The most important category of herbs historically, were the herbs used for fever and infection. Prior to antibiotics and vaccinations, infectious diseases were the biggest threat to people's health. Fevers and infections killed many. As a result every herbal system in the world had a collection of herbal medicines to treat infections.
One particular herb that was used for this was indigo. This is the very same plant that gave us blue dye for blue jeans. There are actually many species of plants that have been used as indigo around the world. They all have similar properties and were used not only for fabric dye but also to clear severe fevers. Some of the plants are referred to as woad or by one of the species names, such as the species Isatis. The use of these various plants as a dye started to decrease about 100 years ago with the advent of synthetic indigo dye. There are some who utilize traditional plants, but the synthetic dye is used in almost all commercial operations.
In Chinese Herbal medicine there are three main variations of Isatis that are used.
Ban lan gen, is the root of the plant and the leaf of the plant is Qing dai. Both are used for fevers and infection. They are said to "clear heat" or essentially bring down the fever associated with the infection. There is a curious variation called Da Qing Ye. It is the processed leaf of the isatis plant. The result of processing is a blue powder. I keep this powder in stock, it comes in very handy for topical infections. It can be mixed with talcum powder to help heal diaper rash in infants. Both the talcum powder and the Da Qing ye help the skin to heal by helping the body control the infection in the skin.
In a world where infectious disease is not the main threat to life, it is easy to forget the historical importance of many common plants that helped people survive. The rise of antibiotic resistant strains of bacteria may make these types of herbs important again, and hopefully make the world a little more colorful.
— David Bock
This article was from David's LakeCountryOnline.com column, "The Practical Herbalist"
David Bock, C. Ac., Dipl. OM, FABORM
Wisconsin Certified Acupuncturist
National Board Certification in Oriental Medicine
Fellow American Board Of Oriental Reproductive Medicine
Bock Acupuncture & Herbal Medicine
888 Thackeray Trail #206
Oconomowoc, Wisconsin 53066