Ancient blue dye as medicine?

Qing Dai 青黛, aka Natural Indigo, or Indigo Naturalis, is a dark blue powder paired with a funky smell. In TCM, its mainly used for the effects of clearing away heat and detoxifying, cooling blood and eliminating spots, purging fire and calming convulsion. It is used for febrile diseases with excessive heat, macules, vomiting blood, hemoptysis, sore throat, epilepsy in children, sores, erysipelas, snake and insect bites, etc.

But did you know that it was also widely used as a pigment for paintings, dating back to the Middle Ages? Ranging from ancients greek and roman painters, all the way to Jeans manufacturing.

An excerpt from 'WebExhibits.Org':

Used for four millennia in the Middle East, Indigo provided the 'blue' of Denim Jeans. The word "jeans" comes from the French phrase bleu de Gênes, literally the blue of Genoa. Jeans fabric, or denim, originated independently in two places: the French town of Nîmes, which 'denim' owes its name to; and in India, where trousers made of denim material were worn by the sailors of Dhunga, which came to be known as dungarees. At around the same time, denim trousers were made near Turin (Italy), during the Renaissance, and were popularised in the 16th century. These trousers were sold through the harbour of Genoa. Traditionally, jeans are dyed to a blue color using indigo dye. Approximately 20 million tons of indigo are produced annually for this purpose, though only a few grams of the dye are required for each pair of trousers. 

Going back to its purposes in Traditional Chinese Medicine, there are new scientific research using modern approaches being done on this pigment. You can now find many new scholarly articles on its benefits on multiple diseases, notably Psoriasis.

That being said, it is always recommended to consult a Registered Traditional Chinese Medicine Practitioner for ways to properly incorporate new herbs into your diet. 

Here are the Results taken from this article's abstract on how Indigo can be an effective therapy to Psoriasis patients:

Results: This manuscript reviews a great deal of information about how Indigo Naturalis can treat psoriasis through immune cells, signal pathways and disease-related mediators. The mechanism of cymbididae is expounded from the aspects of regulating keratinocyte proliferation and differentiation, regulating inflammatory infiltration of cellular immune system and improving microvascular dilation and hyperplasia in skin lesions. 

You can find Indigo Naturalis on our online store here.

Citations:

Zhang Q, Xie J, Li G, Wang F, Lin J, Yang M, Du A, Zhang D, Han L. Psoriasis treatment using Indigo Naturalis: Progress and strategy. J Ethnopharmacol. 2022 Oct 28;297:115522. doi: 10.1016/j.jep.2022.115522. Epub 2022 Jul 22. PMID: 35872288.

Yao, Tianwen; Yang, Baican. Indigo Naturalis (青黛) Comes from Blue, but It Excels Blue. Chinese Medicine and Culture 2(2):p 80-83, Apr–Jun 2019. | DOI: 10.4103/CMAC.CMAC_22_19