Ethnobotanical medicine is effective against the bacterium causing Lyme disease
Lyme disease, also known as borreliosis, is the most common vector-borne disease in the Northern Hemisphere. It is caused by the spirochete (corkscrew-shaped) bacterium Borrelia burgdorferi and is spread mainly by the bite of infected ticks.
Plants against Lyme disease
Currently, more than 300,000 new cases are reported in the United States each year, compared to 65,000 in Europe, and these numbers are increasing due to climate change and urban sprawl. The standard of care for Lyme disease is a 2-4 week course of antibiotics, but this is not always effective: at least 10-20% of patients treated continue to show symptoms after this treatment.
Patients with advanced Lyme disease may have many different symptoms, including fatigue, joint pain, memory problems, facial paralysis, aches and pains, stiff neck, and heart palpitations. The discovery of new treatments for Lyme disease is therefore of great interest.
In a new study, researchers at the Johns Hopkins Bloomberg School of Public Health, along with colleagues at the California Center for Functional Medicine and Focus Health, studied the potency of 14 herbal extracts to kill Borrelia burgdorferi, compared to the antibiotics currently in use - doxycycline and cefuroxime.
Several herbs surpassed the antibiotics tested
Researchers showed that plant extracts of black walnut, cat's claw, sweet wormwood, Mediterranean rock and Chinese skullcap had strong activity against B. burgdorferi; surpassing the two antibiotics tested. But Ghanaian quinine (Cryptolepis sanguinolenta; also known as yellow tincture root, nibima or kadze) and Japanese knotweed (Polygonum cuspidatum) were by far the most effective.
Ghanaian quinine is a West African shrub containing the antimicrobial cryptolepine alkaloid, and is used in ethno-medicine to treat malaria, hepatitis, septicaemia and tuberculosis. Japanese knotweed is a traditional medicine in India and China that contains resveratrol polyphenol. In other preclinical studies, it has been shown to have anti-tumor and anti-inflammatory effects and to protect the nervous system and heart.
Extracts of both plants were found to be effective in killing microcolonies of Borrelia burgdorferi and inhibiting the 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 this bacterium - it did not reappear, even under optimal conditions in the absence of the drug.
Convincing evidence
"This study provides the first convincing evidence that some of the herbs used by patients such as Cryptolepis, black walnut, sweet wormwood, and Japanese knotweed have potent activity against Lyme disease bacteria, particularly the dormant persistent forms, which are not killed by current antibiotics," said Dr. Ying Zhang of the Johns Hopkins Bloomberg School of Public Health.
"These results are exciting because they offer opportunities for better treatment of persistent Lyme disease, which is not eradicated by current standard treatments. We are interested in moving forward and evaluating these herbal medicines through animal studies as well as clinical trials.
