Scientific Name: Acmella oleracea
Common Names: Jambu, Agrião-do-pará, Eyeball Plant, Buzz Buttons, Toothache Plant, Paracress
Native Range: the tropics of Brazil
Acmella oleraceais a perennial that grows quickly and stays fairly close to the ground. When in bloom, it bears clusters of yellow and red flowers that are said to attract fireflies. Though the plant is sometimes used ornamentally, the most prominent property of the plant is the numbing characteristic that accompanies chewing the flowers. This property has implications in cuisine and medicine.
In northern Brazil, shredded fresh leaves of the toothache plant are often added to salads for the unique, but subtle flavor it possesses. The taste of the plant disappears with cooking, and therefore, the plant’s primary culinary uses relate more to its nutritional value and the numbing property. Like other leafy greens, the leaves are rich in vitamins A, C, and K, lutein, and magnesium. Ingestion of the flowers causes a strong tingling sensation and increased production of saliva. It is important to use sparingly because in high doses, the plant is toxic and high doses of the extract produce sudden convulsions. Because of this toxic property, it has been observed to and used to kill insects and ticks. It takes a much higher dose to be detrimental to humans than it does for smaller organisms, and for this reason, it has been used to treat parasitic infections. These uses as an insecticide and an anti-parasitic are primarily practiced by Peruvians, but they have been investigated in laboratory in an effort to commercialize these functions of the plant.
The flowers were traditionally chewed by people living in the Amazon to relieve mouth, tooth, and throat pains, and from this, the common name of “toothache plant” emerged. This traditional use has been applied to modern medicine research as a possible useful analgesic agent; the concentrated extracts from the plant are especially effective as a means of antinociception. Preparing the extract includes isolating the active compound, in this case spilanthol, and forming a concentrated version of it. Spilanthol is found in the flowers of the plant. Currently, the research is mostly limited to data from rat subjects. The results show that the extract not only reduces the perception of pain, but also the physical presence of inflammation, and this is the same way that popular anti-pain and anti-inflammation drugs like acetaminophen and ibuprofen function. Barriers with bringing this extract to the pharmaceutical scene are related to efficiency; it takes a large number of flowers to acquire enough concentrated spilanthol. Therefore, it is timely and costly to produce relative to already existing antinociceptive and anti-inflammatory drugs.
The plant also has other medical implications that do not relate to its analgesic or anti-inflammatory properties. For example, a type of molecule that the plant contains, rhamnogalacturonan, was isolated and shown to inhibit stomach ulcers, making gastroprotective implications a possibility for the toothache plant. The hydroethanolic extract of the flowers has also been administered to female rats in safe doses and shown to be able to impact the reproductive cycle without influencing fertility or other aspects of health; this finding has implications as a contraceptive. Historically, the plant has been claimed to cure scurvy, a disease common with the Crusaders, but this claim has not been well-researched. The toothache plant has antibacterial properties, and the utilization of this characteristic of the plant is not a modern discovery; a decoction of the plant has been used as an antiseptic even before it was known outside of Brazil.
The applications of the toothache plant are widespread, and as more time is devoted to research, more possibilities arise. The many medical applications of the toothache plant are likely an underestimate of the full capabilities of the plant, and as it is studied more thoroughly and with human subjects, the full extent can be discovered more precisely.
Anholeto, Luís Adriano et al. “Potential action of extract of Acmella oleracea(L.) R.K. Jansen to control Amblyomma cajennese(Fabricius, 1787) (Acari: Ixodidae) ticks.” Ticks and Tick-borne Diseases, vol. 8, 2017, pp. 65-72.
Bender, David A. A Dictionary of Food and Nutrition, Oxford University Press, 2014.
Duke, James A. Duke’s Handbook of Medicinal Plants of Latin America, CRC Press, 2008. ProQuest Ebook Central.
Flexa da Rocha, Clarice, et al. “Action of the hydroethanolic extract of the flowers of Acmella oleracea(L.) R.K. Jansen on the reproductive performance of Wistar female rats: A popular female aphrodisiac from the Amazon.” Journal of Ethnopharmacology, vol. 214, 2018, pp. 301-308.
Franca, Julia Vitor et al. “Distinct growth and extractive methods of Acmellaoleracea(L.) R.K. Jansen rising different concentrations of spilanthol: An important bioactive compound in human dietary.” Food Research Journal, vol. 89, 2016, pp. 781-789.
Nascimento, Adamara M. et al. “Gastroprotective effect and structure of a thamnogalacturonan from Acmella oleracea.” Phytochemistry, vol. 85, 2013, pp. 137-142.
Nomura, Ellen Christine Ogata et al. “Antinociceptive effects of ethanolic extracrt from the flowers of Acmella oleracea(L.) R.K. Jansen in mice.” Journal of Ethnopharmacology, vol. 150, 2013, pp. 583-589.
Thompson, T. Shafi et al. “A study on the antimicrobial effect of Acmella oleraceae against dental caries bacteria.” International Journal of Pharmaceutical Sciences and Research, vol. 3, no. 4, 2012, pp. 1194-1197.