Milk thistle (Silybum marianum)

Milk thistle Silybum marinarum

Traditional Indications

Milk thistle is astringent, bitter, cholagogue, diaphoretic, diuretic, emetic, emmenagogue, hepatic, stimulant, stomachic and tonic, hepatic, galactogogue, demulcent and cholagogue. Milk Thistle can be used to increase the secretion and flow of bile from the liver and gall-bladder and contains constituents which protect liver cells from chemical damage. It is traditionally indicated in the treatment of liver and gall bladder diseases, jaundice, cirrhosis, hepatitis and poisoning. It is specifically indicated in skin complaints associated with a sluggish liver. (1)


Milk thistle contains the active compound silymarin which restores depleted Glutathione (2, 3) (GSH) to assist Phase II detoxification processes and help protect the liver.

Milk thistle contains flavonolignans including silymarin, silybin A, silybin B, isosilybin A, isosilybin B, silychristin, isosilychristin, silydianin & one flavonoid, taxifolin. (4) Milk thistle significantly inhibits Phase I P 450. (5) The flavonolignan including Silymarin restores depleted glutathione (GSH) to assist glutathione conjugation. (6) Inhibition of Phase 1 P 450 and u=induction of Phase II is desired in Plastic detoxification

Silymarin protects the liver against chemical induced damage.

Milk thistle has anti-inflammatory, immunomodulating, antifibrotic, antioxidant, and liver-regenerating properties as well as the clinical potential in patients with alcoholic liver disease, nonalcoholic fatty liver disease, viral hepatitis, drug-induced liver injury, and mushroom poisoning. (7)

A meta-analysis of randomised control trials concluded Milk thistle has positive efficacy to reduce transaminases levels in nonalcoholic fatty disease NAFLD patients. SIL can be an encouraging and considerable phytotherapy for NAFLD patients. (8)

According to open studies the long-term administration of silymarin significantly increased survival time of patients with alcohol induced liver cirrhosis. Based on the results of studies using methods of molecular biology, silymarin can significantly reduce tumor cell proliferation, angiogenesis as well as insulin resistance. Furthermore, it exerts an anti-atherosclerotic effect, and suppresses tumour necrosis factor-alpha-induced protein production and mRNA expression due to adhesion molecules. The chemopreventive effect of silymarin on Hepatocellular carcinoma (HCC) has been established in several studies using in vitro and in vivo methods; it can exert a beneficial effect on the balance of cell survival and apoptosis by interfering cytokines. In addition to this, anti-inflammatory activity and inhibitory effect of silymarin on the development of metastases have also been detected. In some neoplastic diseases silymarin can be administered as adjuvant therapy as well. (9)

Silymarin protects the heart against the deleterious effects of an MI and benefits cardiac healing. These benefits may be attributed to the antioxidant and antifibrotic properties. (10)

Milk thistle significantly inhibits Cytochorme P450 Liver detoxification enzymes. (5) This is desirable in excess persistent organic pollutant bioaccumulation (toxicity) as toxins induce or speed up Phase I liver detoxification pathways leading to Phase II detox pathways being overburdened.


1. PFAF. Silybum marinarum. 2019.
2. Valenzuela A, Aspillaga M, Vial S, Guerra R. Selectivity of silymarin on the increase of the glutathione content in different tissues of the rat. Planta Med. 1989;55(5):420-2.
3. Alidoost F, Gharagozloo M, Bagherpour B, Jafarian A, Sajjadi SE, Hourfar H, et al. Effects of silymarin on the proliferation and glutathione levels of peripheral blood mononuclear cells from beta-thalassemia major patients. International immunopharmacology. 2006;6(8):1305-10.
4. Polyak SJ, Morishima C, Lohmann V, Pal S, Lee DYW, Liu Y, et al. Identification of hepatoprotective flavonolignans from silymarin. Proceedings of the National Academy of Sciences of the United States of America. 2010;107(13):5995-9.
5. Kawaguchi-Suzuki M, Frye RF, Zhu H-J, Brinda BJ, Chavin KD, Bernstein HJ, et al. The effects of milk thistle (Silybum marianum) on human cytochrome P450 activity. Drug metabolism and disposition: the biological fate of chemicals. 2014;42(10):1611-6.
6. Kim YC, Na JD, Kwon DY, Park JH. Silymarin prevents acetaminophen-induced hepatotoxicity via up-regulation of the glutathione conjugation capacity in mice. Journal of Functional Foods. 2018;49:235-40.
7. Abenavoli L, Izzo AA, Milić N, Cicala C, Santini A, Capasso R. Milk thistle (Silybum marianum): A concise overview on its chemistry, pharmacological, and nutraceutical uses in liver diseases. 2018;32(11):2202-13.
8. Zhong S, Fan Y, Yan Q, Fan X, Wu B, Han Y, et al. The therapeutic effect of silymarin in the treatment of nonalcoholic fatty disease: A meta-analysis (PRISMA) of randomized control trials. Medicine. 2017;96(49):e9061-e.
9. Feher J, Lengyel G. Silymarin in the prevention and treatment of liver diseases and primary liver cancer. Current pharmaceutical biotechnology. 2012;13(1):210-7.
10. Vilahur G, Casaní L, Peña E, Crespo J, Juan-Babot O, Ben-Aicha S, et al. Silybum marianum provides cardioprotection and limits adverse remodeling post-myocardial infarction by mitigating oxidative stress and reactive fibrosis. International Journal of Cardiology. 2018;270:28-35.