Cancer is a frightening disease that represents abnormal tissue growth, otherwise known as a tumor. Tumors need nutrients and an oxygen supply for their growth and progress. For these purposes, tumors need an influx of large amounts of blood, which can provide them with a sufficient influx of oxygen and nutrients. Therefore, as cancer progresses, it builds its own blood vessel structure that provides it with everything it needs to survive and grow. This process is known as angiogenesis.
Normal tissues that build blood vessels secrete specific polypeptides. Tumors can also form these VEGF and APN polypeptides. The secretion of these peptides results in the disorganized formation of blood vessels, which provide tumor oxygen and nutrients.
Newer methods of treating cancerous diseases use drugs that prevent new blood vessels. These drugs have very low toxicity because their purpose is to affect blood circulation and blood vessel formation but not the tumor itself. When blood vessels’ formation stops, the tumor does not get enough oxygen and nutrients, and thus its cells begin to die.
Judah Folkman was the first doctor to use the possibilities of some drugs against angiogenesis to treat cancer. After his successful attempts, a complete line of drugs was formed, which affects the reduction of the tumor’s supply of new blood supplies.
A new generation of drugs is used to reduce the angiogenesis factor of monoclonal antibodies such as bevacizumab. Such drugs can increase the life expectancy of people with cancer.
Such therapies work best if combined with chemotherapy or radiotherapy. This fact is supported by research. It has been proven that agents that stop angiogenesis are of key importance, but that combined with the above-mentioned therapies, they achieve even greater success.
How do tumors metastasize?
First of all, tumor cells begin to grow. After that, these cells, which are rapidly developing and growing, are supplied with oxygen and nutrients by angiogenesis. This occurs when cancer cells release factors such as VEGF and APN. Then, these cells occupy the tissue that surrounds them. Some of these cells go beyond the tumor’s shape and are released into the bloodstream or lymphatic system. From there, these cells move to other organs where they bind to the tissue and multiply again, causing angiogenesis and forming new blood vessels. In this way, tumors can spread to distant parts of the body.
When VEGF and APN are increased, angiogenesis and tumor development are increased.
Therapy against angiogenesis may depend on the location of the tumor and its environment:
Angiogenesis factors such as VEGF are secreted not only from the tumor but also from the surrounding tissue. Tumor. So the microenvironment of the tumor can also affect the tumor’s development. Due to this fact, any drug used should target both the tumor and the surrounding tissue’s angiogenic factors. In that sense, natural remedies work very well because, in small doses, they affect various points of the angiogenesis pathway. In this way, they can be effective against a variety of tumors.
Use of plants against angiogenesis:
The first anti-angiogenic plant used for this purpose was fumagillin, which is actually an antibiotic produced by a single fungus. Some of the plants used today to inhibit angiogenesis include Aloe barbadensis, Chemillia Sinensis, ginger, garlic, aloe vera, licorice, resveratrol, etc. Some of these plants specifically target VEGF, and these are Angelica Sinensis, Viscum album, Taxus brevifolia, and others. These herbs are given continuously in low doses, so that side effects are minimized.
More about these plants:
Viscum album or Iscador . This plant acts on VEGF and causes the death of tumor cells.
Sweet wormwood or artemisia annua. This plant’s derivative, artemisinin, is used as an anti-malarial agent. This plant also reduces the formation of new blood vessels as it inhibits the formation of internal capillaries called the endothelium.
Resveratrol is obtained from red grapes. This compound reduces the production of VEGF. It also affects other pathways and reduces the production of MMP-2, which is another factor that affects tumor growth.
Silybum marianum: These flavonoids act on many factors involved in tumor growth. This plant is effective against ovarian cancer.
Quercetin: This flavonoid is present in several fruits, including apples and citrus fruits. This compound affects several pathways, including VEGF, COX-2, Lipoxygenas-5, and some enzymes. These pathways are involved in angiogenesis, and inhibiting them limits tumor growth.
Camellia is found in green tea, so green tea is considered very good for health, especially as an anti-tumor agent. This compound has been studied in rodents and humans, and so far, research has shown promising results.
Copper is needed for the various steps of forming new blood vessels. Plants that act as agents on copper can reduce tumor angiogenesis. These are Caryophylli flos and Cinnamomi cortex.
Products obtained from animals:
The formation of cartilage in the body does not allow new blood vessels. Shark cartilage derivatives are being studied to stop angiogenesis. One of the compounds and shark cartilage AE-941 inhibits angiogenesis and reduces tumor formation. Research on this compound is ongoing.
Anti-angiogenesis factors are beneficial for tumor suppression. Using natural products for that purpose is something that medicine should pay more attention to. The best thing is that these drugs are relatively safe and can be given together with chemotherapy to improve the effects of cancer treatment.