Amelioration of trinitrobenzene sulfonic acid-induced colitis in mice by liquiritigenin.

Abstract

The anti-inflammatory effects of liquiritigenin, a major flavonoid isolated from Glycyrrhizae uralensis, have been reported in many inflammation models. However, its protective effects have not been reported in a colitis model. This study investigated the anti-inflammatory effect and mechanism of liquiritigenin for trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. Male mice imprinting control regions (ICR) were randomly divided into five groups: normal, TNBS-induced colitis, colitis treated with liquiritigenin at low dose (10 mg/kg) and high dose (20 mg/kg), or mesalazine (10 mg/kg). TNBS colitis induction was performed except for in the normal group, and they were treated with liquiritigenin or mesalazine except control group. The treatment effect was measured after three days treatment, by body weight, colon length, macroscopic score, histological score, levels of cytokines (tumor necrosis factor-α, interleukin [IL]-1β, IL-6, and IL-10) in colon tissue as well as the nuclear factor kappa-light-chain-enhancer pathway of activated B cells (NF-κB) activation. Mice treated with high-dose liquiritigenin showed significant body weight gain, inhibition of colon shortening, protective effect on histological damages, and myeloperoxidase activity of colon tissue compared with the control group. Furthermore, mice treated with high-dose liquiritigenin experienced significantly suppressed tumor necrosis factor-α, IL-1β, and IL-6 as well as enhanced IL-10 expression (all P < 0.05). High-dose liquiritigenin treatment group showed significant decreases in TNBS-induced phosphorylation of IKKβ, p65, and IκB-α. Liquiritigenin may ameliorate TNBS-induced colitis in mice by suppressing expression of pro-inflammatory cytokines through NF-κB pathway.