Cloves are small, sharp, and tough. On first inspection, they definitely do not look like anything that should be consumed by humans, and in fact their name comes from the Latin word for nails due, likely, to their appearance. On closer inspection however, cloves have a deliciously inviting smell like no other spice, and proves to be a much more pleasant attractant than its aggressive appearance may suggest. Cloves have been used throughout cuisines and medicinal cultures across Asia throughout the past millennia, with written evidence of its use appearing from Chinese scripts from 400 B.C. Despite the fact that these ancient records were specifically directing servants to hold cloves in their mouths to improve their bad breath and ultimately avoid offending the emperor, cloves are known to have much broader and more useful applications.
More potent than cloves themselves, oil of clove which is also called eugenol, is strong enough to elicit immediate numbness if it makes direct contact with skin. This has led it to be a traditional method of numbing toothaches and other mouth sores, and even to this day it can rival more modern numbing medications like benzocaine, for effectiveness.
Cloves contain a series of medicinal compounds, discovered recently by researchers looking into traditional Chinese medicines. One of these is called oleanolic acid, and has been identified for its anticancer potential. They also contain something called phenols, which are a powerful antioxidant. Finally, due to its high eugenol and flavonoids content (kaempferol and rhamnetin), cloves make a great anti-inflammatory agent. These characteristics combine to affect not only the cancer itself, but also the causes and symptoms.
It continues to be an important ingredient within Traditional Chinese Medicine and in Ayurvedic medicinal practices. To this day it has been found to be a powerful antiseptic, antifungal, antibacterial and antifungal. Plus, there is research to also suggest it has anti-inflammatory and antioxidant capabilities. Most excitingly, new research has demonstrated it has potential for treatment of cancerous tumors. While the data is still preliminary, the initial results have been extremely positive. This will, hopefully, lead to further study into the possibility of clove oil and its medicinal contents to be a new avenue of cancer treatment.
Used in traditional Chinese medicine for its warming capabilities, it was typically used to treat pain and inflammation long before science figured out the reasons why. Nowadays, research has found that eugenol is a strong anti-inflammatory agent. One study found that adding cloves into a diet that was already rich in other powerful anti-inflammatory foods, decreased pain and inflammation by another 15-30%. Another animal study found that eugenol in particular had a dramatic effect on the ability of cells to produce a pro-inflammatory agent called cytokines. When essential clove oil was used, these cytokines were inhibited, thus reducing overall inflammation.
One study looking into the antioxidant properties of middle eastern spices determined that cloves, out of the five other spices tested, had the highest antioxidant properties. When it came to inhibiting free radicals, it also had the best performance out of all spices, being able to affect DHHP radical in particular. Cloves had the highest concentration of phenols which are a type of antioxidants found primarily in plants. In the case of cloves, they contain a classification of phenols called flavonoids which have been noted for their free radical fighting capabilities.
In one pivotal study published in 2014 called, Clove Extract Inhibits Tumor Growth and Promotes Cell Cycle Arrest and Apoptosis, researchers discovered that clove extract seemingly has the ability to reduce tumor growth. They were also able to identify the main agent within clove, oleanolic acid, which causes these anti-cancer effects. They tested in vivo and in vitro models, and in both cases found that clove extract and oleanolic acid, both had positive results for reducing the cancerous growths. It was also found to promote cancer-cell death, and to inhibit the movement of cancer cells within the human body.
Researchers noted that when used in vivo (on animals), it was nearly as successful as a common modern chemotherapy called 5-fluorouracil. It also proved to be extremely well tolerated by the animals in the study, at least when used in moderate amounts. According to the researchers they found that animals only experienced mild weight loss, which is significantly better than what is typically experienced with normal chemotherapies. Weight loss is considered a key indicator of toxicity during in vivo trials. In particular scientists noted that in higher doses cloves seemed to be less tolerated, but under the scriptures of traditional Chinese medicinal practice, herbs are always combined for optimal performance and very rarely (if ever) recommended to be used alone. They then theorized that if oleanolic acid was used in concert with 5-fluorouracil, it would only serve to enhance the chemotherapeutic effects.
More research is needed to determine where the antitumor potential of cloves will take us, however the preliminary research seems to indicate promise both as a natural alternative, and also for use in conjunction with current chemotherapies. Due to their antioxidant component, cloves have the added benefit of reducing free radical damage, and thereby reducing the risk of cancer development. Finally, through its use as an anti-inflammatory it can help reduce the pain and inflammation associated with cancer and its treatment.