The Effect Of Magnesium Isoglycyrrhizinate(MgIG) On Dermatitis And The Anti-inflammation Mechanism Study

Dermatitis is a kind of common disease with high incidence rate,which influence the noremal life of patient by accompany with itch,erythema and so on. At present,the drug therapy of dermatitis is confined on symptoms control drugs such as glucocorticoid and antihistamine drug.With complicated pathogenesis and obvious side effect of repeating use of these drugs,a new drug which is well effect on dermatitis and low side effect is badly needed in clinic.Magnesium isoglycyrrhizinate(MgIG) injection is the forth generation of liquorice acid formulation medicine with single optical isomers.Compared with the former ones,it is in the nature of better effent on antifibrotic,antioxidant, and anti-apoptosis.It has been used in liver diseases in clinic,but the effect on dermatitis has not been proved yet.In our research,we demonstrate the effect of MgIG injection on dermatitis,provide the preclinical study date of the drug in this kind of disease.On the basic of the pharmacody-namics study,we investigated the antiinflammation mechanism of MgIQtrying to identify its effect on NF-κB pathway.l,The effect of MgIG injection on allerge condact dermatitis(ACD)The model of ACD was sensitized on abdomen and challenged on ear by 1% 2,4-dinitrofluorobenzene (DNFB).48 SPF grade ICR mice were divided into 6 groups ran-domly.a control group,a model group,three dosage groups and a positive group.The drug was injected through vena caudalis. The change of ear's swelling and the scores of ear's thickness and erythema of each mouse was observed.The INF-γ,IgE,IL-4,IL-1β,IL-8 level in serum was detected by ELISA method.Then the HE staning the pathologic change of mice ears were examined under light microscope.We get the results as follows:MgIG could decrease(P<0.05) the ear's swelling and the scores of ear's thickness and erythe-ma;and decrease(P<0.05) INF-γ,IL-1βand IgE level in mice serum;It was observed that MgIG could significantly alleviate the infiltrate of inflam cell and the hemangiectasis in ear tissue.2, The effect of MgIG injection on chronic dermatitisThe model of chronic dermatitis was sensitized by 7% 2,4-dinitrochlorobenzene (DNCB) on abdomen and challenged by 0.3% DNCB on ear.48 SPF grade BALB/c mice were divided into 6 groups randomly:a control group,a model group,three dosage groups and a positive group.The drug was injected through vena caudalis. The change of ear's swelling and the scores of ear's thickness and erythema of each mouse was observed.The INF-y,IgE,IL-4,IL-1β,IL-6 level in serum was detected by ELISA method.Then the HE staning the pathologic change of mice ears were examined under light microscope. We get the results as follows:MgIG could decrease(P<0.05) the ear's swelling and the scores of ear's thickness and erythema; MgIG could and decrease(P<0.05) IgE and IL-4 level in mice serum;It was observed that MgIG could significantly alleviate the infiltrate of inflam cell and the hemangiectasis in ear tissue.3, The investigation in antiinflammation mechanism of MgIGThe immunohistochemistry of mouse model ears,established during pharmacody-namics study,show that the expression of TNF-αIFN-γand NF-κB in ear tissue were sig-nifitely allievated after the treatment of MgIG injection. Furthermore,we cultured the hu-man fibroblast. Stimulating with TNF-a,the NF-κB signal transduction pathway was acti-vated.The level of NF-κB in the nuclear and cytoplasm which was determined by west-ern-blotting technique show that MgIG could inhibit the activation of NF-κB. At the same time,the reporter gene show that certain concentration MgIG could inhibit the espression of NF-κB significantly.But the mRNA level of IκBawhich was determined by Realtime PCR technique didn't significantly changed with MgIG deal with or without.The pharmacodynamics study show that MgIG injection have certain effect on derma-titis, which is no significantly different compared with the positive drug compound glycyr-rhizin injection.The antiinflammation mechanism study show that MgIG could inhibit the activation of TNF-a-NF-κB signal transduction pathway.The exactly interaction sites of MgIG on this signal transduction pathway maybe concerned with the expression and transposition into nuclear process of NF-κB transcription factor. And the volum of IκBαmaybe have not taken the part of the mechanism of the antiinflammation effect of MgIG.