Acalypha australis L. Extract Attenuates DSS-Induced Ulcerative Colitis in Mice by Regulating Inflammatory Factor Release and Blocking NF-κB Activation

Ulcerative colitis (UC) is a chronic gastroenteric inflammatory disease that may cause life-threatening complications. Currently available therapeutic drugs are not as effective as expected, necessitating the development of new targets and drugs. The etiology and pathogenetic mechanisms of UC are largely unclear; thus, the treatment effects are limited. The aqueous extract of Acalypha australis L. (AAL) has shown good therapeutic efficacy in treating UC. AAL is used in traditional Chinese medicine owing to its hemostasis, detoxification, and heat clearance effects. Although astragalus has such broad-spectrum biological activities closely related to inflammation, its therapeutic efficacy for UC treatment has not been reported, the underlying mechanism remains unknown. We studied the therapeutic effect of AAL on UC in mice and explored its potential mechanism. Mice were treated with AAL aqueous extract for 7 days (20 mg/kg), after which the colon tissue was assessed for damage (colon mucosal damage index [CMDI]), apoptosis (immunohistochemistry), and release of cytokines (enzyme-linked immunosorbent assay). The concentration of AAL aqueous extract at 20 mg/kg significantly improved the CMDI score and colon injury of UC model. It also reduced the serum levels of IL-2, IL-8, IL-17A, IL-22, IFN-γ, and TNF-α, and decreased apoptosis in the colon. AAL water extract also significantly reduced the expression level of NF-κB pathway-related proteins. In conclusion, AAL can protect against UC mainly by inhibiting the expression level of NF-κB pathway-related proteins and reducing the release of inflammatory factors.