Sophora flavescens

Purported Benefits, Side Effects & More

Sophora flavescens

Purported Benefits, Side Effects & More
Sophora flavescens

Common Names

  • Ku Shen Gen
  • Bitter root
  • Yellow sophora root

For Patients & Caregivers

Tell your healthcare providers about any dietary supplements you’re taking, such as herbs, vitamins, minerals, and natural or home remedies. This will help them manage your care and keep you safe.

What is it?

Sophora flavescens has shown anticancer effects in lab studies, but has not been studied for cancer prevention or treatment in humans.

Sophora flavescens or Ku Shen, which in Chinese means "bitter root," is an herb used in Traditional medicine to treat a wide variety of symptoms, with purported effects on the liver, intestinal tract, and skin. Lab and animal studies have shown that some compounds can kill cancer cells and help fight certain viruses. However, human data are lacking.

Sophora flavescens may act like an estrogen in the body. Patients with hormone-sensitive cancer should avoid this product.

What are the potential uses and benefits?
  • Cancer treatment

    Lab studies show anticancer activities through different mechanisms, but this use has not been proven by clinical trials.
  • Antiviral

    Limited evidence suggests that a compound from Sophora flavescens may be useful for hepatitis B and coxsackie B viruses, but more data are necessary to support this use.
  • Skin disorders

    Sophora flavescens is used to treat skin disorders in Traditional Medicine, but this use has not been proven in clinical trials.
What else do I need to know?

Do Not Take if:

  • You are taking paclitaxel: In animal studies, Sophora flavescens flavonoids increased the effects of Taxol against certain tumors. Clinical relevance has yet to be determined.
  • You are taking ampicillin/gentamicin: In the lab, one of the compounds in Sophora flavescens increased the activity of these antibiotics against oral bacteria. Clinical relevance has yet to be determined.
  • You have a hormone-sensitive cancer: Sophora flavescens has estrogenic effects and may stimulate the proliferation of hormone-sensitive cancer cells.

For Healthcare Professionals

Brand Name
Ku shen, Sophora root
Scientific Name
Sophora flavescens
Clinical Summary

Sophora flavescens is a deciduous shrub related to peas. The root known as “Kushen” which means “bitter root” in Chinese, has been used in Traditional Medicine for two thousand years to treat a variety of conditions including diarrhea, jaundice, and skin rashes, and to kill parasites (1). Although this herb is generally not consumed as a dietary supplement in the West, recent lab studies indicate that it has antitumor properties and patients are using it as a natural cancer treatment.

Matrine, an alkaloid present in Sophora flavescens, demonstrated antitumor effects against liver (10) (18), breast (19), pancreatic  (20), myeloma (21) and gastric (22) (23) cancer cell lines. Other flavonoids such as kuraninone and sophoraflavonone are also thought to be biologically active and may have vasodilatory and antiviral effects (5) (6) (7), and benefit patients with ulcerative colitis (31) (32). Adjunctive use of formulas containing Kushen may improve effectiveness of chemotherapy in patients with non-small cell lung cancer (33).

Sophora flavescens acts as a phytoestrogen (24) (25) (26) and therefore, patients with hormone-sensitive cancers should avoid this product.

Purported Uses and Benefits
  • Cancer treatment
  • Antiviral
  • Skin disorders
Mechanism of Action

In animal models, the antiviral properties of sophoridine, an alkaloid constituent, appear to be mediated via upregulation of IL-10 and IFN-gamma cytokines (11). S. flavescens flavonoids may promote vasodilation by inhibiting Ca2+ influx through a voltage-gated channel (12). The flavonoids sophoraflavonone G and kurarinone may be responsible for antioxidant effects, which are mediated through free-radical scavenging (4). Anti-inflammatory effects of Sophoraflavonone G are attributed to inhibition of prostaglandin E2 formation via COX-2 downregulation (13). (2S)-2’-Methoxykurarinone isolated from S. flavescens root inhibits osteoclast differentiation and bone resorption via receptor activator of nuclear factor-κB ligand (RANKL)-induced mitogen-activated protein kinases (MAPKs) and c-Fos-NFATc1 signaling pathways (29).

Most reported antineoplastic effects of S.flavescens are due to the proapoptotic activity of matrine, the main alkaloid constituent. In human hepatocellular carcinoma cells, matrine inhibits matrix metalloproteinase-9 (MMP-9) by downregulating the NF-kappa B pathway (18). It also demonstrates antiangiogenic effects by inhibiting VEGF and VEGFR-2 (19). Matrine triggers the mitochondrial pathway, in which cytochrome C release induces caspase-9 and -3 activation and subsequently induces apoptosis (2) (3) (10) (21).

  • Patients with hormone-sensitive cancers should avoid taking S. flavescens as it demonstrated estrogenic effects in vitro (24) (25) (26), and may stimulate the proliferation of hormone-sensitive cancer cells.
Herb-Drug Interactions
  • Paclitaxel: In mice, S. flavescens flavonoids may enhance the effects of Taxol against certain tumors (16). Clinical relevance has yet to be determined.
  • Ampicillin/gentamicin: In vitro, sophoraflavanone G may increase the activity of these antibiotics against oral bacteria (17).  Clinical relevance has yet to be determined.
  1. Chen JK and Chen TT. Chinese Medical Herbology and Pharmacology. First ed. 2004, City of Industry, CA: Art of Medicine Press, Inc.
  2. Jiang H, Hou C, Zhang S, et al. Matrine upregulates the cell cycle protein E2F-1 and triggers apoptosis via the mitochondrial pathway in K562 cells. Eur J Pharmacol. 2007 Mar 22;559(2-3):98-108.
  3. Liu XS, et al. Matrine-induced apoptosis in leukemia U937 cells: involvement of caspases activation and MAPK-independent pathways. Planta Med. 2006;2(6): 501-6.
  4. Piao XL, et al. Identification and characterization of antioxidants from Sophora flavescens. Biol Pharm Bull. 2006;9(9): 1911-5.
  5. Hoang BX, et al. New approach in asthma treatment using excitatory modulator. Phytotherapy Res. 2007;21(6): p. 554-7.
  6. Chen C, et al. A randomized controlled trial of kurorinone versus interferon-alpha2a treatment in patients with chronic hepatitis B. J Viral Hepat. 2000;7(3): p. 225-9.
  7. Chen SX, et al. [Therapeutic effect of kangke injection on viral myocarditis and its anticoxsackie virus mechanism]. Zhong Guo Zhong Xi Yi Jie He Za Zhi. 1997. 17(4): p. 207-9.
  8. Liu Z, et al. A mannose-binding lectin from Sophora flavescens induces apoptosis in HeLa cells. Phytomedicine. 2008;15(10):867-75.
  9. Lee JH, et al. A new cytotoxic prenylated chalcone from Sophora flavescens. Arch Pharm Res. 2007;30(4): 408-11.
  10. Ma L, et al., Anticancer effects of the chinese medicine matrine on murine hepatocellular carcinoma cells. Planta Med. 2008;74(3): 245-51.
  11. Zhang Y, et al. Antiviral effects of sophoridine against coxsackievirus B3 and its pharmacokinetics in rats. Life Sci. 2006; 78(17):1998-2005.
  12. Yamahara J, et al. Vasodilatory active principles of Sophora flavescens root.J Ethnopharmacol. 1990;29(1): p. 79-85.
  13. Kim DW, et al. Effects of sophoraflavanone G, a prenylated flavonoid from Sophora flavescens, on cyclooxygenase-2 and in vivo inflammatory response. Arch Pharm Res. 2002;25(3): 329-35.
  14. Zhang L, et al. Pharmacokinetic study of matrine, oxymatrine and oxysophocarpine in rat plasma after oral administration of Sophora flavescens Ait. extract by liquid chromatography tandem mass spectrometry. J Pharm Biomed Anal. 2008;47(4-5): 892-898.
  15.  Xiang Q, et al. [Anti-leukemia effect of Sophora flavescens combined with the low molecular weight natural tumor suppressor of the human fetal liver and its mechanism]. Hunan Yi Ke Da Xue Xue Bao. 2002;27(2): 108-10.
  16. Sun M, et al. Novel antitumor activities of Kushen flavonoids in vitro and in vivo. Phytother Res. 2007;21(3): 269-77.
  17. Cha JD, et al. Antibacterial activity of sophoraflavanone G isolated from the roots of Sophora flavescens. J Microbiol Biotechnol. 2007;17(5): 858-64.
  18. Yu HB, Zhang HF, Li DY, et al. Matrine inhibits matrix metalloproteinase-9 expression and invasion of human hepatocellular carcinoma cells. J Asian Nat Prod Res. 2011 Mar;13(3):242-50.
  19. Li H, Tan G, Jiang X, et al. Therapeutic effects of matrine on primary and metastatic breast cancer. Am J Chin Med. 2010;38(6):1115-30.
  20. Liu T, Song Y, Chen H, Pan S, Sun X. Matrine inhibits proliferation and induces apoptosis of pancreatic cancer cells in vitro and in vivo. Biol Pharm Bull. 2010;33(10):1740-5.
  21. Han Y, Zhang S, Wu J, et al. Matrine induces apoptosis of human multiple myeloma cells via activation of the mitochondrial pathway. Leuk Lymphoma. 2010 Jul;51(7):1337-46.
  22. Dai ZJ, Gao J, Ji ZZ, et al. Matrine induces apoptosis in gastric carcinoma cells via alteration of Fas/FasL and activation of caspase-3. J Ethnopharmacol. 2009 May 4;123(1):91-6.
  23. Jiang T, Zhu Y, Luo C, et al. Matrine inhibits the activity of translation factor eIF4E through dephosphorylation of 4E-BP1 in gastric MKN45 cells. Planta Med. 2007 Sep;73(11):1176-81.
  24. Kang SC, Lee CM, Choi H, et al. Evaluation of oriental medicinal herbs for estrogenic and antiproliferative activities. Phytother Res. 2006 Nov;20(11):1017-9.
  25. De Naeyer A, Vanden Berghe W, Pocock V, et al. Estrogenic and anticarcinogenic properties of kurarinone, a lavandulyl flavanone from the roots of Sophora flavescens. J Nat Prod. 2004 Nov;67(11):1829-32.
  26. Yoo HH, Kim T, Ahn S, et al. Evaluation of the estrogenic activity of Leguminosae plants. Biol Pharm Bull. 2005 Mar;28(3):538-40.
  27. Choi SU, Kim KH, Choi EJ, et al. P-glycoprotein (Pgp) does not affect the cytotoxicity of flavonoids from Sophora flavescens, which also have no effects on Pgp action. Anticancer Res. 1999 May-Jun;19(3A):2035-40.
  28. Shen CC, Lin TW, Huang YL, et al. Phenolic constituents of the roots of Sophora flavescens. J Nat Prod. 2006 Aug;69(8):1237-40.
  29. Kim JY, Kim JY, Kim JJ, et al. (2S)-2’-Methoxykurarinone Inhibits Osteoclastogenesis and Bone Resorption through Down-Regulation of RANKL Signaling. Biol Pharm Bull. 2014;37(2):255-61.
  30. Yu Q, Cheng N, Ni X. Identifying 2 prenylflavanones as potential hepatotoxic compounds in the ethanol extract of Sophora flavescens. J Food Sci. 2013 Nov;78(11):T1830-4.
  31. Chen M, Ding Y, Tong Z. Efficacy and Safety of Sophora flavescens (Kushen) Based Traditional Chinese Medicine in the Treatment of Ulcerative Colitis: Clinical Evidence and Potential Mechanisms. Front Pharmacol. 2020 Dec 10;11:603476.
  32. Hou WB, Sun WJ, Zhang XW, et al. Five-Flavor Sophora flavescens Enteric-Coated Capsules for Ulcerative Colitis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. Evid Based Complement Alternat Med. 2022 Jan 12;2022:9633048.
  33. Yu ZY, Peng RY, Han M, et al. Adjunctive effect of compound Kushen Injection to chemotherapy for non-small cell lung cancer: An evidence map and overview of systematic reviews. J Ethnopharmacol. 2021 Dec 5;281:114538.
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