MAPK8 and infection: To investigate the specific mechanism by which HD-13 activates the inflammatory response, following infection with HD-13 for 0 h, 0.5 h, 1 h, and 1.5 h, respectively, Western blot was conducted to assess the levels of MAPK pathway-related proteins, including ERK, p-ERK, p38, p-p38, JNK, and p-JNK in 3D4/21 cells.