TLR4 and ulcerative colitis: In an acetic acid–induced ulcerative colitis model, MRS also proved its protective effects by blocking the expression of Toll-like receptor 4 (TLR4) and myeloid differentiation primary response 88 protein (MyD88) and attenuating the expression levels of p-NF-κB, p65, p-JNK, p-ERK and p-P38.