When cloves are placed in the mouth, many people notice a distinct numbing sensation. This effect is due to natural chemical compounds found within these aromatic flower buds. Understanding the science behind this reveals how plant molecules interact with the body’s sensory systems.
The Key Ingredient: Eugenol
The primary active compound responsible for the numbing sensation associated with cloves is eugenol. This natural organic compound is a pale yellow, aromatic oily liquid with a spicy, clove-like scent. Eugenol is a phenylpropanoid, a type of natural product derived from plants.
While present in smaller amounts in other plants like nutmeg, cinnamon, basil, and bay leaf, eugenol is particularly concentrated in cloves. Clove oil, extracted from the dried flower buds of the Syzygium aromaticum tree, can contain eugenol in very high concentrations. Specifically, clove bud oil typically comprises 80% to 90% eugenol, and clove leaf oil contains 82% to 88% eugenol. Eugenol also exhibits antioxidant, antiseptic, and antimicrobial properties.
How Eugenol Causes Numbing
Eugenol produces its numbing and analgesic effects by interacting with specific receptors on nerve cells. It primarily acts as an agonist for transient receptor potential vanilloid 1 (TRPV1) receptors, which are found on sensory nerve endings, particularly those involved in sensing pain and temperature. When eugenol binds to these receptors, it triggers an initial brief stimulation, leading to a temporary disruption of nerve signals.
This interaction causes an influx of calcium ions into the nerve cells, which is associated with the desensitization of pain sensations. Eugenol desensitizes these nerve endings, reducing their ability to transmit pain signals to the brain. Eugenol has also been shown to inhibit voltage-gated sodium channels in dental nerve endings, contributing to its anesthetic properties by blocking nerve impulse conduction. This combined action results in the temporary numbing and pain-relieving sensation observed in the mouth.
Traditional Applications and Safety Advice
Historically, cloves have been used for their pain-relieving properties, particularly for toothaches. People would traditionally apply whole cloves or diluted clove oil directly to an aching tooth to alleviate discomfort. In modern dentistry, eugenol continues to be used, often combined with zinc oxide, to create temporary fillings and dental cements. These preparations provide both anesthetic and antibacterial benefits, helping to calm sensitive tooth nerves and fight infection.
It is important to recognize that the numbing effect of cloves is temporary and does not address the underlying cause of pain, such as a cavity or infection. Cloves should not be used as a substitute for professional dental care. Excessive or frequent use of concentrated clove oil can lead to side effects, including irritation or damage to the gums, tooth pulp, and other soft tissues in the mouth.
Ingesting large quantities of clove oil can be harmful, potentially causing severe issues like liver damage, seizures, or respiratory problems, especially in children. Always dilute clove oil before topical application and consult a healthcare professional for persistent pain or before using herbal remedies, particularly if pregnant, breastfeeding, or managing other health conditions.