Clear Heat / Relieve Toxicity: Da Qing Ye

The Cliff Notes version added following my earlier post, below:

This is a very cold herb, related to Ban Lan Gen (same plant, different parts) and Da Qing Ye (also the leaf, but prepared differently). Da Qing Ye goes deeper into the blood than Ban Lan Gen. Ban Lan Gen is good for epidemics and external wind-heat disorders, great for the throat, and also cools the blood, but Da Qing Ye goes even deeper. It is used for severe contagious diseases, according to Bensky, especially involving the lungs and throat. Da Qing Ye is also powerful for dissipating maculae due to heat in the blood. High fevers, insatiable thirst, skin eruptions, loss of consciousness due to the heat going deep into the blood. "Especially effective for blazing fire toxin of the Heart, Lung, and Stomach which attacks upward and outward, causing swollen, sore throat, ulcers of the mouth and tongue...mumps" according to Bensky.

So, for severe deep heat (think Red) break out the Big Green Leaf (Da Qing Ye).


Above is a picture of Da Qing Ye (living, before it is dried) I found on Flickr taken by someone at the Botanical Garden in Berkeley. We should take a fieldtrip there as a class, don't you think? It'd be great to see, touch, and smell the herbs before they are dried, charred, and whatever else happens to them before we use them.

And here it is, dried:
Simply, Da Qing Ye also clears heat and relieves fire toxicity (febrile disease) from epidemics and infections. It is considered to be a very cold herb. I guess one reason why I want to know more about the plants -- how and where they're grown, what they look like when they're alive, etc. -- is because I want to find some kind of pattern, some reasoning to understand their properties. For example, what makes Da Qing Ye very cold? What about it directs it to the Heart, Lung, and Stomach channels? Why is it bitter? Why is it salty?

Because it is very cold it cools the blood, and this function leads to the dissipation of macules--those flat red rash looking spots that were all over that guy's back in the picture in Dennis's PowerPoint.
Macules: the flat rash (above)

And so as far as what we need to know about it for class, that's about it. Da Qing Ye (the big green leaf) is in standardized epidemic formulas for infections "from strep to pneumonia to SARS." Feverish conditions where the blood gets hot.

But I want to know more! Apparently, lots of other people do, too. In a brief search for Da Qing Ye, or isatis indigotica, on the Internet, I found a group of Chinese scientists who analyzed the chemical compounds in the leaf (made no meaning to me, at all) and a woman who grows plants in her garden and makes dyes from them. She compared isatis indigotica (otherwise known as Chinese Woad otherwise known as Da Qing Ye) to its cousin isatis tinctoria (just plain "Woad"). She found that indigotica makes a bluer dye. You want to see her experiment? Look here: http://growingcolour.blogspot.com/2008/08/comparison-between-chinese-woad-isatis.html
It's even more esoteric than studying herbs for medicine.

Okay, a little more from Bensky. He says this herb is for any severe febrile disease that "affects people regardless of their constitution." Meaning, this herb is for those diseases that can kick any one's ass. Also, Bensky says it may be used for "a fire toxin anywhere in the body." He notes that mouth ulcers and throat painful obstruction are two problems it can help to cure.