Dr. Carl Thornfeldt discusses the science behind herbal-based therapies as well as the complexities of herbal therapy product development.
Carl Thornfeldt, MD, CT Derm Pc, Fruitland, Idaho, and Owner Epionce and Thornfeldt and Associates Research
“Herbal therapy is focused on the secondary metabolites—the primary bioactives in herbal extracts. They are in the plant to protect against predators and radiation, including ultraviolet light (UVL), and against various toxins,” said Carl Thornfeldt, MD, who presented “Prescription and Nonprescription Herbal Based Therapies” at the 2022 Cosmetic Surgery Forum in Nashville, Tennessee.
“They also store chemicals for metabolism and provide coloration for protection and functionality.”
Traditional medicine has documented for 5 millennia that tonics extracted from plants—extracts that are not highly purified—have better therapeutic benefit than highly purified individual bioactive chemical ingredients known as secondary metabolites, said Dr. Thornfeldt.
“[The reason for this] revolves around what is called the ‘entourage effect.’ To maintain their stability and functionality, secondary metabolites interact with a variety of other compounds, ions, and elements that help provide that additional stability, distribution, and function.”
Of the more than 250,000 known plant species, more than 50,000 have been thoroughly investigated. Research has yielded more than 40,000 secondary metabolites, said Dr. Thornfeldt.
“By combining with the entourage effect, we’re seeing a far greater effect with surprising additional functions.”
Secondary metabolites can be broken into multiple biochemical classes, including flavonoids, anthocyanins, carotenoids, coumarins, lignans, stilbenes, tannins, terpenes, saponins, glycosides, vitamins, minerals, and polyphenols, according to Dr. Thornfeldt.
“These different chemicals can reside in many different plants and many plants have many of these molecules, ions, and elements.”
While the U.S. does not regulate plants, Germany and Japan have regulatory systems that determine safety and efficacy of herbal products, he said.
“The German Commission E currently has 187 herbs and the Japanese Kampo has 294 herbs in it.”
The problem with making herbal products mainstream is simply that adding an herbal ingredient does not necessarily mean the product work and is safe, said Dr. Thornfeldt.
“Whether or not there will be efficacy from an herbal extract is dependent on a variety of factors, primarily the quality of the biomass. In other words, when the material is harvested, and that is dependent on climate factors, soil, the method and duration of storing it, and the time of transporting it prior to processing.”
The next important step that has an impact on efficacy is the processing during manufacturing, said Dr. Thornfeldt.
“Many secondary metabolites, as well as their entourage molecules, are very dependent upon processing. They’re sensitive to ultraviolet, heat, and pollutants in the manufacturing site.”
“It’s not as simple as just taking a plant, grinding it up, extracting some liquid or powder, putting it in a cream and saying, ‘Here, it works.’ It’s an intensive, sophisticated process to develop products that actually work, as proven by randomized controlled clinical trials, and products that have safety as determined by a repeat insult patch test.”
Herbal Remedies to the Test
Among the 20 or so published methods of extraction available today, the most common are pressing, drying, solvent and water baths, and steam distillation, said Dr. Thornfeldt.
“The problem is most of those will damage all the vitamins, likely antioxidants, and elements. They will not only decrease their functionality and their stability, but they will produce some toxins. Consequently, if you actually look at the whole processing of herbal products, it’s much more likely that the herbal extract… could increase the risk of allergic contact dermatitis and contact irritant dermatitis than produce therapeutic effect.”
Dr. Thornfeldt said processing systems using a series of different extraction methods to maximize the amount of not only secondary metabolites, but also entourage molecules, are promising but significantly increase manufacturing costs.
“In a search to try to solve that problem. Our research foundation contributed to developing two proprietary extraction methodologies that we have shown are superior to any of those on the market. We’ve been able to prove this superiority.”
Dr. Thornfeldt and colleagues did a series of in vitro assays of seven herbs evaluating anti-inflammatory and antimicrobial functionality, comparing the two proprietary extracts with herbal extracts from eight commercial brand suppliers, he said.
“The commercial herbal extracts did have some functionality, usually single digits but there were a couple that approached 20%. The extract we produced with these proprietary extracts were significantly more potent. For example, when we looked at suppression of tumor necrosis factor alpha by cork tree, or Phellodendron, we had 87.3% suppression. With purslane, which is Portulaca, there was an 80.4% inhibition. Interleukin (IL)-B was inhibited by purslane by 58%; IL-6 was inhibited 67% by one of the four skullcap species. Skullcap is a Scutellaria species. We have seen some of those recently in some pharmaceuticals and cosmeceuticals. We found that other skullcap species inhibited IL-1 by 54% and 50%.”
When they looked at the antimicrobial impact, Dr. Thornfeldt said they found that cork tree inhibited Cutibacterium acnes by 62%; rhubarb, which is Rheum palmatum, and dandelion, which is Taraxacum officinale, inhibited Malassezia furfur yeast by 48%; and a skullcap species inhibited this yeast by 42%.
“This data was statistically significantly superior (p<0.001) to prescription products including fluconazole, ampicillin, and gentamicin.”
In the anti-inflammatory category, Dr. Thornfeldt and colleagues found the herbal therapies studied were highly statistically superior in blocking inflammatory signals compared to dexamethasone, a cyclooxygenase 2 inhibitor, and histamine 1 and 2 inhibitors, he said.
Anti-viral Effects
“It had been reported back in 1918-1920 that there were communities scattered across North America that had no Spanish flu or if people got Spanish flu… the death rate and severity of disease was essentially zero.”
Scientists uncovered three herbs that people were using in those communities, not only for treatment of common diseases but also for disease prevention. The herbs were Nootka rose (Rosa nutkana), Saskatoon serviceberry (Amelanchier alnifolia), and fernleaf biscuitroot (Lomatium dissectum), according to Dr. Thornfeldt.
When Dr. Thornfeldt studied those herbs and others, he found Nootka rose was two orders of magnitude more potent than acyclovir for herpes simplex virus (HSV) and remdesivir for MERS coronavirus, he said.
“We also found that the Saskatoon and biscuitroot were an order of magnitude more potent in inhibiting HSV and MERS compared to prescription products. All three achieved highly statistically significant superiority over the two prescription products.”
This suggests that the three might be prevention and treatment options for the next viral pandemic, said Dr. Thornfeldt.
“When you go online, you’ll see many of these products are available, but as I said, you have to be careful that they have gone through proper processing and quality assessment. Only stick with products that have human trials performed, even if it’s a large open-label study or a small-to-medium-sized pilot study. Also be sure to look for safety studies.”
