Eggshell membrane promotes homeostasis of elastic skin and lung tissue associated with type III collagen and decorin expression and ameliorates pulmonary fibrosis in a bleomycin mouse model

The skin and lungs are barriers to environmental threats such as toxic chemicals and microbial pathogens. The integrity of the extracellular matrix (ECM) in the dermal papillae in the skin and the interstitium in the lungs is critical for tissue homeostasis. However, it is difficult to improve the ECM integrity in the skin and lung simultaneously. Previously, we reported that eggshell membrane (ESM) provided a young ECM environment to dermal fibroblasts in vitro and in mouse skin and increased the elasticity of human skin. Herein, lung fibroblasts cultured on ESM showed markedly higher type III collagen, decorin, and MMP2 levels. Oral ESM administration in mice markedly increased the type III collagen and decorin levels in lung tissues after 2 weeks, and type III collagen, decorin, and MMP2 levels in the papillary dermis after 4 weeks. Furthermore, in a double-blind study involving 30 adults, the arm skin elasticity significantly increased after 8 weeks of ESM administration. Simultaneously, the Tiffeneau-Pinelli index, which is correlated with lung elasticity, increased also significantly. To further explore the effects of ESM on the lungs, we used a mouse model of bleomycin-induced fibrosis. In these mice, ESM significantly suppressed fibrosis at 2 weeks and increased the type III collagen levels in the bronchioles and decorin levels in the alveoli, which was implicated in the suppression of lung fibrosis. Thus, oral ESM intake may prevent the age-dependent decline of the papillary dermis and pulmonary fibrosis by improving the extracellular environment in skin and lung tissues.