Safety evaluation of the food enzyme glucan 1,4-α-maltohydrolase from the genetically modified Saccharomyces cerevisiae strain LALL-MA.

The food enzyme glucan 1,4-α-maltohydrolase (4-α-d-glucan α-maltohydrolase; EC 3.2.1.133) is produced with the genetically modified Saccharomyces cerevisiae strain LALL-MA+ by Danstar Ferment AG. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in the processing of cereals and other grains for production of baked products. Dietary exposure was estimated to be up to 0.014 mg TOS/kg body weight per day in European populations. Given the QPS status of the production strain and the absence of concerns resulting from the food enzyme manufacturing process, toxicity tests were considered unnecessary by the Panel. A search for the identity of the amino acid sequence of the food enzyme to known allergens was made and four matches were found, three with respiratory allergens and one with an allergen from mosquito (injected). The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety evaluation of a second extension of use of the food enzyme α-amylase from the non-genetically modified Cellulosimicrobium funkei strain AE-AMT.

The food enzyme α-amylase (4-α-d-glucan glucanohydrolase i.e. EC 3.2.1.1) is produced with the non-genetically modified Cellulosimicrobium funkei strain AE-AMT by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that the food enzyme did not give rise to safety concerns when used in seven food manufacturing processes. Subsequently, the applicant has requested to extend its use to include three additional processes. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of ten food manufacturing processes. As the food enzyme-total organic solids (TOS) are removed from the final foods in one food manufacturing process, the dietary exposure to the food enzyme-TOS was estimated only for the remaining nine processes. The dietary exposure was calculated to be up to 0.049 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level previously reported (230 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 4694. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of an extension of use of the food enzyme pullulanase from the non-genetically modified Pullulanibacillus naganoensis strain AE-PL.

The food enzyme pullulanase (pullulan 6-α-glucanohydrolase; EC 3.2.1.41) is produced with the non-genetically modified Pullulanibacillus naganoensis strain AE-PL by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in one food manufacturing process. Subsequently, the applicant has requested to extend its use to include seven additional processes and to revise the previous use level. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of eight food manufacturing processes. As the food enzyme-total organic solids (TOS) are not carried into the final foods in two food manufacturing processes, the dietary exposure was estimated only for the remaining six processes. The dietary exposure was calculated to be up to 0.004 mg TOS/kg body weight (bw) per day in European populations. The Panel evaluated the repeated dose 90-day oral toxicity study in rats submitted in the previous application and identified a no observed adverse effect level of 643 mg TOS/kg bw per day, the highest dose tested. When compared with the calculated dietary exposure, this resulted in a margin of exposure of at least 160,750. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.

Safety evaluation of an extension of use of the food enzyme triacylglycerol lipase from the non-genetically modified Aspergillus luchuensis strain AE-L.

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) is produced with the non-genetically modified Aspergillus luchuensis strain AE-L by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in one food manufacturing process. Subsequently, the applicant has requested to extend its use to include four additional processes and to revise the previous use level. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of five food manufacturing processes. The dietary exposure to the food enzyme-total organic solids (TOS) was calculated to be up to 0.458 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level previously reported (1726 mg TOS/kg bw per day, the highest dose tested), the Panel derived a revised margin of exposure of at least 3769. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.

Safety evaluation of the food enzyme ß-galactosidase from the genetically modified Bacillus licheniformis strain DSM 34099.

The food enzyme ß-galactosidase (ß-d-galactoside galactohydrolase; EC 3.2.1.23) is produced with the genetically modified Bacillus licheniformis strain DSM 34099 by Kerry Group Services International, Ltd. (KGSI). The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. The production strain met the requirements for the qualified presumption of safety (QPS) approach. The food enzyme is intended to be used in two food manufacturing processes. Dietary exposure was estimated to be up to 7.263 mg total organic solids/kg body weight per day in European populations. Given the QPS status of the production strain and the absence of concerns resulting from the food enzyme manufacturing process, toxicity tests, other than an assessment of allergenicity, were considered unnecessary by the Panel. A search for the identity of the amino acid sequence of the food enzyme to known allergens was made and one match with a food allergen from kiwi fruit was found. The Panel considered that a risk of allergic reactions upon dietary exposure to this food enzyme, particularly in individuals sensitised to kiwi fruit, cannot be excluded. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety evaluation of the food enzyme lysophospholipase from the genetically modified Trichoderma reesei strain DP-Nyc81.

The food enzyme lysophospholipase (2-lysophosphatidylcholine acylhydrolase, EC 3.1.1.5) is produced with the genetically modified Trichoderma reesei strain DP-Nyc81 by Genencor International B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in the processing of cereals and other grains for the production of glucose syrups and other starch hydrolysates. Since residual amounts of food enzyme-total organic solids are removed during these food manufacturing processes, dietary exposure was not calculated and toxicological studies were considered unnecessary. A search for the identity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety evaluation of an extension of use of the food enzyme thermolysin from the non-genetically modified Anoxybacillus caldiproteolyticus strain AE-TP.

The food enzyme thermolysin (EC. 3.4.24.27) is produced with the non-genetically modified Anoxybacillus caldiproteolyticus strain AE-TP by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in eight food manufacturing processes. Subsequently, the applicant has requested to extend its use to one additional process, to withdraw two processes and to revise the use levels. In this assessment, EFSA updated the safety evaluation of this food enzyme for use in a total of seven food manufacturing processes. The dietary exposure to the food enzyme-total organic solids (TOS) was calculated to be up to 0.989 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level reported in the previous opinion (700 mg TOS/kg bw per day, the mid-dose tested), the Panel derived a revised margin of exposure of at least 708. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.

Safety evaluation of an extension of use of the food enzyme oryzin from the non-genetically modified Aspergillus ochraceus strain AE-P.

The food enzyme oryzin (EC 3.4.21.63) is produced with the non-genetically modified Aspergillus ochraceus strain AE-P by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in nine food manufacturing processes. Subsequently, the applicant has requested to extend its use to one additional process, to withdraw two food processes and to revise the use levels. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of eight food manufacturing processes. The dietary exposure to the food enzyme-total organic solids (TOS) was calculated to be up to 0.354 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level reported in the previous opinion (1862 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 5260. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.

Safety evaluation of an extension of use of the food enzyme triacylglycerol lipase from the non-genetically modified Rhizopus arrhizus strain AE-TL(B).

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) is produced with the non-genetically modified Rhizopus arrhizus strain AE-TL(B) by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in two food manufacturing processes. Subsequently, the applicant requested to extend its use to include four additional processes and to revise the use levels. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of six food manufacturing processes. As the food enzyme-total organic solids (TOS) are removed from one food manufacturing process, the dietary exposure to the food enzyme-TOS was estimated only for the remaining five processes. Dietary exposure was calculated to be up to 0.086 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level reported in the previous opinion (1960 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 22,791. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.

Nanocomposite hydrogels in skin cancer medicine.

Skin cancer is one of the most common malignancies in white populations. The therapy strategy is important in skin cancer treatment, depending on several criteria such as stage, size, and localization. Removal of cancerous tissue following anticancer therapeutic administration is considered as gold standard in skin cancer treatment. However, annually rising drug resistance, local inflammation, and ineffective treatment result in a reduction in the effectiveness of the patient's treatment. Nanotechnology has emerged as a prospective in the field of skin cancer medicine, offering innovative, promising solutions for therapeutic procedures and targeted drug delivery. Different nanomaterials are investigated for their potential in skin cancer treatment. Nanohydrogels as a hybrid material, have gained considerable attention due to their unique biomedical and pharmaceutical properties, such as biocompatibility, high water content, and tunable physicochemical characteristics. The principal problem with common skin melanoma chemotherapy is the strong side effects because therapeutics used for treatment do not distinguish cancer cells from healthy cells. Nanohydrogels, as a new-generation, versatile system with the possession of dual characteristics of hydrogels and nanoparticles have shown great potential in targeted delivery in cancer therapy thanks to the possibility of their various modifications, and by that overcome problems with side effects of treatment. This scientific review provides an analysis of the current state of research on nanohydrogels in skin cancer medicine, highlighting their design principles, synthesis methods, and applications in drug delivery, imaging, and combination therapies.

Rapid identification of in vitro cell toxicity using an electrochemical membrane screening platform.

This study compares the performance and output of an electrochemical phospholipid membrane platform against respective in vitro cell-based toxicity testing methods using three toxicants of different biological action (chlorpromazine (CPZ), colchicine (COL) and methyl methanesulphonate (MMS)). Human cell lines from seven different tissues (lung, liver, kidney, placenta, intestine, immune system) were used to validate this physicochemical testing system. For the cell-based systems, the effective concentration at 50 % cell death (EC50) values are calculated. For the membrane sensor, a limit of detection (LoD) value was extracted as a quantitative parameter describing the minimum concentration of toxicant which significantly affects the structure of the phospholipid sensor membrane layer. LoD values were found to align well with the EC50 values when acute cell viability was used as an end-point and showed a similar toxicity ranking of the tested toxicants. Using the colony forming efficiency (CFE) or DNA damage as end-point, a different order of toxicity ranking was observed. The results of this study showed that the electrochemical membrane sensor generates a parameter relating to biomembrane damage, which is the predominant factor in decreasing cell viability when in vitro models are acutely exposed to toxicants. These results lead the way to using electrochemical membrane-based sensors for rapid relevant preliminary toxicity screens.

Genome-wide DNA methylome and transcriptome changes induced by inorganic nanoparticles in human kidney cells after chronic exposure.

The unique physicochemical properties make inorganic nanoparticles (INPs) an exciting tool in diagnosis and disease management. However, as INPs are relatively difficult to fully degrade and excrete, their unintended accumulation in the tissue might result in adverse health effects. Herein, we provide a methylome-transcriptome framework for chronic effects of INPs, commonly used in biomedical applications, in human kidney TH-1 cells. Renal clearance is one of the most important routes of nanoparticle excretion; therefore, a detailed evaluation of nanoparticle-mediated nephrotoxicity is an important task. Integrated analysis of methylome and transcriptome changes induced by INPs (PEG-AuNPs, Fe3O4NPs, SiO2NPs, and TiO2NPs) revealed significantly deregulated genes with functional classification in immune response, DNA damage, and cancer-related pathways. Although most deregulated genes were unique to individual INPs, a relatively high proportion of them encoded the transcription factors. Interestingly, FOS hypermethylation inversely correlating with gene expression was associated with all INPs exposures. Our study emphasizes the need for a more comprehensive investigation of INPs' biological safety, especially after chronic exposure.

Pharmacokinetics of PEGylated Gold Nanoparticles: In Vitro-In Vivo Correlation.

Data suitable for assembling a physiologically-based pharmacokinetic (PBPK) model for nanoparticles (NPs) remain relatively scarce. Therefore, there is a trend in extrapolating the results of in vitro and in silico studies to in vivo nanoparticle hazard and risk assessment. To evaluate the reliability of such approach, a pharmacokinetic study was performed using the same polyethylene glycol-coated gold nanoparticles (PEG-AuNPs) in vitro and in vivo. As in vitro models, human cell lines TH1, A549, Hep G2, and 16HBE were employed. The in vivo PEG-AuNP biodistribution was assessed in rats. The internalization and exclusion of PEG-AuNPs in vitro were modeled as first-order rate processes with the partition coefficient describing the equilibrium distribution. The pharmacokinetic parameters were obtained by fitting the model to the in vitro data and subsequently used for PBPK simulation in vivo. Notable differences were observed in the internalized amount of Au in individual cell lines compared to the corresponding tissues in vivo, with the highest found for renal TH1 cells and kidneys. The main reason for these discrepancies is the absence of natural barriers in the in vitro conditions. Therefore, caution should be exercised when extrapolating in vitro data to predict the in vivo NP burden and response to exposure.

Pharmacokinetics, Biodistribution, and Biosafety of PEGylated Gold Nanoparticles In Vivo.

Despite the obvious advantages of gold nanoparticles for biomedical applications, controversial and incomplete toxicological data hamper their widespread use. Here, we present the results from an in vivo toxicity study using gold nanoparticles coated with polyethylene glycol (PEG-AuNPs). The pharmacokinetics and biodistribution of PEG-AuNPs were examined in the rat's liver, lung, spleen, and kidney after a single i.v. injection (0.7 mg/kg) at different time intervals. PEG-AuNPs had a relatively long blood circulation time and accumulated primarily in the liver and spleen, where they remained for up to 28 days after administration. Increased cytoplasmic vacuolation in hepatocytes 24 h and 7 days after PEG-AuNPs exposure and apoptotic-like cells in white splenic pulp 24 h after administration has been detected, however, 28 days post-exposure were no longer observed. In contrast, at this time point, we identified significant changes in lipid metabolism, altered levels of liver injury markers, and elevated monocyte count, but without marked biological relevance. In blood cells, no DNA damage was present in any of the studied time intervals, with the exception of DNA breakage transiently detected in primary kidney cells 4 h post-injection. Our results indicate that the tissue accumulation of PEG-AuNPs might result in late toxic effects.

Minimum Information for Reporting on the Comet Assay (MIRCA): recommendations for describing comet assay procedures and results.

The comet assay is a widely used test for the detection of DNA damage and repair activity. However, there are interlaboratory differences in reported levels of baseline and induced damage in the same experimental systems. These differences may be attributed to protocol differences, although it is difficult to identify the relevant conditions because detailed comet assay procedures are not always published. Here, we present a Consensus Statement for the Minimum Information for Reporting Comet Assay (MIRCA) providing recommendations for describing comet assay conditions and results. These recommendations differentiate between 'desirable' and 'essential' information: 'essential' information refers to the precise details that are necessary to assess the quality of the experimental work, whereas 'desirable' information relates to technical issues that might be encountered when repeating the experiments. Adherence to MIRCA recommendations should ensure that comet assay results can be easily interpreted and independently verified by other researchers.

Nephrotoxicity: Topical issue.

Drug-induced kidney injury is one of the most significant adverse events and dose limiting factor in chemotherapy as well a major cause of prospective drug attrition during pharmaceutical development. Moreover, kidney injury can also occur as a consequence of exposures to environmental xenobiotics such as heavy metals, fungal toxins and nanomaterials. The lack of adequate in vitro human kidney models that mimic more realistically the in vivo conditions and the absence of suitable and robust, cost-effective and predictive cell-based in vitro assays contribute to an underestimation of the kidney toxic potential of new drugs and xenobiotics. Therefore, a rapid screening system capable to detect potential nephrotoxicity at early stages of drug discovery is an urgent need. Here we provide an overview of human cell lines currently used as a surrogate in vitro kidney models in nephrotoxicity studies, including their advantages and limitations. In addition, the capacity of the single cell gel electrophoresis (SCGE)/comet assay as a potential tool in kidney toxicants screening is discussed. Despite a limited number of studies using the comet assay to evaluate the drug-induced kidney damage potential, a considerable variability in SCGE methodology (e.g. lysis, unwinding, and electrophoresis conditions) has been observed. Before the comet assay can be included in nephrotoxicity testing, a basic guideline has to be developed. To test its feasibility, additional in vitro experiments including inter-laboratory validation studies based on this guideline have to be performed.

Comet assay in neural cells as a tool to monitor DNA damage induced by chemical or physical factors relevant to environmental and occupational exposure.

Biomonitoring of the effects of environmental and occupational exposure relevant chemical or physical factors on central nervous system is difficult due to the problems with sampling of biological material. Thus, surrogate systems allowing for the estimation of effect intensity are necessary to evaluate a potential risk of exposure. Cancerous neural cells in culture seem to be a reliable trustworthy alternative to ex vivo primary cells culture, where brain tissue is hardly available. In this review we summarized attempts to test genotoxicity of environmentally related xenobiotics or physical factors. Different neural cells of human and non-human origin are described in respect to their use in genotoxicity testing using the comet assay. Surprisingly, despite the large number of commercially available neural cells of different type and origin, only twelve were used for genotoxicity testing by the comet assay. We also recapitulate the environmentally relevant chemical and physical factors tested on neural cell lines in vitro by the comet assay. The most prevalent were fire retardants, plant protection agents, nanoparticles and magnetic field.

Kidney nanotoxicity studied in human renal proximal tubule epithelial cell line TH1.

Progressive expansion of nanomaterials in our everyday life raises concerns about their safety for human health. Although kidneys are the primary organs of xenobiotic elimination, little attention has been paid to the kidneys in terms of nanotoxicological studies up to now. Here we investigate the cytotoxic and genotoxic potential of four solid-core uncoated inorganic nanoparticles (TiO2NPs, SiO2NPs, Fe3O4NPs and AuNPs) using the human renal proximal tubule epithelial TH1 cells. To mimic the in vivo conditions more realistic, TH1 cells were exposed in vitro to inorganic NPs under static as well as dynamic conditions for 3 h and 24 h. The medium throughput alkaline comet assay (12 minigels per slide) was employed to evaluate the impact of these NPs on genome integrity and their capacity to produce oxidative lesions to DNA. The accumulation and localization of studied inorganic NPs inside the cells was monitored by transmission electron microscopy (TEM) and the efficacy of internalization of particular NPs was determined by atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectrometry (ICP-MS). From all the tested NPs, only Fe3O4NPs induced a slight cytotoxicity in TH1 cells exposed to high concentrations (>700 µg/ml) for 24 h. On the other hand, the inorganic NPs did not increase significantly the level of DNA strand breaks or oxidative DNA damage regardless of the treatment mode (static vs. dynamic conditions). Interestingly, substantial differences were observed in the internalized amount of inorganic NPs in TH1 cells exposed to equivalent (2.2 µg/ml) concentration. Fe3O4NPs were most efficiently taken up while the lowest quantity of particles was determined in TiO2NPs-treated cells. As the particle size and shape of individual inorganic NPs in culture medium was nearly identical, it is reasonable to suppose that the chemical composition may contribute to the differences in the efficacy of NPs uptake.

Assessment of DNA damage in Polish children environmentally exposed to pesticides.

Exposure to pesticides leads to complex, long-lasting adverse effects on human health, and poses a substantial risk to those living in areas devoted to agriculture. Children are particularly vulnerable to the pesticide exposure, due to the developmental, dietary and physiological factors. Small body mass and typical exploratory behavior result in increased risk of intoxication. Thus, even exposure to low concentrations of pesticides, if of sufficient duration, may lead to permanent health disorders and limit their harmonious development. In this study 108 children, living in areas of an intense pesticide use and a control group (n = 92) of children from an agrotouristic area were investigated, whether DNA damage increased due to prolonged pesticide exposure. A presence of DNA breaks and oxidative damage to DNA bases, characterized as Fpg-sensitive sites, were detected by comet assay. Micronuclei (MN) formation was evaluated by cytokinesis-block MN assay. The exposure of children to pesticides resulted in increased number of MN in peripheral blood lymphocytes (P = 0.016), increased DNA strand breaks level (P = 0.002) and oxidative damage to DNA (P < 0.001). Negative correlation was demonstrated between the level of DNA strand breaks and acetylcholinesterase (AChE) activity in exposed group. In conclusion, despite just environmental pesticide exposure in the test group of children, significant biological effects were detected.

The comet assay in animal models: From bugs to whales - (Part 2 Vertebrates).

The comet assay has become one of the methods of choice for the evaluation and measurement of DNA damage. It is sensitive, quick to perform and relatively affordable for the evaluation of DNA damage and repair at the level of individual cells. The comet assay can be applied to virtually any cell type derived from different organs and tissues. Even though the comet assay is predominantly used on human cells, the application of the assay for the evaluation of DNA damage in yeast, plant and animal cells is also quite high, especially in terms of biomonitoring. The present extensive overview on the usage of the comet assay in animal models will cover both terrestrial and water environments. The first part of the review was focused on studies describing the comet assay applied in invertebrates. The second part of the review, (Part 2) will discuss the application of the comet assay in vertebrates covering cyclostomata, fishes, amphibians, reptiles, birds and mammals, in addition to chordates that are regarded as a transitional form towards vertebrates. Besides numerous vertebrate species, the assay is also performed on a range of cells, which includes blood, liver, kidney, brain, gill, bone marrow and sperm cells. These cells are readily used for the evaluation of a wide spectrum of genotoxic agents both in vitro and in vivo. Moreover, the use of vertebrate models and their role in environmental biomonitoring will also be discussed as well as the comparison of the use of the comet assay in vertebrate and human models in line with ethical principles. Although the comet assay in vertebrates is most commonly used in laboratory animals such as mice, rats and lately zebrafish, this paper will only briefly review its use regarding laboratory animal models and rather give special emphasis to the increasing usage of the assay in domestic and wildlife animals as well as in various ecotoxicological studies.