Health Care Professional Information

Scientific Name
Bupleurum chinense, Bupleurum scorzoneraefolium, Bupleurum falcatum
Common Name

Chai Hu, hare’s ear root, thorowax root, saiko

Clinical Summary

Bupleurum is an important herb 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.
The major components, saikosaponins, are believed to contribute to bupleurum's medicinal properties. In vitro studies show that Bupleurum has antiviral (4) (7), hepatoprotective (16), anti-inflammatory (17), antiproliferative (11), and chemopreventive (12) (13) properties.
Bupleurum also demonstrated inhibitory effects against allergic asthma in animal studies (10).

Saikosaponins were found to enhance the cytotoxicity of cisplatin against solid tumors (15).
Herbal formulas such as Xiao Chai Hu Tang (Sho-saiko-to), which contain bupleurum as major ingredient, were found effective in treating hepatitis and liver cancers.

However, poor quality control is a major concern with commercial herbal products. A sample of Bupleurum was found contaminated with a nephrotoxic drug, aristolactone (18).

Purported Uses
  • Cancer treatment
  • Cirrhosis
  • Common cold
  • Fever
  • Hepatitis
  • Infections
  • Inflammation
  • Liver disease
  • Malaria
  • Polysaccharides
  • Triterpene Saponins: Saikosaponins
  • Lignans: Isochaihulactone, kaerophyllin
    (1) (4) (12) (15) (16)
Mechanism of Action

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). The anti-inflammatory activity of bupleurum polysaccharides is attributed to their inhibitory effect on LPS-mediated Toll like receptor 4 (TLR4) signaling(17).
Saikosaponin-d promotes interleukin-2 production and receptor expression as well as modulating T-lymphocyte function (3) (14). The anti-epileptic effects of saikosaponin a were shown to be via enhancing the transient inactivating potassium current in rat hippocampal CA1 neurons (19).
In an animal model, bupleurum showed weak antihistamine activity  (10).

The herb's apoptotic effects are 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 addition, bupleurum demonstrated 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.

Literature Summary and Critique

Many of the published clinical studies involving bupleurum were conducted in Japan using formulas such as Sho saiko to.

  1. Bensky D, Gamble A. Chinese Herbal Medicine: Materia Medica. Revised Ed. Seattle: Eastland Press; 1993.
  2. Huang KC. The Pharmacology of Chinese Herbs, Second Ed. New York: CRC Press; 1999.
  3. Kato M, et al. Characterization of the immunoregulatory action of saikosaponin-d. Cell Immunol 1994;159:15-25.
  4. Bermejo Benito P, et al. In vivo and in vitro antiinflammatory activity of saikosaponins. Life Sci 1998;63:1147-56.
  5. Wu W, Hsu H. Involvement of p-15(INK4b) and p-16(INK4a) gene expression in saikosaponin a and TPA-induced growth inhibition of HepG2 cells. Biochem Biophys Res Commun 2001;285:183-7.
  6. Hsu M, et al. Effect of saikosaponin, a triterpene saponin, on apoptosis in lymphocytes: association with c-myc, p53, and bcl-2 mRNA. Br J Pharmacol 2000;131:1285-93.
  7. Ushio Y, Abe H. Inactivation of measles virus and herpes simplex virus by saikosaponin d. Planta Med 1992;58:171-3.
  8. Ahn B. et al. Inhibitory effect of bupleuri radix saponins on adhesion of some solid tumor cells and relation to hemolytic action: screening of 232 herbal drugs for anti-cell adhesion. Planta Med 1998;64:220-4.
  9. Cheng YL, et al. Acetone extract of Bupleurum scorzonerifolium inhibits proliferation of A549 human lung cancer cells via inducing apoptosis and suppressing telomerase activity. Life Sci. 2003 Sep 19;73(18):2383-94.
  10. Park KH, et al. Effect of saikosaponin-A, a triterpenoid glycoside, isolated from Bupleurum falcatum on experimental allergic asthma. Phytother Res. 2002 Jun;16(4):359-63.
  11. Cheng YL, Lee SC, Lin SZ, et al. Anti-proliferative activity of Bupleurum scrozonerifolium in A549 human lung cancer cells in vitro and in vivo. Cancer Lett. 2005 May 26;222(2):183-93.
  12. Chen YL, Lin SZ, Chang JY, et al. In vitro and in vivo studies of a novel potential anticancer agent of isochaihulactone on human lung cancer A549 cells. Biochem Pharmacol. 2006 Jul 28;72(3):308-19.
  13. Lee CY, Hsu YC, Wang JY, et al. Chemopreventive effect of selenium and Chinese medicinal herbs on N-nitrosobis(2-oxopropyl)amine-induced hepatocellular carcinoma in Syrian hamsters. Liver Int. 2008 Jul;28(6):841-55.
  14. Wong VK, Zhou H, Cheung SS, et al. Mechanistic study of saikosaponin-d (Ssd) on suppression of murine T lymphocyte activation. J Cell Biochem. 2009 May 15;107(2):303-15.
  15. Wang Q, Zheng XL, Yang L, et al. Reactive oxygen species-mediated apoptosis contributes to chemosensitization effect of saikosaponins on cisplatin-induced cytotoxicity in cancer cells. J Exp Clin Cancer Res. 2010 Dec 9;29:159.
  16. Lee TF, Lin YL, Huang YT. Protective effects of kaerophyllin against liver fibrogenesis in rats. Eur J Clin Invest. 2012 Jun;42(6):607-16.
  17. Wu J, Zhang YY, Guo L, Li H, Chen DF. Bupleurum Polysaccharides Attenuates Lipopolysaccharide-Induced Inflammation via Modulating Toll-Like Receptor 4 Signaling. PLoS One. 2013 Oct 22;8(10):e78051.
  18. Rueda DC, Zaugg J, Quitschau M, et al. Discovery of GABA(A) receptor modulator aristolactone in a commercial sample of the Chinese herbal drug “Chaihu” (Bupleurum chinense roots) unravels adulteration by nephrotoxic Aristolochia manshuriensis roots. Planta Med. 2012 Feb;78(3):207-10.
  19. Xie W, Yu YH, Du YP, et al. Saikosaponin a Enhances Transient Inactivating Potassium Current in Rat Hippocampal CA1 Neurons. Evid Based Complement Alternat Med. 2013;2013:413092.

Consumer Information

How It Works

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.

Purported Uses

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.

  • To treat cancer
    Components of bupleurum can cause cancer cell death (apoptosis) in laboratory experiments, but it is not known whether this effect occurs in humans. No clinical trials have been performed to test this use.
  • To treat liver diseases, including hepatitis and cirrhosis of the liver
    Although bupleurum is used in traditional Chinese medicine to treat liver diseases, no scientific evidence supports this use.
  • To treat the common cold
    Bupleurum may have antiviral activity, but clinical trials have not been conducted.
  • As a fever reducer
    Although bupleurum is used in traditional Chinese medicine to reduce fever, there are no clinical data to back this claim.
  • To treat infections
    Bupleurum may have anti-bacterial activity, but human studies are lacking.
  • To reduce inflammation
    Laboratory studies show that components of bupleurum interfere with the processes that cause inflammation. Human studies are needed.
  • To treat malaria
    Bupleurum may have anti-viral activity, but human data are lacking.
Research Evidence

Most of the clinical studies performed using bupleurum have been performed in Japan using formulas such as Sho-saiko-to.

Patient Warnings
  • Bupleurum is the major ingredient in an herbal formula, Sho-saiko-to, which has been associated with interstitial pneumonitis (lung disease characterized by increase in scarring of lung tissue).
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