Uncaria rhynchophylla: an ethnopharmacological review integrating traditional Chinese medicine uses with phytochemical and pharmacological evidence

<i>Uncaria rhynchophylla</i> (Miq.) Jacks. (UR), a climbing shrub of the Rubiaceae family, has been a foundational remedy in traditional Chinese medicine for over 1,500 years, and has long been used to treat neurological disorders, hypertension, and inflammatory conditions associated with "Liver Wind" and "Liver Yang Rising." This review summarizes traditional ethnopharmacological knowledge by integrating it with scientific evidence related to UR's chemical composition, pharmacological mechanisms, and therapeutic potential. This systematic narrative review analyzed 78 studies from databases including PubMed, Web of Science, Scopus, CNKI, and Wanfang (2000-2025), focusing on peer-reviewed articles on UR's phytochemistry, pharmacology, and pharmacokinetics. The plant primarily contains monoterpenoid indole alkaloids, triterpenoids, flavonoids, and phenolics. Preclinical studies have demonstrated potential neuroprotective effects against Alzheimer's disease, Parkinson's disease, epilepsy, and depression, though these are largely limited to <i>in vitro</i> and rodent models with methodological flaws such as small sample sizes and lack of blinding. Its antihypertensive effects involve calcium channel antagonism and nitric oxide-mediated vasodilation, while its immunomodulatory, antiviral, and anti-inflammatory effects further extend its therapeutic scope. Pharmacokinetic studies show poor oral bioavailability due to first-pass metabolism <i>via</i> CYP3A4, as well as stereoselective elimination. Despite some evidence linking traditional applications to modern pharmacology, major challenges remain, including difficulties in standardization, poor bioavailability, and a lack of clinical validation. Prioritizing large-scale clinical studies, development of combined formulations, and identification of biomarkers will help advance UR into the realm of evidence-based therapeutics, addressing unmet needs in neurodegenerative and cardiovascular diseases.