The Effect of $\gamma$-PGA on NC/Nga Mice, a Mouse Model for Mite Antigen-induced Atopic Dermatitis

As one of the mucous components of Cheonggukjang, traditional fermented soybean paste, -PGA is a natural substance with diverse functions. In this paper, an in-vivo experiment has been performed using NC/Nga mice in order to find out the efficacy of -PGA in human atopic dermatitis. The NC/Nga mice with BMAC-induced atopic dermatitis were administered -PGA (PGA-HM) with 300 kDa and low-molecular -PGA (PGA-LM), respectively. As a result, a significant decrease in clinical skin severity score was detected in the group that was administered PGA-LM. In terms of serum IgE levels, a significant decline was observed in PGA-LM, compared to the control group. The serum IgG1 levels also decreased more in PGA-LM than in the control group. However, no significant difference was observed in both groups. To witness the induction of Treg cells, mRNA was sampled from the back of PGA-HM- and PGA-LM-administered NC/Nga mice with atopic dermatitis. In terms of the production amount of foxp3 mRNA, which was measured in real-time PCR, the group that was administered PGA-LM was twice as high as the control group. According to a biopsy on the skin on the backs of the mice, the experimental group was also far lower than the control group in terms of epidermis thickness, mast cell infiltration and the number of cells. Therefore, it has been confirmed that the atopic dermatitis symptoms decreased more in the PGA-LM-administered NC/Nga mice than the PGA-HM-administered group by facilitating Treg cells and suppressing the activity of eosinophils and production of IgE and pro-inflammatory cytokines.