Components Of Dietary Supplements Research Articles

Application of In Vitro Digestion Models in the Evaluation of Dietary Supplements.

Nowadays, dietary supplements are a permanent part of our diet. Using various simulated in vitro digestive models, the bioavailability of dietary supplement ingredients has also been investigated. In most cases, static models are used instead of dynamic ones. This article focuses on the division of applications of in vitro methods, such as assessing the quality of dietary supplements (in chemical and pharmaceutical form), the impact of diet on the assessment of the bioavailability of product ingredients, the impact of supplement ingredients on the state of intestinal microflora, and the development of new products using various encapsulation methods. The review included publications from 2000 to 2024 showing the use of in vitro methods in dietary supplements containing polysaccharides, proteins, elements, vitamins, and bioactive substances, as well as probiotic and prebiotic products. The impact of components in dietary supplements on the human digestive tract and their degree of bioaccessibility were determined through the use of in vitro methods. The application of in vitro methods has also become an effective tool for designing new forms of dietary supplements in order to increase the availability and durability of labile ingredients in these products.

Sustainable Production of Ajuga Bioactive Metabolites Using Cell Culture Technologies: A Review.

The genus Ajuga (Lamiaceae) is rich in medicinally important species with biological activities ranging from anti-inflammatory, antitumor, neuroprotective, and antidiabetic to antibacterial, antiviral, cytotoxic, and insecticidal effects. Every species contains a unique and complex mixture of bioactive metabolites-phytoecdysteroids (PEs), iridoid glycosides, withanolides, neo-clerodane terpenoids, flavonoids, phenolics, and other chemicals with high therapeutic potential. Phytoecdysteroids, the main compounds of interest, are natural anabolic and adaptogenic agents that are widely used as components of dietary supplements. Wild plants remain the main source of Ajuga bioactive metabolites, particularly PEs, which leads to frequent overexploitation of their natural resources. Cell culture biotechnologies offer a sustainable approach to the production of vegetative biomass and individual phytochemicals specific for Ajuga genus. Cell cultures developed from eight Ajuga taxa were capable of producing PEs, a variety of phenolics and flavonoids, anthocyanins, volatile compounds, phenyletanoid glycosides, iridoids, and fatty acids, and demonstrated antioxidant, antimicrobial, and anti-inflammatory activities. The most abundant PEs in the cell cultures was 20-hydroxyecdysone, followed by turkesterone and cyasterone. The PE content in the cell cultures was comparable or higher than in wild or greenhouse plants, in vitro-grown shoots, and root cultures. Elicitation with methyl jasmonate (50-125 µM) or mevalonate and induced mutagenesis were the most effective strategies that stimulated cell culture biosynthetic capacity. This review summarizes the current progress in cell culture application for the production of pharmacologically important Ajuga metabolites, discusses various approaches to improve the compound yield, and highlights the potential directions for future interventions.

Plant-Derived and Dietary Hydroxybenzoic Acids-A Comprehensive Study of Structural, Anti-/Pro-Oxidant, Lipophilic, Antimicrobial, and Cytotoxic Activity in MDA-MB-231 and MCF-7 Cell Lines.

Seven derivatives of plant-derived hydroxybenzoic acid (HBA)—including 2,3-dihydroxybenzoic (2,3-DHB, pyrocatechuic), 2,4-dihydroxybenzoic (2,4-DHB, β-resorcylic), 2,5-dihydroxybenzoic (2,5-DHB, gentisic), 2,6-dihydroxybenzoic (2,6-DHB, γ-resorcylic acid), 3,4-dihydroxybenzoic (3,4-DHB, protocatechuic), 3,5-dihydroxybenzoic (3,5-DHB, α-resorcylic), and 3,4,5-trihydroxybenzoic (3,4,5-THB, gallic) acids—were studied for their structural and biological properties. Anti-/pro-oxidant properties were evaluated by using DPPH• (2,2-diphenyl-1-picrylhydrazyl), ABTS•+ (2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), FRAP (ferric-reducing antioxidant power), CUPRAC (cupric-reducing antioxidant power), and Trolox oxidation assays. Lipophilicity was estimated by means of experimental (HPLC) and theoretical methods. The antimicrobial activity against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Salmonella enteritidis (S. enteritidis), and Candida albicans (C. albicans) was studied. The cytotoxicity of HBAs in MCF-7 and MDA-MB-231 cell lines was estimated. Moreover, the structure of HBAs was studied by means of experimental (FTIR, 1H, and 13C NMR) and quantum chemical DFT methods (the NBO and CHelpG charges, electrostatic potential maps, and electronic parameters based on the energy of HOMO and LUMO orbitals). The aromaticity of HBA was studied based on the calculated geometric and magnetic aromaticity indices (HOMA, Aj, BAC, I6, NICS). The biological activity of hydroxybenzoic acids was discussed in relation to their geometry, the electronic charge distribution in their molecules, their lipophilicity, and their acidity. Principal component analysis (PCA) was used in the statistical analysis of the obtained data and the discussion of the dependency between the structure and activity (SAR: structure–activity relationship) of HBAs. This work provides valuable information on the potential application of hydroxybenzoic acids as bioactive components in dietary supplements, functional foods, or even drugs.

Nutraceutical management of male infertility-towards new generation therapeutics

Infertility is one of the most significant public health-related concerns globally. Both male and female factors can cause it. Male factors include poor sperm quality, idiopathic oligospermia, asthenozoospermia, and isolated asthenozoospermia. Many substances, collectively known as nutraceuticals, have been studied for their capacity to enhance hormonal state and sperm parameters through different mechanisms. Nutraceuticals are components in dietary supplements prescribed to prevent or treat a wide range of diseases. This article aims to highlight certain nutrients that can help improve male fertility based on recent advancements in the management of male infertility.

Influence of chromium (III), cobalt (II) and their mixtures on cell metabolic activity

Abstract Chromium (III) and cobalt (II) are necessary elements required for the proper functioning of the organism, but their excess can cause toxic effects. They are the basic components of implants and are also commonly used in medicine as components of dietary supplements, vitamin and mineral products and energy drinks. The aim of this study was to investigate the effect of cobalt (II) and chromium (III) and their combination on BJ cells. In the study, BJ cells were exposed to CoCl2 or CrCl3 at concentrations ranging from 100 to 1400 µM, and the cytotoxicity of chromium (III) and cobalt (II) and their mixtures was assessed by MTT reduction, LDH release and NRU assays. The outcome of this work reveals the cytotoxic effects of chromium (III) and cobalt (II) and their mixtures on BJ cells. In the cytotoxicity assays, at low concentrations of CoCl2 and CrCl3, stimulation of cell proliferation was observed. In higher concentrations, the cell viability decreased for the tested line in all the assays. During the simultaneous incubation of fibroblasts with 200 µM of CrCl3 and 1000 µM of CoCl2, antagonism was observed: chromium (III) at the concentration of 200 µM induced protection from cobalt (II) toxicity; in the case of interaction of chromium chloride at 1000 µm and cobalt chloride at 200 µM, the protective effect of CrCl3 on CoCl2 was not observed. In the latter case, synergism between these elements was noted. Our work indicates that cobalt (II) and chromium (III) show cytotoxic properties. These metals have a destructive effect on the cell membrane, lysosomes and mitochondria, which leads to disorders of cell metabolism.

In vitro antimicrobial and antipro-inflammation potential of honokiol and magnolol against oral pathogens and macrophages

Honokiol and magnolol are natural components isolated from Magnolia bark that is used in traditional Chinese and Japanese herbal medicine. These two isomers are used as a component of dietary supplements and cosmetic products. In this study, we investigated the antimicrobial effect of honokiol and magnolol on pathogens causing oral diseases, their mechanism of action in biofilm formation and drug resistance of oral pathogens, and inflammatory regulation in mammalian cells. We determined the minimum inhibitory concentration and minimum bactericidal concentration of honokiol and magnolol, and their stability at different temperatures and pH. We also evaluated their effect on biofilm formation, antibiotic-resistance gene expression in MRSA, and pro-inflammatory gene expression in mammalian cells. Honokiol showed better antimicrobial activity than magnolol. Both honokiol and magnolol showed stable bacterial inhibitory activity over a wide range of temperature and pH, reduced biofilm formation, and antibiotic resistance in oral pathogens. The biofilm formation- and antibiotic resistance-related gene expression was consistent with the respective phenotypes. Furthermore, these two isomers repressed the expression of pro-inflammatory genes in RAW264.7cells. Our study provides evidence of the potential application of honokiol and magnolol in dental medicine to cure or prevent oral diseases.

Współpraca lekarza i farmaceuty w zakresie optymalizacji farmakoterapii w trakcie doustnego leczenia niepłodności u kobiet. Stan badań klinicznych oceniających skuteczności składników suplementów diety stosowanych w trakcie leczenia niepłodności

Współpraca lekarza i farmaceuty w zakresie optymalizacji farmakoterapii w trakcie doustnego leczenia niepłodności u kobiet. Stan badań klinicznych oceniających skuteczności składników suplementów diety stosowanych w trakcie leczenia niepłodności

HPLC-determination of active components in dietary supplement «L-CARNITINE smart»

Dietary supplements are compositions of biologically active substances intended for consumption with food or addition to food products for the purpose of optimization of metabolic processes and functions of the human body. The dietary supplements include: vitamins, trace elements, amino acids, enzymes, proteins, probiotics, oils that can provide antioxidant, detoxifying, immunomodulatory, adaptogenic effects, etc.
 Detection of physiologically active components in dietary supplements is a difficult task and requires the use of modern highly informative research methods. One of the most powerful and versatile methods of determination is the method of high performance liquid chromatography (HPLC), combining the selective separation of the studied mixtures and high sensitivity.
 The purpose of this study was to develop a simple, rapid and selective method for determining ascorbic acid and L-carnitine L-tartrate in a multicomponent dietary supplement, produced in the form of sachets, using HPLC with spectrophotometric detection.
 The object of the study is the dietary supplement «L-CARNITINE smart», powder for oral solution of 16 g each in a sachet (INTERСHЕM). For the quantitative determination of the applied method of high-performance liquid chromatography. Chromatography was performed on an Agilent 1260 Infinity 2D LC System (USA) liquid chromatograph with a UV detector.
 The optimal conditions for the analysis have been experimentally determined: the type of sorbent, the composition of the eluent and its gradient, the wavelength and the detection time for ensuring the release of all components (including auxiliary substances) from the column, selective separation of ascorbic acid, potassium acesulfame and L-carnitine L-tartrate, minimization analysis time. The method has been validated according to the following parameters: specificity, linearity, accuracy, limit of quantitation.

In vitro and in silico studies of the membrane permeability of natural flavonoids from Silybum marianum (L.) Gaertn. and their derivatives

BackgroundIn recent years the number of natural products used as pharmaceuticals, components of dietary supplements and cosmetics has increased tremendously requiring more extensive evaluation of their pharmacokinetic properties. PurposeThis study aims at combining in vitro and in silico methods to evaluate the gastrointestinal absorption (GIA) of natural flavonolignans from milk thistle (Silybum marianum (L.) Gaertn.) and their derivatives. MethodsA parallel artificial membrane permeability assay (PAMPA) was used to evaluate the transcellular permeability of the plant main components. A dataset of 269 compounds with measured PAMPA values and specialized software tools for calculating molecular descriptors were utilized to develop a quantitative structure-activity relationship (QSAR) model to predict PAMPA permeability. ResultsThe PAMPA permeabilities of 7 compounds constituting the main components of the milk thistle were measured and their GIA was evaluated. A freely-available and easy to use QSAR model predicting PAMPA permeability from calculated physico-chemical molecular descriptors was derived and validated on an external dataset of 783 compounds with known GIA. The predicted permeability values correlated well with obtained in vitro results. The QSAR model was further applied to predict the GIA of 31 experimentally untested flavonolignans. ConclusionsAccording to both in vitro and in silico results most flavonolignans are highly permeable in the gastrointestinal tract, which is a prerequisite for sufficient bioavailability and use as lead structures in drug development. The combined in vitro/in silico approach can be used for the preliminary evaluation of GIA and to guide further laboratory experiments on pharmacokinetic characterization of bioactive compounds, including natural products.

Determination of Flavonoids and Phenolic Acids in Plant Materials Using SLE-SPE-UHPLC-MS/MS Method

Today, great emphasis is placed on the search for and dissemination of native plant materials in various industries, with particular emphasis on food, cosmetics, dietary supplements, and as livestock feed and a source of biomass. Solid-liquid extraction (SLE), solid phase extraction (SPE), and ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) methods were developed for the simultaneous determination of 30 flavonoids and phenolic acids in plant materials (lucerne (Medicago sativa L.), goldenrod (Solidago virgaurea L.), phacelia (Phacelia tanacetifolia Benth.), buckwheat (Fagopyrum esculentum), licorice (Glycyrrhiza glabra), and lavender (Lavandula spica L.)). Different SLE methods were tested to evaluate their applicability for the isolation of polyphenols from plants. Then extracts were purified with a C18 reversed-phase SPE cartridge. After extraction, samples were analyzed by UHPLC-MS/MS. The SLE-SPE-UHPLC-MS/MS assay method has been fully validated. For the most compounds, good recoveries and RSDs (< 10%) were obtained. Limits of quantification range from 0.4 to 20 ng/mL. The main phenolic acids in the studied plants have been found to be 3-(4-hydroxyphenyl)propionic acid, 4-hydroxybenzoic acid, and 3,4-dihydroxybenzoic acid. Quercetin, rutin, glabridin, and naringenin are the major flavonoids detected in the analyzed samples. The obtained scientific data can be useful to select plant materials with high nutritional value and the presence of many biologically active ingredients, as well as selecting samples used as a plant biomass, as food, and as a component of dietary supplements.

Licorice root components in dietary supplements are selective estrogen receptor modulators with a spectrum of estrogenic and anti-estrogenic activities

Licorice root extracts are often consumed as botanical dietary supplements by menopausal women as a natural alternative to pharmaceutical hormone replacement therapy. In addition to their components liquiritigenin (Liq) and isoliquiritigenin (Iso-Liq), known to have estrogenic activity, licorice root extracts also contain a number of other flavonoids, isoflavonoids, and chalcones. We have investigated the estrogenic activity of 7 of these components, obtained from an extract of Glycyrrhiza glabra powder, namely Glabridin (L1), Calycosin (L2), Methoxychalcone (L3), Vestitol (L4), Glyasperin C (L5), Glycycoumarin (L6), and Glicoricone (L7), and compared them with Liq, Iso-Liq, and estradiol (E2). All components, including Liq and Iso-Liq, have low binding affinity for estrogen receptors (ERs). Their potency and efficacy in stimulating the expression of estrogen-regulated genes reveal that Liq and Iso-Liq and L2, L3, L4, and L6 are estrogen agonists. Interestingly, L3 and L4 have an efficacy nearly equivalent to E2 but with a potency ca. 10,000-fold less. The other components, L1, L5 and L7, acted as partial estrogen antagonists. All agonist activities were reversed by the antiestrogen, ICI 182,780, or by knockdown of ERα with siRNA, indicating that they are ER dependent. In HepG2 hepatoma cells stably expressing ERα, only Liq, Iso-Liq, and L3 stimulated estrogen-regulated gene expression, and in all cases gene stimulation did not occur in HepG2 cells lacking ERα. Collectively, these findings classify the components of licorice root extracts as low potency, mixed ER agonists and antagonists, having a character akin to that of selective estrogen receptor modulators or SERMs.

Physiological and pharmacokinetic effects of oral 1,3-dimethylamylamine administration in men

Background1,3-dimethylamylamine (DMAA) has been a component of dietary supplements and is also used within "party pills," often in conjunction with alcohol and other drugs. Ingestion of higher than recommended doses results in untoward effects including cerebral hemorrhage. To our knowledge, no studies have been conducted to determine both the pharmacokinetic profile and physiologic responses of DMAA.MethodsEight men reported to the lab in the morning following an overnight fast and received a single 25 mg oral dose of DMAA. Blood samples were collected before and through 24 hours post-DMAA ingestion and analyzed for plasma DMAA concentration using high-performance liquid chromatography–mass spectrometry. Resting heart rate, blood pressure, and body temperature was also measured.ResultsOne subject was excluded from the data analysis due to abnormal DMAA levels. Analysis of the remaining seven participants showed DMAA had an oral clearance of 20.02 ± 5 L∙hr-1, an oral volume of distribution of 236 ± 38 L, and terminal half-life of 8.45 ± 1.9 hr. Lag time, the delay in appearance of DMAA in the circulation following extravascular administration, varied among participants but averaged approximately 8 minutes (0.14 ± 0.13 hr). The peak DMAA concentration for all subjects was observed within 3–5 hours following ingestion and was very similar across subjects, with a mean of ~70 ng∙mL-1. Heart rate, blood pressure, and body temperature were largely unaffected by DMAA treatment.ConclusionsThese are the first data to characterize the oral pharmacokinetic profile of DMAA. These findings indicate a consistent pattern of increase across subjects with regards to peak DMAA concentration, with peak values approximately 15–30 times lower than those reported in case studies linking DMAA intake with adverse events. Finally, a single 25 mg dose of DMAA does not meaningfully impact resting heart rate, blood pressure, or body temperature.Trial registrationNCT01765933

Simultaneous determination of pharmaceutical components in dietary supplements for weight loss by capillary electrophoresis tandem mass spectrometry

A simple capillary electrophoresis tandem mass spectrometry method was developed for the simultaneous determination of 20 pharmaceutical components such as cathartics and appetite suppressants in dietary supplements for weight loss. This method allowed multidrug target screening and confirmation in differing radically in chemical structure. The separation was achieved on an uncoated fused-silica capillary using 20 mM ammonium formate in 20 % v/v acetonitrile-water (pH 8.0) as the electrolyte, followed by detection mixed with a sheath liquid that consisted of a mixture of 5 mM ammonium formate and 0.1 % v/v formic acid in 50 % v/v methanol-water. Samples were hydrodynamically injected and separated at 30 kV within 25 min. The limits of detection were 1.0-750 µg/g for the target analytes. The method was successfully applied to 12 dietary supplements for weight loss and 3 non-prescription drugs. The proposed method was suitable as the determination and identification of pharmaceutical components in dietary supplements for weight loss.

Updates on chemical and biological research on botanical ingredients in dietary supplements

Increased use of dietary supplements is a phenomenon observed worldwide. In the USA, more than 40% of the population recently reported using complementary and alternative medicines, including botanical dietary supplements. Perceptions that such dietary supplements are natural and safe, may prevent disease, may replace prescription medicines, or may make up for a poor diet, play important roles in their increased use. Toxicity of botanical dietary supplements may result from the presence of naturally occurring toxic constituents or from contamination or adulteration with pharmaceutical agents, heavy metals, mycotoxins, pesticides, or bacteria, misidentification of a plant species in a product, formation of electrophilic metabolites, organ-specific reactions, or botanical-drug interactions. The topics discussed in this review illustrate several issues in recent research on botanical ingredients in dietary supplements. These include (1) whether 1,3-dimethylamylamine is a natural constituent of rose geranium (Pelargonium graveolens), (2) how analysis of the components of dietary supplements containing bitter melon (Momordica charantia) is essential to understanding their potential biological effects, and (3) how evolving methods for in vitro studies on botanical ingredients can contribute to safety evaluations. The virtual explosion in the use of botanical ingredients in hundreds of products presents a considerable challenge to the analytical community, and the need for appropriate methods cannot be overstated. We review recent developments and use of newer and increasingly sensitive methods that can contribute to increasing the safety and quality of botanical ingredients in dietary supplements.

Merging Traditional Chinese Medicine with Modern Drug Discovery Technologies to Find Novel Drugs and Functional Foods

Traditional Chinese Medicines (TCM) are rapidly gaining attention in the West as sources of new drugs, dietary supplements and functional foods. However, lack of consistent manufacturing practices and quality standards, fear of adulteration, and perceived deficiencies in scientific validation of efficacy and safety impede worldwide acceptance of TCM. In addition, Western pharmaceutical industries and regulatory agencies are partial toward single ingredient drugs based on synthetic molecules, and skeptical of natural product mixtures. This review concentrates on three examples of TCM-derived pharmaceuticals and functional foods that have, despite these usual obstacles, risen to wide acceptance in the West based on their remarkable performance in recent scientific investigations. They are: Sweet wormwood (Artemisia annua), the source of artemisinin, which is the currently preferred single compound anti-malarial drug widely used in combination therapies and recently approved by US FDA; Thunder god vine (Tripterygium wilfordii) which is being developed as a botanical drug for rheumatoid arthritis; and green tea (Camellia sinensis) which is used as a functional beverage and a component of dietary supplements.

Isolation of Pyrrolizidine Alkaloid Isomers from Symphytum Species by Semi-Preparative Chiral Chromatography

Comfrey is a common name given to plants belonging to the genus Symphytum (family Boraginaceae) [1]. The comfrey root and leaf contain varying levels of the hepatotoxic pyrrolizidine alkaloids (PAs) that have been reported to cause veno-occlusive disease in humans [2]. However, the exact alkaloid profile of different species has not been clearly established, in part because comfrey PAs are not commercially available and the isolation of the individual isomers is difficult. Milligram quantities of PA components from Symphytum are needed for use as analytical standards in quantitating these components in dietary supplements containing these botanicals. Results will be presented on the isolation of PAs from the roots of S. uplandicum. Briefly, a 1.0 kg quantity of plant material was extracted with methanol and the PAs were reduced with zinc dust to convert the N-oxides to free bases. The PAs were enriched on a Chem Elut cartridge (Varian Inc.) and then fractionated on a silica gel chromatographic column, followed by further isolation by semi-preparative HPLC. For the compounds occurring as racemic mixtures, their separation was achieved by semi-preparative chiral HPL C. These chiral stationary phases consist of cellulose immobilized on silica with carbamates as chiral selectors (Chiralpak IA and IC, Chiral technologies Inc. West Chester PA). The compositions of individual fractions were monitored by GC-MS or LC-MS and the purified components were characterized by mass and NMR spectroscopic studies [3–5]. The isolated PAs will be used for the development of analytical methods that can be applied to develop chemical profiles of different species of Symphytum and to determine alkaloid contents of comfrey preparations sold in the market.

Evaluation of magnolia bark extract in chromosomal aberration assays

Magnolia bark extract (MBE) has been used historically in traditional Chinese and Japanese medicines, and more recently as a component of dietary supplements and cosmetic products. The genotoxic potential of MBE was studied in two in vitro chromosomal aberration assays. In Chinese hamster ovary (CHO) cells, exposure for 3 h to MBE at concentrations of 0–30 μg/ml in the absence of a metabolic activation system (S9) and 0–7 μg/ml with S9 did not induce chromosomal aberrations, whereas higher concentrations were cytotoxic and did not allow for analysis of aberrations. Extended exposure for 18 h without metabolic activation at concentrations up to 15 μg/ml also resulted in a negative response. In V79 cells derived from Chinese hamster lung tissue, treatment for 6 h with concentrations up to 52 and 59 μg/ml in the absence and presence of S9, respectively, did not increase the incidence of chromosomal aberrations compared to negative controls. Furthermore, MBE exposure for 24 h without metabolic activation did not induce aberrations. The results of these studies demonstrate that MBE is not genotoxic under the conditions of the in vitro chromosomal aberration assays in CHO and V79 cells, and support the safety of MBE.

Evaluation of the in vitro and in vivo genotoxicity of magnolia bark extract

Magnolia bark extract (MBE) is an extract of the dried stem, root, or branch bark of magnolia trees that has been used historically in traditional Chinese and Japanese medicines, and more recently as a component of dietary supplements and cosmetic products. To study the genotoxic potential of MBE, a bacterial reverse mutation assay and an in vivo micronucleus test were conducted. Compositional analysis of the test substance revealed that MBE contains 94% magnolol and 1.5% honokiol. MBE exerted no mutagenic activity in various bacterial strains of Salmonella typhimurium and in Escherichia coli WP2 uvrA, either in the absence or presence of metabolic activation at all doses tested. In the micronucleus test, various doses of MBE did not affect the proportions of immature to total erythrocytes, nor did it increase the number of micronuclei in the immature erythrocytes of Swiss albino mice. The results of these studies demonstrate that MBE is not genotoxic under the conditions of the in vitro bacterial reverse mutation assay and the in vivo micronucleus test, and support the safety of MBE for dietary consumption.

Determination of Caffeine and Caffeine-Related Metabolites in Ephedra-Containing Standard Reference Materials Using Liquid Chromatography with Absorbance Detection and Tandem Mass Spectrometry

The concentrations of caffeine and caffeine-related compounds in 2 ephedra-containing reference materials have been determined by 3 independent methods with measurements performed by the National Institute of Standards and Technology (NIST) and a collaborating laboratory. Results from the 3 methods were used for value assignment of caffeine, theobromine, and theophylline in these Standard Reference Materials (SRMs). The methods used at NIST to determine the concentration levels of caffeine, theobromine, and theophylline in SRM 3243 Ephedra-Containing Solid Oral Dosage Form and SRM 3244 Ephedra-Containing Protein Powder used reversed-phase liquid chromatography with absorbance detection and tandem mass spectrometry. These reference materials are part of the first suite in a series of NIST SRMs that provide concentration values for multiple components in dietary supplements. These SRMs are primarily intended for method validation and for use as control materials to support the analysis of dietary supplements and similar materials.

Determination of St. John's Wort Components in Dietary Supplements and Functional Foods by Liquid Chromatography

St. John's wort (Hypericum perforatum L.) preparations, a top-selling botanical dietary supplement used primarily as an antidepressant, has recently been used as an ingredient in some food products sold as functional foods. A rapid extraction technique followed by a liquid chromatographic (LC) method was developed to determine 4 characteristic bioactive compounds (pseudohypericin, hypericin, hyperforin, and adhyperforin) from St. John's wort in dietary supplements and functional foods to which it was added. Solid samples, including dried leaf/flower mixture, dietary supplement capsules, tea bags, puff and snack bar, were extracted with methanol by sonication. Noncarbonated, fruit-flavored drinks were centrifuged and mixed with methanol. Compounds were then determined by isocratic, reversed-phase LC with UV detection at 2 wavelengths and further identified or confirmed by photodiode array spectra and LC/mass spectrometry. Within-laboratory method variations (% RSD) were satisfactory. Very low amounts, if any, of the 4 components were found in drink and puff samples, and none was found in the snack bar. The methods developed provide a useful means for the determination of St. John's wort components in dietary supplements and functional foods.