Dietary supplements may contain heavy metals with the property of bioaccumulation in humans. The aim of this research was to validate and apply two analytical methods to determine Pb, As, Cr, and Hg in dietary supplements by Total Reflection X-ray Fluorescence Spectroscopy (TXRF). Methods validation was conducted through a multivariate analysis using a central composite design (CCD) and a desirability function. Critical values for each study variable were established. The TXRF_DS_1 method was proposed for Pb, As, and Cr determinations, while the TXRF_DS_2 was established for Hg analysis. The digestion method with an acid mixture (HNO₃+HCl+H₂O₂) was used to break down the organic material of dietary supplements. A solution of 10μgL⁻¹ Ga was used as an internal standard. Excellent analytical performance was obtained as LODs of 0.59, 0.41, 0.57, and 0.75μgL⁻¹ and LOQs of 1.95, 1.35, 1.90, and 2.50μgL ⁻¹ for Pb, As, Cr, and Hg, respectively. Calibration curves showed a good linearity for all elements (R²>0.999). Excellent accuracy and precision in measurements ( RSD) was achieved. The real and spiked samples analysis demonstrated the applicability of the TXRF technique (percentage recovery 91108). Besides, two samples were analyzed in a comparison study between the TXRF_DS_1 method and the ICP-OES method. The results obtained showed good agreement between both techniques. The TXRF technique allows the analysis of toxic heavy metals in dietary supplements, which are marketed in a wide variety of presentations.

Lead and chromium contamination represents one of the most serious problems in the aquatic environments. The aim of this work was to develop and validate an accurate, sensitivity, and rapid method for the simultaneous determination of Pb and Cr at trace levels in tissues and fat of marine organisms such as turtle (Chelonia mydas), shark (Rhizoprionodon terraenovae), and dolphin (Tursiops truncatus), utilizing the total reflection X-Ray fluorescence (TXRF) spectroscopy. Working solutions were prepared in 10 mL of a solution 0.005 mol·L⁻¹ EDTA and 1 mol·L⁻¹ HNO₃. In order to correct possible instrument drifts, 20 μg·L⁻¹ of gallium was used as internal standard (IS). The results showed that TXRF method was linear over the concentration ranges of 5.242–100 μg·L⁻¹ for Pb and 2.363–100 μg·L⁻¹ for Cr. Limits of detection (LOD) achieved were 1.573 and 0.709 μg·L⁻¹ for Pb and Cr, respectively, while limits of quantification achieved were 5.242 μg·L⁻¹ for Pb and 2.363 μg·L⁻¹ for Cr. The validated method was accurate and precise enough for determination of these heavy metals in samples of marine organisms as indicated by acceptable values of recovery between 90–101%. In addition, a certified reference material (BCR-279, sea lettuce) and a Centrum tablet were satisfactory analyzed, and the T-test for comparison of means revealed that there were no significant differences at the 95% confidence level between the values obtained with the proposed TXRF method and the certificated values. The repeatability of the method, expressed as relative standard deviation (RSD), was 5.1% and 4%, for Pb and Cr, respectively. In addition, other features of the developed method were a low sample volume of 10 μL, and the sample frequency achieved was 20 h⁻¹.

The objective of this work was to analyze the bisphenols and phthalates (PAEs) migration from meat packages (of sausages, Winnies, and ham found in Mexican markets) to a water simulant. The determination of these compounds was realized by high performance liquid chromatography (HPLC) and diode array detection (DAD) at a wavelength of 254nm. The mobile phase utilized was a mixture of acetonitrile:H₂O (70:30). Elution was performed isocratically at a temperature of 25°C and at a flow rate of 1mL min⁻¹. The LOQs obtained for BPA, DEP, BADGE, DBP, BisDMA, DHP, DOP, and PA in µg mL⁻¹ were 0.53, 2.09, 0.85, 1.45, 5.81, 1.03, 3.12, and 29.6, respectively. Calibration curves exhibited an adequate determination coefficient for all compounds (R² >0.999). Excellent accuracy and precision in measurements ( RSD) were achieved. The recovery study showed good applicability of the method (percentage recovery 80 to 106). The BPA, BADGE, DBP, and DOP concentrations found in samples exceeded the simulant migration limits (SMLs) established by the European Union. The contribution of the current investigation was to provide information related to the presence of bisphenols and PAEs in the package of meat products, highlighting the health risks associated with their exposure.

Ambient air pollution is a major global public health concern; little evidence exists about the effects of short-term exposure to ozone on components of metabolic syndrome in young obese adolescents. The inhalation of air pollutants, such as ozone, can participate in the development of oxidative stress, systemic inflammation, insulin resistance, endothelium dysfunction, and epigenetic modification. Metabolic alterations in blood in components of metabolic syndrome (MS) and short-term ambient air ozone exposure were determined and evaluated longitudinally in a cohort of 372 adolescents aged between 9 to 19 years old. We used longitudinal mixed-effects models to evaluate the association between ozone exposure and the risk of components of metabolic syndrome and its parameters separately, adjusted using important variables. We observed statistically significant associations between exposure to ozone in tertiles in different lag days and the parameters associated with MS, especially for triglycerides (20.20 mg/dL, 95% CI: 9.5, 30.9), HDL cholesterol (−2.56 mg/dL (95% CI: −5.06, −0.05), and systolic blood pressure (1.10 mmHg, 95% CI: 0.08, 2.2). This study supports the hypothesis that short-term ambient air exposure to ozone may increase the risk of some components of MS such as triglycerides, cholesterol, and blood pressure in the obese adolescent population.

This study used Total X-ray Fluorescence Spectrometry (TXRF) to analyze toxic heavy metals, specifically lead (Pb), arsenic (As), and chromium (Cr), in 45 dietary supplement samples consumed by the Mexican population. A health risk assessment was performed using the Target Hazard Quotient (THQ), Hazard Index (HI), and Cumulative Cancer Risk (CCR). The mean concentrations of Pb, Cr, and As were found to be 1.99 ± 0.13, 26.88 ± 0.23, and 2.39 ± 0.11 mg/kg, respectively. For Pb, 80% of dietary supplements showed low EDIs compared to the reference value of 1.08 × 10⁻⁴ mg/Kg bw/day set by the FDA. For Cr, 100% of the analyzed products had EDIs below the limit of 0.3 mg/Kg bw/day established by EFSA. Additionally, some dietary supplements of animal origin had EDIs exceeding the reference value of 6 × 10⁻⁵ mg/kg bw/day set by the Integrated Risk System and EFSA for daily arsenic intake. When evaluating the variables THQ_Pb, THQ_Cr, and THQ_As using mean comparison tests to determine whether they exceeded the reference value of 1, we found that, in general, the available statistical evidence is insufficient (p > 0.05) to conclusively state that the dietary supplements under review surpass this reference parameter. Regarding HI values, the Animal and Vegetable category showed higher values than 1. All dietary supplements had CCR values in ranges greater than 1 × 10⁻⁴, indicating a probability of an individual developing cancer over their lifetime due to metal exposure. Effectively communicating these risks to consumers is crucial for promoting informed choices and improving public health.

Resumen Objetivo: Conocer la influencia de los aminoácidos provenientes de la dieta en la expresión de genes, mediante una revisión bibliográfica. Materiales y método: Revisión bibliográfica de las principales bases de datos: Scielo, PubMed, MedlinePlus, Ebsco, ELSEVIER, US National Library of Medicine National Institutes of Health (NCBI), Springer y Journal Citation Report (JCR). Además, se consultaron libros relacionados con la nutrición y expresión génica. Resultados: La búsqueda arrojó 108 referencias, de las cuales, 34 artículos cumplieron por lo menos con tres de los criterios de selección: i) factor de impacto (0.500-5.000), b) año de publicación (2000-2018), iii) número de citas (>5) y iv) si fueron publicados en revistas indizadas. Conclusiones: existen genes que se regulan en varias etapas, incluyendo transcripción, procesado post-transcripcional, exportación nuclear y traducción de los mRNA maduros. Los aminoácidos pueden tener influencia en dichos procesos, a través de la activación de factores de transcripción. En la traducción, los AA pueden regular la síntesis de proteínas mediante cambios en eIF2B, fosforilación de 4E-BP1 y de proteínas S6. Además, los AA tienen efecto en la regulación de la expresión de Factores de crecimiento, como el factor de crecimiento análogo a la insulina IGF-I, en el ser humano.