Native to Southern Europe and Northern Africa, milk thistle yields silymarin, a flavonoid mix with silybin (most abundant/active). Silymarin has low toxicity (few side effects unless over 10g/d) and multiple benefits: antioxidant, hepatoprotective, anti-tumor, etc. Once used mainly for liver issues, it now shows promise for other chronic diseases. This article covers its health benefits, market uses, and product trends.
Imagine strolling through the sun-drenched fields of southern Europe, where among the golden blooms, a distinctive plant with spiky leaves and vibrant purple flowers sways gently in the breeze. This is milk thistle – an herb that has been cherished in traditional European medicine for centuries and continues to attract widespread attention from researchers, health enthusiasts, and the market in Europe and the United States.
Milk thistle, a herbaceous plant belonging to the Asteraceae family and native to Southern Europe and Northern Africa, has garnered significant attention due to its extract, silymarin. Silymarin, a novel class of flavonoids extracted from milk thistle seeds, boasts a wide range of biological activities, including hepatoprotective, hypolipidemic, antioxidant, anti-diabetic, cardioprotective, anti-platelet aggregation, and anti-tumor effects.
Composed mainly of silybin, isosilybin, silydianin, and silychristin, with silybin being the most abundant (60%-70%) and biologically active component, silymarin exhibits low toxicity, with adverse reactions only likely to occur when the dose exceeds 10 g/d. Traditionally used clinically for treating chronic liver damage and as a liver health supplement, silymarin has shown promising therapeutic effects on other chronic diseases with advancing research.
Milk thistle is a herbaceous plant of the genus Silybum in the Asteraceae family, and its place of origin is Southern Europe and Northern Africa. Silymarin is a type of new flavonoid compound extracted from milk thistle seeds, and it has various functions like protecting the liver, reducing blood lipid levels, resisting oxidation, preventing diabetes, protecting the heart muscle, inhibiting platelet aggregation, and combating tumors. The main components of silymarin are silybin, isosilybin, silydianin, and silychristin. Among these components, silybin has the highest content, accounting for 60%-70%, and it also has the strongest activity.
The low toxicity of silymarin means that it almost has no side effects; adverse reactions may only occur when the dosage exceeds 10 g per day. In the past, silymarin was often used in clinical settings as a therapeutic drug for chronic liver damage and as a liver health supplement. However, with the continuous progress of relevant research, silymarin is no longer limited to the treatment of liver diseases. Studies have shown that silymarin also has therapeutic effects on other chronic diseases.
Health Benefits of Milk Thistle Extract
1.1 Antioxidant Effect
Milk thistle extract can carry out redox reactions with the excess reactive oxygen species (ROS) produced. It achieves this by increasing the expression of antioxidant enzymes such as glutathione peroxidase, glutathione synthesis rate-limiting enzyme, and nuclear factors, enhancing the production of antioxidants like glutathione, and boosting the activity of superoxide dismutase. Silymarin itself has a strong ability to scavenge free radicals, which seems to be attributed to the fact that all its components contain 4-6 phenolic hydroxyl groups (Ph-OH). This structure endows silymarin with strong reducibility, enabling it to directly scavenge oxidized free radicals in the body. Through DPPH free radical scavenging assays, the 20-OH group has been identified as the most active free radical-scavenging functional group, and it is also the most important group responsible for the activity of inhibiting lipid peroxidation.
1.2 Hepatoprotective Effect
The liver is an important organ in vertebrate organisms that mainly focuses on metabolism, and it also performs many other functions, such as oxidation, storing liver glycogen, and producing secretory proteins. According to multiple studies, the extract of milk thistle contains a variety of bioactive substances that have hepatoprotective effects, and silybin is the main pharmacologically active compound in the silymarin extract, which is also known as a "natural liver-protecting drug". The impact on the liver mainly lies in the antioxidant properties that flavonoids themselves possess.
They can control the synthesis of phosphatidylcholine, thereby promoting the synthesis of RNA and proteins in the liver. Milk thistle extract can protect against liver damage caused by substances such as CCl4, galactosamine, and alcohols. It can protect the liver cell membrane through its anti-lipid peroxidation effect, enhancing the liver cell membrane's resistance to various damaging factors. Silymarin can prevent hepatotoxic substances from entering liver cells, thereby maintaining the integrity of the liver cell membrane and achieving the effect of protecting liver cells.
1.3 Anti-tumor Effect
Milk thistle extract has an inhibitory effect on various cancers and tumors such as lung cancer, liver cancer, bladder cancer, and skin cancer. Silybin inhibits the growth of small cell lung cancer (SCLC) SHP-77 cells and non-small cell lung cancer (NSCLC) A-549 cells by affecting MMPs-mediated cell invasion, urokinase in the PI3K-Akt and MAPK signaling pathways, and accelerates the apoptosis of these cells. In addition, silymarin can reduce the proportion of myeloid-derived suppressor cells (MDSCs), inhibit the function of MDSCs, promote the infiltration of CD8+ T cells and the release of perforin and enzymes, activate the function of the Fas/FasL pathway, and inhibit the growth and reproduction of tumor cells.
For prostate cancer, silymarin induces apoptosis of PC-3 prostate cancer cells by activating NOX4 attached to mitochondria, which generates more ROS, leading to the disruption of intracellular calcium ion homeostasis and further causing endoplasmic reticulum stress. For pancreatic cancer, silymarin can significantly induce the production of ROS in pancreatic cancer cells, further activating JNK/SAPK to promote the apoptosis and autophagy signaling of SW1990 human pancreatic cancer cells.
Market Applications and Product Dynamics
Milk thistle is an economic crop with multiple uses such as medicinal, food, and health care. The silymarin extracted from it can not only stabilize liver cells and improve liver function but also plays a very important role in the treatment of hepatobiliary diseases. Milk thistle health care products can be used to protect the liver, repair liver damage, have a protective effect on chemical liver damage, and enhance immunity.
In the European and American markets, milk thistle products are widely available in various forms, such as capsules, tablets, and liquid extracts, and are favored by consumers who pay attention to liver health and overall wellness. With the increasing awareness of natural health products in these regions, the market demand for milk thistle products is showing a growing trend.