Known since antiquity across at least 4 continents, #indigo dye can be produced from a variety of different plants. By Roman times, India had emerged as a major producer,
👉with the Indigofera tinctoria plant as a primary source. Indigo plants contain #indican, a colorless molecule comprised of #indole coupled to a sugar.
Blue dye is produced by fermenting the leaves and allowing the product to oxidize.
👉All organisms contain indole-based molecules, notably the amino acid tryptophan that humans get from food. Some individuals with defective tryptophan metabolism have enough indican in their urine to turn it blue (#bluediapersyndrome).
Plants are a particularly good source of indican because
their cells have a place to accumulate it in significant amounts.
All cells are surrounded by a membrane that separates “inside” from “outside”, but plant cells have a large internal #vacuole
separated by a membrane from the rest of the cell - think of it as a courtyard that for storing materials like indican and other molecules that don’t belong inside the main cell compartment.
👉Besides being a dye, indigo also has medical applications. In traditional Chinese medicine, indigo is known as #Qingdai
and advised for medicating numerous conditions.
In contemporary medicine, indigo is recognized as a remedy for inflammatory bowel disease, and also for the skin condition #psoriasis where it restores #tightjunction barrier function by upregulating their #claudin component.
Thus by accessing the plant’s indican store, we humans have not only been able to make an excellent dye for cloth, but also produce yet another medicinal phytochemical.
Indigo dye. In Wikipedia, The Free Encyclopedia. Retrieved 13:58, December 16, 2021. https://lnkd.in/gFGR6jRs
Sun, Quan, et al. "A Comprehensive Review of the Chemistry, Pharmacokinetics, Pharmacology, Clinical Applications, Adverse Events, and Quality Control of Indigo Naturalis." Frontiers in Pharmacology 12 (2021): 1269. https://lnkd.in/gAyQtY4c