Cat's Claw safety in humans
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Cat's Claw Safety in Human Use
Clinical Safety in Human Trials
Studies examining cat's claw (Uncaria guianensis and Uncaria tomentosa) in human subjects have found it to be generally safe. In a clinical trial involving patients with osteoarthritis of the knee, cat's claw did not cause harmful effects on blood or liver function, nor did it result in significant side effects compared to placebo. The treatment was well tolerated over a four-week period, with no notable adverse events reported during the study duration 1. Similarly, another randomized, double-blind, placebo-controlled trial in breast cancer patients using aromatase inhibitors found that cat's claw extract was safe, with no evidence of severe toxicity (grade 3 or 4) and no significant changes in laboratory or inflammatory markers between the treatment and placebo groups 5.
Safety of Cat's Claw Teas and Elemental Content
Analysis of cat's claw teas for inorganic elements such as calcium, magnesium, phosphorus, and trace metals showed that the levels present in both infusions and decoctions are within safe limits for human consumption. The study concluded that cat's claw teas are safe and may even serve as a dietary source of certain minerals, with particularly low levels of potentially harmful elements like lead and selenium 2.
Genotoxicity and Cytotoxicity Considerations
Research into the genotoxic and cytotoxic effects of different cat's claw chemotypes (based on oxindole alkaloid profiles) found no significant genotoxic potential in human cell models. While the cytotoxic activity varied depending on the chemotype, especially in malignant versus non-malignant cells, there was no indication of harmful effects on normal human leukocytes. This suggests that, when properly identified and used, cat's claw does not pose a genotoxic risk to humans 4.
Topical and Extract Safety
A water-soluble extract of cat's claw, essentially free of oxindole alkaloids, was tested on human skin organ cultures and found to reduce cell death from UV exposure by enhancing DNA repair. The study did not report any adverse effects from the extract, supporting its safety for topical or supplemental use in this context 3.
Conclusion
Current research indicates that cat's claw, whether consumed as a supplement, tea, or topical extract, is generally safe for human use. Clinical trials and laboratory analyses have not identified significant toxicity, genotoxicity, or harmful side effects in humans. However, as with any herbal supplement, proper identification of the plant chemotype and adherence to recommended dosages are important for ensuring safety 12345.
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