Abstract:

The research aimed to study the mechanism of dipotassium glycyrrhizinate in promoting skin repair and its relationship with inflammatory reaction. The inflammatory model of mouse monocyte macrophage （RAW264.7） induced by LPS was treated with different mass fractions of dipotassium glycyrrhizinate, and the expressions of TLR2 and CD163 on the surface of RAW264.7 cells were detected by flow cytometry. The results show that dipotassium glycyrrhizinate inhibits the expression of TLR2 on the cell membrane and promotes the expression of CD163, indicating that dipotassium glycyrrhizinate inhibits the M1 polarization of macrophages and promotes the M2 polarization. It is confirmed by immunofluorescence that dipotassium glycyrrhizinate can prevent M1 polarization by inhibiting the production of ROS in macrophages. By detecting the NO content and the secretion of TNF-α, IL-4, IL-6 and IL-10, the inflammatory factors and mediators related to M1/M2 polarization were studied. Among them, the contents of NO, TNF-α and IL-6 decrease, while the contents of IL-4 and IL-10 increase, which prove that dipotassium glycyrrhizinate regulates LPS-induced M1 polarization of macrophages and promotes the secretion of M2 polarization marker protein. In order to study the mechanism of promoting skin repair by dipotassium glycyrrhizinate, the scratch and proliferation experiments of HaCaT human keratinocytes （HaCaT） were carried out with different mass fractions of dipotassium glycyrrhizinate and the culture medium of RAW264.7 cells treated with dipotassium glycyrrhizinate. The results confirm that dipotassium glycyrrhizinate can promote the proliferation of HaCaT cells, but can not directly promote the migration of HaCaT cells. However, it can promote the migration and proliferation of HaCaT cells by regulating the polarization of RAW264.7 cells. To sum up, dipotassium glycyrrhizinate can improve the M1 polarization of RAW264.7 cells induced by LPS, regulate the secretion of inflammatory factors, and promote the migration of HaCaT cells and skin repair.

Key words: dipotassium glycyrrhizinate, macrophage polarization, skin repair