P5554 - Coloring Outside the Lines: Indigo Naturalis to Treat Ulcerative Colitis

Nina Quirk, MD, MS¹, Yllen Hernandez Blanco, MD², Erin Rubin, MD³, Andrew Dupont, MD¹
1University of Texas Health Sciences Center in Houston, Houston, TX; 2University of Texas at Houston, Houston, TX; 3McGovern Medical School at UTHealth Houston, Houston, TX

Introduction: Due to the unrelenting nature of symptoms associated with ulcerative colitis (UC), some patients seek alternative therapies for treatment. Indigo naturalis (IN) is a traditional Chinese herb used most commonly in Eastern medicine although popularity in the West is increasing. The mechanism is not entirely known, but IN may decrease activity of pro-inflammatory cytokines and increase that of anti-inflammatory cytokines and tight junction protein occludin. Observational and randomized studies suggest IN can reduce inflammation and symptoms of UC. Adverse effects such as pulmonary hypertension and liver dysfunction have been described. FDA approval has not been obtained for further investigations of side effects, potential therapeutic uses, dosage and routes of administration are warranted. Presented is an interesting case of a patient achieving complete remission of UC after a short course of IN without any significant side effects and maintained remission.

Case Description/

Methods: The patient is a 54-year-old man with a history of diverticulosis who presented with 3 weeks of rectal bleeding, diarrhea, and abdominal pain. Colonoscopy revealed moderate proctosigmoid colitis and he was treated with mesalamine. One month later, the patient lost 10 pounds and continued to have abdominal pain. Fecal calprotectin was 7,560 μg/g. Repeat colonoscopy showed pan-ulcerative colitis with histopathologic findings of moderate to severe active chronic colitis (Images A&B). Despite medical therapy with mesalamine and budesonide, his symptoms persisted. He was prescribed vedolizumab but chose not to start treatment. He established care with an alternative medicine clinic, and stopped budesonide and mesalamine. After taking IN 0.5 g twice a day for one week, his rectal bleeding and abdominal pain stopped. He continued the IN supplement for 1.5 months with complete resolution of symptoms and started to gain weight. Fecal calprotectin decreased to 37 μg/g. Colonoscopy 5 months afterwards was unremarkable (Images C&D). He continues to take herbal supplements with great symptomatic control.

Discussion: Indigo naturalis has been shown to decrease inflammation in UC. This is a case in which a patient had complete resolution of symptoms and histologic remission of UC in response to IN supplementation. More studies are warranted to demonstrate how IN can be integrated in treatment options either alone or alongside traditional medications.


Figure: Image A (Right colon) and Image B (Left colon): H&E stain, 10x. Biopsies of colon September 2024 showing eroded luminal surface with numerous neutrophilic crypt abscesses and cryptitis.


Figure: Image C (Right Colon) and Image D (Left colon): H&E stain, 10x. Biopsies of colon February 2025. No significant histopathologic findings. The glandular architecture is restored without active inflammation.

Disclosures:
Nina Quirk indicated no relevant financial relationships.
Yllen Hernandez Blanco indicated no relevant financial relationships.
Erin Rubin indicated no relevant financial relationships.
Andrew Dupont indicated no relevant financial relationships.

Nina Quirk, MD, MS¹, Yllen Hernandez Blanco, MD², Erin Rubin, MD³, Andrew Dupont, MD¹. P5554 - Coloring Outside the Lines: Indigo Naturalis to Treat Ulcerative Colitis, ACG 2025 Annual Scientific Meeting Abstracts. Phoenix, AZ: American College of Gastroenterology.