Two popular herbs used in cooking contain compounds that are of great interest to scientists because they have powerful anti-cancer properties.
Up until recently, scientists couldn’t extract enough of these healing compounds for these herbs to be of any medicinal value to patients. However, a new breakthrough is changing that.
Soon, thyme and oregano may be as valued for their ability to help cancer patients as they are for their taste.
Thyme is a staple herb used in French cuisine. And oregano, its close relative, is often used in pizza sauce and other Mediterranean dishes. Both belong to a family of herbs called Lamiaceae. Other members of this family include basil, mint, rosemary, and sage.
Of course, scientists aren’t interested in these herbs for their culinary value, but because they contain two compounds of great medicinal importance. These compounds - which bestow the typical aroma and flavors of the herbs - are called thymol and carvacrol. They’re classified as monoterpene alcohols and are found in high concentrations in the essential oils of these herbs.
These compounds show great promise in the prevention and treatment of cancer.
A plethora of positive lab research
Last year, researchers from Brazil carried out a systematic review of the anti-tumor effects of thymol and carvacrol. They uncovered 1,170 records, of which 77 met their criteria.
They examined cellular studies in lung, liver, colorectal, breast, cervical, oral, gastric, bladder, skin, brain, blood, and prostate cancers using either one or both herbal compounds. In all of these studies, the researchers identified numerous anti-cancer actions.
They also reported positive findings in rodent studies for both herbal compounds. The effects included an increase in apoptosis (cancer cell death), increased antioxidant activity, elevated body weight, and longer survival.
The team also found fewer precancerous polyps, and among the ones they did find, fewer of these precancerous growths transformed into cancer. And when cancer did occur, they also noted fewer tumor markers, slowed tumor growth, and a lower risk of tumor spread.
67 percent reduction in tumor development
In one of the reviewed studies, published in 2020, rodents with breast cancer given carvacrol saw a significant decrease in the number and volume of tumors. There was a 75 percent decrease in tumor frequency and a 67 percent reduction in the incidence of tumors.
The Brazilian authors concluded their paper by writing, “The knowledge obtained through the reviewed studies provides strong evidence of the anti-tumor and anti-proliferative activity promoted by carvacrol and thymol.”1
A second paper, published in 2021, looked at the effect of both compounds combined on acute myeloid leukemia cell lines and found they “induced tumor cell death with low toxicity on normal cells.”2
However, to take this research further into human cancer trials and turn the compounds into drugs, isolating them from thyme and oregano was not really feasible. Scientists needed to reproduce thymol and carvacrol in the lab. To do this they have to determine how the plant produces these compounds, a process that’s known to involve many chemical steps.
Scientists at Purdue University College of Agriculture, West Lafayette, Indiana, took on the challenging problem and claim to have found a solution.
Entire pathway uncovered
Natalia Dudareva, a Distinguished Professor of Biochemistry who co-led the project, explained the importance of their research.
"These plants contain important compounds, but the amount is very low, and extraction won't be enough. By understanding how these compounds are formed, we open a path to engineering plants with higher levels of them or to synthesizing the compounds in microorganisms for medical use.”3
Working with scientists from Martin Luther University Halle-Wittenberg in Germany and Michigan State University, the team uncovered the entire biosynthetic pathway to thymol and carvacrol and beyond, stretching to two other monoterpenes in the herbs called thymohydroquinone and thymoquinone. These also exhibit anti-cancer activity.
Professor Jörg Degenhardt at Martin Luther University explained the multi-stage process. "It's like a production line in a factory: Every step needs to be coordinated and the desired product only emerges when the steps are carried out in the right order."
In the plant, specific enzymes carry out this work in special glands on the surface of the leaves, but how the plant performs these tasks is a decades-old mystery.
Mystery solved
Assumptions that had been made turned out to be wrong as Professor Degenhardt goes on to explain, saying, "For a long time, it was assumed that [the monoterpene] p-Cymene was an intermediate product of thymol and carvacrol synthesis. However, it was chemically not feasible for thymol or carvacrol to ultimately be produced from this substance.”
Instead, an unstable intermediate product is produced.
"This is only present for a few moments in the plant cells, which is why observing it is so difficult. However, it represents the hitherto missing step in the synthesis of the two substances." These new findings were then used to genetically reprogram a species of tobacco to produce thymol.
"Even though this only happened in small quantities, it meant that we were able to fully understand the synthesis pathways and the associated enzymes.”4
An upbeat Professor Dudareva added, "We, as scientists, are always comparing pathways in different systems and plants. We are always in pursuit of new possibilities. The more we learn, the more we’re able to recognize the similarities and differences that could be key to the next breakthrough.
"It is an amazing time for plant science right now. We have tools that are faster, cheaper and provide much more insight. It is like looking inside the cell; it is almost unbelievable."
Potent healing properties that go beyond cancer
Quite a few years will pass by before we see this scientific breakthrough put into clinical practice. But there's no need to wait. Even though herbs (and spices) are added to foods in small quantities, it doesn't mean they can't have a major impact on our health.
Thymol is mainly extracted from thyme and because it can break up mucus it's found in cough syrups, in tea to relieve colds, and as an herbal remedy to treat bronchitis.
Thymol also has antibacterial properties and is used in toothpastes and mouthwashes and by dentists to treat infections of the oral cavity. It can also be found in ointments to relieve muscle spasms.
A research review found thymol possesses antibacterial, antifungal, anti-parasitic, anti-inflammatory, antioxidant, and analgesic properties. In addition, it kills ticks and mites, prevents convulsions, inhibits the development of epilepsy, promotes wound healing, safeguards red blood cells, protects against radiation, and prevents mutations.5
Carvacrol is especially high in oregano and has similar attributes to thymol. Carvacrol possesses anti-inflammatory, antioxidant, analgesic, antibacterial, antifungal, and antiparasitic properties. It also protects against heart disease, diabetes, kidney toxicity, and cancer in lab research.6
A recent study from Penn State found remarkable health benefits of using herbs to improve heart health. Volunteers with risk factors for heart disease added a 6.5-gram blend (just over a teaspoon) of 24 herbs and spices to their food each day. The blend included thyme, oregano, basil, rosemary, and sage.
After four weeks the 71 participants saw a drop in their blood pressure.
Co-principal investigator Penny Kris-Etherton said, “I think it’s really significant that participants consumed an average American diet throughout the study, and we still found these results.
“We didn’t decrease sodium, we didn’t increase fruits and vegetables, we just added herbs and spices. It begs the next question that if we did alter the diet in these ways, how much better would the results be?”7
Sounds like more research is in order. I’ll keep you posted.
Best regards,
Lee Euler,
Publisher
References:
- https://www.frontiersin.org/articles/10.3389/fphar.2021.702487/full
- https://www.mdpi.com/1420-3049/26/2/410/htm
- https://www.eurekalert.org/news-releases/938409
- https://www.sciencedaily.com/releases/2021/12/211221102749.htm
- https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5483461/
- https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC8623889/
- https://www.psu.edu/news/story/adding-herbs-and-spices-meals-may-help-lower-blood-pressure/
