A guideline of antiphotoaging activity of polysaccharide assay in vitro and in vivo

People have become increasingly concerned about skin beauty and health issues, especially skin photoaging. Previous studies showed that skin photoaging was characterized by skin roughness and dryness. It was caused by UV radiation-related dysregulation of matrix metalloproteinases (MMPs) and oxidative stress. Therefore, to investigate the antiphotoaging activity of polysaccharides, it is critical to establish the skin photoaging model, including the in vitro cellular model and the in vivo animal model. The in vitro cellular model is judged by cell viability, the MMPs expression, oxidative detection, and the quantities of inflammation cytokines. Moreover, both the damage to the epidermis and dermis of nude mice and the change of collagen content in the skin are indicators of the in vivo animal model. Thus, in this guideline, we tried to summarize the practice of antiphotoaging activity for polysaccharides.