Milk thistle extract has been used as an herbal supplement for more than 2,000 years, mostly to treat liver and gallbladder disorders. Over the past decade, hundreds of clinical trials have been conducted to further understand how and why the active ingredient in milk thistle produces such a beneficial effect on hepatic health. However, its anti-carcinogenic properties have prompted new research into milk thistle revealing that the liver is not this herb’s sole benefactor.
About Lung Cancer
Lung cancer – like all cancers – is the result of an abnormality in cell growth. Normally, the body maintains a system of checks and balances on cell growth in order for cell division to produce new cells only when they are needed. Disruption of this system can lead to an uncontrolled division and proliferation of cells that eventually forms a mass known as a tumor.
Tumors can be benign or malignant. Benign tumors can usually be removed and do not spread to other parts of the body. On the other hand, malignant tumors are cancerous and can grow aggressively, capable of invading and spreading to other tissues of the body. Since lung cancer tends to spread (metastasize) very early after it forms, it is life-threatening and one of the most difficult types of cancer to treat. Lung cancer is the leading cause of cancer deaths in the United States among both men and women – claiming more lives each year than colon, prostate, ovarian and breast cancers combined.
A Brief on Milk Thistle
A plant native to Europe, the active constituent of milk thistle is silymarin, a flavonoid found in the plant’s seeds. After years of silymarin research, experts have discovered that one component of silymarin, silybin or silibinin, is the constituent responsible for milk thistle’s hepatoprotective properties. Besides being a strong antioxidant, silibinin has been known to tout some impressive biochemical characteristics that are valuable in fighting cancer.
The Cellular Chain of COX2 and iNOS
In a cell, a chain of signals leads to an end product. In the case of cancerous cell growth, it is desirable to eliminate that end product – a feat that can be accomplished by breaking a link in the chain. More specifically, the end products COX2 and iNOS are enzymes involved with the inflammatory response that can aid tumor growth. In this signaling chain are two undesirable enzymes: STAT1 and STAT3. By stopping STAT1 and STAT3, the chain that leads to COX2 and iNOS is broken. This interruption is capable of stopping the growth of cancerous lung tumors.
The New Research on Silibinin and Lung Cancer
Recent research has found that silibinin has a specific capacity to fight lung cancer by blocking these inflammatory chemicals that perpetuate cancer growth and inhibiting the migration of existing lung cancer cells. As published in an August 2011 online version of the journal Molecular Carcinogenesis, researchers at the University of Colorado found that silibinin was able to inhibit the signals (STAT1 and STAT3) that lead to the expression of COX2 and iNOS.
The researchers compared silibinin to the multimillion dollar drugs currently in clinical development for lung cancer. By inhibiting STAT1 and STAT3, they found that silibinin blocked not only the expression of COX2 and iNOS, but also the migration of existing lung cancer cells.
The concept of using silibinin as a lung cancer preventative and therapeutic agent is in its infancy; nonetheless, this Colorado-based research is exciting. Besides supporting and protecting the liver’s well-being, it appears that the active component of milk thistle might also be capable of protecting against the development of malignant lung tumors.