Andrographolide, a diterpenoid lactone derived from the plant Andrographis paniculata, has been studied for its anti-inflammatory and immunomodulatory properties. Preclinical studies, primarily in animal models of inflammatory bowel disease (IBD) such as colitis, have demonstrated that andrographolide can reduce intestinal inflammation by inhibiting pro-inflammatory cytokine production (e.g., TNF-α, IL-6, IL-1β), suppressing NF-κB signaling, and decreasing oxidative stress in the gut mucosa. These effects contribute to improvements in histological and clinical markers of IBD in these models.

Some small-scale clinical studies and pilot trials have also explored the use of Andrographis paniculata extracts (which contain andrographolide as a major active component) in human subjects with ulcerative colitis. For example, a randomized, double-blind, placebo-controlled study published in Alimentary Pharmacology & Therapeutics (2007) found that an extract standardized to andrographolide content was more effective than placebo in inducing remission in mild-to-moderate ulcerative colitis. However, the number of clinical trials is limited, sample sizes are modest, and many studies use whole-herb extracts rather than isolated andrographolide.

In summary, while there is preclinical and limited clinical evidence supporting the potential benefit of andrographolide in IBD, the overall evidence is moderate. More large-scale, well-controlled clinical trials are needed to firmly establish its efficacy and safety in this indication.