Woodcut illustration from an edition of 1833 (13th year of Daoguang reign period of Qing dynasty). he image and text give an account of the principles of diseases treated with Minor Bupleurum decoction (xiao chaihu tang), and the therapeutic effects of the individual ingredients of this remedy. Minor Bupleurum decoction is chiefly used to treat cases where, five or six days after the onset of cold damage, malign Qi has entered the shaoyang channel. The patient presents with alternating fevers and chills and a feeling of bitterness and fullness (kuman) in the chest and sides; disinclination to speak, eat or drink; distress; nausea; a bitter taste in the mouth; dry throat; blurred vision; deafness; and a rapid wirey pulse - the symptoms of semi-exterior, semi-interior shaoyang channel syndrome.
This prescription uses thorowax (chaihu, Bupleurum) to harmonise the semi-exterior semi-interior pathogen, pinellia tuber (banxia) to dissolve mucus and check the upward counterflow of Qi so as to stop vomiting, Golden Thread (huanglian, Rhizoma Coptidis) to clear away the malign Qi and heat that has penetrated the interior, as well as ginseng, Chinese dates, fresh ginger, liquorice etc. to strengthen and protect the Central Region (zhongzhou) so as prevent malign Qi from penetrating more deeply. Indeed such is the synergetic effect of this combination of ingredients, that malign Qi is not only blocked from entering further into the body, but is actually expelled directly to the exterior, and thus the semi-external, semi-internal pathogen is cleared.
