OBJECTIVETo explore the effects of acidic fraction of Pheratima extract in an ovalbumin (OVA) induced asthma mouse model, and to provide the experimental evidences for the anti-asthmatic application of Pheratima extract with further purification and development.

METHODMice model of allergic asthma was established through the OVA challenge. To investigate the inflammatory cell level and Th1/Th2 levels as well as the therapeutic effects of acidic fraction from Pheratima extract, cell count of bronchoalveolar lavage fluid (BALF) was performed to evaluate the secretion of eosinophils (EOS) cells, and IgE, IL-4, IL-5, IL-13, IFN-y levels were detected by ELISA.

RESULTCompared with control group, the EOS count of BALF in the model group was remarkably increased (P<0.01), and IgE, IL-4, IL-5, IL-13 levels were also increased (P<0.01), while IFN-gamma decreased (P<0.01). Acidic fraction from Pheratima (S) extract and its 30% ethanol washed fraction (S30) significantly inhibited the increase of EOS count (P<0.01), decreased the IgE, IL-4, IL-5, IL-13 levels (P<0.05), and inhibited the decrease of IFN-gamma level (P<0.01).

CONCLUSIONThe results indicate that inhibition of the EOS secretion and balancing of the altered Th1/Th2 levels may be important mechanisms of Pheratima's therapeutic effect in asthmatic mice model, and S30 is pharmacologically effective as evaluated with the above mentioned parameters, as a representative fraction of the Pheratima extract.