Experimental Studies On The Mechanism Of Astragalus Urticaria

Objective:To investigate the effect and mechanism of astragalus on urticaria animal model.Methods:1.construct the animals model of urticarial with PCA:â‘ antiserum of rats with ovalbumin was prepared.â‘¡experimental animals were divided into five groups randomly: model group,low-dose astragalus group (5g/kg),mid-dose astragalus group (10g/kg) high-dose astragalus group (20g/kg),and ketotifen group (0.7mg/kg).corresponding drugs injected into their stomachs. antiserum within the skin. the experimental animals were attacked with ovalbumin-Evans blue solution, urticarious animals were constrcted.2. measure OD (the optical density) of locus ceruleus with spectrophotometer.3. observe the effect of astragalus on the mast cell degranulation with toluidine blue.4. detect the production of histamine by Elisa.5. observe the effect of astragalus anti histamine with spectrophotometer.Results:1.urticarious model is conducted succeedingly with ovalbumin.2. astragalus significantly lower OD (p<0.05), the inhibition of mid-dose and high-dose is better inhibition on urticaria is the same,of mid-dose astragalus group,high-dose astragalus group and ketotifen group.but the difference between mid-dose and high-dose is not significant.3. astragalus inhibit the degranulation of mast cells.and lower the releasing of histamine (p <0.05).the effect of mid-dose astragalus group,high-dose astragalus group and ketotifen group is not different. and the difference between mid-dose and high-dose is not significant.4. astragalus significantly inhibit telangiectasis caused by histamine (p<0.005).the antagonism is dose-effect relationship.the effect of high dose is the best.the effect of each astragalus group is all lower than ketotifen group.Conclusions:astragalus has an therapeutical effect on urticaria, stabilizing mast cell membrane and inhibiting the degranulation of mast cell are maybe its main mechanisms,besides it maybe rivalry the angiotelectasis caused by histamine.