Identification and quantification of vinpocetine and picamilon in dietary supplements sold in the United States

Unauthorized ingredients in "nootropic" dietary supplements: A review of the history, pharmacology, prevalence, international regulations, and potential as doping agents

The first nootropic prohibited in sport was fonturacetam (4-phenylpiracetam, carphedon) in 1998. Presented here 25 years later is a broad-scale consideration of the history, pharmacology, prevalence, regulations, and doping potential of nootropics viewed through a lens of 50 selected dietary supplements (DS) marketed as "cognitive enhancement," "brain health," "brain boosters," or "nootropics," with a focus on unauthorized ingredients. Nootropic DS have risen to prominence over the last decade often as multicomponent formulations of bioactive ingredients presenting compelling pharmacological questions and potential public health concerns. Many popular nootropics are unauthorized food or DS ingredients according to the European Commission including huperzine A, yohimbine, and dimethylaminoethanol; unapproved pharmaceuticals like phenibut or emoxypine (mexidol); previously registered drugs like meclofenoxate or reserpine; EU authorized pharmaceuticals like piracetam or vinpocetine; infamous doping agents like methylhexaneamine or dimethylbutylamine; and other investigational substances and peptides. Several are authorized DS ingredients in the United States resulting in significant global variability as to what qualifies as a legal nootropic. Prohibited stimulants or ß2-agonists commonly used in "pre-workout," "weight loss," or "thermogenic" DS such as octodrine, hordenine, or higenamine are often stacked with nootropic substances. While stimulants and ß2-agonists are defined as doping agents by the World Anti-Doping Agency (WADA), many nootropics are not, although some may qualify as non-approved substances or related substances under catch-all language in the WADA Prohibited List. Synergistic combinations, excessive dosing, or recently researched pharmacology may justify listing certain nootropics as doping agents or warrant additional attention in future regulations.

Picamilon, a γ-aminobutyric acid (GABA) analogue and marketed nootropic, is inactive against 50 biological targets

Picamilon is an analogue of the neurotransmitter γ-aminobutyric acid (GABA), which is marketed as a nootropic claiming to enhance cognition. There is a lack of in silico, in vitro and in vivo data on the safety of picamilon. Therefore, to ascertain potential physiological effects of picamilon, it was screened against 50 safety-related biological targets (receptors, ion channels, enzymes and transporters) by in silico and in vitro methods. Using two in silico tools, picamilon was not predicted to bind to the targets. Similarly, picamilon exhibited weak or no binding to the targets when measured in vitro at 10 μM. Overall, this data shows that picamilon, although structurally similar to other GABA analogues, has a different biological target binding profile. Picamilon's lack of binding to the 50 targets fills important data gaps among GABA analogues, a group of structurally related substances found in drugs and other consumer products.

Nootropics as Cognitive Enhancers: Types, Dosage and Side Effects of Smart Drugs

Nootropics, also known as "smart drugs" are a diverse group of medicinal substances whose action improves human thinking, learning, and memory, especially in cases where these functions are impaired. This review provides an up-to-date overview of the potential effectiveness and importance of nootropics. Based on their nature and their effects, this heterogeneous group of drugs has been divided into four subgroups: classical nootropic compounds, substances increasing brain metabolism, cholinergic, and plants and their extracts with nootropic effects. Each subgroup of nootropics contains several main representatives, and for each one, its uses, indications, experimental treatments, dosage, and possible side effects and contraindications are discussed. For the nootropic plant extracts, there is also a brief description of each plant representative, its occurrence, history, and chemical composition of the medicinal part. Lastly, specific recommendations regarding the use of nootropics by both ill and healthy individuals are summarized.

The unapproved drug centrophenoxine (meclofenoxate) in cognitive enhancement dietary supplements

INTRODUCTION

Centrophenoxine (meclofenoxate) is prescribed in China and elsewhere to treat a variety of conditions including alcoholism and dementia, but the US Food and Drug Administration has not approved the drug for any indication. We designed our study to determine the presence and quantity of centrophenoxine in dietary supplements sold over-the-counter in the US.

METHODS

Supplements were included in our study if the label included (a) the term "dietary supplement" and (b) "centrophenoxine" as a declared ingredient. Supplements were purchased online, and powder from each dietary supplement product was reconstituted in methanol and analyzed using ultra high-performance liquid chromatography.

RESULTS

Seven products were analyzed. Centrophenoxine was present in all products in dosages ranging from 79 to 251 mg per serving. Consumers following the maximum recommended daily intake on the label would be exposed to 237 to 752 mg of centrophenoxine per day. Only 1 of 7 products (14%) listed a quantity of centrophenoxine on the label within ±10% of the actual amount.

CONCLUSION

Clinicians should be aware and advise patients that cognitive enhancement supplements may contain unapproved and prohibited drugs.

Vinpocetine (A comprehensive profile)

Vinpocetine (VIN) is a herbal supplement extracted from the periwinkle plant. It is a multi-action agent, which is used to treat various neurological disorders such as Alzheimer's and Parkinson's disease. Vinpocetine has also anti-inflammatory, analgesic, antioxidant property and treats various thinking and memory problems. Currently, vinpocetine is also available in the market as a dietary supplement to enhance cognition and memory. This profile explains the physicochemical properties, methods of preparation, content of related impurities and different spectroscopical behavior of vinpocetine. It also discusses the reported methods of analysis of the drug, which include Compendial Methods, Electrochemical Methods, Spectrophotometric Methods and Chromatographic Methods of analysis. Furthermore, this profile explains the stability of the drug subjected to stress conditions of acid, alkaline and photolytic degradation. In addition, the clinical applications of the drug, its uses, side effects, dosing information, pharmacokinetics and mechanism of action are also discussed.

Development of a Validated Stability-Indicating HPLC Method for Vinpocetine in the Presence of Potential İmpurities in Tablet Dosage Form by Multi-Response Optimization

BACKGROUND

Vinpocetine has been prescribed for the treatment of ischemic brain diseases for many years. The drug, which has side effects such as headache, flushing, and decreased blood pressure, is not found in nature, but it can be synthesized by several approaches.

OBJECTIVES

A simple, rapid, selective, stability-indicating high performance liquid chromatographic method was developed for the simultaneous estimation of vinpocetine and their potential impurities in a tablet formulation.

METHODS

Optimum HPLC conditions were tried to be determined by statistical experimental design method. The proposed method was validated as per the ICH guidelines. Stress study was used to demonstrate the stability-indicating ability of the developed method in the quantification of vinpocetine and potential impurities within the same run.

RESULTS

According to multi-response optimization using the Derringer's desirability function, the mobile phase consisted of acetonitrile: Phosphate Buffer (pH 6.0) in the ratio of 65:35 ʋ/ʋ at a flow rate of 1.7 mL/min. Significant degradations were observed for the drug product under acid hydrolysis and alkali hydrolysis. The new method showed reasonable detection and quantification limits with good selectivity, precision, linearity and recovery.

CONCLUSIONS

These validation results have shown that this method is suitable for quantitative determination of vinpocetine and its impurities in quality control laboratories.

HIGHLIGHTS

A reliable and rapid HPLC method which was optimized with response surface methodology and multi-response optimization based on Derringer's desirability function was developed for the simultaneous analysis of vinpocetine and its impurities in a tablet formulation.

Five Unapproved Drugs Found in Cognitive Enhancement Supplements

Objective

To identify the presence of unapproved pharmaceutical drugs in over-the-counter dietary supplements marketed to improve memory and cognitive function.

Methods

Supplements were identified by searching 2 supplement databases for products labeled as containing omberacetam, aniracetam, phenylpiracetam, or oxiracetam, 4 drugs not approved for human use in the United States. Products were purchased online and analyzed using nontargeted liquid chromatography-quadrupole time-of-flight mass spectrometry methods.

Results

In the 10 products tested, omberacetam and aniracetam were detected along with 3 additional unapproved drugs (i.e., phenibut, vinpocetine and picamilon). By consuming recommended serving sizes, consumers could be exposed to pharmaceutical-level dosages of drugs including a maximum of 40.6 ± 0.4 mg omberacetam (typical pharmacologic dose of 10 mg), 502 ± 0.8 mg of aniracetam (typical pharmacologic dose 200-750 mg), 15.4 ± 0.3 mg of phenibut (typical pharmacologic dose 250-500 mg), 4.3 ± 0.1 mg of vinpocetine (typical pharmacologic dose 5-40 mg), and 90.1 ± 0.7 mg of picamilon (typical pharmacologic dose 50-200 mg). Several detected drugs were not declared on the label, and several declared drugs were not detected in the products. For those products with drug quantities provided on the labels, 75% (9/12) of declared quantities were inaccurate. Consumers could be exposed to up to four-fold greater than pharmaceutical dosages and as many as 4 unapproved drugs when using individual products.

Conclusions

Over-the-counter cognitive enhancement supplements may contain multiple unapproved drugs. The health effects of consuming untested combinations of unapproved drugs at unpredictable dosages without clinician oversight in supplements are unknown.

Risk Associated with the Use of Selected Ingredients in Food Supplements

This review focuses on four new product categories of food supplements: pre-workout, fat burner/thermogenic, brain/cognitive booster, and hormone/testosterone booster. Many food supplements have been shown to be contaminated with unauthorized substances. In some cases, the ingredients in the new categories of dietary supplements were medicinal products or new synthetic compounds added without performing clinical trials. Some of the new ingredients in dietary supplements are plant materials that are registered in the pharmacopoeia as herbal medicines. In other cases, dietary supplements may contain plant materials that have no history of human use and are often used as materials to 'camouflage' stimulants. In the European Union, new ingredients of dietary supplements, according to European Food Safety Authority or unauthorized novel food. Furthermore, selected ingredients in dietary supplements may be prohibited in sports and are recognized as doping agents by World Anti-Doping Agency.

Boost Me: Prevalence and Reasons for the Use of Stimulant Containing Pre Workout Supplements Among Fitness Studio Visitors in Mainz (Germany)

The rapidly increasing interest in fitness related sports over the past few years has been accompanied by a booming industry of nutritional supplements. Many of these substances have unproven benefits and are even potentially harmful to the user. The aim of this study was to determine the prevalence and reasons for nutritional supplement (NS) use among fitness studio visitors in Mainz (Germany), emphasizing new multi-ingredient based supplements such as pre workout boosters (PWBs). Some of the PWBs contain stimulants such as DMAA, N,α-DEPEA, DMAE and DMBA with so far unknown risks, harms and benefits. Four-Hundred and Ninety Two participants in 13 fitness studios completed a questionnaire on the use of nutritional supplements. Descriptive statistics and chi-square tests were used to examine differences in supplement use regarding training- and intake-reasons. About 57.0% of the participants reported the use of NS during the last 4 weeks. The all-time prevalence of creatine use was 28.7%, whereas 12.2% of the participants stated creatine use during the past 4 weeks. The all-time prevalence of PWB intake was 25.8%, whereas the last month prevalence was 11.8%. Among the group of PWB users, 20.5% stated to search specifically for substances such as DMAA, N,α-DEPEA, DMAE or DMBA. Logistic regression analysis showed positive relations between creatine use and the predictor variables gender, strength training and bodybuilding, as well as the stated exercisers' training reasons to increase physical- and sports-performance, and quality of life. PWB consumption was related to the variables gender, training frequency, and the reason for sports performance enhancement. Specific ingredient focus was related to the predictor variables competition participation and increase of mental performance. The results of the study show a high prevalence of PWB consumption among fitness studios visitors, which is comparable with creatine use. The predicting variables for consumption seem to be slightly different between the supplements, especially if the users are searching for stimulating agents. The current findings help to create preliminary consumption patterns and can help to identify potential endangered fitness studio visitors for prevention and risk communication, especially for PWBs.

Embryo-fetal development studies with the dietary supplement vinpocetine in the rat and rabbit

Dietary supplement and natural product use is increasing within the United States, resulting in growing concern for exposure in vulnerable populations, including young adults and women of child-bearing potential. Vinpocetine is a semisynthetic derivative of the Vinca minor extract, vincamine. Human exposure to vinpocetine occurs through its use as a dietary supplement for its purported nootropic and neuroprotective effects. To investigate the effects of vinpocetine on embryo-fetal development, groups of 25 pregnant Sprague-Dawley rats and 8 pregnant New Zealand White rabbits were orally administered 0, 5, 20, or 60 mg vinpocetine/kg and 0, 25, 75, 150, or 300 mg/kg daily from gestational day (GD) 6-20 and GD 7-28, respectively. Pregnant rats dosed with vinpocetine demonstrated dose-dependent increases in postimplantation loss, higher frequency of early and total resorptions, lower fetal body weights, and fewer live fetuses following administration of 60 mg/kg, in the absence of maternal toxicity. Additionally, the rat fetuses displayed dose-dependent increases in the incidences of ventricular septum defects and full supernumerary thoracolumbar ribs. Similarly, albeit at higher doses than the rats, pregnant rabbits administered vinpocetine displayed an increase in postimplantation loss and fewer live fetuses (300 mg/kg), in addition to significantly lower fetal body weights (≥75 mg/kg). In conclusion, vinpocetine exposure resulted in similar effects on embryo-fetal development in the rat and rabbit. The species differences in sensitivity and magnitude of response is likely attributable to a species difference in metabolism. Taken together, these data suggest a potential hazard for pregnant women who may be taking vinpocetine.

Role of Plant Derived Alkaloids and Their Mechanism in Neurodegenerative Disorders

Neurodegenerative diseases are conventionally demarcated as disorders with selective loss of neurons. Conventional as well as newer molecules have been tested but they offer just symptomatic advantages along with abundant side effects. The discovery of more compelling molecules that can halt the pathology of these diseases will be considered as a miracle of present time. Several synthetic compounds are available but they may cause several other health issues. Therefore, natural molecules from the plants and other sources are being discovered to replace available medicines. In conventional medicational therapies, several plants have been reported to bestow remedial effects. Phytochemicals from medicinal plants can provide a better and safer alternative to synthetic molecules. Many phytochemicals have been identified that cure the human body from a number of diseases. The present article reviews the potential efficacy of plant-derived alkaloids, which possess potential therapeutic effects against several NDDs including Alzheimer's disease (AD), Huntington disease (HD), Parkinson's disease (PD), Epilepsy, Schizophrenia, and stroke. Alkaloids include isoquinoline, indole, pyrroloindole, oxindole, piperidine, pyridine, aporphine, vinca, β-carboline, methylxanthene, lycopodium, and erythrine byproducts. Alkaloids constitute positive roles in ameliorating pathophysiology of these illnesses by functioning as muscarinic and adenosine receptors agonists, anti-oxidant, anti-amyloid and MAO inhibitors, acetylcholinestrase and butyrylcholinesterase inhibitor, inhibitor of α-synuclein aggregation, dopaminergic and nicotine agonist, and NMDA antagonist.

Simultaneous quantitative determination of bioactive terpene indole alkaloids in ethanolic extracts of Catharanthus roseus (L.) G. Don by ultra high performance liquid chromatography-tandem mass spectrometry

A rapid, sensitive and reproducible method using ultra-high-performance liquid chromatography coupled with electrospray ionization hybrid triple quadrupole-linear ion trap mass spectrometry (UHPLC-ESI-QqQ_LIT-MS/MS) in multiple reaction monitoring (MRM) mode was developed and validated for simultaneous quantitation of anticancer (vincristine, vinblastine, vindesine), antihypertensive (ajmaline, ajmalicine, reserpine), aphrodisiac (yohimbine), sedative (serpentine) agents, dietary supplement (vinpocetine, yohimbine) and precursor of vinblastine (vindoline) from crude extracts of Catharanthus roseus. The precursor to product ion transitions for these compounds were observed at m/z 327 → 144, 355 → 144, 754 → 355, 353 → 144, 349 → 317, 825 → 225, 811 → 224, 458 → 188, 351 → 280 and 609 → 195, respectively in positive ionization mode. Chromatographic separation of all targeted TIAs was performed on ACQUITY UPLC BEH™ C₁₈ column (1.7 μm, 2.1 mm × 50 mm). The calibration curves were linear within the concentration range 0.5-1000 ng/mL and correlation coefficients (R²) were closer to 1. Limit of detection (LOD) and limit of quantitation (LOQ) ranged from 0.039-0.583 ng/mL and 0.118-1.767 ng/mL, respectively. The intra-day (0.23-2.71% RSD) and inter-day (0.40-2.90% RSD) precision, stability (0.69-3.45% RSD) and recovery (99.63-104.30% ± %RSD ≤ 3.03%) were acceptable indicating good accuracy of the developed method. The method was successfully applied in ethanolic extracts of 39 samples of C. roseus parts (leaf, stem and root) collected from five different locations in India. Serpentine was detected as one of the most abundant TIA. Principal component analysis (PCA) was able to successfully discriminate among C. roseus samples on the basis of content of targeted TIAs.

Quantitative Determination of Vinpocetine in Dietary Supplements

Current United States regulatory policies allow for the addition of pharmacologically active substances in dietary supplements if derived from a botanical source. The inclusion of certain nootropic drugs, such as vinpocetine, in dietary supplements has recently come under scrutiny due to the lack of defined dosage parameters and yet unproven short- and long-term benefits and risks to human health. This study quantified the concentration of vinpocetine in several commercially available dietary supplements and found that a highly variable range of 0.6-5.1 mg/serving was present across the tested products, with most products providing no specification of vinpocetine concentrations.

The Effect of Vinpocetine on Human Cytochrome P450 Isoenzymes by Using a Cocktail Method

Vinpocetine is a derivative of the alkaloid vincamine, which had been prescribed for chronic cerebral vascular ischemia and acute ischemic stroke or used as a dietary supplement for its several different mechanisms of biological activities. However, information on the cytochrome P450 (CYP) enzyme-mediated drug metabolism has not been previously studied. The present study was performed to investigate the effects of vinpocetine on CYPs activity, and cocktail method was used, respectively. To evaluate the effects of vinpocetine on the activity of human CYP3A4, CYP2C9, CYP2C19, CYP2D6, and CYP2E1, human liver microsomes were utilized to incubate with the mixed CYPs probe substrates and the target components. The results indicate that vinpocetine exhibited weak inhibitory effect on the CYP2C9, where the IC₅₀ value is 68.96 μM, whereas the IC₅₀ values for CYP3A4, CYP2C19, CYP2D6, and CYP2E1 were all over range of 100 μM, which showed that vinpocetine had no apparent inhibitory effects on these CYPs. In conclusion, the results indicated that drugs metabolized by CYP2C9 coadministrated with vinpocetine may require attention or dose adjustment.