A man portions out herbs.Share on Pinterest
Researchers studied if Indigo naturalis affected symptoms of ulcerative colitis. Marcus Chung/Getty Images
  • People with ulcerative colitis who continued taking a Chinese herbal medicine were more likely to be symptom-free after a year, compared to those who stopped treatment, a small, preliminary study found.
  • Ulcerative colitis is a type of inflammatory bowel disease (IBD) that causes inflammation and ulcers on the lining of the large intestine and rectum.
  • The Chinese herbal medicine used in the study, indigo naturalis, may work by healing the lining of the intestines. However, larger, more rigorous studies are needed.

An herb used in Chinese herbal medicine helped people with ulcerative colitis stay symptom-free for up to a year with no serious negative side effects, a preliminary study found.

Ulcerative colitis is a type of inflammatory bowel disease (IBD) that causes inflammation and ulcers (sores) on the lining of the large intestine and rectum. Severity of symptoms vary, but can include abdominal pain, bloody stools and diarrhea.

In the study, which included a small group of people with ulcerative colitis who had already been receiving oral treatment with indigo naturalis, those who continued the therapy were more likely to be in remission after one year, compared to those who stopped taking the Chinese herbal medicine.

“[Indigo naturalis] appears to be very effective in maintaining remission,” the authors wrote in the abstract, which was presented Jan. 25 at the Crohn’s & Colitis Congress taking place in Las Vegas.

However, Dr. Rudolph Bedford, a gastroenterologist at Providence Saint John’s Health Center in Santa Monica, Calif., cautioned that more research is needed.

“There are reasons to consider using something [like indigo naturalis], but it’s certainly going to need further study, and under very rigorous protocols,” he told Healthline.

Twenty patients with ulcerative colitis took part in the new study, which was carried out in Japan. Around half of the patients were male, and the average age was around 33 years.

All patients had been receiving treatment with indigo naturalis for at least one year. Researchers randomly assigned patients to either continue with indigo naturalis therapy or discontinue it, with half in each group.

Researchers monitored patients over the next year to see how many in each group saw a return of their ulcerative colitis symptoms.

Patients who relapsed during this time were treated with other medications commonly used for ulcerative colitis, such as azathioprine (Imuran) or tumor necrosis factor (TNF) inhibitors (anti-TNF drugs).

After one year, 90% of patients who continued indigo naturalis therapy were in remission, meaning they had no symptoms. In contrast, 20% of those who discontinued indigo naturalis therapy were in remission at that time.

Of the nine patients who relapsed during the year, seven restarted indigo naturalis therapy or increased their dose if they were still on the therapy. All of these patients went into remission again, researchers found.

This suggests that stopping indigo naturalis therapy after remission may be an option, the researchers write. If symptoms return, patients can start taking the herbal medicine again and once again achieve remission.

Researchers did not observe any serious negative side effects during the study period.

The use of this Chinese herbal medicine for ulcerative colitis is not new. Other research has found that it is effective for the treatment of this condition.

“Indigo naturalis has been used for some time,” said Bedford. “It’s known, certainly in parts of Asia, as an induction therapy for ulcerative colitis and even Crohn’s disease.”

Induction therapy in inflammatory bowel disease (IBD) is used to get you into remission by quickly reducing inflammation in the digestive system. This is followed by long-term maintenance therapy to keep your IBD under control.

“The problem, as has been noted previously [in other studies], is that there may be some adverse events that make long-term use of indigo naturalis somewhat of a challenge for many patients,” said Bedford.

Previous studies of indigo naturalis have raised concerns about side effects such as liver, stomach or intestinal problems; or pulmonary high blood pressure, which affects the arteries in the lungs and the right side of the heart. However, some research suggests that short-term use may be safe.

Whether people experience adverse events with indigo naturalis “may have to do with dosaging and dose reductions,” said Bedford. “But the bottom line is that it needs much more formal study, using randomized trials with larger populations.”

Additionally, herbs and supplements are not regulated by the U.S. Food and Drug Administration, so someone seeking out this herb in the U.S. could be at risk of consuming other substances.

In a small preliminary study, researchers found that people with ulcerative colitis who continued taking the Chinese herbal medicine indigo naturalis were more likely to be symptom-free after a year, compared to those who stopped the treatment.

In addition, many people whose symptoms returned during the study’s observation period saw improvements in their symptoms when they started taking indigo naturalis again or increased their dose.

The study was small and has not yet been published in a peer-reviewed journal. More research is needed, including larger, randomized controlled trials.