Pepper-rosmarin Essential Oil Controls Cavity and Gum Disease Bacteria

Lippia species inhibit gum disease bacteria

Lippia alba: Photo by Dick Culbert

By Case Adams, Naturopath

Research from Brazil’s Federal University of Ceará’s schools of medicine and dentistry has determined that a toothpaste made from a common herb that grows in the wild significantly reduces the bacteria in the mouth that cause dental decay and periodontal disease.

The researchers tested 81 boys and girls between six and 12 years old. The researchers divided the children into five groups. They gave each group either a chlorhexidine gel or mouthwash, or one of three products with 1.4% essential oil of Lippia sidoides Cham: These included a mouthwash, a gel and a toothpaste.

For five days, each child used their respective toothpaste or mouthwash for one minute per day. The children who brushed did so for one minute and the children who used the mouthwash gargled for one minute per day.

The researchers took saliva samples from each child before the treatment, after the treatment and for 30 days. With these saliva samples, the scientists measured the level of salivary Streptococcus mutans in each child.

For those who are unaware of chlorhexidine, this is a convention chemical oral wash that has been shown to significantly reduce oral bacteria. The problem, however, is that the bacteria come back – and often in stronger, more pathogenic colonies.

The research found that those who brushed with the herbal toothpaste had a decrease in Streptococcus mutans similar to those who used the chlorhexidine.

However – and more importantly – after the five days and up to 30 days later, the chlorhexidine group’s counts of Streptococcus mutans had returned to the same levels as before the treatment began.

Meanwhile, the toothpaste with Lippia sidoides Cham essential oil also reduced Streptococcus mutans – but the reduced levels of Streptococcus mutans remained through the 30 days of testing.

Pepper-rosmarin essential oil shown to be antimicrobial in other research

Other studies have illustrated the pepper-rosmarin plant is significantly antimicrobial. Another study from Brazil – from the Federal University of Rio de Janeiro – found that the essential oil from the leaves of the plant – which contain antimicrobial monoterpenes inclusive of thymol and carvacrol, significantly inhibited numerous genera of bacteria.

A 2007 study from Brazil’s Federal University of Ceará found that pepper-rosmarin significantly inhibited Candida albicans and Streptococcus mutans. They also confirmed that the essential oil contained 56.7% thymol and 16.7% carvacrol, along with others, such as linalool and estragole. The researchers stated:

“The essential oil of L. sidoides and its major components exert promising antimicrobial effects against oral pathogens and suggest its likely usefulness to combat oral microbial growth.”

Other studies have found the pepper-rosmarin essential inhibits the potent bacteria Staphylococcus aureus and Pseudomonas aeruginosa.

The pepper-rosmarin is an aromatic plant in the family of Verbenaceae – meaning it is a verbena type plant. It has a long history of use in herbal medicine, specifically among South Americans and North American Indians – who used the plant to treat skin, throat, mouth and vagina infections.


Note that the ability to reduce S. mutans populations in the mouth long exceeded the ability of chlorhexidine to keep populations reduced. This relates directly to the ability of selective nature of herbal antimicrobials. The second study discussed tested the essential oils against some of the same bacteria that resided on the outside of the plant – on its stems primarily. They found that the essential oil selectively inhibited these.

This illustrates that intelligence of nature. After millions of years of biodiversity, plants have developed certain compounds that inhibit those invasive bacteria and yeasts they need to protect themselves from.

Protective probiotic bacteria species, on the other hand, often have different immune systems and will thus survive the plant oil. It is obvious that the reason the saliva S. mutans populations remained low is that probiotic populations were allowed to grow – which inhibit S. mutans. This became obvious when it was found that the S. mutans inhibition did not take place for those children with active cavities – as those cavities were harboring the S. mutans, where the toothpaste could not reach.

Note also the low concentration of the essential oil used in the first study – 1.4%. More than this could be harmful.

Learn how to increase oral probiotic populations.


Lobo PL, Fonteles CS, Marques LA, Jamacaru FV, Fonseca SG, de Carvalho CB, de Moraes ME. The efficacy of three formulations of Lippia sidoides Cham. essential oil in the reduction of salivary Streptococcus mutans in children with caries: A randomized, double-blind, controlled study. Phytomedicine. 2014 Jul-Aug;21(8-9):1043-7. doi: 10.1016/j.phymed.2014.04.021.

da Silva TF, Vollú RE, Jurelevicius D, Alviano DS, Alviano CS, Blank AF, Seldin L. Does the essential oil of Lippia sidoides Cham. (pepper-rosmarin) affect its endophytic microbial community? BMC Microbiol. 2013 Feb 7;13:29. doi: 10.1186/1471-2180-13-29.

Botelho MA, Nogueira NA, Bastos GM, Fonseca SG, Lemos TL, Matos FJ, Montenegro D, Heukelbach J, Rao VS, Brito GA. Antimicrobial activity of the essential oil from Lippia sidoides, carvacrol and thymol against oral pathogens. Braz J Med Biol Res. 2007 Mar;40(3):349-56.

Case Adams is a California Naturopath with a PhD in Natural Health Sciences, and Board Certified Alternative Medicine Practitioner. He has authored 26 books on natural healing strategies. “My journey into writing about alternative medicine began about 9:30 one evening after I finished with a patient at the clinic I practiced at over a decade ago. I had just spent the last two hours explaining how diet, sleep and other lifestyle choices create health problems and how changes in these, along with certain herbal medicines and other natural strategies can radically yet safely turn ones health around. As I drove home that night, I realized I needed to get this knowledge out to more people. So I began writing about health with a mission to reach those who desperately need this information. The strategies in my books and articles are backed by scientific evidence along with wisdom handed down through traditional medicines for thousands of years.” Case connects with the elements by surfing, hiking and being a beach bum.

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