Folium Isatidis
Source
Leaf of Isatis tinctoria L., family Cruciferae or Baphicacanthus cusia
(Nees) Brem., family A canthaceae.
Characteristics
I
tinctoria: Leaf long-elliptical, apex obtuse, base narrowing downwards
into wing; margin entire, 5-20 cm long, petiole 4-10 cm long. B. cusia:
Leaf elliptical, margin shallowly serrate, 5-12 cm long. The two kinds
of leaves are papyraceous, and blue green when dried. Bitter and salty
in taste, cold in nature, and attributive to heart, lung and stomach channels.
Indication
Clear away heat and toxic material, cool blood and eliminate eruption:
For qifen and xuefen heat-syndrome with high fever, thirst, restlessness
and skin eruptions, especially for pestilence. Now usually used for influenza,
epidemic cerebrospinal meningitis, encephalitis B, viral pneumonia, mumps,
etc., also for sorethroat, aphthae, inflammatory diseases with 
redness
of skin, etc.
Pharmacological
Action
1. Broad-spectrum antibiotic and also for leptos pirosis.
2. Antipyretic. Its decoction lowers vaccine-induced fever in rabbits.
3. Anti-inflammatory effect on formaldehyde-induced acute arthritis in
rats.
4. Its decoction inhibits toads heart in vitro, more evident with increasing
dose.
Administration
Decoction:
9-15g or 30-60g of fresh herb.