Immunomodulatory effects of Astragalus gypsicolus hydroalcoholic extract in ovalbumin-induced allergic mice model

Several studies have demonstrated that herbal extracts possess various biological effects including anti-inflammatory and anti-cancer activities. The present study was aimed to investigate the protective effects of the Astragalus gypsicolus (AG) hydroalcoholic extract in early allergic sensitized mice induced by ovalbumin. Phytochemical assay was used to recognize the main active constituents in the AG hydroalcoholic extract. Mice were immunized with subcutaneous injection of ovalbumin and aluminum hydroxide. Efficiency of sensitization was assessed by serum IgE levels and eosinophil count. After sensitization, two doses of extract (250 mg/kg and 500 mg/kg) were injected intrapritoneally. On day 14, mice were challenged with intrapritoneal injection of ovalbumin. IL-4 and IFNγ levels in broncoalveolar lavage fluid, which had been collected on day 15, were assessed by Enzyme-Linked Immunosorbent Assay (ELISA) kit. Our results indicate two main active constituents including flavonoids and terpenoids are present in the AG hydroalcoholic extract. Intrapritoneal injection of the AG hydroalcoholic extract was able to decrease IL-4 and increase IFNγ. It seems the AG hydroalcoholic extract has the potential to modulate the balance of Th1/Th2 cytokines in allergy.