Screening the Effective Fraction of Gerbera Piloselloides (Linn.) Cass Against Bronchial Asthma Induced by Ovalbumin in Mice

OBJECTIVE To establish an ovalbumin(OVA)-induced bronchial asthma mouse model and screen the effective fraction of Gerbera piloselloides (Linn.) Cass extract against asthma. METHODS The 50% ethanol extract of G. piloselloides was segmented and enriched by D101 macroporous adsorption resin, obtaining three elution fractions regarding water fraction, 60% ethanol fraction and 95% ethanol fraction. The asthma model was established, after the mice being sensitized with OVA solution by intraperitoneal injections, and the mice being challenged through aerosol inhalation of OVA. Mice were treated with corresponding drugs for 6 consecutive days during the OVA excitation phase. The effect of different fractions on behaviors about asthma symptoms was assessed through recording and calculating behavior score, and the concentration of cytokines IL-5 in serum and bronchoalveolar lavage fluid(BALF) and serum immunoglobulin IgE was measured by enzyme linked immunosorbent assay(ELISA). Additionally, histopathological changes of lung tissue were evaluated with HE staining. RESULTS The behavior scores of asthma symptoms and the levels of IgE and IL-5 in serum were significantly raised, and the concentration of IL-5 in BALF was also significantly increased in model group. Compared with model group, the asthma symptoms were significantly improved, and the levels of IgE, IL-5 in serum or BALF were significantly decreased in the mice of 60% ethanol fraction with high-dose group. For histopathological examination, the results showed that the extent of alveolar septal thickening was reduced and the infiltration of inflammatory cells around blood vessels and bronchi was significantly cut down in mice treated with 60% ethanol part relative to mice in the model group. CONCLUSION The 60% ethanol fraction of the 50% ethanol extract from G. piloselloides is the active fraction on treating asthma, in which the major chemical compounds are phenolic acids, flavonoids and coumarins.