Health Benefits of Milk Thistle (Silymarin)

Written by Joyce Smith, Staff Writer. Milk Thistle, a strong liver detoxifier that protects against obesity, fatty liver disease, hepatitis and cancer.

Silymarin, commonly known as a standardized extract of milk thistle, which is a Mediterranean native plant well known for its contribution to overall health and longevity. The plant’s name is derived from the milky sap that oozes from its leaves. Researchers are now finding that milk thistle can protect against metabolic syndrome, guard against chronic liver diseases like fatty liver disease 1, liver fibrosis 2 and cirrhosis2, and neutralize the hepatitis C virus.3 Current research is also showing us how Milk Thistle may be a potential anti-cancer agent.

Milk Thistle’s active, liver-protective ingredient or an extract is known as silymarin, a composition extracted from its seeds. While it is well known for its ability to stimulate liver regeneration and prevent toxins from penetrating the liver, Silymarin has many additional potential health promoting properties. Among them are the following:

Protects against Metabolic Syndrome: People with metabolic syndrome usually have abdominal obesity, an inability to control blood sugar levels, high blood pressure and elevated blood lipids such as triglycerides and LDL cholesterol. 4 Diets high in sugars, starches and unhealthy fats set the stage for obesity and metabolic syndrome. When the liver is unable to effectively handle this onslaught of sugar and fats, non-alcoholic fatty liver disease develops. 1 When inflammation in the body is high, liver cells undergo fibrosis, and a more advanced stage of this disease, called non-alcoholic steatohepatitis, develops, which can progress into liver cirrhosis and death or hepatocellular liver cancer. 1 5

Protects against Fatty Liver Disease: Silybin, a component of silymarin, targets abdominal obesity by breaking down lipids (lipolysis) and helping prevent weight gain. Silymarin reduces inflammation, promotes fat metabolism, improves insulin resistance, and reduces oxidative stress. 1 5

Enhanced Silybin/phosphatidylcholine: Silybin does not dissolve in water and is poorly absorbed in the body. However, when used in combination with phosphatidylcholine, absorption in the body is 5 times greater than with silymarin alone. Its concentration in the liver is also 10 times greater than sylmarin alone. 6

  • In a recent study using a silybin/phosphatidyl combination and Vitamin E, silybinin significantly improved blood markers of liver damage and insulin sensitivity. 7 Overweight and obese participants (85% of subjects) improved their body mass index by 15%. For those participants who had hepatitis C viral infection along with obesity, Silybin /Vitamin E combination improved markers of liver fibrosis as well. 7
  • In a 2015 study those who added diet and exercise to their silybin/phosphatidyl and Vitamin E regimen, significantly reduced their abdominal fat and liver size compared to patients in the diet/exercise only group. (P<0.001) 8

Antiviral: Viral hepatitis C infection affects approximately 170 million people worldwide and can lead to hepatocellular carcinoma 3, one of the most virulent and aggressive forms of cancer. 9

  • A phase 2 trial of advanced fibrosis patients, who had recurrence of hepatitis C following liver transplant, found that after receiving 16 weeks of intravenous silibinin, their viral load of HCV was significantly reduced, and silibinin was well tolerated. 10
  • A 2013 study demonstrates how silibinin blocks pathways that prevent Hepatitis C virus from entering liver cells. 3

Liver Detoxification: Silymarin neutralizes harmful toxins that damage the liver and increase the risk of cancer. 1

Anti-aging:

  • A recent study demonstrated how silibinin reacts to UVB radiation (about 5% of the sun’s rays). When cells were pretreated with silibinin, them exposed to UVB, there was no sunscreen effect; however, there was significant repair of UVB damaged DNA in cells compared to control.(P<0.001)11

Cancer prevention: Perhaps most exciting is the volume of pre-clinical studies indicating how milk thistle may protect against a host of common and deadly malignancies. A sampling of studies demonstrating silymarin anti-cancer effects are as follows:

  • Colorectal cancers: Silymarin regulates cell division cycle that is out of control in cancers. In this study silybin reduced inflammation levels and slowed the cell division cycle in human colorectal cancer cells. 12
  • Breast cancer: Study shows oral intake of silybin-phosphatidylcholine in presurgical breast cancer patients resulted in high concentration in breast tissue.13
  • Ovarian cancer: Silymarin induced cell cycle arrest and programmed cell death in ovarian cancer cells 14
  • Human pharynx squamous cancer: Silymarin reduced cancer cell survival and inhibited growth of squamous cell cancers from the human pharynx 15
  • Cervical cancer: This study showed that silymarin significantly inhibited the survival, migration and invasion of C-33A human cervical cancer cells. (P<0.05), P<0.01) 16
  • Liver cancer: Silymarin significantly reduced cell proliferation, increased cell death and increased detoxification in a rat model of liver cancer. (P<0.05) 17

The human liver is active in multiple chemical reactions that contribute to our good health. Therefore, it is critical that we take good care of our liver. We can do this by limiting our intake of unhealthy dietary fats, sugars, starches, and alcoholic calories and increasing our physical activities. Supplementing with a high quality milk thistle extract will also go a long way in protecting the liver and potentially extending life.

Posted April 25, 2016. r/cw

References:

  1. Bhala N, Angulo P, van der Poorten D, et al. The natural history of nonalcoholic fatty liver disease with advanced fibrosis or cirrhosis: an international collaborative study. Hepatology. 2011;54(4):1208-1216.
  2. Clichici S, Olteanu D, Nagy A-L, Oros A, Filip A, Mircea PA. Silymarin inhibits the progression of fibrosis in the early stages of liver injury in ccl4-treated rats. Journal of medicinal food. 2015;18(3):290-298.
  3. Blaising J, Lévy PL, Gondeau C, et al. Silibinin inhibits hepatitis C virus entry into hepatocytes by hindering clathrin‐dependent trafficking. Cellular microbiology. 2013;15(11):1866-1882.
  4. Gargari BP, Mobasseri M, Valizadeh H, Asghari-Jafarabadi M. Effects of Silybum marianum (L.) Gaertn.(silymarin) extract supplementation on antioxidant status and hs-CRP in patients with type 2 diabetes mellitus: A randomized, triple-blind, placebo-controlled clinical trial. Phytomedicine. 2015;22(2):290-296.
  5. Pais P, D’Amato M. In Vivo Efficacy Study of Milk Thistle Extract (ETHIS-094™) in STAM™ Model of Nonalcoholic Steatohepatitis. Drugs in R&D. 2014;14(4):291-299.
  6. Kidd PM. Bioavailability and activity of phytosome complexes from botanical polyphenols: the silymarin, curcumin, green tea, and grape seed extracts. Alternative medicine review : a journal of clinical therapeutic. 2009;14(3):226-246.
  7. Loguercio C, Andreone P, Brisc C, et al. Silybin combined with phosphatidylcholine and vitamin E in patients with nonalcoholic fatty liver disease: a randomized controlled trial. Free Radical Biology and Medicine. 2012;52(9):1658-1665.
  8. Sorrentino G, Crispino P, Coppola D, De Stefano G. Efficacy of lifestyle changes in subjects with non-alcoholic liver steatosis and metabolic syndrome may be improved with an antioxidant nutraceutical: a controlled clinical study. Drugs in R&D. 2015;15(1):21-25.
  9. Han K, Kim JH, Ko G-Y, Gwon DI, Sung K-B. Treatment of hepatocellular carcinoma with portal venous tumor thrombosis: A comprehensive review. World journal of gastroenterology. 2016;22(1):407.
  10. Rendina M, D’Amato M, Castellaneta A, et al. Antiviral activity and safety profile of silibinin in HCV patients with advanced fibrosis after liver transplantation: a randomized clinical trial. Transplant International. 2014;27(7):696-704.
  11. Roy S, Deep G, Agarwal C, Agarwal R. Silibinin prevents ultraviolet B radiation-induced epidermal damages in JB6 cells and mouse skin in a p53-GADD45α-dependent manner. Carcinogenesis. 2012;33(3):629-636.
  12. Eo HJ, Park GH, Song HM, et al. Silymarin induces cyclin D1 proteasomal degradation via its phosphorylation of threonine-286 in human colorectal cancer cells. International immunopharmacology. 2015;24(1):1-6.
  13. Lazzeroni M, Guerrieri-Gonzaga A, Gandini S, et al. A Presurgical Study of Oral Silybin-Phosphatidylcholine in Patients with Early Breast Cancer. Cancer Prevention Research. 2016;9(1):89-95.
  14. Fan L, Ma Y, Liu Y, Zheng D, Huang G. Silymarin induces cell cycle arrest and apoptosis in ovarian cancer cells. European journal of pharmacology. 2014;743:79-88.
  15. Su C-H, Chen L-J, Liao JF, Cheng J-T. Increase of phosphatase and tensin homolog by silymarin to inhibit human pharynx squamous cancer. Journal of medicinal food. 2013;16(9):778-784.
  16. Yu HC, Chen LJ, Cheng KC, Li YX, Yeh CH, Cheng JT. Silymarin inhibits cervical cancer cell through an increase of phosphatase and tensin homolog. Phytotherapy Research. 2012;26(5):709-715.
  17. Gopalakrishnan R, Sundaram J, Sattu K, Pandi A, Thiruvengadam D. Dietary supplementation of silymarin is associated with decreased cell proliferation, increased apoptosis, and activation of detoxification system in hepatocellular carcinoma. Molecular and cellular biochemistry. 2013;377(1-2):163-176.