Uncaria Rhynchophylla Stem Extract
Also known as: Uncaria rhynchophylla (Miq.) Miq. ex Havil., Gou Teng, Cat’s Claw (be aware of confusion with Uncaria tomentosa), Uncaria rhynchophylla
Overview
Uncaria rhynchophylla, commonly known as Gou Teng in traditional Chinese medicine, is a woody vine native to East Asia. It has been used for centuries primarily for its antihypertensive and neuroprotective properties. The plant contains several bioactive indole alkaloids, including rhynchophylline, isorhynchophylline, corynoxeine, and isocorynoxeine, which are believed to contribute to its therapeutic effects. Research suggests that Uncaria rhynchophylla may help manage hypertension, neurological disorders such as epilepsy and stroke, and inflammation. While preclinical studies show promising results, clinical evidence is still limited, and more high-quality randomized controlled trials are needed to confirm its efficacy and safety in humans. It is important to distinguish Uncaria rhynchophylla from Uncaria tomentosa (another species known as Cat's Claw), as they have different bioactive profiles and uses.
Benefits
The primary evidence-based benefits of Uncaria rhynchophylla stem extract include antihypertensive and neuroprotective effects, primarily demonstrated in preclinical studies. Animal models have shown that standardized extracts and specific alkaloids like rhynchophylline and isorhynchophylline can reduce blood pressure and liver lipid content. These effects are significant, with blood pressure reductions of 10-20% observed in some animal studies. Neuroprotective benefits have also been observed in preclinical models of stroke and epilepsy, suggesting potential for reducing excitotoxicity and oxidative stress. However, clinical data in humans are limited, and further research is needed to confirm these benefits and determine the optimal dosage and duration of treatment. Anti-inflammatory and antioxidant effects have been reported in preclinical studies, but their clinical relevance remains unclear.
How it works
Uncaria rhynchophylla exerts its effects through several biological pathways. Its antihypertensive action is primarily attributed to calcium channel blockade and modulation of vascular tone. The neuroprotective effects involve inhibiting excitotoxicity, reducing oxidative stress, and modulating neurotransmitter systems. Specifically, it interacts with calcium channels, NMDA receptors, and inflammatory mediators. While the alkaloids in Uncaria rhynchophylla are absorbed orally, the bioavailability and pharmacokinetics in humans are not well studied. The extract primarily affects the cardiovascular and central nervous systems, contributing to its antihypertensive and neuroprotective properties.
Side effects
Uncaria rhynchophylla is generally considered safe based on traditional use and preclinical studies, but clinical safety data are limited. Common side effects have not been reported in available literature. Mild gastrointestinal upset is a possible but uncommon side effect. Rare side effects have not been reported. Potential drug interactions exist with antihypertensive and CNS-active drugs due to its effects on calcium channels and neurotransmitter systems. Caution is advised during pregnancy and lactation due to a lack of safety data. It is not recommended for use in children or pregnant women without medical supervision. Due to the limited clinical data, it is important to monitor for any adverse effects when using Uncaria rhynchophylla, especially in individuals with pre-existing conditions or those taking other medications.
Dosage
The minimum effective dose of Uncaria rhynchophylla has not been established in humans. Animal studies have used doses equivalent to 100–300 mg/kg body weight, but these are not directly translatable to humans. Typical traditional doses range from 3–12 g of dried herb per day, but standardized extract doses are not well defined. The maximum safe dose is also not established, although traditional use suggests that up to 12 g/day is tolerated. It is usually taken in divided doses throughout the day. Bioavailability may vary by preparation, with dried herb decoctions and standardized extracts being common forms. Taking it with food may improve absorption, but data are lacking. Long-term safety is unknown, so caution is advised with prolonged use.
FAQs
Is Uncaria rhynchophylla safe?
It is generally considered safe based on traditional use, but clinical data are limited. Monitor for any adverse effects, especially if you have pre-existing conditions or are taking other medications.
When is the best time to take it?
It is best taken with meals to minimize potential gastrointestinal upset. Divided doses throughout the day may also be beneficial.
What are the expected results?
Modest reductions in blood pressure and potential neuroprotective benefits are expected, but clinical evidence is limited. Results may vary.
Is Uncaria rhynchophylla the same as Uncaria tomentosa?
No, they are distinct species with different bioactive profiles and uses. Be sure to verify the species before use.
Research Sources
- https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2020.00910/full – This study investigated the effects of Uncaria extract and its alkaloids (rhynchophylline, isorhynchophylline) on blood pressure and liver lipid content in rodent models. The findings indicated that the extract and alkaloids reduced blood pressure and liver lipid content, suggesting potential antihypertensive and lipid-lowering effects. However, the study was conducted on animal models, which limits its direct translatability to humans.
- https://www.mdpi.com/2673-9623/2/1/1 – This systematic review and meta-analysis examined the anti-inflammatory and immunomodulatory activities of Uncaria tomentosa extracts. The review found that these extracts exhibited anti-inflammatory and immunomodulatory activities with low toxicity. However, this review focuses on Uncaria tomentosa, not Uncaria rhynchophylla, highlighting the need for species-specific research.
- https://pubs.acs.org/doi/10.1021/np50074a016 – This comprehensive review details the bioactive compounds found in Uncaria species, including Uncaria rhynchophylla. It provides a detailed profile of these compounds, contributing to a better understanding of the chemical basis of Uncaria's effects. However, the review does not report any clinical outcomes.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11176511/ – This study investigates the protective effects of Uncaria rhynchophylla against cerebral ischemia. The results suggest that Uncaria rhynchophylla may have potential as a neuroprotective agent in the context of cerebral ischemia. The study provides insights into the mechanisms underlying these protective effects.
- https://pubmed.ncbi.nlm.nih.gov/38881881/ – This study explores the neuroprotective effects of rhynchophylline, a major alkaloid in Uncaria rhynchophylla, against cerebral ischemia-reperfusion injury. The findings suggest that rhynchophylline can protect against neuronal damage by inhibiting ferroptosis. This research highlights the potential therapeutic applications of rhynchophylline in neurological disorders.