This study aimed to explore the efficacy and mechanism of combined rhein and emodin in the treatment of ulcerative colitis(UC) from the aspects of network pharmacology, animal inflammation improvement and molecular mechanism. Network pharmacology predicted that combined rhein and emodin acted on 52 potential targets, mainly participating in signaling pathways such as cancer, PI3 K/AKT, microRNAs in cancer and apoptosis. PI3 K/AKT signaling pathway has been reported to be closely related to UC, and the optimal candidate pathway for combined therapy. The UC mice model was established by dextran sodium sulfate, and then the modeled mice were randomly divided into control group, model group, rhein group, emodin group, rhein+emodin group and sulfasalazine group. After administration, compared with the conditions in model group, body weight, disease activity index(DAI) score, colon length, TNF-α, IL-6, IL-1β and myeloperoxidase(MPO) of mice in rhein+emodin group were improved(P<0.01); colonic mucosal injury was significantly reduced; the expression of p-PI3 K/PI3 K and p-AKT/AKT proteins were down-regulated(P<0.01). All the above indices were better than those in the rhein/emodin group alone. The Jin's Q-values of the effect of combined rhein and emodin on colon length, TNF-α, IL-6, IL-1β, MPO, p-PI3 K/PI3 K and p-AKT/AKT were all greater than 1.15, which indicated that there was obvious synergistic effect between rhein and emodin. In all, rhein and emodin have synergistic effect in the treatment of UC, and the mechanism may be related to the inhibition of PI3 K/AKT signaling pathway and the down-regulation of proinflammatory factors. They are the new components in the treatment of UC, which is worthy of attention.
Keywords: combined therapy; emodin; network pharmacology; rhein; ulcerative colitis.