Relationship of arsenic speciation and bioavailability in mine wastes for human health risk assessment

2016 ◽  
Vol 13 (4) ◽  
pp. 641 ◽  
Author(s):  
Violet Diacomanolis ◽  
Barry N. Noller ◽  
Raijeli Taga ◽  
Hugh H. Harris ◽  
Jade B. Aitken ◽  
...  

Environmental context X-ray absorption near-edge spectroscopy (XANES) was applied to give arsenic chemical forms directly in the solid phase of mine wastes from two mine sites, including fluvial dispersion. The arsenic speciation data explained the variation of in vitro bioaccessibility and in vivo bioavailability (rat uptake) data of the mine wastes. The As speciation from XANES fitting supported the hypothesis that when soil intake is adjusted for bioaccessibility, the potential health risk estimate to local residents is significantly lower. Abstract X-ray absorption near-edge spectroscopy (XANES) was used for arsenic speciation in mine processing and waste samples from two mines in northern Australia. XANES fitting of model compound spectra to samples was used, in combination with in vitro bioaccessibility data for the pure compounds, to predict bioaccessibility of each mine waste sample (Pearson’s correlation R2=0.756, n=51). The XANES fitting data for a smaller set of the samples (n=12) were compared with in vivo bioavailability and in vitro bioaccessibility data. The bioavailability of arsenic (As) in the mine wastes, which is dependent, at least in part, on its oxidation state, was found to be <14% (0.9–13.5%) for arsenite (AsIII) and <17% (3.5–16.4) for arsenate (AsV). Arsenic bioaccessibility in the mine wastes ranged from 8–36% in the stomach to 1–16% in the intestinal phase, indicating that a small portion of the total As concentration in the mine waste was available for absorption. A significant correlation showed that bioaccessibility can be used as a predictor of bioavailability. The XANES results support that bioavailability and bioaccessibility results were very similar and show a strong association with the presence of ferric arsenate and As sulfides. It can be concluded that, when soil intake is adjusted for bioaccessibility, the potential health risk estimate to local residents exposed to the mine waste was significantly lower than that estimated based on a 100% bioavailability often employed for the risk assessment.

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3480
Author(s):  
Adriana Maite Fernández-Fernández ◽  
Eduardo Dellacassa ◽  
Tiziana Nardin ◽  
Roberto Larcher ◽  
Adriana Gámbaro ◽  
...  

The present investigation aimed to provide novel information on the chemical composition and in vitro bioaccessibility of bioactive compounds from raw citrus pomaces (mandarin varieties Clemenule and Ortanique and orange varieties Navel and Valencia). The effects of the baking process on their bioaccessibility was also assessed. Samples of pomaces and biscuits containing them as an ingredient were digested, mimicking the human enzymatic oral gastrointestinal digestion process, and the composition of the digests were analyzed. UHPLC-MS/MS results of the citrus pomaces flavonoid composition showed nobiletin, hesperidin/neohesperidin, tangeretin, heptamethoxyflavone, tetramethylscutellarein, and naringin/narirutin. The analysis of the digests indicated the bioaccessibility of compounds possessing antioxidant [6.6–11.0 mg GAE/g digest, 65.5–97.1 µmol Trolox Equivalents (TE)/g digest, and 135.5–214.8 µmol TE/g digest for total phenol content (TPC), ABTS, and ORAC-FL methods, respectively; significant reduction (p < 0.05) in Reactive Oxygen Species (ROS) formation under tert-butyl hydroperoxide (1 mM)-induced conditions in IEC-6 and CCD-18Co cells when pre-treated with concentrations 5–25 µg/mL of the digests], anti-inflammatory [significant reduction (p < 0.05) in nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW264.7 macrophages], and antidiabetic (IC50 3.97–11.42 mg/mL and 58.04–105.68 mg/mL for α-glucosidase and α-amylase inhibition capacities) properties in the citrus pomaces under study. In addition, orange pomace biscuits with the nutrition claims “no-added sugars” and “source of fiber”, as well as those with good sensory quality (6.9–6.7, scale 1–9) and potential health promoting properties, were obtained. In conclusion, the results supported the feasibility of citrus pomace as a natural sustainable source of health-promoting compounds such as flavonoids. Unfractionated orange pomace may be employed as a functional food ingredient for reducing the risk of pathophysiological processes linked to oxidative stress, inflammation, and carbohydrate metabolism, such as diabetes, among others.


Chemosphere ◽  
2021 ◽  
pp. 130826
Author(s):  
Anabel González-Acedo ◽  
Enrique García-Recio ◽  
Rebeca Illescas-Montes ◽  
Javier Ramos-Torrecillas ◽  
Lucía Melguizo-Rodríguez ◽  
...  

Author(s):  
Alessio Facciolà ◽  
Giuseppa Visalli ◽  
Marianna Pruiti Ciarello ◽  
Angela Di Pietro

Plastics are ubiquitous persistent pollutants, forming the most representative material of the Anthropocene. In the environment, they undergo wear and tear (i.e., mechanical fragmentation, and slow photo and thermo-oxidative degradation) forming secondary microplastics (MPs). Further fragmentation of primary and secondary MPs results in nanoplastics (NPs). To assess potential health damage due to human exposure to airborne MPs and NPs, we summarize the evidence collected to date that, however, has almost completely focused on monitoring and the effects of airborne MPs. Only in vivo and in vitro studies have assessed the toxicity of NPs, and a standardized method for their analysis in environmental matrices is still missing. The main sources of indoor and outdoor exposure to these pollutants include synthetic textile fibers, rubber tires, upholstery and household furniture, and landfills. Although both MPs and NPs can reach the alveolar surface, the latter can pass into the bloodstream, overcoming the pulmonary epithelial barrier. Despite the low reactivity, the number of surface area atoms per unit mass is high in MPs and NPs, greatly enhancing the surface area for chemical reactions with bodily fluids and tissue in direct contact. This is proven in polyvinyl chloride (PVC) and flock workers, who are prone to persistent inflammatory stimulation, leading to pulmonary fibrosis or even carcinogenesis.


Author(s):  
Marco Raffaele ◽  
Khaled Greish ◽  
Luca Vanella ◽  
Giuseppe Carota ◽  
Fatemah Bahman ◽  
...  

Background: Pomegranate is a fruit rich in bioactive compounds such as punicalagins, gallic acid, and ellagic acid derivatives. It has been widely used since ancient times in traditional medicine for a wide variety of diseases. It has been reported that bioactive compounds, such as polyphenols, are able to induce the expression of cytoprotective enzymes, including HO-1. The contribution of HO-1 activity to the prevention of intestinal inflammation has been shown in different models of Inflammatory bowel diseases (IBD). Objective: Aim of the present research was to investigate the molecular mechanisms involved in the beneficial effects of a pomegranate extract (PE), rich in bioactive compounds in intestinal inflammation. Methods: Caco-2 cells exposed to LPS and DSS induced colitis were chosen as convenient experimental models of intestinal inflammation. Results: Results obtained in our experimental conditions, showed that PE in vitro was able to induce HO-1 and to reduce cellular damage and oxidative stress through increase of GSH levels. Moreover, PE was able to decrease the pro-inflammatory marker IL-8 levels and to activate TIGAR pathway. The results obtained in vivo, in agreement with the data obtained in vitro, highlighted the ability of PE to reduce intestinal inflammation, preserve the colon length and histological features and reduce IL-6 levels compared to the DSS treated group. Conclusion: PE, rich in bioactive compounds, could contribute, as supportive therapy, to enhance the effects of the conventional therapeutic strategies to the management of IBD.


2021 ◽  
Author(s):  
Yanhui Hao ◽  
Wenchao Li ◽  
Hui Wang ◽  
Jing Zhang ◽  
Haoyu Wang ◽  
...  

Abstract Background With the development of science and technology, microwaves are being widely used. More and more attention has been paid to the potential health hazards of microwave exposure. The regulation of miR-30a-5p (miR-30a) on autophagy is involved in the pathophysiological process of many diseases. Our previous study found that 30 mW/cm2 microwave radiation could reduce miR-30a expression and activate neuronal autophagy in rat hippocampus. However, the roles played by miR-30a in microwave-induced neuronal autophagy and related mechanisms remain largely unexplored. Results In the present study, we established neuronal damage models by exposing rat hippocampal neurons and rat adrenal pheochromocytoma (PC12) cell-derived neuron-like cells to 30 mW/cm2 microwave, which resulted in miR-30a downregulation and autophagy activation in vivo and in vitro. Bioinformatics analysis was conducted, and Beclin1, Prkaa2, Irs1, Pik3r2, Rras2, Ddit4, Gabarapl2 and autophagy-related gene 12 (Atg12) were identified as potential downstream target genes of miR-30a involved in regulating autophagy. Based on our previous findings that microwave radiation can cause a neuronal energy metabolism disorder, Prkaa2, encoding adenosine 5’-monophosphate-activated protein kinase α2 (AMPKα2, an important catalytic subunit of energy sensor AMPK), was selected for further analysis. Dual-luciferase reporter assay results showed that Prkaa2 is a downstream target gene of miR-30a. Microwave radiation increased the expression and phosphorylation (Thr172) of AMPKα both in vivo and in vitro. Moreover, the transduction of cells with miR-30a mimics suppressed AMPKα2 expression, inhibited AMPKα (Thr172) phosphorylation and reduced autophagy flux in neuron-like cells. Importantly, miR-30a mimics abolished microwave-activated autophagy and inhibited microwave-induced AMPKα (Thr172) phosphorylation. Conclusions AMPKα2 was a newly founded downstream gene of miR-30a involved in autophagy regulation, and miR-30a downregulation after microwave radiation could promote neuronal autophagy by increasing AMPKα2 expression and activating AMPK signaling.


Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 359
Author(s):  
Masuma Zawari ◽  
Bettina Poller ◽  
Greg Walker ◽  
Andree Pearson ◽  
Mark Hampton ◽  
...  

Broccoli sprout powder is a rich source of glucosinolates, which are hydrolysed to isothiocyanates in the presence of the enzyme myrosinase. We showed that in vitro incubation of broccoli sprout powder extract with isolated lymphocytes resulted in the upregulation of transcription factor Nrf2, however, there was no increase in Nrf2 protein levels in lymphocytes isolated 3 h following the ingestion of broccoli sprout powder by healthy volunteers. This highlights the general issue that potential health benefits of food-derived compounds can be compromised by limitations in bioavailability. In vitro experiments showed that the generation of isothiocyanates was reduced when the powder was first exposed to the low pH (1.2) of the stomach and then transferred to the higher pH (6.8) of the intestine. The loss of activity due to pre-exposure to the low stomach pH indicates that formulating the broccoli sprout powder in gastro-resistant formulations should increase that amount of isothiocyanate generated in the intestine for absorption. Gelatin capsules were hand-coated with either Eudragit® L100 or Eudragit® L100-55 and were assessed for their gastro-resistant properties using paracetamol as a model active for dissolution studies. Disintegration and dissolution studies showed that Eudragit® L100-55 coated capsules and DRcapsTM (Capsugel®) failed the United States Pharmacopeia (USP) requirements for gastro-resistant capsules, whereas the Eudragit® L100 coated capsules passed. Five healthy participants were administered 1 g of broccoli sprout powder, ingested either with water or encapsulated in uncoated or gastro-resistant capsules. Urinary excretion of isothiocyanate metabolites over the 24 h period post ingestion was assessed by HPLC. Broccoli sprout powder and uncoated gelatin-encapsulated powder showed comparable excretion of isothiocyanate metabolites (18.4 ± 2.3 and 23.9 ± 2.7 µmol, respectively). The enteric coated capsules provided a significantly longer Tmax than the uncoated gelatin capsules (15.4 ± 2.3 versus 3.7 ± 0.7 h, respectively), indicating protection from disintegration in the stomach, however, the excretion of isothiocyanate metabolites was significantly decreased compared with uncoated capsules (i.e., 8.5 ± 1.1 µmol). The lower in vivo formation or absorption of isothiocyanates observed for the gastro-resistant capsules may be due to participant variation in intestinal pH or transit times, resulting in inappropriate pH conditions or insufficient time for the complete disintegration and dissolution of the capsules.


2019 ◽  
Vol 25 (16) ◽  
pp. 1817-1827 ◽  
Author(s):  
Vesna Vučić ◽  
Milkica Grabež ◽  
Armen Trchounian ◽  
Aleksandra Arsić

Background:: Pomegranate (Punica granatum L.) fruits are widely consumed and used as preventive and therapeutic agents since ancient times. Pomegranate is a rich source of a variety of phytochemicals, which are responsible for its strong antioxidative and anti-inflammatory potential. Objective:: The aim of this review is to provide an up-to-date overview of the current knowledge of chemical structure and potential health benefits of pomegranate. Method: : A comprehensive search of available literature. Results:: The review of the literature confirms that juice and extracts obtained from different parts of this plant, including fruit peel, seeds, and leaves exert health benefits in both in vitro and in vivo studies. The antidiabetic, antihypertensive, antimicrobial and anti-tumour effects of pomegranate fruit are of particular scientific and clinical interest. Conclusion:: Further investigations are required to clarify the mechanism of action of the bioactive ingredients and to reveal full potential of pomegranate as both preventive and therapeutic agent.


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