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

## TL;DR

This review explores the traditional uses and scientific evidence for Uncaria rhynchophylla, highlighting its potential in treating neurological and cardiovascular conditions.

## Contribution

The paper integrates traditional Chinese medicine knowledge with modern phytochemical and pharmacological evidence for Uncaria rhynchophylla.

## Key findings

- UR contains monoterpenoid indole alkaloids and shows neuroprotective effects in preclinical models.
- Antihypertensive effects are linked to calcium channel antagonism and vasodilation.
- Poor oral bioavailability and lack of clinical validation remain major challenges.

## Abstract

Uncaria rhynchophylla (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 in vitro 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 via 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.

Infographic illustrating the research framework for Uncaria rhynchophylla, showing three stages: traditional medicine use in TCM for over 1500 years, scientific investigation of phytochemistry and pharmacology, and exploration of therapeutic potential for neuroprotection and cardiovascular health, with future directions highlighted including clinical validation and biomarker discovery.