December 1 2024 Lunar Cycle
Milk thistle
Silybum marianum
Common Name
Milk thistle, Carduus marianus, holy thistle, St. Mary’s thistle, our lady’s thistle, Marian thistle
Key Constituents
Flavolignans (including isosilybinin, silybinin, silychristin, and silydianin, which together are referred to as silymarin), fixed oil, sterols (cholesterol, campesterol, stigmasterol, sitosterol), gamma linoleic acid, amines (tyramine, histamine, betaine), bitter principles, flavonoids (apigenin, quercetin, kaempferol), lignans, mucilage (McIntyre, n.d).
Uses
Although this sunflower-family member is native to a small area in the Mediterranean, milk thistle has not only spread widely and naturalized in North America, Europe, and Asia, but also been in cultivation on these continents, in Europe for centuries. Stephen Foster (2009) notes that milk thistle is a common weed in the state of California, thought to have been brought along by early European settlers for food and fodder and now proliferating along roadsides and in abandoned agricultural areas. Similar naturalization of milk thistle has also occurred in some parts of South America and Australia, forming thick prickly patches to the frustration of many cultivators and growers (Foster, 2009).
Medicinally, the most researched and utilized part of milk thistle is the seed, referred to by Felter and Lloyd (1898) as “Fructus silybi” or “Semen cardui mariae.” The leaves, flowers, and roots have been used as food materials for both human and people, and this author can remember many a field lecture in which the late herbalist and ethnobotanist Frank Cook would remind students, “All parts of all thistle are edible — if you can get to them.”
In his studies of medicinal plants in the Old and New Testaments, Dr. James Duke (2010) describes his belief that the thistle most likely used as foodstuff and even potentially in the sparing of early humans who inadvertently consumed toxic substances was Silybum marianum, milk thistle. Milk thistle is eaten in myriad ways across the globe, including boiling the young green shoots or adding them to salads, which McIntyre mentions was considered a delicacy in Middle Eastern cuisines. The heads can be boiled and consumed like artichokes; the seeds roasted similarly to chicory and coffee; the roots prepared like fresh salsify; and careful preparations of the nutritious de-thorned stalks can be enjoyed roasted or in stir-fry (Duke, 2010). The first century naturalist and physician Pliny the Elder (A.D. 23-79) discussed the nutritious properties of milk thistle but offered his perspective that it was too difficult an ingredient to cook with (Foster, 2009).
In much of the world, the seeds are eaten during times of famine or used as animal fodder, although in some places such as Pakistan they are sold as a street snacks like sunflower seeds (Duke, 2010). A well-loved condiment, often called gomasio, that can be added to a variety of hot and cold dishes consists of dry-roasted milk thistle and sesame seeds, ground seaweed and black pepper, and sea salt (McIntyre, n.d.). Herbalist Matthew Wood writes that milk thistle leaves, once stripped of their thorns, offer a delicious crunchy salad green that can be eaten throughout the season, unlike lettuce which grows bitter with age (p. 445).
Herbalist and researcher Stephen Foster (2009) notes that milk thistle has been used at least since the first century A.D., when the Greek physician Dioscorides gave the genus Silybum to a variety of edible thistles. The existent species name marianum refers to the association of milk thistle with Mary. Often referred to as Our Lady’s Thistle in medieval Europe, milk thistle was thought of as the particular provenance of the Virgin Mary, the legend holding that the plant’s white veins came from the milk of the mother of Jesus, although in modern usage its cousin Blessed Thistle (Cnicus benedictus) is more commonly used as a galactagogue (Foster, 2009; Wood, 1997). Written accounts spanning from ancient Greece to medieval Europe to 20th century physiomedicalists document milk thistle’s various capacities, from assisting in lactation to lifting melancholy moods, preventing plague and infection, as well as cleaning the blood (McIntyre, n.d.).
Foster (2009) speculates that the first recorded use of milk thistle for liver-related conditions comes from Pliny the Elder, who wrote of mixing the juice of the plant with honey for “carrying off bile.” In 1150, the renowned herbalist and scholar Hildegarde von Bingen wrote in her manuscript Physica that “Venus Thistle” was a medicinal and food plant of which the entirety could be used (Foster, 2009). In 1789, the herbalist Nicolas Culpepper wrote that both internal and topical use of “the seed and distilled water” were useful in the cases of jaundice and “obstructions of the liver and spleen” (Foster, 2009). The 18th century German physician Stahl recorded his opinion that the seeds of Carduus marianum were extremely useful in respiratory conditions associated with hepatic fever, prompting another German physician named Rademacher to use milk thistle decoction with beneficial results (Wood, 1997, p. 446). In 1929, upon finding information from Rademacher on the use of milk thistle for chronic liver disease, acute hepatitis, and jaundice, the German scientist H. Schultz began to research the clinical value of milk thistle, heralding a resurgence of interest during the 1930s in the medicine and science of Silybum marianum. The first attempts to isolate milk thistle constituents began in 1958, and in 1968 researchers in Munich successfully isolated the flabonolignan complex they name silymarin, which was later found to be made up primarily of silybinin, silydianin, and silychristin (Foster, 2009). In ripe seeds, these components can be found in 4-6% concentrations in ripe seeds, while standardized extracts in Europe tend to contain 70-80% silymarin (Foster, 2009).
In Traditional Chinese Medicine (TCM), milk thistle seed is considered a cooling and nourishing therapeutic support to liver-spleen Blood and Yin, reducing heat in the liver (inflammation), strengthening function and structure by offering tone where there is weakness, and resolving toxins (Garran, 2008). In TCM, roasted milk thistle is thought to offer a neutral temperature to the digestive tract to balance and enhance the quality of digestion and assimilation in sluggish metabolisms. In this capacity, milk thistle is taken as a tonic over time, and a strong resilient liver is considered more able to effectively deal with the stress and toxicity of the modern world (Garran, 2008).
In Ayurvedic herbal practice, milk thistle is likewise thought of as relating to the liver and digestion in its cleansing, detoxifying, and nourishing properties. Western herbalist and Ayurvedic practitioner Anne McIntyre (n.d) notes that milk thistle is used in particular to relieve skin conditions, flush toxic materials from the digestive tract, regulate the metabolism of fat, support metabolic dysregulation in cases of diabetes, and nourishes nursing individuals so that milk supply is plentiful.
Dr. Duke (2010) offers insight about the use of milk thistle in countries where Unani-Tibb is the predominant traditional medicine practice. He notes that current practices in Lebanon make use of an infusion of the blooms for an alterative and cooling tonic and the leaves boiled in vinegar are used for skin ailments, while the seed infusion is applied for the treatment of gallstones and liver obstructions (2010). In various communities in northern Africa, a tincture of the seeds are used for pelvic congestion and varicosities, while in Turkey, milk thistle has been applied to the respiratory system in a decoction of ground roasted seeds (Duke, 2010). A 2010 study of Tibb folk medicine practices in Pakistan among healers (hakims) and lay people found that milk thistle was used by 75% of the persons interviewed in the communities, with the primary therapeutic uses being for liver dysfunction and disease, including hepatitis A and C, as well as conditions of the stomach, skin, and blood (Hussain et al., 2010).
Milk thistle seed as a therapeutic agent has been used in Western herbalism for thousands of years as a nourishing, restorative, and cooling tonic for the liver and digestive tract, and is nearly always indicated in situations where the liver appears to be stressed, such as signs of poor lipid digestion, headaches, thick/dark/clotted menstrual fluid, or inability to shake sluggishness upon waking (McIntyre). Other subclinical and/or Western energetic indications that the liver is overwhelmed include lethargy and fatigue, sensations of heat throughout the body, itchiness especially in the dermis, irritability and impatience, the taste of bitter in the mouth, and consistent poor reaction to a variety of drugs and/or herbs (Tillotson, n.d.). Eclectic and physiomedicalist physicians including Dr. Finley Elingwood (1919) observed milk thistle’s particular applications in “general bilious condition” in which swelling, heat, pain, jaundice, distension/tenderness/hardness in the abdomen, and constipation are present.
Although the isolation of “active constituents” such as silymarin and silybinin has led many allopathic physicians and Western herbalists to view milk thistle as first and foremost a hepatic remedy, Wood (1997) argues that its energetics are more complex in their “antipodal” action. Citing the tendency of milk thistle to behave similarly to yarrow in its ability to both move congested blood as well as address hemorrhage, Wood offers the perspective that milk thistle should be seen principally as a spleen and lymphatic herb whose secondary effects support the portal and hepatic systems (1997, p. 448-449). Felter and Lloyd, in King’s American Dispensatory, note that the German physician Rademacher “valued the seeds in hemorrhages associated with splenic or hepatic disorders” (1989). The decongestive properties of milk thistle extends to other systems of movement in the body, including the spleen, kidneys, and veins, and is indicated specifically in situations of dull and aching pain from the spleen to the left scapula with when weakness and “despondency” is present, even when no swelling or hypertrophy of the spleen can be detected (Felter and Lloyd, 1898). Specific psycho-emotional indications of spleen and lymphatic dysfunction include melancholy, while the liver is more often associated with frustration and anger. Whether poor spleen and lymphatic function adversely effect the liver or vice versa may be specific to individuals and their etiology of disease, but dysfunction in either indicate chronic and deep-seated illness, and milk thistle is often called upon in situations of serious ongoing disease (Wood, 1997).
The mechanisms by which milk thistle relieves congestion and nourishes the body’s systems are many, principally acting in protective, restorative, and stimulating ways to the liver, digestion, and other eliminative and circulatory systems. Current research has shown certain isolates of milk thistle to exhibit “in vitro and/or in vivo anti-hepatotoxic, anti-oxidant, free radical scavenging, anti-inflammatory, anti-proliferative, anti-cancer, chemotherapy potentiating, anti-melanogenic, anti-bacterial, vasorelaxing, anti-platelet aggregation and/or hypotriglyceridemic activity” (Chambers et al., 2015). As a liver stimulant, milk thistle interacts with the digestive tract and metabolic mechanism by supporting the flow of bile from liver and gallbladder. This in turns aids in digestion of lipids, reduced and regulates LDL cholesterol, regulation of blood sugar, insulin, and metabolism, and promotes elimination in cases of constipation (McIntyre, n.d.).
Silybum marianum is thought to protect the liver from damage created by ingested toxins, alcohol, recreational and pharmaceutical drugs, and environmental toxins such as heavy metal, with both preventative and curative potential actions (McIntyre, n.d.). In this protective capacity, milk thistle has been shown to alert the cell membrane so that certain toxins, such as those present in the death cap (Amanita) mushroom, are unable to enter the cells (Foster, 2009). The rapid liver cell regeneration for which milk thistle is so well known appears to be due to silymarin, a compound of milk thistle, which stimulate the enzyme RNA polymerase A, which in turn increases protein synthesis by cellular ribosomes which facilitates the development of new liver cells (Cacciapuoti, 2013; Foster, 2009). This process is supported by milk thistle’s ability to encourage selective inhibition of particular inflammatory molecules within the liver cells (Thamsborg et al., 1996). The silymarin compound is also thought to displace toxins attempting to bind to liver cells as well as help to elevate the levels of protective antioxidants, reducing the harm of free radicals and inflammatory agents within the liver (Lovelace et al., 2015; Foster, 2009). Other research suggests milk thistle assists the liver with through enhancing glucuronidation, selective inhibiting the formation of leukotrienes by Kupffer cells, and inhibiting peroxidation of the cell membranes (Cacciapuoti, 2013).
Milk thistle’s anti-inflammatory and antioxidant actions may combine with its immune-enhancing capacities, stimulating production and function of neutrophils, T lymphocytes, and leucocytes, in turn inhibiting the growth of certain cancer cells in the breasts, prostate, and cervix (Bonavida, 2008). Research has shown silibinin to inhibit cancer cell signaling via multiple pathways (Bosch-Barrera & Menendez, 2015), as well as inducing autophagy in cases of renal cell carcinoma with the effect of preventing metastasis (Li et al., 2015) and inducing apoptosis and preventing proliferation in breast cancer cells (Pirouzpanah, 2015). Other immune-related research in the past year has shown silibinin, a standardized extract of milk thistle, to have significant antibacterial activity, while both silibinin and silymarin exhibit antifungal activity in laboratory studies. The research further suggests that milk thistle extracts can be combined favorably with antibacterial drug in synergistic manners (de Oliveira et al., 2015).
Other research has shown the compounds silibinin and silicristin to be protective to the cells of the kidneys, offering similar support in cases of intoxication by environmental chemicals and pharmaceutical interventions (Sonnenbichler et al., 1999). While not particularly emphasized for its effects on the nervous system, recent research has shown milk thistle extracts to have potential ameliorating effects on neurological and aging-related conditions such as Alzheimer’s and Parkinson’s disease (Kumar et al., 2015).
Two thousand years of documented traditional use and nearly 40 years of research on the phytochemical, pharmacological, and clinical behaviors of milk thistle have offered modern herbalists much information about the active constituents, energetics, mechanisms of actions, and efficacy in human health and healing (Foster, 2009). Although most of the research and contemporary use of milk thistle relates to the liver and its associated systems, current research continues to offer new possibilities for the uses of this humble little seed.
McIntyre (n.d.) suggests that milk thistle is a primary therapeutic ally of 21st century living due to its ability to assist the human body in the liver function and detoxification needed to deal with modern industrial fast-paced lifestyles. Contemporary research shows the primary common causes of liver intoxication are alcohol consumption, exposure to industrial chemicals, and pharmaceuticals, particularly those used for psychiatric purposes, and many argue that silymarin and milk thistle preparations have been shown to be the best documented treatment for liver intoxication (Foster, 2009). Conditions and disorders in which milk thistle and its derivatives have been shown to restore liver damage include alcohol-induces cirrhosis, fatty liver disease, chronic hepatitis (particularly viral hepatitis C), chemotherapy, and in cases of toxicity such as from mushroom poisoning, in the last preventing fatality if given intravenously within 48 hours (Cacciapuoti et al., 2013; McIntyre, n.d.). It has been suggested for use in reducing elevated liver enzymes due to prescription or over-the-counter medication (McIntyre, n.d.). As a detoxifier in less acute conditions, milk thistle can help clear inflammatory situations such as in cases of food intolerance, acnes, psoriasis, and other skin conditions, while its laxative effects can be effective in cases of constipation and hemorrhoids (Foster, 2009).
Some research suggests the potential of supercritical antioxidant-rich preparations of milk thistle extracts for their cytotoxic properties on cancer cells, particularly those related to the hepatitis C virus (Rahal et al., 2015; Mastron et al., 2015). The extract of silymarin, the flavonolignan isolated as a principle constituent in milk thistle, is one of the top four herbs favored by cancer patients as an alternative to or complementary to cytotoxic chemotherapy (Bonavida, 2008). Research has shown both silymarin and silybinin to be cytotoxic to proliferating cancer cells, while silymarin has also shown signs of antiangiogenic activity (Landis-Piwowar & Iyer, 2014). Laboratory studies investigating human breast carcinomas found silybin to increase the therapeutic effects of the chemotherapy agents doxorubicin, cisplatin, and carboplatin, inhibiting cancer cell growth and increasing apoptosis (Bonavida, 2008). The National Cancer Institute offers education around the use of milk thistle during chemotherapy, citing research that milk thistle supplementation may agonize the effects of aforementioned chemotherapy drugs against ovarian and breast cancer cell growth, as well as helping the body to deal with the effects of chemotherapy by protecting the liver cell walls from the toxic effects of the chemotherapeutic agents as well as repairing liver tissue (Landis-Piwowar & Iyer, 2014).
Other clinical indications that suggest the use of milk thistle seeds include poor supply of milk in nursing parents, feelings of “hangover” without apparent intoxication, physical debility, poor absorption, environmental sensitivity, gastric ulcers, elevated cholesterol, diabetes, gut dysbiosis, poor appetite, pelvic tension, and PMS (McIntyre, n.d.). Felter and Lloyd note that milk thistle preparations are further indicated in conditions of the ovo-uterine system including during vomiting in pregnancy, amenorrhea associated with portal congestion, uterine hemorrhaging, and poor lactation (1898). Ellingwood (1919) notes that milk thistle is particularly indicated in cases of circulatory stagnation where there is “venous stasis” with veins that are “enlarged and clogged with blood.”
Traditional clinical pairings of milk thistle seed include combining with dandelion root, turmeric root, and/or artichoke leaf for tonic that repairs and stimulates detoxification processes in the liver (Tillotson, n.d.). Chinese medicine practices suggest pairing milk thistle with white peony, dong quai, and cramp bark for “tendon contracture due to blood vacuity,” as well as with yellow dock and Baical skullcap for dermatological issues and for toxin accumulation and liver heat associated with alcoholism (Garran, 2008).
In terms of its energetic or vibrational medicine, milk thistle’s beautiful purple flowers can be used as essences. Herbalist, ayurvedic practitioner, and flower essence practitioner Anne McIntyre writes that milk thistle flower essence helps people who experience difficulty in appreciating and loving themselves and who may compensate by catering to others. The flower essence supports such individuals in being open to the vulnerable experiences of love by releasing fears that restrict their capacities.
Safety
Most clinicians consider milk thistle to be a very safe herb that can complement most health practices and formulas, as the reports of toxicity and side effects are few and limited to mild laxative effects in some individuals (Foster, 2009). Because research suggests the milk thistle may induce the cytochrome p450 pathway in the liver, its possible that the use of milk thistle may interfere with the levels of certain pharmaceuticals (cardiac glycosides, cyclosporine, birth control, metronidazole (Flagyl)) that are metabolized via this process (Duke, 2010; McIntyre, n.d.). Individuals who have allergic reactions to plants in the thistle/daisy family (Asteraceae) may experience reactions to milk thistle. It is also possible that milk thistle may interfere with the use of insulin and other medications used for hypoglycemia (McIntyre, n.d).
References
Ben Rahal, N., Barba, F.J., Barth, D., Chevalot, I. (2015). Supercritical CO₂ extraction of oil, fatty acids and flavonolignans from milk thistle seeds: Evaluation of their antioxidant and cytotoxic activities in Caco-2 cells. Food Chemistry Toxicology. 83. 275-82.
Bonavida, B., ed. (2008). Sensitization of Cancer Cells for Chemo/Immuno/Radio-therapy. Humana Press. Totowa, NJ.
Bosch-Barrera, J., Menendez, J.A. (2015). Silibinin and STAT3: A natural way of targeting transcription factors for cancer therapy. Cancer Treatment Review. 41(6):540-546.
Cacciapuoti, F., et al. (2013). Silymarin in non alcoholic fatty liver disease. World Journal of Hepatology. 5(3): 109–113.
Chambers, C.S., Valentova, K., Kren, V. (2015). “Non-Taxifolin” derived flavonolignans: Phytochemistry and biology. Current Pharmacology Des. 21(38): 5489-5500.
Duke, J.A. (2010). Duke’s Handbook of Medicinal Plants of the Bible. Boca Raton, FL. CRC Press.
de Oliveira D.R., Tintino S.R., Braga, M.F., Boligon, A.A., Athayde, M.L., Coutinho, H.D., de Menezes, I.R., Fachinetto, R. (2015). In vitro antimicrobial and modulatory activity of the natural products silymarin and silibinin. Biomedical Research International. 2015;2015:292797. doi: 10.1155/2015/292797. Epub 2015 Mar 11.
Ellingwood, F. (1919). American Materia Medica: Therapeutics and Pharmacognosy. Retrieved from http://www.henriettes-herb.com/eclectic/ellingwood/index.html
Felter, H.W.. Lloyd, J.U. (1898). King’s American Dispensatory. Cinncinnati, OH: Ohio Valley Company.
Foster, S. (2009). Milk Thistle Monograph. Stephen Foster Group, Inc. Retrieved from http://www.stevenfoster.com/education/monograph/milkthistle.html
Garran, T.A. (2008). Western Herbs According to Traditional Chinese Medicine. Rochester, VT. Healing Arts Press.
Hussain, K., Zia-ul-Hussnain, S., Shahazas, A. (2010). Distributions and Folk Tibb Knowledge of Milk Thistle (Silybum marianumL.) in NWFP, Pakistan. Ethnobotanical Leaflets. 14: 268-73.
Kumar, J., Park, K.C., Awasthi, A., Prasad, B. (2015). Silymarin extends lifespan and reduces proteotoxicity in C. elegans Alzheimer’s model. CNS Neurological Disorders Drug Targets. 14(2):295-302.
Landis-Piwowar, K.R., and Iyer, N.R. (2014). Cancer Chemoprevention: Current State of the Art. Cancer Growth Metastasis. 7: 19–25.
Li, F., et al. (2015). Autophagy induction by silibinin positively contributes to its anti-metastatic capacity via AMPK/mTOR pathway in renal cell carcinoma. International Journal of Molecular Science. 16(4): 8415-29.
Lovelace, E.S., et al. (2015). Silymarin Suppresses Cellular Inflammation By Inducing Reparative Stress Signaling. J Nat Prod. 78(8):1990-2000.
Mastron, J.K., Siveen, K.S., Sethi, G., Bishayee, A. (2015). Silymarin and hepatocellular carcinoma: a systematic, comprehensive, and critical review. Anticancer Drugs. 26(5):475-86.
McIntyre, Anne. (n.d.). Milk Thistle: Silybum marianum (Monograph). Retrieved from http://annemcintyre.com/silybum-marianum-milk-thistle/
Moore, M. (n.d.) Herb Formulas for Clinic and Home. Southwest School of Botanical Medicine. Retrieved from http://www.swsbm.com/ManualsMM/Formulary2.pdf
National Cancer Institute. (n.d.). Milk Thistle (PDQr). Retrieved from http://www.cancer.gov/about-cancer/treatment/cam/patient/milk-thistle-pdq
Pirouzpanah, M.B., et al. (2015). Silibilin-induces apoptosis in breast cancer cells by modulating p53, p21, Bak and Bcl-XL pathways. Asian Pacific Journal of Cancer Prevention. 16(5):2087-92.
Sonnenbichler, J., et al. (1999). Stimulatory effects of silibinin and silicristin from the milk thistle Silybum marianum on kidney cells. Journal of Pharmacological Experimental Therapies. 290(3):1375-83.
Tillotson, A. (n.d.) Milk Thistle Seed (Silybum marianum). Retrieved from http://oneearthherbs.squarespace.com/important-herbs/milk-thistle-seed-silybum-marianum.html
Wood, M. (1997). The Book of Herbal Wisdom: Using plants as medicines. Berkley, CA: North Atlantic Books.