ARG1 and colitis: Likewise, IP injection of AT-MSCs in combination with oral administration of sulfasalazine, an anti-rheumatic drug with immunomodulatory potential, could alleviate TNBS-induced colitis in vivo through the improving M2/M1 macrophage ratio, attenuation of monocyte chemoattractant protein-1 (MCP-1/CCL2), CXCL9, and improving IL-10, arginase 1 (Arg-1) levels [127].