Many of the 240,000 to 440,000 patients who are diagnosed with Lyme disease annually in the U.S. fully recover after a conventional course of antibiotics for 2 to 4 weeks. However, roughly 10% to 20%, and potentially up to 63% of patients develop persisting symptoms that often manifest as neurological and rheumatic symptoms. In many of these cases, the persistent symptoms, known as post-treatment Lyme disease syndrome, negatively impact quality of life and may even become debilitating.

The persistence of Lyme disease is possible, even after aggressive antibiotic treatment. This is due to the complicated nature of the bacterial cause of Lyme disease, which is Borrelia burgdorferi and the related Borrelia species. These bacteria have immune system evasion tactics, making them hard to battle. They may also have atypical forms, and they may develop biofilms, adding to the difficulty to eradicate them using traditional antibiotics. Therefore, researchers are looking for other ways to combat B. burgdorferi and the other bacteria behind Lyme disease, especially in persistent cases. One important, potential treatment option is the use of herbal remedies, especially those with a long history of medicinal uses such as Cat’s claw (also known as Uncaria tomentosa).

In traditional medicine, Cat’s claw is commonly used to help support blood glucose metabolism, intestinal problems, and inflammatory conditions. It has demonstrated antioxidant activity and anti-inflammatory properties, inhibits tumor necrosis factor–α production, and may help stimulate the immune system. Although much of the research of Cat’s claw is focused on its antioxidant and anti-inflammatory properties, more research is starting to focus on its immune-modulation and potential for antimicrobial activity.

One study found that 2 months of daily consumption enhanced the lymphocyte-to-neutrophil ratios, demonstrating a selective immunomodulating activity. Another in vitro study found promising antiviral activity against Dengue virus, while researchers in another study found promising antimicrobial activity against Micrococcus flavus and Bacillus subtilis, but this was weaker than the standard antibiotic. Cat’s claw has also been shown to be effective against endodontic pathogens such as Enterococcus faecalis, Staphylococcus aureus, and Candida albicans.

Due to the promising studies demonstrating its potential antimicrobial effects, researchers included it in their study as they tested sixteen botanical medicines including Cat’s claw to combat B. burgdorferi. They found Cat’s claw to be among the seven most active herbal products. Even at a concentration of 0.25%, Cat’s claw had better activity than the control drugs against the stationary phase of the culture. It did not completely eradicate it, but neither did the control drugs, and only 1% of Cryptolepis sanguinolenta of the seven studied for regrowth led to no additional growth. Although Cat’s claw performed well in the stationary study, it did have a higher minimum inhibitory concentration (MIC) value against the growing bacteria than some of the other herbs, meaning it did not perform as well against the live bacteria.

Cat’s claw may potentially play a role in the management of persistent Lyme disease by supporting a healthy inflammatory response, promoting immune health, and possibly demonstrating antimicrobial properties against B. burgdorferi. Although there are no clinical studies validating these effects yet, the in vitro research currently available demonstrates that Cat’s claw could provide a favorable protocol component for Lyme disease.

By Kendra Whitmire, MS, CNS