Researchers in Japan have found a common herbal remedy that protects against colitis, an inflammatory bowel disease condition.
A new study by Zhengzheng Shi and colleagues at the RIKEN Center for Integrative Medical Sciences (IMS) found that DKT – a herbal medicine containing ginger, pepper, ginseng, and maltose reduced the severity of inflammatory bowel disease in lab mice. The herbal medicine prevented the loss of important gut bacteria and increased immune cell levels in the colon that fight inflammation.
Colitis, one of two inflammatory bowel disease conditions, is the chronic inflammation of the colon. It is characterised by an imbalance in the gut bacteria and an abnormal immune response. The prevalence of this condition has doubled over the last 20 years, and although treatments are available, they are only partially effective. This pushed researchers to look at alternative options such as traditional herbal medicines.
The findings were published in Frontiers in Immunology.
What is Daikenchuto (DKT)?
DKT is a formula containing specific amounts of ginger, pepper, ginseng and maltose. It is one of the 148 herbal medicines called Kampo, which was developed in Japan and prescribed by doctors to treat different illnesses.
Previous research has eluded that DKT may be useful for treating colitis, but evidence, particularly at the molecular level, has been lacking. The lack of research in this area led the researchers to conduct a detailed examination of its effects on a mouse model of inflammatory bowel disease.
Treating inflammatory bowel disease with herbal tea
Colitis, one form of inflammatory bowel disease, was induced in mice using dextran sodium sulphate, which is toxic to the cells that line the colon. When the mice were given DKT, their body weights remained normal, and they had lower clinical scores for colitis. Further analysis found much less damage to the cells lining the colon. This showed that DKT does protect against inflammatory bowel disease; the researchers then analysed the gut microbiome of the mice and the expression levels of anti-inflammatory immune cells.
Gut microbiomes contain multiple bacteria and fungi that aid in digestion and the immune system. Treating the mice with DKT restored the missing bacteria seen in inflammatory bowel disease, particularly those from the genus Lactobacillus— and levels of propionate were normal.
Colitis is also associated with an abnormal immune response causing intestinal inflammation. The team analysed the innate intestinal immune cells and found levels of a type called ILC3 were lower in the untreated colonic mice, and the mice lacking ILC3 suffered more and did not benefit from the tea. Lastly, the qPCR analysis indicated that these important immune cells had receptors for propionate, called GPR43, on their surface.
“Daikenchuto is commonly prescribed to prevent and treat gastrointestinal diseases, as well as for reducing intestinal obstruction after colorectal cancer surgery,” said Satoh-Takayama, one of the researchers. “Here we have shown that it can also alleviate intestinal diseases like colitis by rebalancing Lactobacillus levels in the gut microbiome. This likely helps reduce inflammatory immune responses by promoting the activity of type 3 innate lymphoid cells.”
