Protective effects of Scrophularia striata in Ovalbumin-induced mice asthma model

Background: Scrophularia striata Boiss. (Scrophulariaceae) is a plant growing in the northeastern part of Iran and being used as a traditional herb for various inflammatory disorders. This study was designed to investigate the protective effects of the Scrophularia striata extract in Ovalbumin (OVA) induced-asthma mice model. Methods: OVA-sensitized mice were intrapritonealy treated with two doses (100 and 200 mg/kg) of the extract on days 8 to 14 separately. Broncoalveolar lavage fluids (BALF) was collected 48 h after the final OVA challenge and then the number of eosinophils and other inflammatory cells were assessed by direct microscopic counting. In addition, total immunoglubolin (Ig) E and OVA-specific IgE levels in serum, IL-4 and IL-5 cytokines in BALF were determined by Enzyme-Linked Immunosorbent Assay. Moreover, phytochemical assay by thin layer chromatography (TLC) and the 2, 2 diphenyl-1-picrylhydrazyl (DPPH) were used to evaluate the main compounds and the antioxidant capacity of the plant extract, respectively. Results: The results showed that the main components; including flavonoids, phenolic compounds and phenyl propanoids were presented in the S. striata extract. In addition, the treatment with extract significantly reduced the number of inflammatory cells and suppressed T-helper 2 (Th2) cytokines including IL-4 and IL-5 in BALF. Also, total IgE and OVA-specific IgE levels in the serum decreased. Conclusion: Collectively, it is concluded that the extract has the potential to modulate the Th2 cytokines and could be used as immunomodulatory agent in the treatment of allergic asthma.