Dose-response relationship between arsenic exposure and the serum enzymes for liver function tests in the individuals exposed to arsenic: a cross sectional study in Bangladesh

<p>Abstract</p> <p>Background</p> <p>Chronic arsenic exposure has been shown to cause liver damage. However, serum hepatic enzyme activity as recognized on liver function tests (LFTs) showing a dose-response relationship with arsenic exposure has not yet been clearly documented. The aim of our study was to investigate the dose-response relationship between arsenic exposure and major serum enzyme marker activity associated with LFTs in the population living in arsenic-endemic areas in Bangladesh.</p> <p>Methods</p> <p>A total of 200 residents living in arsenic-endemic areas in Bangladesh were selected as study subjects. Arsenic concentrations in the drinking water, hair and nails were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The study subjects were stratified into quartile groups as follows, based on concentrations of arsenic in the drinking water, as well as in subjects' hair and nails: lowest, low, medium and high. The serum hepatic enzyme activities of alkaline phosphatase (ALP), aspartate transaminase (AST) and alanine transaminase (ALT) were then assayed.</p> <p>Results</p> <p>Arsenic concentrations in the subjects' hair and nails were positively correlated with arsenic levels in the drinking water. As regards the exposure-response relationship with arsenic in the drinking water, the respective activities of ALP, AST and ALT were found to be significantly increased in the high-exposure groups compared to the lowest-exposure groups before and after adjustments were made for different covariates. With internal exposure markers (arsenic in hair and nails), the ALP, AST and ALT activity profiles assumed a similar shape of dose-response relationship, with very few differences seen in the higher groups compared to the lowest group, most likely due to the temporalities of exposure metrics.</p> <p>Conclusions</p> <p>The present study demonstrated that arsenic concentrations in the drinking water were strongly correlated with arsenic concentrations in the subjects' hair and nails. Further, this study revealed a novel exposure- and dose- response relationship between arsenic exposure metrics and serum hepatic enzyme activity. Elevated serum hepatic enzyme activities in the higher exposure gradients provided new insights into arsenic-induced liver toxicity that might be helpful for the early prognosis of arsenic-induced liver diseases.</p

Analytical methods applied to diverse types of Brazilian propolis

Propolis is a bee product, composed mainly of plant resins and beeswax, therefore its chemical composition varies due to the geographic and plant origins of these resins, as well as the species of bee. Brazil is an important supplier of propolis on the world market and, although green colored propolis from the southeast is the most known and studied, several other types of propolis from Apis mellifera and native stingless bees (also called cerumen) can be found. Propolis is usually consumed as an extract, so the type of solvent and extractive procedures employed further affect its composition. Methods used for the extraction; analysis the percentage of resins, wax and insoluble material in crude propolis; determination of phenolic, flavonoid, amino acid and heavy metal contents are reviewed herein. Different chromatographic methods applied to the separation, identification and quantification of Brazilian propolis components and their relative strengths are discussed; as well as direct insertion mass spectrometry fingerprinting

Association between arsenic exposure and soluble thrombomodulin: A cross sectional study in Bangladesh

<div><p>Chronic exposure to arsenic is associated with increased morbidity and mortality from cardiovascular disease (CVD); however, plausible biomarker for early prediction and the underlying mechanism of arsenic-related CVD have not yet been clearly understood. Endothelial dysfunction plays a central role in the development of CVD. We hypothesized that endothelial damage or dysfunction is an important aspect and may be an early event of arsenic-related CVD. Soluble thrombomodulin (sTM) in serum is thought to be a specific and stable marker for endothelial damage or dysfunction. This study was designed to evaluate the association between chronic exposure to arsenic and sTM among human subjects in arsenic-endemic and non-endemic rural areas in Bangladesh. A total of 321 study subjects (217 from arsenic-endemic areas and 104 from a non-endemic area) were recruited. Subjects’ arsenic exposure levels (i.e., drinking water, hair and nail arsenic concentrations) were measured by Inductively Coupled Plasma Mass Spectroscopy. The subjects’ serum sTM levels were quantified by immunoassay kit. The average sTM levels of the subjects in arsenic-endemic and non-endemic areas were 4.58 ± 2.20 and 2.84 ± 1.29 (ng mL^-1) respectively, and the difference was significant (<i>p</i><0.001). Arsenic exposure levels showed a significant (water arsenic: <i>r</i>_<i>s</i> = 0.339, <i>p</i><0.001, hair arsenic: <i>r</i>_<i>s</i> = 0.352, <i>p</i><0.001 and nail arsenic: <i>r</i>_<i>s</i> = 0.308, <i>p</i><0.001) positive associations with sTM levels. Soluble TM levels were higher in the higher exposure gradients if we stratified the subjects into tertile groups (low, medium and high) based on the arsenic concentrations of the subjects’ drinking water, hair and nails. Finally, increased levels of sTM were negatively correlated with high density lipoprotein cholesterol (HDL-C), and positively correlated with intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Results of this study show that chronic exposure to arsenic has mild to moderate association with sTM levels.</p></div

Dose-response relationship between arsenic exposure and sTM levels.

<p>Data were presented as mean ± SE. Dose-response relationship between arsenic exposure and sTM levels in one-way ANOVA was examined by F-test, followed by Bonferroni multiple comparison test between each group of exposure level. Arsenic concentrations in water: low (0.03–5.22 μg L^-1; n = 101), medium (5.30–127.00 μg L^-1; n = 110), and high (129.00–546.00 μg L^-1; n = 110). Arsenic concentration in hair: low (0.02–0.62 μg g^-1; n = 106), medium (0.64–3.36 μg g^-1; n = 106), and high (3.40–37.24 μg g^-1; n = 109). Arsenic concentrations in nail: low (0.15–2.12 μg g^-1; n = 104), medium (2.14–7.45 μg g^-1; n = 109), and high (7.45–37.42 μg g^-1; n = 108). ^a and ^b, Significant from low and medium groups, respectively. ***<i>p</i> < 0.001; **<i>p</i> < 0.01; *<i>p</i> < 0.05.</p

Associations of arsenic exposure and other variables with sTM levels through multiple linear regression analyses.

<p>Associations of arsenic exposure and other variables with sTM levels through multiple linear regression analyses.</p