Indigo's therapeutic uses
Indigo, derived from the plant species *Indigofera tinctoria*, has a rich history of use in traditional medicine, particularly in India and China, where it has been used to treat various conditions, including liver disease, epilepsy, and bronchitis. While it is well-known for its exquisite blue dye, scientific support for its therapeutic benefits is limited. Some research suggests that indigo extracts may offer liver protection against chemical injuries, although there have been findings indicating potential liver dysfunction at higher doses. Additionally, the related species *Indigofera oblongifolia* has shown promise in laboratory studies for antibacterial and antifungal activity, as well as potential antioxidant and anti-inflammatory properties. Preliminary studies suggest therapeutic possibilities for conditions like psoriasis and gastrointestinal issues, such as ulcerative colitis. Despite its traditional safety profile, concerns regarding its use persist, especially for pregnant or nursing women, children, and individuals with severe liver or kidney issues. Furthermore, some indigo species can be toxic, underscoring the importance of proper sourcing and preparation. Overall, while indigo holds historical significance in herbal medicine, further research is necessary to substantiate its efficacy and safety for therapeutic use.
Indigo's therapeutic uses
DEFINITION: Natural plant product used to treat specific health conditions.
PRINCIPAL PROPOSED USES: None
OTHER PROPOSED USES: Antiseptic, liver protection
Overview
The leaflets and branches of the indigo plant yield an exquisite blue dye; people around the globe have used it to color textiles and clothing for centuries. Before the development of synthetic blue dyes, indigo was cultivated for this pigment rather than for medicinal use. It is also sometimes called Qing Dai.
In the traditional medicine of India and China, indigo was used in the treatment of conditions now known as epilepsy, bronchitis, liver disease, and psychiatric illness. It was also used for sore throats, fever, Crohn's disease, and skin boils. However, few scientific studies support the medicinal use of indigo.
Therapeutic Dosages
No standard dosage of indigo has been established. Doses over 30 grams are known to cause adverse side effects.
Therapeutic Uses
Based on its traditional use for liver problems, researchers have investigated whether indigo might protect the liver against chemically induced injury. Animal studies suggest that extracts of the indigo species Indigofera tinctoria protect the liver from damage by toxic chemicals. One study examining indigo’s effects on the liver found it caused mild liver dysfunction.
The species I. oblongifolia has been tested for its antibacterial and antifungal activity. In a test-tube trial, this plant showed significant activity against certain bacteria and fungi. This research is still in its preliminary stages, so it is too early to tell whether I. oblongifolia will prove useful for the treatment of any infectious diseases. The species I. oblongifolia also showed antioxidant, anti-inflammatory, and antiapoptotic properties in another clinical study. Preliminary evidence also suggests it may aid in treating psoriasis and gastrointestinal issues, such as ulcerative colitis.
A different plant called wild indigo (Baptisia tinctoria), in combination with echinacea and white cedar, has been studied as a possible immune stimulant. However, wild indigo is not part of the Indigofera genus of plants and is not discussed here.
Safety Issues
The indigo species I. tinctoria has a history of use in traditional medical systems, and it is regarded by herbalists as safe; occasional allergic reactions have been reported. However, comprehensive safety tests have not been performed. For this reason, indigo should not be used by pregnant or nursing women, young children, or persons with severe liver or kidney disease. Safety in other persons is unknown. Long-term use can cause pulmonary hypertension. Individuals who regularly use Indigo to treat ulcerative colitis experience negative effects and a return of their ulcerative colitis symptoms when trying to stop using the herb.
The species I. spicata (formerly I. endecaphylla), however, is poisonous: It has killed cattle and other animals and has caused congenital abnormalities in rats. Other indigo species have also been found to be lethal. For this reason, it is important to avoid ingesting indigo internally unless one is certain that it has been harvested and processed expertly and reliably.
Bibliography
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Dkhil, Mohamed A., et al. "Effect of Indigofera Oblongifolia on the Hepatic Oxidative Status and Expression of Inflammatory and Apoptotic Genes during Blood-Stage Murine Malaria." Oxidative Medicine and Cellular Longevity, 2019, doi.org/10.1155/2019/8264861.
“Indigo Uses, Benefits & Dosage.” Drugs.com, 18 Dec. 2023, www.drugs.com/npp/indigo.html. Accessed 20 Sept. 2024.
Matsuno, Yuichi, et al. “One-year Clinical Efficacy and Safety of Indigo naturalis for Active Ulcerative Colitis: A Real-world Prospective Study.” Intestinal Research, vol. 20, no. 2, 2022, pp. 260-68. doi:10.5217/ir.2021.00124.
Shimada, F., et al. "Clinical Outcomes of Patients with Remitting Ulcerative Colitis after Discontinuation of Indigo Naturalis." Scientific Reports, vol. 14, no. 5778, 2024, doi.org/10.1038/s41598-024-56543-y.
Speranza, Jasmine, et al. "Isatis Tinctoria L. (Woad): A Review of Its Botany, Ethnobotanical Uses, Phytochemistry, Biological Activities, and Biotechnological Studies." Plants, vol. 9, no. 3, 2020, doi.org/10.3390/plants9030298.
Wustenberg, P., et al. “Efficacy and Mode of Action of an Immunomodulator Herbal Preparation Containing Echinacea, Wild Indigo, and White Cedar.” Advances in Therapy vol. 16, 1999, pp. 51-70.