Crioceras

Synopsis

Crioceras (Crioceras longiflorus / Crioceras dipladeniiflorus): A Natural Source of Vincamine and Vinpocetine

1. Overview and Identity

In the dietary supplement and natural-ingredient literature, the term Crioceras refers specifically to the tropical African plant Crioceras longiflorus Pierre — a name that is now treated as a synonym of the currently accepted species Crioceras dipladeniiflorus (Stapf) K.Schum. The relevance of this plant to human health lies entirely in its content of the alkaloid vincamine, from which the semi-synthetic pharmaceutical and dietary supplement compound vinpocetine (ethyl apovincaminate) is derived. When ingredient databases, regulatory filings, and pharmaceutical monographs list "Crioceras longiflorus" as an alternate name or synonym for vinpocetine, they are denoting the botanical origin of that compound's precursor alkaloid.

1.1 Botanical Classification

Crioceras is a plant genus in the family Apocynaceae, first described as a genus in 1897. It contains only one currently accepted species, Crioceras dipladeniiflorus, native to tropical central Africa — specifically Gabon, the Republic of Congo, and the Angolan province of Cabinda. The type species is Crioceras longiflorus, described by the French botanist Jean Baptiste Louis Pierre, which is now treated as a synonym of C. dipladeniiflorus.

The native range of this species is West-Central Tropical Africa, where it grows as a shrub or tree primarily in the wet tropical biome. Within the family Apocynaceae, the genus belongs to the subfamily Rauvolfioideae, tribe Tabernaemontaneae, and subtribe Tabernaemontaninae. According to the NCBI Taxonomy Browser, Crioceras dipladeniiflorus K.Schum. is classified within the order Gentianales, family Apocynaceae, subfamily Rauvolfioideae, tribe Tabernaemontaneae.

1.2 Nomenclature and Alternate Names

Because vinpocetine is derived from vincamine — an alkaloid found in several Apocynaceae species — the compound carries a wide array of botanical and pharmacological synonyms in the literature. Vinpocetine is also known under names including 14-Ethoxycarbonyl-(3alpha, 16alpha-ethyl)-14,15-eburnamine, apovincaminate acid, Cavinton®, ethyl apovincaminate, Eusenium®, Intelectol®, kavinton, Crioceras longiflorus, RGH-4405, TCV-3b, vinRx, vintoperol, and Voacanga africana. When "Crioceras" appears on a supplement ingredient list or in a regulatory document, it functions as a declaration of the botanical source of vincamine, the natural-product precursor to vinpocetine.

1.3 The Active Compound: Vincamine and Vinpocetine

Vinpocetine is a semi-synthetic component derived from the vincamine alkaloid; vincamine is present in the aerial parts of Vinca minor, Crioceras longiflorus, and the seeds of Voacanga africana — all plants belonging to the Apocynaceae family. Vinpocetine (14-ethoxycarbonyl-(3a,16a-ethyl)-14,15-eburnamine) is a synthetic derivative of the vinca alkaloid vincamine, which is an alkaloid extracted from the periwinkle plant Vinca minor. Vincamine itself is hypotensive, negatively chronotropic, spasmolytic, hypoglycemic, and sympatholytic; it alters neuronal metabolism by favoring aerobic glycolysis and increases blood flow to the brain, particularly toward ischemic areas.

The FDA formally describes vinpocetine as a synthetic compound derived from vincamine, an alkaloid found in the Vinca minor L. plant. Vinpocetine can be synthesized in several ways from vincamine; one method involves heating (+)-14-oxo-15-hydroxyimino-E-homo-eburnane with ethanol and sulfuric acid.

1.4 Common Forms and Preparations

Vinpocetine was initially discovered, developed, and marketed under the trade name Cavinton® by the Chemical Works of Gedeon Richter Ltd., Budapest, Hungary, and is approved by the European and British Pharmacopoeias. Vinpocetine has been clinically used in many countries for the treatment of cerebrovascular disorders such as stroke and dementia for more than 30 years; currently, it is also available in the market as a dietary supplement to enhance cognition and memory.

Citrate salt, sustained-release, and transdermal delivery forms of vinpocetine have been evaluated in the research literature. In practice, oral tablet and capsule forms are most commonly encountered in both clinical and over-the-counter supplement contexts.

2. Traditional and Historical Use

The traditional and historical use of Crioceras per se — as an ethnobotanical preparation — is not documented in the peer-reviewed or institutional literature that has been identified. What is documented is the traditional use of its Apocynaceae relatives, particularly Vinca minor (lesser periwinkle), from which vincamine was first isolated and characterized, and from which most of the world's vinpocetine supply is ultimately derived.

Traditional uses for lesser periwinkle (Vinca minor) include its use as an antilactagogue and emmenagogue. The broader cultural and medical history of vinpocetine as a pharmaceutical product is European and East Asian in character. The first clinical studies on the cerebrovascular hemodynamic properties of vinpocetine occurred in the 1970s, and it was first introduced as a drug under the trade name Cavinton® in 1978 by pharmaceutical formulator Gedeon Richter Nyrt in Hungary.

Vinpocetine has been used to maintain the brain and its blood vessels by European and Japanese medical practitioners for more than two decades. It has since been used widely in Japan, Germany, Russia, Poland, and Hungary for the treatment of cerebrovascular-related pathologies. These are modern pharmaceutical uses, not traditional ethnobotanical applications.

3. Key Constituents and Active Compounds

3.1 Vincamine: The Primary Natural Alkaloid

The pharmacologically relevant constituent of Crioceras longiflorus is the indole alkaloid vincamine. In the plant kingdom, vincamine belongs to the monoterpenoid indole alkaloid (MIA) class, characteristic of the Apocynaceae family. It is the direct natural precursor from which vinpocetine is semi-synthetically derived.

3.2 Vinpocetine: Chemical Identity

Vinpocetine is a white crystalline solid with a molecular mass of 350.45 g/mol. It has an estimated boiling point of 420°C, a melting point of 147–153°C, a log K_OW of 4.31, and a vapor pressure of 3.02 × 10⁻⁷ mm Hg at 25°C. Its IUPAC chemical name is (3α,16α)-eburnamenine-14-carboxylic acid ethyl ester (CAS No. 42971-09-5), also known as ethyl apovincaminate.

3.3 Mechanisms of Action

The biological activity of vinpocetine — and by extension the pharmacological relevance of Crioceras as its alkaloid source — operates through several mechanistically distinct pathways.

Phosphodiesterase Type 1 (PDE1) Inhibition

Vinpocetine's neuroprotective actions are multifaceted and include inhibition of phosphodiesterase type 1 (PDE1), blockade of voltage-dependent Na_V1.8 channels, reduction of oxidative stress, and suppression of neuroinflammatory processes triggered by cerebral ischemia–hypoxia. Vinpocetine inhibits PDE1 activity and improves cerebral blood flow by elevating cGMP and cAMP, increasing mitochondrial function, and improving glucose and oxygen utilization by the brain. Because PDE1 catalyzes the hydrolysis of cAMP and cGMP, its inhibition by vinpocetine increases the levels of these cyclic nucleotides, ultimately leading to the expression of plasticity-related genes.

Cerebral Vasodilation and Blood Flow

In the brain, vinpocetine improves brain blood flow by acting as a cerebral vasodilator and enhances cerebral metabolism by increasing oxygen and glucose uptake. This vasodilatory effect is considered one of the primary mechanisms underlying its use in cerebrovascular conditions.

Anti-Inflammatory Effects via NF-κB Inhibition

Vinpocetine inhibits NF-κB-dependent inflammation via an IKK-dependent but PDE-independent mechanism. Most pro-inflammatory cytokines released from macrophages are inhibited by vinpocetine via an NF-κB-dependent mechanism; it blocks monocyte adhesion and migration by inhibiting the expression of pro-inflammatory cytokines and is effective in reducing oxidative stress through inhibition of NF-κB and PDE1.

Sodium Channel Blockade and Neuroprotection

A large body of experimental preclinical evidence has accumulated demonstrating vinpocetine's neuroprotective potential and complex mechanisms of action in cerebral ischemia–hypoxia. Comprehensive in vitro studies and animal experiments have significantly elucidated the molecular basis and the signaling pathways through which it prevents or mitigates ischemic injury.

Antioxidant Properties

In vitro, antioxidant and hydroxyl radical scavenging properties of vinpocetine have been observed. Animal models suggest that vinpocetine has anti-inflammatory, antioxidant, antimitotic, antiatherogenic, antithrombotic, and antiepileptic effects.

Cardiovascular Effects

Recent studies have revealed novel functions of vinpocetine including anti-inflammation, antagonizing injury-induced vascular remodeling, countering high-fat-diet-induced atherosclerosis, and attenuating pathological cardiac remodeling. Vinpocetine promotes plaque stability and helps prevent erosion and rupture of atherosclerotic plaque.

4. Scientific Evidence by Area of Use

The scientific literature contains numerous human clinical studies and animal investigations on the pharmacological and biochemical actions of vinpocetine. However, the quantity and quality of evidence varies substantially by indication. The following sections characterize the evidence by area, separating preclinical findings from human/clinical data, and explicitly noting the strength of the evidence where assessable.

4.1 Cerebrovascular Disease and Stroke

Clinical evidence — mixed and limited quality: Vinpocetine has been clinically used in many Asian and European countries for the prevention and treatment of stroke, senile dementia, and memory disturbances.

A pilot study (N = 30) reported improved scores in acute ischemic stroke, while a Russian study (N = 100) reported improvements in reversible vascular diseases including intermittent cerebral insufficiency. A large, multicenter study (N = 4,865) reported a reduction in patient complaints, severity of neurological symptoms, and improvements in Tinetti scale scores and Mini Mental Status Exam scores.

A Cochrane systematic review of the effects of vinpocetine administered within two weeks in ischemic stroke found no evidence of benefit in reducing early (one month) or late fatalities. A Cochrane review (Bereczki 1997) concluded that there is insufficient evidence to justify the use of vinpocetine for the acute phase of cerebrovascular disease.

A 2022 systematic review and meta-analysis concluded that vinpocetine as a neuroprotective agent is effective in acute ischemic stroke in some randomized controlled trials (RCTs); the last prior systematic review, published in 2008, had not found conclusive evidence favoring its use, but two more RCTs have since been completed. Because of various methodological limitations, some clinical trials could not be included in that review, and the regimen, route, and dose of vinpocetine varied across studies; no obvious dose–response relationship could be identified.

Summary: Evidence in ischemic stroke is present but inconsistent and of limited methodological quality. No strong evidence exists from high-quality, large RCTs meeting modern standards.

4.2 Cognitive Impairment and Dementia

Clinical evidence — weak and inconclusive: Preclinical data of uneven quality suggest a potential beneficial effect of vinpocetine in chronic cerebrovascular diseases and on cognitive performance in a variety of animal models. Clinical trials to test these hypotheses were performed before currently used criteria for dementia had become generally accepted. The results show improvement after treatment with vinpocetine versus placebo, but the number of demented patients treated for at least six months was small.

All identified studies used in the Cochrane review were performed before the 1990s and used various terms and criteria for cognitive decline and dementia. The three studies included in the review involved a total of 583 people with dementia treated with vinpocetine or placebo.

Although the basic science is interesting, the evidence for beneficial effect of vinpocetine on patients with dementia is inconclusive and does not support clinical use.

The Cochrane review reported that vinpocetine 30 to 60 mg/day may be beneficial in dementia; however, few quality clinical trials were available for the review.

A meta-analysis of three randomized controlled trials in dementia patients concluded that the trials were not adequate to recommend the use of vinpocetine. No clinical trials have determined whether vinpocetine can prevent dementia or promote brain health.

Vinpocetine has been studied as a potential treatment for Alzheimer's disease, but a systematic review did not find benefit. In both healthy adult volunteers and patients with focal epilepsy, no significant cognitive benefits were seen with the vinpocetine dosages tested in one study.

Anecdotal reports and preclinical studies suggest vinpocetine can improve memory, but clinical evidence to support this is lacking. No clinical research suggests that vinpocetine protects against dementia or slows brain aging.

One double-blind, randomized cross-over trial with only 12 healthy female volunteers reported that a three-day regimen of 40 mg vinpocetine may improve reaction time.

Summary: Overall evidence for vinpocetine in cognitive impairment and dementia is weak. Existing RCTs are small, methodologically outdated, and insufficiently powered. The Cochrane collaboration does not support clinical use for dementia.

4.3 Memory Enhancement in Healthy Individuals

Clinical evidence — very limited: Human studies suggest vinpocetine enhances short-term memory and cognitive performance, and improves chronic cerebral dysfunction in elderly patients. However, these findings are based on small studies and the evidence base is not sufficient to draw definitive conclusions. Anecdotal reports and preclinical studies suggest vinpocetine can improve memory, but clinical evidence to support this is lacking.

4.4 Neuroinflammation and Neuroprotection

Preclinical evidence predominates: In addition to studies on vinpocetine's effects in cerebral ischemia and hypoxia, nearly 100 further publications describe its protective actions against various toxic agents (e.g., manganese, lead, toluene, carbon tetrachloride, ethanol). Beneficial effects have been reported in animal models of diverse conditions including depression, inflammatory diseases, β-amyloid-related cerebral changes, cognitive deficits after brain trauma, Parkinsonism, and schizophrenia, affecting organs such as the brain, liver, heart, lungs, and the vascular system. The explanation may be that many diseases share common pathologies that can be improved by vinpocetine, such as antagonizing inflammation in a variety of cell types, protecting different cells from death during ischemia injuries, and stimulating vasodilation to increase blood flow in diverse tissues. It should be noted that recent findings aimed to explore novel functions of vinpocetine are largely dependent on animal models.

Summary: Neuroinflammation and neuroprotection data are predominantly preclinical (in vitro and animal). Translation to human clinical outcomes has not been demonstrated in adequately powered trials.

4.5 Cardiovascular Disease

Emerging preclinical evidence: Research reviews have uncovered novel functions of vinpocetine in cardiovascular diseases, including atherosclerosis, obesity, neointimal hyperplasia, vasoconstriction, pathological cardiac remodeling, and ischemic stroke. These findings may suggest broadened usage of vinpocetine against relevant cardiovascular diseases in humans, but human clinical trials in these specific cardiovascular indications are not yet available.

4.6 Hearing, Vision, and Other Conditions

The scientific literature on vinpocetine also encompasses investigations of antioxidant effects, menopause-related outcomes, eye disorders, kidney impairment, stroke, uncontrolled micturition, reductions in platelet aggregation, antiulcer activity, phosphodiesterase-1 inhibition, cerebrovascular vasodilation, hearing defects of neurological origin, and other brain disorders. Research in humans suggests that vinpocetine may be useful for treating brain disorders, hearing impairment, memory, eye disorders, kidney impairment, stroke, and uncontrolled urination, though the evidence quality for these indications is generally preliminary and, in several cases, limited to small or methodologically limited studies.

5. Body Systems and Health Areas

Based on the available scientific literature, the following body systems have been investigated in relation to vinpocetine (the active compound derived from Crioceras-source vincamine):

Central Nervous System: Cerebrovascular blood flow, neuroprotection in ischemia, cognitive function, memory, dementia, epilepsy, Alzheimer's disease, depression (preclinical).
Cardiovascular System: Atherosclerosis (preclinical), vascular smooth muscle proliferation, cardiac remodeling, platelet aggregation, coagulation.
Sensory Organs: Hearing impairment of neurological origin; microcirculation in the inner ear and eyes.
Renal System: Kidney impairment (limited data).
Gastrointestinal/Hepatic: Antiulcer activity (preclinical); hepatic protective effects against toxic insults (animal data only).
Inflammatory and Immune Pathways: NF-κB-mediated inflammation across multiple cell types.

The majority of publications explore the vasodilating, anti-inflammatory, and neuromodulating properties of vinpocetine in relation to various diseases. Furthermore, most studies employ in vitro, ex vivo, and animal models.

6. Pharmacokinetics and Dosage

6.1 Absorption and Bioavailability

In humans, absorption of vinpocetine following ingestion is fast, with a maximum plasma concentration reached within 2 hours after ingestion and a plasma elimination half-life of ≤2 hours. The reported oral bioavailability in humans varies from 6.7% to 57%. Vinpocetine bioavailability differs if administered with or without food: relative bioavailability was 60–100% higher in individuals administered vinpocetine under non-fasting conditions compared with fasting conditions.

Due to poor aqueous solubility and a high first-pass effect, oral bioavailability is poor (7%), unless taken with food (increases upward of 60% have been suggested).

In humans, plasma protein binding is 66%. The volume of distribution is 246.7 ± 88.5 L. Vinpocetine was orally administered to rats in radiolabeled studies and the maximum drug concentration was found in the liver and gastrointestinal tract.

6.2 Metabolism and Elimination

Vinpocetine is metabolized exclusively in the liver and widely distributed in body systems, including the CNS. The pharmacokinetics of vinpocetine (Cavinton) and of its main metabolite apovincaminic acid (AVA) were studied in 5 healthy male volunteers after administration of 3 × 5 and 3 × 10 daily doses for seven days. Both vinpocetine and AVA show linear pharmacokinetics at the doses used, and there is no accumulation or autoinduction.

Vinpocetine can pass the blood–brain barrier and enter the brain after oral or intravenous administration.

6.3 Dosages Used in Studies

The following dosages have been reported specifically in research studies and clinical trials cited in the peer-reviewed literature:

In a Japanese study, dementia patients were given 15 mg vinpocetine for three weeks, with a subsequent study showing an increased ATP concentration.
In a crossover study, 207 patients with brain-damaging conditions received 5 mg vinpocetine or comparator drugs three times a day for four weeks.
In a double-blind trial, twenty-two elderly patients with cerebral dementia received 10 mg of vinpocetine three times daily for 30 days, followed by 5 mg three times daily for another 60 days.
The Cochrane review reported that vinpocetine at 30 to 60 mg/day may be beneficial in dementia.
One double-blind, randomized cross-over trial used a three-day regimen of 40 mg vinpocetine in 12 healthy female volunteers.
A pharmacokinetic study used 3 × 5 mg and 3 × 10 mg daily doses for seven days in healthy male volunteers.

Pharmacokinetic studies have shown that parameters in elderly patients do not differ significantly from those in a non-elderly adult population and no drug accumulation is observed. Dose adjustment is not considered necessary in patients with hepatic and renal disorders because the drug does not accumulate in these patient groups.

7. Safety Considerations and Interactions

7.1 General Tolerability

No significant side effects and toxicity have been reported for vinpocetine at therapeutic doses, and it is generally considered safe for long-term use. Vinpocetine has thus attracted considerable attention from academic, scientific, and pharmaceutical communities to characterize its novel therapeutic functions, mechanism of actions, and pharmacological targets. The available data do not demonstrate many problems of adverse effects, but intention-to-treat data were not available for any of the clinical trials reviewed.

7.2 Reproductive and Developmental Toxicity — FDA Warning

This is the most consequential, formally documented safety issue associated with vinpocetine as a dietary supplement ingredient.

On June 3, 2019, the FDA issued a safety warning for women of childbearing age about vinpocetine. According to data reviewed by FDA, consumption of vinpocetine is associated with adverse reproductive effects — vinpocetine may cause a miscarriage or harm fetal development. Accordingly, FDA advises pregnant women and women who could become pregnant not to take vinpocetine. The agency also advises dietary supplement firms marketing products containing vinpocetine to evaluate their product labeling to ensure that it provides safety warnings against use by pregnant women and women who could become pregnant.

According to data reviewed by the FDA, including a report by the NIH's National Toxicology Program (NTP), consumption of vinpocetine is associated with adverse reproductive effects — vinpocetine may cause a miscarriage or harm fetal development. Due to limited literature indicating that vinpocetine may not be safe for use during pregnancy and the possibility for widespread exposure to women of childbearing age, the NTP conducted prenatal developmental toxicology studies.

Due to limited safety data, vinpocetine is contraindicated during pregnancy and lactation. Animal studies have shown potential reproductive toxicity, including embryotoxicity and teratogenicity, and there is insufficient data on the safety of vinpocetine in human pregnancy or breastfeeding.

There are no studies that have examined vinpocetine exposure and adverse reproductive or prenatal outcomes in humans specifically.

7.3 Labeling Accuracy Concerns

Analysis of vinpocetine supplements has shown that in a significant number of products, the actual vinpocetine content varied from what was stated on the label, which could result in higher doses than those recommended by the product labels.

7.4 Antiplatelet and Anticoagulant Effects

Vinpocetine may have antiplatelet and anticoagulant effects and should therefore be used with caution or avoided in individuals with bleeding disorders or a history of bleeding events. It may increase the risk of bleeding or interact with other anticoagulant medications, leading to serious bleeding complications. Limited studies from the 1990s showed an effect of vinpocetine on prothrombin time; however, clinically important interaction was not demonstrated.

7.5 Regulatory Status

Vinpocetine has never been approved for use as a drug in the United States by the FDA for any condition. It has been lawfully marketed as a dietary ingredient for use in dietary supplements, and holds the distinction of having five New Dietary Ingredient (NDI) notifications filed with FDA's Center for Food Safety and Applied Nutrition (CFSAN). The FDA has published a notice in the Federal Register requesting comment on the regulatory status of vinpocetine as a dietary ingredient, with the FDA tentatively concluding that vinpocetine does not meet the definition of a dietary ingredient and is excluded from the definition of a dietary supplement in the Food, Drug, and Cosmetic Act. This administrative proceeding has not been finalized.

Vinpocetine is approved by the European and British Pharmacopoeias. It has been used widely in Japan, Germany, Russia, Poland, and Hungary for the treatment of cerebrovascular-related pathologies.

7.6 Minor Adverse Effects Reported in Studies

In a small study, jitters, increased heart rate, and insomnia were possibly related to vinpocetine.

8. Summary of Evidence Strength

The table below summarizes the strength of evidence across the major investigated areas for vinpocetine, the bioactive compound derived from the alkaloid found in Crioceras longiflorus and related Apocynaceae species.

Cerebrovascular disease / ischemic stroke: Weak to mixed. Multiple small RCTs show some positive signals but Cochrane reviews (2008) found insufficient evidence. A 2022 meta-analysis noted favorable results but acknowledged methodological limitations.
Dementia / cognitive impairment: Inconclusive. Cochrane review of three small, pre-modern RCTs found results did not support clinical use. No adequately powered modern trials available.
Memory in healthy individuals: Very limited. One very small RCT (N=12), no replication.
Neuroinflammation / neuroprotection: Preliminary (preclinical). Rich body of animal and cell-based evidence; human translation not established.
Cardiovascular: Emerging preclinical. Animal models only; no human clinical data in cardiovascular-specific indications.
Hearing/vision disorders: Limited. Mentioned in clinical literature, but no substantial controlled trials identified.

Synthesized more than 60 years ago, vinpocetine — the active ingredient of Cavinton®, with over five decades of clinical use — has remained the subject of extensive investigation. A large body of experimental preclinical evidence has accumulated demonstrating its neuroprotective potential and complex mechanisms of action in cerebral ischemia–hypoxia. Nonetheless, translation of these preclinical findings into robust human clinical evidence remains a significant gap in the literature.