The antiallergic activity of flavonoids extracted from <italic>Citri Reticulatae</italic> Pericarpium.

Abstract: The fruits of Citrus are popular all over the world. It was reported that the extracts of fruits possessed antiallergic activities. In China, <italic>Citri Reticulatae</italic> Pericarpium (CRP) is a production of peels. In this study, flavonoids were extracted by solvent method, and enriched by polyamide. Then antiallergic activity of flavonoids was investigated in vivo and in vitro. Under optimal parameters, most abundant compounds of extracts were hesperidin and narirutin, their contents were 232.0325 and 98.7946 mg/g, respectively. In vitro, RBL‐2H3 cell line was used to investigate the antiallergic activity. As the results shown, β‐hexosaminidase release of antigen‐induced degranulation was decreased by flavonoids. An ovalbumin‐induced allergic asthmatic model was used to test the activity of the flavonoids in vivo. After treated with different concentrations of flavonoids, the levels of IgE, IL‐4, and IL‐13 decreased significantly. These findings provide evidence that flavonoids extracted from CRP have potential using in antiallergic therapeutic area. Practical applications: Oranges are popular all over the world as fruit, besides a little percent of peels are applied as traditional medicine in China, the others are thrown away as rubbish. To explore the new way to extend the application of peels, we extracted the total flavonoids from <italic>Citri Reticulatae</italic> Pericarpium (CRP) and evaluated the antiallergic activity of it. Fortunately, the total flavonoids have antiallergic activity in vitro and vivo. The findings provide evidence that extracts from CRP have potential using in antiallergic therapeutic area. It can also afford a theoretical basis for the new application of orange peel. [ABSTRACT FROM AUTHOR]