Freshly erupted volcanic ash contains a range of soluble elements, some of which can generate harmful effects in living cells and are considered potentially toxic elements (PTEs). This work ...investigates the leaching dynamics of ash-associated PTEs in order to optimize a method for volcanic ash respiratory hazard assessment. Using three pristine (unaffected by precipitation) ash samples, we quantify the release of PTEs (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, Zn) and major cations typical of ash leachates (Mg, Na, Ca, K) in multiple simulated lung fluid (SLF) preparations and under varying experimental parameters (contact time and solid to liquid ratio). Data are compared to a standard water leach (WL) to ascertain whether the WL can be used as a simple proxy for SLF leaching. The main findings are: PTE concentrations reach steady-state dissolution by 24 h, and a relatively short contact time (10 min) approximates maximum dissolution; PTE dissolution is comparatively stable at low solid to liquid ratios (1:100 to 1:1000); inclusion of commonly used macromolecules has element-specific effects, and addition of a lung surfactant has little impact on extraction efficiency. These observations indicate that a WL can be used to approximate lung bioaccessible PTEs in an eruption response situation. This is a useful step towards standardizing in vitro methods to determine the soluble-element hazard from inhaled ash.
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•Investigation of a lung fluid leachate method to assess inhalation hazards of ash.•Element release in leachates is both method-parameter and sample dependent.•Inclusion of lung surfactant is not necessary when assessing ash leachates.•Optimal method parameters are extraction up to 24 h at 1:100 ratio.•Water leach can be used as a conservative estimate of lung bioaccessible elements.
Generally, human oral exposure assessments of contaminants have not considered the absorption factor in the human gastrointestinal tract, thus overestimating human exposure and associated health ...risk. Currently, more researchers are adding the absorption factor into human exposure assessment, and bioaccessibility measured by in-vitro methods is generally replacing bioavailability for estimation because of the cheap and rapid determination. However, no single unified in-vitro method is used for bioaccessibility measurement of organic pollutants, although several methods have been developed for these pollutants and have shown good in vitro-in vivo correlation between bioaccessibility and bioavailability. The present review has focused on the development of in-vitro methods, validation of these methods through in-vivo assays, determination of factors influencing bioaccessibility, application of bioaccessibility in human exposure assessment, and the challenges faced. Overall, most in-vitro methods were validated using bioavailability, and better in vitro-in vivo correlations were obtained when absorption sinks were added to the digestion solution to mimic dynamic absorption of organic chemicals by small intestine. Incorporating bioaccessibility into the estimation of human exposure by oral ingestion significantly decreases the estimated exposure dose. However, more investigations on bioaccessibility of hydrophobic organic compounds are urgently needed because many challenges for in-vitro methods remain to be overcome.
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•Progress in in-vitro test for bioaccessibility of organic pollutants is reviewed.•Factors influencing on the bioaccessibility of organic pollutants were focused.•Validation of in-vitro methods by in-vivo assays was surveyed.•Application of bioaccessibility in the human exposure assessment was highlighted.•Faced challenges of validation and application were discussed and anticipated.
Good Cell Culture Practices (GCCP) is of high relevance to in vitro toxicology. The European Society of Toxicology In Vitro (ESTIV), the Center for Alternatives for Animal Testing (CAAT) and the In ...Vitro Toxicology Industrial Platform (IVTIP) joined forces to address by means of an ESTIV 2016 pre-congress session the different aspects and applications of GCCP. The covered aspects comprised the current status of the OECD guidance document on Good In Vitro Method Practices, the importance of quality assurance for new technological advances in in vitro toxicology including stem cells, and the optimized implementation of Good Manufacturing Practices and Good Laboratory Practices for regulatory testing purposes. General discussions raised the duality related to the difficulties in implementing GCCP in an academic innovative research framework on one hand, and on the other hand, the need for such GCCP principles in order to ensure reproducibility and robustness of in vitro test methods for toxicity testing. Indeed, if good cell culture principles are critical to take into consideration for all uses of in vitro test methods for toxicity testing, the level of application of such principles may depend on the stage of development of the test method as well as on the applications of the test methods, i.e., academic innovative research vs. regulatory standardized test method.
•ESTIV 2016 pre-congress session on Good Cell Culture Practices.•Good In Vitro Method Practices.•Quality assurance for new technological advances in in vitro toxicology.•Implementation of a stem cell based assay following GCCP principles.•Optimized GLPs/GMPs for conducting in vitro studies for regulatory use.
Many in vitro methods can be used to classify eye irritation or damage caused by exposure to a substance. In this study, a recently described method called the Cytotoxicity Assay to Assess Eye ...Irritation (CEI) was compared with other selected in vitro methods adopted in the OECD guidelines. Furthermore, the influence of combining more than one in vitro method was investigated. Basic performance indices were considered and a risk assessment based on the number of correct and incorrect results (overestimated or underestimated) was performed. The CEI results were similar to those of other in vitro tests, however, the CEI can also directly classify substances irritating to the eyes. When the CEI preceded an eye irritation test based reconstructed human corneal-like epithelium, there were fewer underestimates compared with other method combinations. This combination can better protect human health and provides results comparable to those obtained in animal tests.
•A cytotoxicity Assay to Assess Eye Irritation was compared with in vitro tests.•The potential risk of eye irritation caused by chemicals was assessed.•The proposed classification approach combines two in vitro methods.•The results were validated using with animal test data.
The use of cell and tissue‐based methods in basic, applied and regulatory science has been increasing exponentially. Animal‐derived components, including serum, coating materials, growth factors and ...antibodies are routinely used in cell/tissue cultures and in general laboratory practices. In addition to ethical issues, the use and production of animal‐derived materials and reagents raises many scientific concerns, generally associated with presence of undefined components and batch‐to‐batch variability, which may compromise experimental reproducibility. On the other hand, non‐animal materials and reagents, such as human cells, alternatives to animal sera or non‐animal recombinant antibodies, are becoming increasingly available, and their use is encouraged by the EU Directive 2010/63 and the Guidance Document on Good In vitro Method Practices (GIVIMP), published by the Organization for Economic Cooperation and Development (OECD). In an effort to map the current state of use of animal‐derived reagents across different sectors and to identify the obstacles possibly hampering the implementation of non‐animal derived alternatives, a global online survey addressed to scientists working on in vivo, in vitro, in silico methods, in academia as well as pharmaceutical or cosmetic companies, was conducted with the goal to understand: 1) the most commonly used animal‐derived materials and reagents, 2) the main issues associated with the production and use of animal‐derived materials and reagents, 3) the current level of knowledge on available non‐animal alternative materials and reagents, and 4) what educational and information sources could be most useful or impactful to disseminate knowledge on non‐animal alternatives. This paper provides an overview of the survey replies and discusses possible proposals to increase awareness, acceptance and use of non‐animal ingredients.
Micronutrients are needed for the human body in very small amounts and have a visible impact on human health. Deficiencies of micronutrients like iron (Fe), zinc (Zn), calcium (Ca) and other minerals ...can cause life threatening conditions while Fe deficiency and anemia has been the biggest issue. Through the proper selection of food these micronutrients deficiencies can be prevented to a reasonable extent. This review highlights the dietary sources of Fe, Zn and Ca, their biological significance, and effects against various diseases. Also, it focuses on the bioavailability of Fe, Zn, Ca and the factors affecting their bioavailability. The effects of phytate, tannin, oxalate, ascorbic acid, food processing, soaking, germination/sprouting, fermentation, cooking methods and interaction among minerals, which inhibit or enhance minerals bioavailability, have also been reviewed and critically discussed. The food processing techniques which reduce phytate concentration in foods and enhance minerals bioavailability have also been reviewed.
•The review shows dietary sources of Fe, Zn & Ca and their biological significance.•The review focuses on Fe, Zn, Ca and the factors affecting their bioavailability.•The factors affecting Fe, Zn & Ca bioavailability have been critically reviewed.•Phytate, tannin & ascorbic acid effects on nutrients bioavailability are reviewed.•The effects of food processing techniques & minerals interaction have been reviewed.
•Cooking reduced bioaccessibility of Cd and As in rice.•Cadmium bioaccessibility was higher in gastric than gastrointestinal phase.•Arsenic bioaccessibility was higher in gastrointestinal than ...gastric phase.•Different water to rice ratio has different changes on metal(loid)s bioaccessibility.
The health risks associated with rice consumption may decrease if consumers use cooking practices which can reduce the bioaccessibility of metal(loid)s. The effects of cooking on the Cd and As bioaccessibility, at three contamination levels of rice, were studied. Results indicated that cooking reduced bioaccessibility of Cd and As in rice. Cooking resulted in a significant increase (p<0.01) of Cd and As concentrations in the residual fraction. Low volume water-cooking of rice to dryness reduced total Cd by about 10% for rices A and B, while medium or high volume water-cooking had no effect on Cd bioaccessibility in all rice types. In contrast, low volume cooking did not remove As, but a significant decrease (p<0.05) was observed when cooking with higher volumes of water. This study provides information for a better understanding of more realistic estimation of metal(loid)s exposure from rice and the possible health risks.
Although photosensitization remains a major toxicological endpoint for the safety assessment of cosmetic products and their raw materials, there is no validated in vitro method available for the ...evaluation of this adverse effect so far. Given that previous studies have proposed that the Interleukine-18 (IL-18) plays a key role in keratinocyte-driven pro-inflammatory responses specific of the skin sensitization process, we hypothesize that IL-18 might be used as a specific biomarker for in vitro photosensitization assessment. The aim of the present study was the set-up of a new in vitro assay using IL-18 as a biomarker for the identification of photosensitizers in a reconstructed human epidermis (RHE) model. EpiCS™ RHE were incubated with a set of 16 known sensitising / phototoxic / photosensitizing substances and exposed to ultra-violet (UV) irradiation. Then, the cell viability was analysed by MTT assay, while the IL-18 secretion was quantified by ELISA. Preliminary assays have shown that 1 h of incubation followed by a recovery period of 23 h induced the highest IL-18 production in response to UV exposure. This protocol was used to test 16 substances and a ratio of IL-18 production (UV+/UV- ratio) was then generated. Our data shows that the cut-off of 1.5 (UV+/UV- ratio) is the most predictive model among the tested conditions, being capable of identifying true positive photosensitizers (8 of 9) with a good prediction in comparison with in vivo data. In a nutshell, our data suggests that the PhotoSENSIL-18 is a promising in vitro method for identification of photosensitizing substances. Although further studies are necessary to optimize the model, we foresee that the PhotoSENSIL-18 assay can be used in the context of an Integrative Approach to Testing and Assessment (IATA) of chemicals.
In this study, PBET (Physiologically Based Extraction Test), IVG (In Vitro Gastrointestinal), and SBRC (Solubility Bioavailability Research Consortium) were used to compare the bioavailability of Cd ...in 10 potato varieties and evaluate the risks to human health. The results show that the dissolved Cd content in the gastric and small intestine phase under the three methods is IVG > SBRC > PBET. The most bioavailable method in the gastric and small intestine phases is IVG, and the varieties are Weiyu 5 and Weiyu 7. In the gastric phase, Weiyu 7 had the highest availability, at 73.36%, and in the small intestine phase, Weiyu 5 had the highest availability at 67.48%, and compared with SBRC and PBET, the difference reached a significant level; the varieties with higher bioavailability are Weiyu 5 and Weiyu 7, and the lower varieties are Lishu 13 and Lishu 15 among the 10 potato varieties. Three methods were used to assess the human health risk of Cd in potatoes. The HQ values of different varieties were all less than 1. The ADD and HQ values of Cd ingested by adults and children through potato are generally IVG > SBRC > PBET.
