Abstract
The Dai prescription Yajieshaba is widely used in Traditional Dai Medicine to treat food allergies and intolerance. However, information on the active chemical ingredients, effects and mechanisms of action of Yajieshaba is limited. The present study aimed to elucidate the effects and underlying mechanisms of Yajieshaba in the treatment of food allergies. Liquid chromatography with a diode array detector was used to measure the levels of palmatine and berberine, the active ingredients of Yajieshaba. A food allergy model was established in female BALB/c mice by three injections of ovalbumin (OVA) at 0, 48, and 96 h. OVA-sensitized mice recieved no treatments (control), Yajieshaba, loratadine, palmatine or berberine. The scratching frequency, serum immunoglobulin (Ig)G, IgE, interleukin (IL)-4, IL-10, IL-17, IL-21, interferon-γ and tumor necrosis factor-α levels were assessed at 50 and 98 h. The percentage of regulatory T cells (Tregs) was evaluated by flow cytometry at 98 h. The scratching frequency induced by OVA was significantly suppressed in mice treated with loratadine, palmatine, berberine or 3.50 and 4.70 g/kg Yajieshaba. The frequency of CD4+CD25+Treg in the spleen increased from 6.80% in mice in the control group to 12.50% in mice treated with 4.70 g/kg body weight Yajieshaba. Mice treated with palmatine or 4.70 g/kg body weight Yajieshaba had increased forkhead box p3 expression compared with those in the control group. Treatment with Yajieshaba decreased the scratching frequency and increased CD4+CD25+Foxp3+ Treg frequency in the spleen. This indicated that symptoms of allergic reaction were alleviated following Yajieshaba treatment. Palmatine was identified as one of the major active components of Yajieshaba. The present study identified the possible mechanism through which Yajieshaba treatment may alleviate food allergy symptoms.