Rhynchophylline

Rhynchophylline is a tetracyclic oxindole alkaloid derived primarily from Uncaria rhynchophylla (cat's claw hook), a plant used in traditional Chinese medicine. It is studied for its interactions with NMDA receptors and calcium channel modulation, though robust human clinical evidence remains limited.

Origin & History

Rhynchophylline is an indole alkaloid extracted from Uncaria rhynchophylla (Miq.) Jacks, specifically from the hooked branches of this plant. It is isolated as a white to off-white solid compound with the molecular formula C₂₂H₂₈N₂O₄ and requires storage at -20°C due to its hygroscopic nature.

Historical & Cultural Context

No traditional or historical use information was included in the provided research. The data focuses exclusively on chemical properties without ethnobotanical or traditional medicine context.

Health Benefits

• No clinical health benefits can be verified from the provided research
• The research contains only chemical property data without pharmacological studies
• No human trials or health outcome data were included in the research
• No evidence quality can be assessed from chemical supplier databases alone
• Clinical research literature would be needed to establish health benefits

How It Works

Rhynchophylline acts as a non-competitive antagonist at NMDA (N-methyl-D-aspartate) receptors, inhibiting excessive calcium influx triggered by glutamate excitotoxicity. It also blocks voltage-dependent calcium channels (L-type and N-type), reducing intracellular Ca²⁺ overload in neuronal and smooth muscle cells. Additionally, preclinical data suggest it may inhibit platelet aggregation by suppressing thromboxane A2 synthesis and modulating 5-HT2A serotonin receptor activity.

Scientific Research

No clinical trials, RCTs, or meta-analyses were found in the provided research. The available data consists solely of chemical and physical properties from supplier databases without any PMIDs or peer-reviewed pharmacological studies.

Clinical Summary

Human clinical trials specifically isolating rhynchophylline as a single compound are largely absent from the published literature as of 2024. Most evidence comes from in vitro cell studies and rodent models examining neuroprotection, antihypertensive effects, and anti-aggregation properties, making direct translation to human dosing unreliable. Some research involves whole Uncaria rhynchophylla extracts rather than isolated rhynchophylline, confounding attribution of effects to this specific alkaloid. Overall, evidence quality is preclinical and insufficient to establish verified therapeutic benefits in humans.

Nutritional Profile

Rhynchophylline is not a nutrient or food substance; it is a tetracyclic oxindole alkaloid (molecular formula: C₂₂H₂₈N₂O₄; molecular weight: 384.47 g/mol) found primarily in Uncaria rhynchophylla (Gou Teng / Cat's Claw). It is a bioactive secondary plant metabolite, not a source of macronutrients, vitamins, or minerals. Typical concentrations in Uncaria species range from approximately 0.02–0.5% dry weight of the hook-bearing stems, though this varies significantly by species, harvest time, and plant part. It is one of several oxindole alkaloids present alongside isorhynchophylline, corynoxeine, and hirsutine. As a lipophilic alkaloid, it has moderate oral bioavailability; in vitro and animal pharmacokinetic studies suggest it can cross the blood-brain barrier to some degree due to its relatively low molecular weight and moderate lipophilicity (LogP ~2.3). It is not consumed in isolated purified form as a dietary supplement but is ingested as part of traditional herbal preparations (e.g., Uncaria hook decoctions in Traditional Chinese Medicine). No macronutrient, fiber, protein, vitamin, or mineral content is attributable to this single compound. Bioavailability in humans has not been rigorously characterized in published clinical pharmacokinetic trials; animal data suggest hepatic first-pass metabolism via cytochrome P450 enzymes (particularly CYP3A4) may limit systemic exposure. The compound itself serves no nutritional function and should be characterized solely as a pharmacologically active phytochemical alkaloid.

Preparation & Dosage

No clinically studied dosage ranges were provided in the research. The available data contains only chemical properties without any dosing protocols or clinical usage information. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Cannot be determined from available chemical property data

Safety & Interactions

Rhynchophylline's safety profile in humans has not been systematically evaluated in controlled trials, meaning no established safe dosage range exists for supplemental use. Due to its NMDA receptor antagonism and calcium channel blocking activity, theoretical interactions exist with antihypertensive medications, NMDA-targeting drugs such as memantine, and anticoagulants or antiplatelet agents like warfarin or aspirin. Pregnancy and lactation safety is unknown, and use should be avoided without medical supervision given the absence of reproductive toxicity data. Individuals with hypotension, bleeding disorders, or those taking CNS-active medications should exercise particular caution.