Lyme disease, also called borreliosis, is the most common vector-borne disease in the Northern hemisphere.
It is caused by the spirochete (corkscrew-shaped) bacterium Borrelia burgdorferi and close relatives and mainly spread through the bite of infected ticks.
Currently, more than 300,000 new cases are reported in the USA each year, compared to 65,000 in Europe, and these numbers are rising due to climate change and urban sprawl.
The standard of care for Lyme disease, a course of antibiotics over 2-4 weeks, is not always effective: at least 10-20% of treated patients continue to experience symptoms after treatment.
Late-stage Lyme patients may experience many different symptoms, including fatigue, joint pains, memory problems, facial paralysis, aches, stiffness in the neck, heart palpitations, and severe headaches.
The discovery of novel treatments against Lyme disease is therefore of great interest.
In a new study published in Frontiers in Medicine, researchers from the Johns Hopkins Bloomberg School of Public Health, with colleagues at the California Center for Functional Medicine and Focus Health, surveyed the power of 14 plant-based extracts to kill Borrelia burgdorferi, compared to the currently used Lyme antibiotics doxycycline and cefuroxime.
The researchers tested these extracts’ effectiveness in vitro (outside of a living organism) against the free-swimming “planktonic” form of the bacterium as well as against microcolonies.
Microcolonies are aggregates of bacteria, the first stage in the development of biofilms – structured bacterial communities that stick to a surface and are embedded in a slimy extracellular matrix.
The researchers show that plant extracts from black walnut, cat’s claw, sweet wormwood, Mediterranean rockrose, and Chinese skullcap had strong activity against B. burgdorferi, outperforming both tested antibiotics.
But by far the strongest performers were Ghanaian quinine (Cryptolepis sanguinolenta; also known as yellow-dye root, nibima, or kadze) and Japanese knotweed (Polygonum cuspidatum).
Ghanaian quinine is a shrub from West Africa containing the antimicrobial alkaloid cryptolepine, and is used in ethnomedicine to treat malaria, hepatitis, septicemia, and tuberculosis.
Japanese knotweed is a traditional medicine in India and China that contains the polyphenol resveratrol.
In other preclinical studies it has been found to have anti-tumor and anti-inflammatory effects and protect the nervous system and heart.
Extracts from both plants were found to kill microcolonies of Borrelia burgdorferi and inhibit division of the planktonic form, even at low concentrations (0.03-0.5%).
Remarkably, a single 7-day treatment with 1% Ghanaian quinine could completely eradicate the bacterium – it did not regrow, even under optimal conditions in the drug’s absence.
“This study provides the first convincing evidence that some of the herbs used by patients such as Cryptolepis, black walnut, sweet wormwood, cat’s claw, and Japanese knotweed have potent activity against Lyme disease bacteria, especially the dormant persister forms, which are not killed by the current Lyme antibiotics,” says Dr Ying Zhang from the Johns Hopkins Bloomberg School of Public Health.
“These findings are exciting as they offer opportunities for improved treatment of persistent Lyme disease, which is not helped by the current standard treatment.
We are interested in further evaluating these potent herbal medicines through animal studies as well as clinical trials.”
The researchers show that plant extracts from black walnut, cat’s claw, sweet wormwood, Mediterranean rockrose, and Chinese skullcap had strong activity against B. burgdorferi, outperforming both tested antibiotics. Image is credited to the CDC.
However, not all tested compounds or herbs yielded positive results against the bacterium. Extracts of grapefruit seeds, green chiretta, ashwagandha, candy leaf (also known as stevia), fuller’s teasel, and Japanese teasel had little or no effect, and neither did the chemicals colloidal silver, monoglyceride monolaurin, or antimicrobial peptide LL37 from human immune cells.
This was surprising, as anecdotal and preclinical studies suggested that they might be effective, and they are often used in the community of Lyme disease practitioners and patients.
“Many thousands of Lyme patients today, especially those with later-stage symptoms who have not been effectively treated, are in great need of efficacious, accessible treatment options,” says Dr Sunjya K. Schweig, CEO and co-Director of the California Center for Functional Medicine and Scientific Advisory Board Member of the Bay Area Lyme Foundation.
Coauthor Jacob Leone of the FOCUS Health Group stresses: “Patients and their clinicians are increasingly turning to herbal remedies as additional treatment options, and we hope that these findings will help point the way toward a greater understanding of these therapies. But further preclinical studies and clinical trials will be required to establish evidence for effective treatment of Lyme disease patients.”
Funding: This research was supported by the Bay Area Lyme Foundation and the Steven & Alexandra Cohen Foundation.
A growing interest has recently been observed in natural medicine, with phytotherapy being its main branch. According to the World Health Organization (WHO), currently, nearly 80% of the world’s population relies on this form of medicine as part of health care.
Herbal medicine is also more widely used by proponents of alternative medicine. According to its practitioners, properly selected and consistently conducted herbal therapy cannot only support the immune system, but even stop the development of a chronic disease.
It is for this reason that the focus of this article is on the Japanese knotweed (Reynoutria japonica, synonym Fallopia japonica) .
It should be noted, however, that Japanese knotweed is now considered an invasive species, posing a threat to native wildlife due to its capability to produce substances that inhibit the growth of other plants and make its eradication difficult .
Despite its parasitic nature, it is commonly used in phytotherapy. The root of Fallopia multiflora (Thunb.), as a wild edible plant, is used to make beverages in Korea .
The knotweed herb (Herba Polygoni cuspidati) is also used for therapeutic purposes, albeit less frequently, due to the narrower range of its therapeutic effects [4,5].
Roots of Reynoutria japonica, which are formally listed in the Chinese Pharmacopoeia , are also used in traditional Chinese medicine, owing to their therapeutic effects on diverse inflammatory diseases, tumors, and hepatitis.
The most important from the therapeutic point of view of the plants are compounds that belong to the group of polyphenols. Worthy of attention are resveratrol, quercetin, and luteolin [6,7]. Due to the high content of resveratrol in knotweed, its supplementation may have a broad spectrum of activities: neuropoietic (Alzheimer’s disease), antibacterial, antiviral, antimutagenic, antiallergic, as well as inhibiting the accumulation of triglycerides and cholesterol in the liver [4,5,7,8,9].
This plant has also the potential to inhibit Lyme disease. According to Goc et al. , knotweed supplementation at 200–500 μg/mL reduced the number of Borrelia burgdorferi sensu stricto colonies by 30–60%.
Research has shown that preparations including knotweed can also be administered to oncological patients. Finally, they are suitable for phytoremediation and phytomelioration of soils contaminated with pesticides, hydrocarbons, and metals [5,6,9].
According to Bralley et al. , the coupled action of all knotweed compounds has an interesting effect in relation to the immune system. On one hand, knotweed preparations exhibit immunostimulatory activity, while on the other hand, they inhibit the processes of immunological self-recognition.
The better understanding of the potential of the whole plant and its individual parts and their applicability is feasible via thorough analysis of compounds with health-promoting effects. Therefore, the main goal of this study was to evaluate the content of triterpenoids and polyphenols as well as their antioxidative activity in leaves, stalks, and roots of the wild Fallopia japonica Houtt. and Fallopia sachalinensis (F. Schmidt) species. An additional aim was to determine the main dependencies between the tested material and its phytochemical components using principal components analysis.
In conclusion, the study results provided complete and important information about the bioactive compounds of plants of wild Fallopia japonica Houtt. and Fallopia sachalinensis species that were associated with their antioxidative properties.
In addition, the analyzed wild Fallopia species had a similar profile of polyphenols and triterpenoids, but contents of these compounds in leaves, stalks, and roots were different. Generally, the wild Fallopia japonicaHoutt. species had a 1.2 times statistically significant higher content of bioactive compounds and antioxidative activity than Fallopia sachalinensis.
The leaves were a better source of polymeric procyanidins, phenolic acids, flavones, and flavonols, as well as oleanolic and ursolic acids than the other morphological parts of the tested plants. However, the roots were an excellent source of flavan-3-ols (monomeric and oligomer) and stilbenes, such as resveratrol, and their derivatives.
Additionally, plants of wild Fallopia species and their individual parts may be deemed an attractive plant material and, a good source of many substances with a high health-promoting potential. However, further in vivo and in vitro investigations are necessary to confirm interactions between bioactive compounds.
The results obtained showed significant differences between wild Fallopia species and their morphological parts, and enabled selecting the most valuable morphological part of the tested plants to be used for food enrichment and nutraceuticals production.
Therefore, the leaves seem to the best from the point of view of the food additives to be used as super food and functional food beneficial for health, due to the above-average content of polyphenolic compounds and triterpenoids.
In turn, roots, with their high contents of stilbenes and polyphenolic compounds, represent a good material for the medical, pharmaceutical, and cosmetic industries. The principal component analysis of the plants of wild Fallopia species and their morphological parts confirmed significant differences in their chemical composition.