Abstract
The seeds of Phaseolus calcaratus Roxburgh (PHCR) are common legumes that comprise part of the daily diet in Chinese and Korean culture. Recent findings highlight anti-inflammatory and anti-septic potentials of catechin-7-O-β-D-glucopyranoside (CGP) isolated from PHCR seeds. We investigated the intestinal anti-inflammatory activity and associated mechanisms of CGP using a rat model of trinitrobenzenesulfonic acid (TNBS)-induced colitis. Oral treatment with CGP (10mg/kg body weight) suppressed body weight loss and intestinal inflammatory damages in TNBS-induced colitic rats. This treatment reduced myeloperoxidase activity and malondialdehyde level, but increased glutathione level in the TNBS colitic rats. CGP treatment also inhibited the TNBS-mediated increases in nitric oxide synthase, cyclooxygenase-2, interleukin-1β, tumor necrosis factor-α, intercellular adhesion molecule-1, and monocyte chemotactic protein-1 proteins or mRNA levels. This inhibition was accompanied by the increased mRNA levels of mucins MUC2 and MUC3. The CGP treatment prevented phosphorylation of p38 mitogen-activated protein kinase, IκB-α, and DNA-nuclear factor-κB binding, all of which were increased in the inflamed colons of TNBS-treated rats. Furthermore, oral administration with a crude PHCR butanol extract (100mg/kg body weight) which contains 1.5% of CGP showed intestinal anti-inflammatory potentials similar to that of CGP. Collectively, our current findings suggest that CGP or CGP-containing PHCR seeds may have favorable effects on intestinal inflammatory diseases.