Written by Julia Green, Alexander Kalisch and the CAM-Cancer Consortium.
Updated January 29, 2015

Milk thistle (Silybum marianum)

Abstract and key points

  • Milk thistle herbal preparations are produced from the seeds of Silybum marianum (L.) Gaertn.
  • Several potential uses of milk thistle in cancer are supported only by pre-clinical evidence
  • Milk thistle is generally considered safe

Milk thistle herbal products are made from seeds of Silybum marianum. Milk thistle has a long history of medicinal use. It is widely used to treat digestive and liver disorders. Claims in relation to cancer are that milk thistle prevents cancer initiation, reduces cancer development, reduces adverse effects of chemotherapy and radiotherapy, and supports the action of some anticancer drugs.

While numerous animal and in vitro models support these claims, they are not supported by data from clinical studies. Only one randomised pilot study is available which is merely showing a trend towards a reduction of hepatic toxicity.
Milk thistle is generally well tolerated and appears safe.

In summary, currently there is insufficient clinical evidence to support or refute the claims for milk thistle in relation to cancer management.

Read about the regulation, supervision and reimbursement of herbal medicine at NAFKAMs website CAM Regulation.

Citation

Julia Green, Alexander Kalisch, CAM-Cancer Consortium. Milk thistle (Silybum marianum) [online document]. http://cam-cancer.org/The-Summaries/Herbal-products/Milk-thistle-Silybum-marianum. January 29, 2015.

Document history

Assessed as up to date in January 2015 by Barbara Wider.
Summary first published in May 2013, authored by Julia Green and Alexander Kalisch.

References

  1. USDA dARS, National Genetic Resources Program. Germplasm Resources Information Network (GRIN) [Online Database]. 2012. National Germplasm Resources Laboratory, Beltsville, Maryland. Available at: http://www.ars-grin.gov/cgi-bin/npgs/html/index.pl [Accessed 7th November 2012].
  2. Natural Medicines Comprehensive Database: professional version. Milk Thistle monograph. Stockton (CA): Therapeutic Research Faculty. 2012. Available at: http://naturaldatabase.therapeuticresearch.com. [Accessed 12th November 2012].
  3. Cheung CW, Gibbons N, Johnson DW, Nicol DL. Silibinin-a promising new treatment for cancer. Anticancer Agents Med Chem. 2010;10:186-95.
  4. Kroll DJ, Shaw HS, Oberlies NH. Milk thistle nomenclature: why it matters in cancer research and pharmacokinetic studies. Integrative cancer therapies 2007;6(2):110-119.
  5. Loguercio C, Festi D. Silybin and the liver: from basic research to clinical practice. World J Gastroenterol. 2011;17:2288-301.
  6. Brantley SJ, Oberlies NH, Kroll DJ, Paine MF. Two flavonolignans from milk thistle (Silybum marianum) inhibit CYP2C9-mediated warfarin metabolism at clinically achievable concentrations. J Pharmacol Exp Ther. 2010;332:1081-87.
  7. Wichtl M. Cardui mariae fructus in: Herbal drugs and phytopharmaceuticals. Medpharm Scientific Publishers; 2004.
  8. Braun L, Cohen M. Herbs & natural supplements: an evidence-based guide. 3rd ed: Churchill Livingstone; 2010.
  9. European Scientific Cooperative on Phytotherapy. ESCOP MONOGRAPHS The Scientific Foundation for Herbal Medicinal Products. 2nd edition supplement. Thieme, 2009: 222-248.
  10. Flaig TW, Glode M, Gustafson D, van BA, Tao Y, Wilson S et al. A study of high-dose oral silybin-phytosome followed by prostatectomy in patients with localized prostate cancer. Prostate. 2010;70:848-55.
  11. Hoh C, Boocock D, Marczylo T, Singh R, Berry DP, Dennison AR et al. Pilot study of oral silibinin, a putative chemopreventive agent, in colorectal cancer patients: silibinin levels in plasma, colorectum, and liver and their pharmacodynamic consequences. Clin Cancer Res. 2006;12:2944-50.
  12. Mills S, Bone K. Principles and practice of phytotherapy. Modern herbal medicine. : Churchill Livingstone; 2000.
  13. Phytopharmaka II - Forschung klinische Anwendung. Darmstadt: Stinkopff; 1996
  14. Greenlee H, Abascal K, Yarnell E, Ladas E. Clinical applications of Silybum marianum in oncology. Integrative cancer therapies 2007;6(2):158-165.
  15. Post-White J, Ladas EJ, Kelly KM. Advances in the use of milk thistle (Silybum marianum). Integrative cancer therapies 2007;6(2):104-109.
  16. Deep G, Agarwal R. Antimetastatic efficacy of silibinin: molecular mechanisms and therapeutic potential against cancer. Cancer Metastasis Rev 2010;29(3):447-463.
  17. Saller R, Melzer J, Reichling J, Brignoli R, Meier R. An updated systematic review of the pharmacology of silymarin. Forschende Komplementärmedizin/Research in Complementary Medicine 2007;14(2):70-80.
  18. Olaku O, White JD. Herbal therapy use by cancer patients: A literature review on case reports. Eur J Cancer 2011 3;47(4):508-514.
  19. McBride A, Augustin KM, Nobbe J, Westervelt P. Silybum marianum (milk thistle) in the management and prevention of hepatotoxicity in a patient undergoing reinduction therapy for acute myelogenous leukemia. Journal of Oncology Pharmacy Practice 2012;18(3):360-365.
  20. Deep G, Agarwal R. Chemopreventive efficacy of silymarin in skin and prostate cancer. Integr Cancer Ther. 2007;6:130-145.
  21. Colombo V, Lupi M, Falcetta F, Forestieri D, D’Incalci M, Ubezio P. Chemotherapeutic activity of silymarin combined with doxorubicin or paclitaxel in sensitive and multidrug-resistant colon cancer cells. Cancer Chemother Pharmacol 2011;67(2):369-379.
  22. Scambia G, De Vincenzo R, Ranelletti P, Benedetti Panici P, Ferrandina G, D'Agostino G, et al. Antiproliferative effect of silybin on gynaecological malignancies: Synergism with cisplatin and doxorubicin. Eur J Cancer 1996;32(5):877-882.
  23. Bright-Gbebry M, Makambi K, Rohan J, Llanos A, Rosenberg L, Palmer J, et al. Use of multivitamins, folic acid and herbal supplements among breast cancer survivors: the black women's health study. BMC Complementary and Alternative Medicine 2011;11(1):30
  24. Damery S, Gratus C, Grieve R, Warmington S, Jones J, Routledge P, et al. The use of herbal medicines by people with cancer: a cross-sectional survey. Br J Cancer 2011;104(6):927-933
  25. Werneke U, Earl J, Seydel C, Horn O, Crichton P, Fannon D. Potential health risks of complementary alternative medicines in cancer patients. Br J Cancer 2004;90(2):408-413.
  26. MHRA. Traditional Herbal Medicines Registration Scheme: Guidance for Retailers, Wholesalers, Importers and Manufacturers on the Requirements of the THMRS. 2007 Available from: <http://www.mhra.gov.uk/home/groups/pl-p/documents/websiteresources/con2030651.pdf> [Accessed 29 October 2012]
  27. Blumenthal M, Goldberg A, Brinckmann J. Herbal Medicine. Expanded Commission E monographs. : Integrative Medicine Communications; 2000.
  28. European Medicines Agency. Community monographs: call for evidence 22/3/2010. Available at: http://www.ema.europa.eu/ [Accessed 13th November 2012]
  29. Rambaldi A, Jacobs BP, Iaquinto G, Gluud C. Milk thistle for alcoholic and/or hepatitis B or C liver diseases--a systematic cochrane hepato-biliary group review with meta-analyses of randomized clinical trials. Am J Gastroenterol. 2005;100:2583-91.
  30. Tamayo C, Diamond S. Review of Clinical Trials Evaluating Safety and Efficacy of Milk Thistle (Silybum marianum [L.] Gaertn.). Integrative Cancer Therapies 2007 June 01;6(2):146-157
  31. Ladas EJ, Kroll DJ, Oberlies NH, Cheng B, Ndao DH, Rheingold SR et al. A randomized, controlled, double-blind, pilot study of milk thistle for the treatment of hepatotoxicity in childhood acute lymphoblastic leukemia (ALL). Cancer. 2010;116:506-13.'Schröder FH, Roobol MJ, Boevé ER, de Mutsert R, Zuijdgeest-van Leeuwen SD, Kersten I, et al. Randomized, Double-Blind, Placebo-Controlled Crossover Study in Men with Prostate Cancer and Rising PSA: Effectiveness of a Dietary Supplement. Eur Urol 2005 12;48(6):922-931.
  32. Vidlar A, Vostalova J, Ulrichova J, Student V, Krajicek M, Vrbkova J, et al. The safety and efficacy of a silymarin and selenium combination in men after radical prostatectomy–a six month placebo-controlled double-blind clinical trial. Biomedical Papers 2010;154(3):239-244.
  33. Becker-Scheibe, M., Mengs, M., Schaefer, M., Bulitta, M/ and Hoffman, W. Topical use of a silymarin-based preparation to prevent radiodermatitis: results of a prospective study in breast cancer patients. Strahlentherapie und Onkologie. 2011;187(8):485-491
  34. van Erp NPH, Baker SD, Zhao M, Rudek MA, Guchelaar HJ, Nortier JWR, et al. Effect of milk thistle (Silybum marianum) on the pharmacokinetics of irinotecan. Clinical cancer research 2005;11(21):7800-7806.
  35. Han Y, Guo D, Chen Y, Chen Y, Tan ZR, Zhou HH. Effect of silymarin on the pharmacokinetics of losartan and its active metabolite E-3174 in healthy Chinese volunteers. Eur J Clin Pharmacol. 2009;65:585-91.
  36. Flaig TW, Gustafson DL, Su LJ, Zirrolli JA, Crighton F, Harrison GS et al. A phase I and pharmacokinetic study of silybin-phytosome in prostate cancer patients. Invest New Drugs. 2007;25:139-46.