Determination of ephedra alkaloid and caffeine concentrations in dietary supplements and biological fluids

Dietary supplements containing botanical forms of caffeine and ephedra alkaloids have been widely promoted and used in the U.S. for weight loss and athletic enhancement despite a lack of adequate research on the pharmacology of these botanical stimulants. In order to analyze dietary supplements and perform human pharmacokinetic studies, an analytical approach with good precision and accuracy was needed with sufficient sensitivity to detect very low levels of ephedra alkaloids. A liquid chromatography-atmospheric pressure chemical ionization (APCI) tandem mass spectrometry (LC-MS-MS) method was developed for quantitating the various ephedrine-group alkaloids found in dietary supplements that contain Ephedra species, and in plasma and urine of persons consuming these supplements. Using this method, low nanogram-per-milliliter concentrations of ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, methylephedrine, methylpseudoephedrine, and caffeine can be quantitated in a 12-min LC-MS-MS run.     

Investigation of quality in ephedrine-containing dietary supplements

Ephedra alkaloids in 47 dietary supplements were measured to examine variability within and between products as well as for comparison of actual constituents with label claims of manufactured products. Samples were analyzed for (-)-ephedrine, (+)-pseudoephedrine, (-)-methylephedrine, (+)-methylpseudoephedrine,(-)-norephedrine, and (+)-norpseudoephedrine without derivatization using gas chromatographic mass spectrometry (GC/MS). Samples were then screened for pharmaceutically derived chiral contaminants. The resulting data demonstrated that label claims matched total ephedra alkaloid content to within about 25% for most of the supplements, and no products purporting to be ephedrine-free contained any ephedra alkaloids. Furthermore, chiral analysis of these dietary supplements revealed only naturally occurring ephedra alkaloids. (-)-Ephedrine and (+)-pseudoephedrine accounted for > 95% of the alkaloid content in each of the ephedra-containing products. Examination of identical supplements originating from different lots revealed consistency in total alkaloid content between lots but large variations in specific individual alkaloid content.     

Content versus label claims in ephedra-containing dietary supplements.

The content of ephedra alkaloids in herbal dietary supplements containing ephedra (ma huang) was studied. The ephedra alkaloid content of 20 ephedra-containing supplements was determined by high-performance liquid chromatography. Contents of (-)-ephedrine, (+)-pseudoephedrine, (-)-methylephedrine, (-)-norephedrine, and (+)-norpseudoephedrine were measured. Ephedra alkaloid content varied considerably among products. Total alkaloid content ranged from 0.0 to 18.5 mg per dosage unit. Ranges for (-)-ephedrine and (+)-pseudoephedrine were 1.1-15.3 mg and 0.2-9.5 mg, respectively. (+)-Norpseudoephedrine, a Schedule IV controlled substance, was often present. Significant lot-to-lot variations in alkaloid content were observed for four products. For one product, lot-to-lot variations in the content of (-)-ephedrine, (+)-pseudoephedrine, and (-)-methylephedrine exceeded 180%, 250%, and 1000%, respectively. Half of the products exhibited discrepancies between the label claim for ephedra alkaloid content and actual alkaloid content in excess of 20%. One product was devoid of ephedra alkaloids. Assay of 20 ephedra-containing dietary supplements showed that alkaloid content often differed markedly from label claims and was inconsistent between two lots of some products.     

Effects of harvesting time and processing on the contents of five alkaloids in the herbaceous stems of Ephedra sinica

In the present study, we studied the changes of the contents of alkaloids in the herbaceous stems of Ephedra sinicaduring different harvest periods as well as before and after processing. The alkaloid contents of 39 batches of ephedra herb, prepared slices ephedra and honey-fried ephedra, 24 batches of ephedra herb with different harvesting periods, which were all collected from cultivation base in Inner Mongolia, and 38 batches of prepared slices ephedra purchased from the market were detected by taking norephedrine (NE), norpseudoephedrine (NPE), ephedrine (E), pseudoephedrine (PE) and methylephedrine (ME) as indicators by using HPLC method. The content of total alkaloid in prepared slices ephedra (1.71%–3.14%) was higher than that in ephedra herb (1.20%–2.53%) and honey-fried ephedra (1.52%–2.99%). Contents of different alkaloids in these three types of samples were significantly different. Prepared slices ephedra and honey-fried ephedra showed significant differences in the contents of NE, NPE and ME (P<0.05), and the contents of E were significantly different between ephedra herb and honey-fried ephedra (P<0.05). The total alkaloid content of ephedra herb was the highest in September (3.10%). Alkaloid contents of prepared slices ephedra collected in the market were uneven and 13%–91% lower than those collected from cultivation base. The results provided a basis for the quality evaluation of ephedra herb and its processed products, and had certain guiding significance for the selection of processed ephedra according to different drug purposes in clinical application. It also provided data support for the harvesting time of ephedra herb.     

Analysis of bitter orange dietary supplements for natural and synthetic phenethylamines by LC–MS/MS

Citrus aurantium, commonly known as bitter orange, is a popular dietary supplement ingredient sold worldwide. Bitter orange supplements are sold primarily as weight management and sports performance products and have gained popularity after Ephedra products were banned from the US market. Supplements containing synephrine are reported to exhibit adverse cardiovascular effects especially in the presence of caffeine. In this study, an LC–MS/MS method was established to quantify five natural amines (synephrine, octopamine, tyramine, N‐methyltyramine, and hordenine) and four synthetic phenethylamines (phenylephrine, methylsynephrine, etilefrine, and isopropyloctopamine) in dietary supplements sold in the US. The method was validated and found to have acceptable performance to accurately measure analytes in complex botanical products. The average recoveries from a blank matrix were 88–125% with an RSD of 0.5–7.0%. Fifty‐nine products labeled to contain bitter orange peel, extract, or its amines were purchased and their amine content was measured. Several products were found to contain higher amounts of amines than that expected from a typical bitter orange extract. Of the 23 products that made label claims for synephrine, only 5 products (22%) were within 80–120% of labeled synephrine content. The presence of synthetic amines, methylsynephrine (up to 240 mg/daily serving), and isopropyloctopamine (up to 76 mg/daily serving), whose effects in humans are not known, were detected in six products and one product, respectively. While the use of methylsynephrine and isopropyloctopamine are not permitted in dietary supplements, hordenine, N‐methyltyramine, and octopamine are currently listed on the FDA's Dietary Supplement Ingredient Advisory List.     

配伍对麻黄甘草药对中麻黄类生物碱在大鼠体内组织分布的影响

目的：研究麻黄与甘草配伍前后麻黄类生物碱在 SD 大鼠组织分布特点,从药物相互作用角度揭示甘草对麻黄类生物碱组织分布的影响。方法采用超高效液相色谱-串联质谱（ UPLC - MS/ MS）法在多反应监测（MRM）模式下测定麻黄与甘草配伍前后不同时间点大鼠各组织液中麻黄类生物碱的浓度,比较麻黄与甘草配伍前后麻黄类生物碱组织分布的差异。结果与麻黄组相比,麻黄与甘草配伍后,促进了去甲基麻黄碱、麻黄碱和伪麻黄碱在研究组织中的吸收和分布;加快了去甲基麻黄碱、麻黄碱、伪麻黄碱和甲基麻黄碱从脑组织中消除;抑制了去甲基伪麻黄碱在心和脑组织中的吸收和分布,并加快了其从心和脑组织中的消除;不同程度地加快了去甲基麻黄碱从心、肺、肾的消除,加快了麻黄碱从心组织中消除,加快了甲基麻黄碱从肺和肾中的消除。结论麻黄与甘草配伍对麻黄类生物碱在大鼠组织中的分布具有显著的影响。     

Complicated hypertension related to the abuse of ephedrine and caffeine alkaloids

Ephedra containing products (ECPs), which most often contain additional sources of caffeine alkaloids, may be an under-recognized cause of hypertension. ECPs, especially when used in combination or at higher than recommended doses, can cause life-threatening cardiovascular and neurological complications. We present a case of hypertensive encephalopathy with new onset generalized tonic-clonic seizure secondary to concomitant use of two OTC supplements containing a mixture of ephedrine and caffeine alkaloids.     

Determination of ephedrine alkaloids in Ephedra natural products using HPLC on a pentafluorophenylpropyl stationary phase

In this study a pentafluorophenylpropyl (PFPP) stationary phase was applied to the fast and reliable qualitative and quantitative analysis of ephedrine alkaloids in Ephedra plant material and derivatives. A Discovery HS F5 column (150mmx4.6mm i.d., 5microm) was used, with an isocratic mobile phase composed of ammonium acetate (7mM) in acetonitrile-water (90:10, v/v), at a flow rate of 1.0ml/min. The column temperature was set at 45 degrees C. UV detection was set at 215 and 225nm. The total analysis time was 16min. The validation parameters, such as linearity, sensitivity, accuracy, precision and specificity, were found to be highly satisfactory. Sonication and microwave extractions were compared in order to optimize the yield of the target analytes. Under the optimized extraction conditions (based on two cycles of sonication with methanol at 40 degrees C for 15min), different matrices containing Ephedra were successfully analyzed for their alkaloid content. The method was applied to the analysis of standard reference materials (SRMs) containing Ephedra. Furthermore, the developed technique allowed the simultaneous determination of ephedrine alkaloids and synephrine, the main phenethylamine alkaloid of Citrus aurantium, that has replaced Ephedra in dietary supplements used in the treatment of obesity. The results indicated that this procedure is suitable for the phytochemical analysis of Ephedra plant material and extracts, and can be applied to demonstrate the label claims for product content, including the absence of ephedrine alkaloids in Ephedra-free products.     

Simultaneous determination of six alkaloids in ephedrae herba by high performance liquid chromatography

A new and rapid analytical method for the simultaneous determination of six EPHEDRA alkaloids (ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, methylephedrine, and methylpseudoephedrine) in Ephedrae Herba by high performance liquid chromatography (HPLC) has been developed. Recoveries of each alkaloid were 96.0-101.6% with coefficients of deviation of 1.7-3.0%. The contents of six alkaloids in three species of EPHEDRA indigenous to China are determined and reported.     

A rapid and simple procedure for the determination of ephedrine alkaloids in dietary supplements by gas chromatography-mass spectrometry

A simple method for the determination of ephedrine alkaloids: ephedrine (EF), pseudoephedrine (PE), norpseudoephedrine (NPE), norephedrine (NE) and methylpseudoephedrine (MPE) in dietary supplements by gas chromatography–mass spectrometry is described. After the addition of 3,4-methylenedioxypropylamphetamine as internal standard, a liquid–liquid extraction procedure in alkaline conditions with chloroform/isopropanol (9:1, v/v) was applied to the samples prior to analysis. Chromatography was performed on a fused capillary column and analytes, derivatized with pentafluoropropionic anhydride, were determined in the selected-ion-monitoring (SIM) mode. The method was validated in the range 0.3–10 μg/mg for EP, 0.06–2.5 μg/mg for PE and NPE and 0.04–1 μg/mg NE and MPE. Mean recovery ranged between 65.7 and 81.3% for the different analytes in dietary supplements. The quantification limits were 0.3 μg/mg for EP, 0.06 μg/mg for PE, 0.04 μg/mg for NPE, NE and MPE. The method was applied to analysis of various dietary supplements containing Ma-huang (Ephedra Sinica) and Sida Cordifolia plant extracts promoted for aiding weight control and boosting sports performance and energy.     

Caffeine-herbal ephedra combination increases resting energy expenditure, heart rate and blood pressure

1. The purpose of the present study was to determine whether the consumption of an acute dose of caffeine and Ma Huang increases resting energy expenditure (REE), heart rate (HR) and blood pressure (BP) over a 3 h period. 2. A randomized, double-blind cross-over study was performed evaluating the acute effects of caffeine (150 mg)/herbal ephedra (Ma Huang; 20 mg ephedra alkaloids) versus a placebo. A total of eight healthy subjects (four males and four females) with a mean (+/-SD) age of 23.4+/-0.8 years (mean ages for males and females: 25.3+/-0.7 and 22.0+/-0.7 years, respectively) and 22.5+/-3.1% body fat (15.7+/-1.2 and 27.6+/-3.5% body fat for males and females, respectively) were recruited to the study. Participants were moderate caffeine users (approximately 150-300 mg/day). 3. Subjects reported to the laboratory following a 12 h fast and 48 h of a caffeine-free diet. Resting energy expenditure was measured prior to supplementation and for 15 min every 30 min for 3 h following supplementation. Heart rate and BP were obtained every 15 min. Blood samples were obtained every 30 min following the measurement of REE and analysed for caffeine, ephedrine, free fatty acids and glucose. 4. By 3 h, HR was 22.7+/-5.5% higher (P<0.05) than baseline for the caffeine/ephedra trial compared with 8.9+/-2.2% higher for the placebo group. At 3 h, systolic BP was 9.1+/-2.2% higher (P<0.05) than baseline for the caffeine/ephedra trial compared with only 1.9+/-2.9% different from baseline for the placebo trial. There was no effect of the caffeine/ephedra combination on diastolic BP. Resting energy expenditure during the last 30 min was 4.5+/-2.5% higher in the placebo trial and 10.7+/-2.5% higher (P<0.05) in the caffeine/ephedra trial; REE was 8.5 +/- 2.0% higher (P<0.05) in the caffeine/ephedra trial compared with the placebo trial. Free fatty acids increased over time in the placebo and caffeine/ephedra trials (from 0.5+/-0.05 to 0.63+/-0.05 mEq/L and from 0.48+/-0.06L to 0.8+/-0.05 mEq/L, respectively). 5. Caffeine and herbal ephedra, at doses of 150 mg and 20 mg (ephedrine), respectively, result in a significant elevation in REE, HR and BP. Although significant, the increase in energy expenditure is negligible in terms of weight loss.     

HPLC-UV法同时测定麻黄中5种麻黄生物碱的含量

目的建立同时分离检测麻黄中麻黄碱(Ephedrine)、伪麻黄碱(Pseudoephedrine)、去甲麻黄碱(Norephedrine)、去甲伪麻黄碱(Norpseudoephedrine)和甲基麻黄碱(Methylephedrine)的含量测定方法。方法采用HPLC-UV法,色谱柱:苯基柱(Alltima Phenyl,250mm×4.6 mm,5μm);流动相:0.02 mol/L磷酸二氢钾溶液-乙腈(96∶4);流速:0.6 ml/min;检测波长:210 nm;柱温:25℃。结果 5种生物碱在13.5 min内即可达到完全分离,E在2.000 8～40.016 0μg/ml线性关系良好;PE在1.003 6～20.072 0μg/ml线性关系良好;NME在0.199 2～3.984 0μg/ml线性关系良好;NMP在0.200 0～4.00 0μg/ml线性关系良好;ME在0.200 4～4.008 0μg/ml线性关系良好。各生物碱的平均回收率均在92%～104%(RSD≤5.76%)。结论本方法可操作性强,简便快速,分离效果好,重现性好,可为麻黄及含麻黄的中西药制剂提供有效的检测手段。     

Drug use in sports: a veritable arena for pharmacists.

OBJECTIVE: To describe opportunities and obligations for pharmacists regarding doping control in sports, and to present information and resources on drugs and dietary supplements that are popular among athletes for performance enhancement. DATA SOURCES: Sports medicine journals and articles in English obtained from Medline (1966 through June 2003) using the search terms doping in sports, drugs in sports, dietary supplements, sports, amphetamine, stimulants, ephedrine, ephedra, caffeine, anabolic steroids, human growth hormone, erythropoietin, darbepoetin, androstenedione, dehydroepiandrosterone, and creatine. Information was also obtained from sports-governing agencies, such as the National Collegiate Athletic Association and the International Olympic Committee. STUDY SELECTION: Studies and reports that were credible and scientifically sound that evaluated the ergogenic effects of drugs and dietary supplements. DATA EXTRACTION: By the author. DATA SYNTHESIS: Pharmacists can participate in doping control programs in a number of ways. Pharmacists also have an obligation when counseling, advising, and treating athletes to help them avoid banned substances. Athletes use a host of drugs for their performance-enhancing effects, many of which are banned by major sports-governing bodies. Myriad dietary supplements are marketed to athletes, claiming to have ergogenic effects. Some of these popular supplements have proven performance-enhancing effects, while others do not. Adverse effects of these drugs and dietary supplements are discussed. CONCLUSION: A variety of drugs and dietary supplements have proven performance-enhancing effects in athletes. However, many of these substances have adverse effects and are banned by various sports-governing organizations. Pharmacists can play a key role in participating in doping control programs, and can prevent athletes from inadvertently consuming a banned substance.     

Determination of thyroid hormones in dietary supplements using liquid chromatography–tandem mass spectrometry

More than 27 million Americans have some kind of thyroid disease. Numerous dietary supplements claiming to support healthy thyroid function and healthy metabolism and balance or promote weight loss are available for purchase in retail stores and on the internet. In the literature, there have been reports of adverse events associated with the consumption of thyroid hormone-containing products. In this study, an LC-MS/MS method was developed and validated for the analysis of thyroxine (T4), 3,3′,5-triiodo-l -thyronine (T3), 3,3′,5′-triiodothyronine (rT3), 3,5-diiodothyronine (3,5-T2) and 3,3′-diiodothyronine (3,3′-T2) in dietary supplements. Sonication with methanol was used for the extraction of free hormones from nonglandular products. The tissue-bound hormones from glandular thyroid products were extracted using a modified enzymatic digestion, in which the matrix was first extracted by sonication with methanol and then by enzymatic digestion with proteases. Both extraction methods provided acceptable recovery values between 78% and 116%. Fifty-eight products making claims related to thyroid management were purchased over the internet from 2017–2018 and quantitatively analyzed for five hormones using the validated methods. Eleven out of 19 glandular products were found to contain quantifiable amounts of hormones. Maximum daily servings were also calculated for each product based on label information. The maximum amount of T4, T3, and rT3 per daily serving in the glandular products were up to 210, 32, and 7.6 μg/day, respectively. In the case of nonglandular products, which were labeled to contain plant extracts, vitamins, minerals, diiodo compounds, and so forth, the amounts of 3,5-T2 and 3,3′-T2 were up to 740 and 2700 μg/day, respectively.