

Chai Hu, hare's ear root, thorowax root, saiko
Bupleurum is a common herb, the root of which is used in traditional Chinese and Japanese medicine. It is frequently prescribed in combination with other herbs to treat cold, fever, malaria, gastrointestinal disorders and chronic liver diseases (1).
The major components, saikosaponins, are believed to contribute to bupleurum’s medicinal properties. In vitro studies show that Bupleurum has anti-inflammatory, antiviral (4) (7), antiproliferative (11), and chemopreventive (12) (13) properties, and saikosaponins were found to enhance the cytotoxicity of cisplatin against solid tumors (15). Further, Bupleurum demonstrated inhibitory effects against allergic asthma in animal studies (10).
Herbal formulas such as Xiao Chai Hu Tang (Sho-saiko-to), that contain bupleurum as major ingredient were found effective in treating hepatitis and liver cancers.
Large doses of bupleurum may cause nausea and vomiting (1).
The saikosaponins in bupleurum are mainly responsible for the plant’s medicinal activities. In vitro studies indicate that saikosaponins exert anti-inflammatory effects by inhibiting arachidonic acid metabolism (4). Saikosaponin-d immunoregulates by promoting interleukin-2 production and receptor expression as well as modulating T-lymphocyte function (3) (14). Bupleurum also shows a weak antihistamine activity in animals (10). Its in vitro apoptotic effect is thought to be partly mediated by increases in c-myc and p53 mRNA levels accompanied by a decrease in bcl-2 mRNA level (6) and by inhibition of telomerase activity (9). In additon, bupleurum demonstrates anti-adhesive and hemolytic effects in some solid tumor cells (5) (8).
Bupleurum is the major ingredient in an herbal formula, Sho-saiko-to, which has been associated with interstitial pneumonitis.
Most published clinical studies involving bupleurum were conducted in Japan using formulas like Sho saiko to.
Bottom Line: Bupleurum is used in herbal formulas such as Sho-saiko-to that may be effective in treating heptatitis and liver cancer.
Compounds called saikosaponins, isolated from bupleurum, are considered responsible for the plant’s medicinal activities. In laboratory studies, saikosaponins are able to interfere with the processes that cause inflammation, as well as cause cell death (apoptosis) in cancer cells by increasing the expression of tumor-suppressor genes. Saikosaponin-d in particular has shown ability to enhance mouse T-lymphocytes function in laboratory tests. It is not known whether these effects occur in the human body. Scientists also think that bupleurum may kill bacteria and viruses.
NOTE: The following uses and descriptions of effectiveness apply to bupleurum only. Please see the Sho-saiko-to monograph for information regarding the effectiveness of bupleurum in combination with other herbs.
Most of the clinical studies performed using bupleurum have been performed in Japan using formulas like Sho-saiko-to.