The extract from the roots of var. (Coll. et Hemsl.) Rehd. et Wils attenuates DSS-induced ulcerative colitis by regulating the Nrf2/NF-κB signaling pathways.

Ulcerative colitis (UC) is a chronic non-specific inflammatory bowel disease. Many natural medicines or ethnic drugs have been proven to be effective and beneficial in the treatment of UC. Among these, the root of var. (Coll. et Hemsl.) Rehd. et Wils. (ROS), a kind of Yi nationality medicine called "GU-GONG-GUO," has been shown to be useful as a therapeutic agent for sputum and diarrhea. However, the effects and mechanisms of ROS extract (ROE) on UC remain relatively unknown. The aim of this study was to explore the protective effects and the underlying mechanisms of ROE on UC. First, we established a dextran sulfate sodium (DSS)-induced experimental colitis mouse model and then evaluated the anti-inflammatory effects of ROE . Then, RAW264.7 cells were stimulated with lipopolysaccharide (LPS) in the presence or absence of ROE to explore its mechanisms . It was found that ROE attenuated DSS-induced colon length shortening, body weight loss, and colonic pathological damage. Furthermore, ROE inhibited the activity of nitric oxide synthase (NOS), myeloperoxidase (MPO), and malondialdehyde (MDA). Also, ROE decreased several LPS-induced inflammatory cytokines including TNF-α, IL-6, and IL-1β in RAW264.7. In addition, ROE inhibited the expression of p-NF-κB, p-IKKα/β, and Keap1 proteins and increased the expression of Nrf2 and HO-1 proteins. Our study suggested that ROE prevented DSS-induced colitis though the Nrf2/NF-κB pathway. Overall, it can be concluded that ROE may be a promising and effective agent for UC.