Visit our Re-post guidelines
You might like the spicy taste of cloves in your meal. But cloves have a deeper side: Preclinical research reveals their ability to halt the growth of a number of types of cancers.
So you like the taste of cloves as a spice? Turns out that cloves run deeper than taste.
Quite simply, cloves are dried flower buds from a plant scientifically called Syzygium aromaticum L.
Cloves have been used for centuries in several traditional medicines, including Ayurveda and Traditional Chinese Medicine. They have also been used in Indonesian, Thai and Kampo medicine of Japan for centuries.
This means that cloves have been clinically used as a medicine on billions of people for thousands of years.
Cloves have been used for numerous types of infections, including those caused by bacteria, viruses and fungi. They also have a way of deadening pain, which is why they are often used for relieving teeth infections. Traditional therapies have used cloves for gastrointestinal disorders, disorders of the kidneys and spleen, and for pain.
But because cancers are more of a modern disease, the use of medicinal herbs such as cloves has been overlooked as anticancer agents. Nonetheless, over a third of today's anticancer agents are in fact based upon plant-derived pharmaceuticals.
As it turns out, cloves are not simply antibacterial, antifungal, antiviral and carminative: Cloves are also potent anticancer agents.
Cloves stop cancer in laboratory research
This has been confirmed by research by scientists from the University of Minnesota, the University of Pittsburg and China's Capital Medical University in a series of experiments.
The researchers tested a variety of human cancer cells in the laboratory using different whole clove extracts. The researchers tested SKOV-3 human ovarian cancer cells, human HeLa cervical epithelial cells, BEL-7402 human liver cancer cells, HT-29 human colon cancer cells, MCF-7 human breast cancer cells and PANC-1 human pancreatic cancer cells. They also tested normal colon wall cells and normal lung cells as controls.
The acronym names of the cancer cells above relate to a specific human cancer taken from a specific cancer sufferer. In other words, these are live human cancer cells that have been allowed to grow within the laboratory.
The researchers found that the clove extract halted the activity and growth of the colon cancer cells, the breast cancer cells, the ovarian cancer cells, the liver cancer and the colon cancer cells.
Meanwhile, the clove extract was not dangerous to the normal cells.
This of course means that the cloves were smart. They stopped the growth of the cancer cells while allowing regular cells to grow.
Not only that, but they halted the cancer cells in a dose-dependent manner. This means that the more clove was applied, the greater the anticancer effect. This is considered the gold-standard of determining whether a particular compound is causing the effect.
Extracting the anticancer compounds
The extract that proved the most efficacious was an ethanol extract. This means basically that the cloves were soaked in alcohol and the resulting solution was used (don't self-medicate – talk to your doctor). More specifically, the cloves were soaked in 95% alcohol for 72 hours at room temperature. The whole extract was then concentrated.
The extracting process had the effect of releasing the medicinal compounds from cloves that may or may not be released when they are eaten. This is a common method used by herbalists for centuries. Today these are called tinctures.
Cloves have many different medicinal compounds. Some have been isolated while others have not. Those that have been isolated and identified include eugenol, β-caryophyllene, humulene, chavicol, methyl salicylate, α-ylangene, eugenone, eugenin, rhamnetin, kaempferol, eugenitin, oleanolic acid, stigmasterol, campesterol and others.
The variety of these compounds have been categorized as sesquiterpenes, flavonoids, triterpenoids and others.
This whole array of compounds within natural herbs provides the basis for the safety of many medicinal herbs. When compounds are isolated and prescribed without nature's blend of other constituents, the medicine often produces side effects. These other compounds provide a buffering effect.
That said, the two compounds that the researchers found provided critical anticancer potency were oleanolic acid and eugenol. The former is a triterpenic acid.
This is not the first time that oleanolic acid has been found to be a potent anticancer agent. A 2013 study from the Chinese Academy of Sciences found that oleanolic acid was able to arrest and halt the cell cycle of human pancreatic cancer cells.
The researchers further found that oleanolic acid accomplished this using several different strategies, including interferring with the mitochondria of the cancer cells and altering the genes of the cancer cells.
Yes, this natural constituent of clove altered the cancer cells' DNA. This is nature, folks. Nature is smart.
Liu H, Schmitz JC, Wei J, Cao S, Beumer JH, Strychor S, Cheng L, Liu M, Wang C, Wu N, Zhao X, Zhang Y, Liao J, Chu E, Lin X. Clove extract inhibits tumor growth and promotes cell cycle arrest and apoptosis. Oncol Res. 2014;21(5):247-59. doi: 10.3727/096504014X13946388748910.
Wei J, Liu M, Liu H, Wang H, Wang F, Zhang Y, Han L, Lin X. Oleanolic acid arrests cell cycle and induces apoptosis via ROS-mediated mitochondrial depolarization and lysosomal membrane permeabilization in human pancreatic cancer cells. J Appl Toxicol. 2013 Aug;33(8):756-65. doi: 10.1002/jat.2725.