Abstract: Objective To investigate the therapeutic value and possible mechanism of diammonium glycyrrhizinate (DG) in
treatment of airway remodeling in a murine model of chronic asthma. Methods Thirty male BALB/C mice were randomly
divided into control group, OVA + DG group and OVA group (n=10). HE staining was used to observe the pathological
changes, and Masson’s staining was used to detect and measure collagen deposition. Alpha-SMA and PPARγ mRNA
expressions were analyzed by RT-PCR, and the protein expressions of α-SMA and PPARγ were measured by Western blotting.
Results After 75 days of OVA sensitization and challenge, obvious pathological changes occurred in the lung tissues, which
was more severe in OVA group than in OVA + DG group. Collagen deposition was significantly increased after OVA
stimulation, but was obviously milder in OVA+DG group than in OVA group. OVA-induced up-regulation of α-SMA was
notably attenuated by DG injection. The expression of PPARγ was markedly down-regulated after OVA stimulation but was
substantially enhanced after DG intervention. Conclusion DG can inhibit airway smooth muscle proliferation possibly
through up-regulation of PPARγ in a murine model of chronic asthma.