungs. In addition, BPPE treatment showed partial protection on the anaphylactic shock reaction induced by OVA. Treatment with myricetin (5 mg/kg) also inhibited pulmonary cell migration and IgE and IgG(1) OVA-specific production.. These results support the hypothesis the myricetin is one of the flavonoids of BPPE responsible for the anti-allergic effect and a potential tool to treat allergies.

Topics: Anaphylaxis; Animals; Anti-Allergic Agents; Bees; Bronchoalveolar Lavage Fluid; Cell Movement; Disease Models, Animal; Eosinophil Peroxidase; Female; Flavonoids; Immunoglobulin E; Immunoglobulin G; Leukocytes; Male; Mice; Mice, Inbred BALB C; Ovalbumin; Plant Extracts; Pollen; Rats; Rats, Wistar