What is it?
Isatis root has not been adequately studied in clinical trials, so it is not known if it works in humans.
Isatis root extract is derived from the same plant from which indigo dye is made. It has been used in combination with other botanicals in traditional Chinese medicine and Ayurveda for a variety of conditions. In animal tests, it reduced inflammation and fever. Other lab experiments show that isatis extract can kill certain viruses and counteract some symptoms and tissue damage from bacterial infections, but it remains uncertain whether these same effects occur in humans.
Lab studies of indirubin, an active compound in isatis, suggest it might stop cell duplication and may be useful in cancer treatment. A small study in humans indicates that an isatis root extract solution may help reduce radiation-induced mucositis in head and neck cancer patients, but more studies are needed.
Isatis leaf has both similar and different properties from isatis root.
What are the potential uses and benefits?
- To treat bronchitis and relieve chest congestion
Lab research suggests that isatis root has anti-inflammatory and immune-stimulating activity, but there is no proof from clinical trials that it can relieve bronchitis and chest congestion. - To treat infections
Although antiviral and immune-stimulating activity has been shown in lab studies, there is no proof from clinical trials that isatis root can effectively treat the common cold, reduce fever, or fight viral infections. In addition, no human studies have been done to verify anecdotal reports that isatis may help ward off severe acute respiratory syndrome (SARS). - To prevent or treat cancer
Lab studies show that an active compound in isatis stops cell duplication, but there is no evidence from clinical trials that it can prevent or treat cancer. In China, isatis is used in combination with other botanicals to treat chronic myelogenous leukemia. - To reduce severity of radiation-induced mucositis
A small study in head and neck cancer patients suggested that a specific isatis root extract solution could reduce severity of mucositis, anorexia, and difficulty swallowing in treated patients compared with a control group.
What are the side effects?
Oral: None reported.
Eyedrops: Feeling a foreign substance or irritation in the eyes (one report each). Symptoms resolved after patients closed their eyes and rested for 3 minutes.
What else do I need to know?
Patient Warnings:
- Some compounds in isatis root could have activity against SARS, but these are only lab experiments. These compounds would need to be further developed and tested because many compounds in isatis root occur only at low levels. Relying solely on herbal supplements to prevent or treat SARS may induce a false sense of security from this deadly disease. Patients with suspected SARS should limit interactions outside the home. The CDC recommends proper hygiene such as frequent hand washing and wearing a surgical mask to help prevent the spread of SARS.
Do Not Take if:
You are taking CYP450 3A4 substrate drugs: Lab studies suggest that indirubin, a component of the isatis plant, may affect how these drugs are metabolized. Clinical relevance has yet to be determined.