The Effect Of Oxymatrine On DNCB-induced Mouse AD Model

Objective: To investigate the therapeutic effect of different concentrations of OMT on DNCB-induced mouse AD models,and to explore the therapeutic effect and mechanism of OMT,in order to provide experimental basis for clinical application.Methods: Thirty-five Balb/c mice were randomly divided into 5 groups: normal saline group(20 ml/kg),hydrocortisone group(25 mg/kg),OMT1 group(25 mg/kg),OMT2 group(50 mg/kg)and OMT3 group(100 mg/kg).Each group of mice were irradiated with 100?L of 0.5% DNCB solution to sensitize the abdomen,and once after3 days.On the 7th day of the experiment,0.2% DNCB solution was coated with 100?L of the mice's back,2 times a week for 3 weeks,and the total duration was 4 weeks.At the same time,on the 7th day of the experiment,the mice were given intragastric administration twice a day for 3 weeks.On the 28 th day of the experiment,the skin lesions of the mice were observed and scored.The thickness of the skin lesions was measured by the vernier caliper.The epidermis,spine thickness and inflammatory cell infiltration were observed under microscope.Results:1.The levels of skin reaction in OMT2 group,OMT3 group and hydrocortisone group were significantly higher than those in control group.The difference was statistically significant,suggesting that hydrocortisone and medium and high concentration OMT improve the local skin lesions in AD mice.OMT2 group and OMT3 group were compared with hydrocortisone group,which OMT2 group and OMT3 group P>0.05,the difference was not statistically significant,suggesting that medium and high concentrations of OMT have no significant difference with hydrocortisone in improving the skin lesions of AD mice.2.The thickness of the dorsal skin flap before treatment(0d)and after treatment(28days)of each group was measured.There was significant difference in control group(P<0.01).The result indicates successful modeling of this experiment,and the skin swelling of AD mice were obvious.OMT1 group P<0.05,the difference was statistically significant,indicating that after the treatment of low concentration of OMT,AD mice skin cells were swelling and thickening significantly,which suggests that low concentrations of OMT can not obviously improve skin swelling of AD mice.OMT2 group,OMT3 group and hydrocortisone group P>0.05,the difference was not statistically significant,indicating that after the treatment of medium and high concentration of OMT and hydrocortisone,AD mice skin was not obviously swelled and thickened,which suggests that the medium and high concentration of OMT and hydrocortisone can obviously improve skin swelling and thickening of AD mice.The thickness of the dorsal skinfold was respectively compared between the control group and the other four groups,OMT2 group,OMT3 group and hydrocortisone group were statistically significant than control group(P<0.05),suggesting that the medium and high concentration of OMT and hydrocortisone can improve the formation of DNCB induced AD skin swelling and thickening.OMT2 group and OMT3 group were compared with hydrocortisone group,P> 0.05,the difference was not statistically significant,suggesting that medium and high concentrations of OMT in improving AD skin swelling and thickening has no significant difference with hydrocortisone.OMT2 group was compared with OMT3 group,P> 0.05,the difference was not statistically significant,suggesting that the high concentration of OMT in improving DNCB induced formation of AD mice skin swelling and thickening has no significant difference with medium concentration.3.The number of dermal inflammatory cells in the pathological sections of the control group and the other four groups was compared at the 28 th day.OMT2 group,OMT3 group and hydrocortisone group P<0.05,the difference was statistically significant,suggesting that medium and high concentration of OMT and hydrocortisone all can reduce the AD mice skin lesions inflammatory response.OMT2 group and OMT3 group were compared with hydrocortisone group,OMT2 group P<0.05,the difference was statistically significant,OMT3 group P>0.05,the difference was not statistically significant,which indicates that high concentrations of OMT and hydrocortisone have similar anti-inflammatory effect,while the medium concentration of OMT is poor.Conclusion:1.Medium and high concentration of OMT can reduce the degree of skin lesions,improve local skin lesions and reduce inflammatory cell infiltration in AD mice which were induced by DNCB.2.Medium and high concentration of OMT have similar effect with hydrocortisone in reducing skin lesions swelling degree,improve the symptoms of local skin lesions inthe DNCB induced AD mice.3.High concentration of OMT was similar to that of hydrocortisone in reducing the infiltration of skin lesions in DNCB-induced AD mice,and better than that of medium concentration OMT.