Clinical and analytical toxicology of dietary supplements: a case study and a review of the literature

Optimized Green Nanoemulsions to Remove Pharmaceutical Enoxacin from Contaminated Bulk Aqueous Solution

We attempted to develop green nanoemulsions (ENE1-ENE5) using capryol-C90 (C90), lecithin, Tween 80, and N-methyl-2-pyrrolidone (NMP). HSPiP software and experimentally obtained data were used to explore excipients. ENE1-ENE5 nanoemulsions were prepared and evaluated for in vitro characterization parameters. An HSPiP based QSAR (quantitative structure-activity relationship) module established a predictive correlation between the Hansen solubility parameter (HSP) and thermodynamic parameters. A thermodynamic stability study was conducted under stress conditions of temperature (from -21 to 45 °C) and centrifugation. ENE1-ENE5 were investigated for the influence of size, viscosity, composition, and exposure time on emulsification (5-15 min) on %RE (percent removal efficiency). Eventually, the treated water was evaluated for the absence of the drug using electron microscopy and optical emission spectroscopy. HSPiP program predicted excipients and established the relationship between enoxacin (ENO) and excipients in the QSAR module. The stable green nanoemulsions ENE-ENE5 possessed the globular size range of 61-189 nm, polydispersity index (PDI) of 0.1-0.53, viscosity of 87-237 cP, and ζ potential from -22.1 to -30.8 mV. The values of %RE depended upon the composition, globular size, viscosity, and exposure time. ENE5 showed %RE value as 99.5 ± 9.2% at 15 min of exposure time, which may be due to the available maximized adsorption surface. SEM-EDX (scanning electron microscopy-X-ray dispersive energy mode) and inductively coupled plasma-optical emission spectroscopy (ICP-OES) negated the presence of ENO in the treated water. These variables were critical factors for efficient removal of ENO during water treatment process design. Thus, the optimized nanoemulsion can be a promising approach to treat water contaminated with ENO (a potential pharmaceutical antibiotics).

Dietary Ingredients as an Alternative Approach for Mitigating Chronic Musculoskeletal Pain: Evidence-Based Recommendations for Practice and Research in the Military

OBJECTIVE

Approximately 55-76% of Service members use dietary supplements for various reasons, including pain and related outcomes. This work evaluates current research on dietary ingredients for chronic musculoskeletal pain to inform decisions for practice and self-care, specifically for Special Operations Forces personnel.

METHODS

A steering committee convened to develop research questions and factors required for decision-making. Key databases were searched through August 2016. Eligible systematic reviews and randomized controlled trials were assessed for methodological quality. Meta-analysis was applied where feasible. GRADE was used to determine confidence in the effect estimates. The committee made evidence-informed judgments and recommendations for practice and self-care use.

RESULTS

Nineteen eligible dietary ingredients were assessed for quality, efficacy, and safety. Avocado soybean unsaponifiables, capsaicin, curcuma, ginger (as a food source), glucosamine, melatonin, polyunsaturated fatty acids, and vitamin D were conditionally recommended as their benefits outweighed risks, but there was still some uncertainty about the trade-offs. No recommendations were made for boswellia, ginger (as a dietary supplement), rose hip, or s-adenosyl-L-methionine. Recommendations were made against the use of collagen, creatine, devil's claw, l-carnitine, methylsulfonylmethane, pycnogenol, willow bark extract, and vitamin E. Research priorities were developed to address gaps precluding stronger recommendations.

CONCLUSIONS

Currently the scientific evidence is insufficiently robust to establish definitive clinical practice guidelines, but processes could be established to track the impact of these ingredients. Until then, providers have the evidence needed to make informed decisions about the safe use of these dietary ingredients, and future research can address existing gaps.

A Systematic Review of the Effect of Dietary Supplements on Cognitive Performance in Healthy Young Adults and Military Personnel

Intake of dietary supplements has increased, despite evidence that some of these have adverse side effects and uncertainty about their effectiveness. This systematic review examined the evidence for the cognitive benefits of a wide range of dietary supplements in healthy young adult samples; the aim was to identify if any might be useful for optimising cognitive performance during deployment in military personnel. Searches were conducted in 9 databases and 13 grey literature repositories for relevant studies published between January 2000 and June 2017. Eligible studies recruited healthy young adults (18-35 years), administered a legal dietary supplement, included a comparison control group, and assessed cognitive outcome(s). Thirty-seven of 394 identified studies met inclusion criteria and were included for synthesis. Most research was deemed of low quality (72.97%; SIGN50 guidelines), highlighting the need for sound empirical research in this area. Nonetheless, we suggest that tyrosine or caffeine could be used in healthy young adults in a military context to enhance cognitive performance when personnel are sleep-deprived. Caffeine also has the potential benefit of improving vigilance and attention during sustained operations offering little opportunity for sleep. Inconsistent findings and methodological limitations preclude firm recommendations about the use of other specific dietary supplements.

Simultaneous separation of arsenic and cadmium from interfering salt matrix of multivitamin/mineral supplements by sequential coprecipitation and determination by inductively coupled plasma mass spectrometry

Multivitamin/mineral (MVM) supplements possess highly saline matrix which, unless eliminated, precludes accurate determination of trace amounts of toxic metal impurities by inductively coupled plasma mass spectrometry (ICP-MS). Multi-step separations (up to four-steps) are described in literature; often for single element determinations due to difficulties in removing the matrix components. In this study, we developed a three-step sequential coprecipitation procedure for simultaneous separation of As and Cd impurities from MVM supplements for determination by ICP-MS. The procedure provided effective elimination of salt matrix, including Ca, Mg and KCl along with the interfering molybdenum (Mo) and tin (Sn) from MVM solutions. KCl, Mo and Sn were removed by two-step Mg(OH)₂ coprecipitation to about 34 µg mL^-1 K (ca. 31 µg mL^-1 Cl) and 0.4 µg mL^-1 Mo. Levels of Sn and Na were not significant. A third coprecipitation of the resulting MVM solution with HF + NH₄OH mixture precipitated virtually all Ca and Mg to as low as 1 and 10 µg mL^-1, respectively. The recoveries for As and Cd in the spiked MVM solutions were about 96% and 95%, respectively. The accuracy of the method was validated with analysis of multivitamin/multielement tablets certified reference material (SRM 3280). Experimental values were 112 ± 37 ng g^-1 for ⁷⁵As, and 76 ± 5, 79 ± 5, and 78 ± 7 ng g^-1 for ¹¹⁰Cd, ¹¹¹Cd and ¹¹⁴Cd isotopes, respectively, that were not significantly different from the certified values of As (132 ± 44 ng g^-1) and Cd (80.2 ± 0.9 ng g^-1) at 95% confidence level. Several commercially available MVM supplements were analyzed with the procedure. Mean As levels measured in the tablets varied between 24 and 128 ng g^-1 and that for Cd were between 28 and 125 ng g^-1 indicating total amount of As or Cd ingested per serving size were below the safe daily exposure limits. In addition, the results obtained for As and Cd with the procedure were lower in comparison to the values reported in literature indicating that ICP-MS analysis of complex MVM supplements could be prone to higher risks of inaccuracy without removal of interfering matrix.

Sequential coprecipitation and matrix removal for determination of cadmium impurities from multivitamin supplements by inductively coupled plasma mass spectrometry and method validation by isotope dilution analysis of SRM 3280 multivitamin/multielement tablets

In this paper, we examined three different sequential coprecipitation schemes based on Mg(OH)₂ and CaF₂ precipitation using triethylamine (TEA) and hydrofluoric acid (HF), respectively, for determination of cadmium (Cd) impurities from multivitamin/mineral (MVM) supplements by isotope dilution (ID) inductively coupled plasma mass spectrometry (ICP-MS). The schemes involved three-step coprecipitation with either TEA alone or in combination with HF and are designated as Scheme 1 (TEA-TEA-TEA), Scheme 2 (TEA-HF-TEA) and Scheme 3 (HF-TEA-TEA) according to the addition sequence of each reagent. Experiments were carried out with MVM solutions spiked with 60 μg L^-1 Cd from a multielement standard solution. All schemes provided quantitative separation of Cd from MVM matrix. Scheme 1 was the least effective in removal of interfering concomitant elements, molybdenum (Mo) and tin (Sn). Scheme 2 performed better for Sn, but failed in eliminating Mo. Scheme 3 was the most effective in eliminating both Mo and Sn. Mo levels in test MVM solutions reduced from 4.3 μg mL^-1 to as low as 0.014 μg mL^-1 while that for Sn decreased from 0.5 μg mL^-1 to 0.018 μg mL^-1 allowing interference-free determination of Cd to be achieved. Salt-matrix due to Mg, Ca, P and K along with the essential elements (Mn, Fe, Cu and Zn) levels was also reduced significantly. Reagent blanks from HF and TEA were insignificant (0.008 μg L^-1) allowing a limit of detection of 0.004 μg L^-1 or 0.26 ng g^-1 Cd to be achieved (3σ, n = 6). The performance of the coprecipitation method (Scheme 3) was validated by determination of Cd in multivitamin/multielement tablets certified reference material (SRM 3280) by ID-ICP-MS. Experimental results (ng g^-1) and recoveries were 78.8 ± 4.7 (98.5%), 77.9 ± 5.2 (97.4%) and 76.5 ± 4.8 (95.6%) for ¹¹⁰Cd, ¹¹¹Cd and ¹¹⁴Cd isotopes, respectively. Several commercial MVM supplements were analyzed using the method. Mean Cd concentration ranged from 21.4 ng g^-1 to 93.3 ng g^-1. These values are much lower than those reported to date for various MVM supplements by ICP-MS determinations without chemical separation.

Scientific and Regulatory Perspectives in Herbal and Dietary Supplement Associated Hepatotoxicity in the United States

In the United States (US), the risk of hepatotoxicity linked to the widespread use of certain herbal products has gained increased attention among regulatory scientists. Based on current US law, all dietary supplements sold domestically, including botanical supplements, are regulated by the Food and Drug Administration (FDA) as a special category of foods. Under this designation, regulatory scientists do not routinely evaluate the efficacy of these products prior to their marketing, despite the content variability and phytochemical complexity that often characterizes them. Nonetheless, there has been notable progress in the development of advanced scientific methods to qualitatively and quantitatively measure ingredients and screen for contaminants and adulterants in botanical products when hepatotoxicity is recognized.

An unusual case of peripheral neuropathy possibly due to arsenic toxicity secondary to excessive intake of dietary supplements

A 74-year-old woman presented to the neurology clinic with worsening of her longstanding peripheral neuropathy of unknown cause. There was below knee loss of spinothalamic sensation, reduced joint position of toes, absent below hips vibration sensation and absent ankle jerks. Neurophysiology studies showed further progression of her axonal sensory neuropathy. Urine and blood analysis previously carried out in Australia suggested elevated levels of arsenic. After abstinence from seafood, a random urine sample was collected and this confirmed the elevation in urine arsenic (622.1 nmol/L, reference range <534 nmol/L). The household water was found to be uncontaminated and the patient had no occupational or environmental exposure to arsenic. On questioning the patient admitted to taking fish oils, omega-3 oils and glucosamine sulphate dietary supplements in excess of the recommended dosage. These supplements were identified as possible sources of arsenic and the patient was asked to stop all supplements. One month later the urine arsenic had reduced to 57.5 nmol/L. There was an improvement in patient wellbeing, she no longer required Gabapentin for pain relief and the neurophysiology studies also showed improvement. Clinicians should consider heavy metal toxicity as a cause of peripheral neuropathy of unknown cause. A detailed patient history including all dietary supplements is essential to help elucidate the source of heavy metal toxicity.

Exposure to multiple metals from groundwater-a global crisis: geology, climate change, health effects, testing, and mitigation

This paper presents an overview of the global extent of naturally occurring toxic metals in groundwater. Adverse health effects attributed to the toxic metals most commonly found in groundwater are reviewed, as well as chemical, biochemical, and physiological interactions between these metals. Synergistic and antagonistic effects that have been reported between the toxic metals found in groundwater and the dietary trace elements are highlighted, and common behavioural, cultural, and dietary practices that are likely to significantly modify health risks due to use of metal-contaminated groundwater are reviewed. Methods for analytical testing of samples containing multiple metals are discussed, with special attention to analytical interferences between metals and reagents. An overview is presented of approaches to providing safe water when groundwater contains multiple metallic toxins.

Analytical methods for heavy metals in herbal medicines

INTRODUCTION

It is estimated that about 70-80% of the world's population relies on non-conventional medicine, mainly of herbal origin. However, owing to the nature and sources of herbal medicines, they are sometimes contaminated with toxic heavy metals such as lead, arsenic, mercury and cadmium, which impose serious health risks to consumers. It is critical to analyse source materials for heavy metals in order to ensure that their concentrations meet the related standards or regulations limiting their concentrations in herbal medicines. In this review, different analytical methods for analysis of heavy metals in herbal medicines are discussed.

OBJECTIVE

To provide a comprehensive review of the current state of the art in analytical methods used to detect heavy metals in herbal medicines.

METHODOLOGY

We systematically searched and reviewed the research articles regarding analytical methods for heavy metals in herbal medicine from various databases, such as Medline/PubMed, ScienceDirect, SciFinder, Google Scholar, EBSCO, Gale InfoTrac, Ingenta, Ovid, ProQuest and ISI Web of Knowledge.

RESULTS

In this review, we discuss in detail several commonly used and sensitive analytical techniques, including atomic absorption spectrometry, inductively coupled plasma optical emission spectrometry or mass spectrometry, X-ray fluorescence spectrometry, high-performance liquid chromatography, differential pulse polarography, neutron activation analysis and anodic stripping voltammetry. We also provide some application examples of these analytical techniques for heavy metals in herbal medicines.

Commentary: Iron deficiency and hair loss: problems with measurement of iron

Iron is involved in many critical physiologic processes within the hair follicle, suggesting that iron deficiency could disrupt hair synthesis. However, studies of iron as a cause of hair loss have produced conflicting results. Some of the discrepancies may relate to limitations of assays for iron deficiency. This commentary discusses the sensitivity and specificity of available tests for iron deficiency and presents practical guidelines for testing and supplementation.