Houtt. Extract Suppresses Colitis-Associated Colorectal Cancer by Regulating Inflammation and Tight-Junction Integrity in Mice.

Irritable bowel disease (IBD), which results in an elevated risk of colitis-associated colorectal cancer (CAC), is characterized by inflammation and barrier disruption of the gut. The genus has anti-oxidative and anti-inflammatory effects, and the roots of Houtt (RJ) have been traditionally used in East Asia to treat digestive problems. We investigated the protective effect of RJ against azoxymethane (AOM)-and dextran sulfate sodium (DSS)-induced CAC in C57BL/6N male mice. The mice were intraperitoneally injected with AOM on the first day and orally treated with 2% DSS for 2 weeks (on the third and sixth weeks). RJ extract (100 mg/kg) was administered to the mice in the RJ group for 4 weeks (from the third to sixth week), and all mice were sacrificed on the final day of the eighth week. Changes in morphology, tight junctions (TJs), inflammation-related factors in the colon and serum inflammatory cytokine levels were measured. The colons of AOM/DSS-treated mice were shorter and heavier than those of normal mice. The number of tumors in the colons of AOM/DSS-treated mice increased; however, RJ suppressed these changes. RJ also reduced the levels of tumor necrosis factor-α, interleukin (IL)-6, and IL-1β in the colon and serum, and it increased the level of IL-10 in the colon. Moreover, RJ inhibited the barrier disruption and apoptosis in the colons of AOM/DSS-treated mice. RJ effectively suppressed AOM/DSS-induced CAC by inhibiting tumor formation, inflammation, disruption of TJ, and apoptosis in the colon.