Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD), which is characterized by chronic intestinal inflammation and leads to an increased risk of colon cancer. There are many studies using phyto-ingredients as a novel approach for the treatment of UC. The plant Andrographis paniculata (Acanthaceae) is a safe and edible vegetable that has been extensively adopted in traditional Chinese medicine for conditions involving inflammation, and the most active phytochemical agent is andrographolide. The andrographolide derivative 3,14,19-triacetyl andrographolide, which is known as CX-10 (a hemi chemical synthesized from andrographolide), has been found to possess strong anti-inflammatory properties. In the present study, we investigated the therapeutic potential of CX-10 as a complementary and alternative medicine against dextran sulphate sodium (DSS)-induced ulcerative colitis in mice. Our results revealed that CX-10 treatment reduced body weight loss, reduced colon length shortening, decreased colon weight, decreased the spleen index, decreased the disease activity index (DAI), and alleviated histological damage in the colon. The expression of TNF-α and IL-6 and the activity of myeloperoxidase (MPO) in colonic tissues were significantly reduced in CX-10 supplemented mice. It is noteworthy that the efficacy of 200 mg/kg of CX-10 was equivalent to that of the mesalazine positive control (200 mg/kg). Furthermore, western blot analysis revealed that CX-10 treatment reduced the expression of nuclear factor-κB (NF-κB) p65 and p-IκBα, increased the expression of IκBα and down-regulated the phosphorylation of p38 mitogen-activated protein kinase (MAPK), ERK and JNK. In conclusion, CX-10 treatment attenuated DSS-induced UC in mice through inhibiting the activation of NF-κB and MAPK pathways and reducing TNF-α and IL-6 levels, suggesting that CX-10 is a potential therapeutic drug for UC.