How to understand causes of asthma from TCM

Condition analysis:
The name of Xiao Chuan was initially introduced in Dan Xi Xin Fa (Zhu Danxi’s Central Methods, literally, "heart" methods). But similar terms describing the symptoms, like abnormal rising of Qi and gasp, were way earlier in Huangdi Neijing (The Inner Canon of Huangdi). Chinese medicine believes that the root cause lies in deficiency combined with underlying chronic phlegm in lung. On top of exogenous pathogenic attacks, eating disorders, disorders in minds and emotions, and overstrains causing internal damage, it will lead to retention of phlegm in airway and adverse rising of lung Qi, which in turn induce these symptoms and signs. Clinically it divides into the attack stage and chronic remission stage (symptom-free for very long periods), in which different herbs for asthma should be used respectively.

Instructions:
1. Adhatoda (Adhatoda vasica)
This herb is a small evergreen shrub that is found at lower altitudes in India and South East Asia.

The leaves of the herb have been used for centuries to treat asthma where they work as a bronchodilator and mild expectorant. Adhatoda also works by decreasing the viscosity of mucous to assist with expectoration.

Key constituents of adhatoda leaves are the quinazoline alkaloids (0.5–2%). The major alkaloid is vasicine present at levels of 45–95% and is the original source of the drug bromhexine, which is often still used to assist expectoration.

2. Ginkgo Biloba (Ginkgo biloba)
One of the oldest herbs in use today, ginkgo has a broad range of indications.

For asthma sufferers, ginkgo works to inhibit PAF (platelet activating factor), a powerful inducer of platelet aggregator and anaphylactic reactions.

Medicinal herbs that stimulate anti-PAF activity are known to assist in the treatment of Asthma, allergic reactions, thrombosis and shock.

3. Chinese Skullcap (Scutellaria baicalensis)
The root of this plant has been used in traditional Chinese medicine (TCM) for a variety of conditions including asthma.

Chinese skullcap contains flavone derivatives including baicalin, wogonin, and baicalein which inhibit histamine release from mast cells in vitro.

Baicalin showed antiasthmatic activity (antihistaminic and anticholinergic activity) in isolated tracheal muscle from asthmatic guinea pigs. Reducing hypersensitivity and inflammation in airways is vital to managing asthma.