Absence Of Metabolic Activation Research Articles

Toxicity Assessment of a No-Pain Pharmacopuncture Extract Using a Standard Battery of In Vitro Chromosome Aberration Tests.

Genotoxicity is evaluated through a chromosomal aberration test using cultured mammalian cells to determine the toxicity of no-pain pharmacopuncture (NPP), which has recently been used to treat musculoskeletal pain disorders in Korean medical clinical practice. An initial test was performed to determine the dosage range of the NPP, followed by the main test. In this study, NPP doses of 10.0, 5.0, and 2.5%, and negative and positive controls were tested. An in vitro chromosome aberration test was performed using Chinese hamster lung cells under short-term treatment with or without metabolic activation and under continuous treatment without metabolic activation. Compared with the saline negative control group, NPP did not significantly increase the frequency of chromosomal abnormalities in Chinese hamster lung cells, regardless of the presence or absence of metabolic activation. Additionally, the number of cells with structural chromosomal abnormalities was significantly higher in the positive control group than that in the negative control group that received saline. Based on the above results, the chromosomal abnormality-producing effect of NPP was determined to be negative under these test conditions.

In vitro and in vivo genotoxicity evaluation of ALP1018, a nanomineral food supplement

The use of nano-based dietary supplements is increasing around the world, as nanotechnology can help enhance nutrient bioavailability. ALP1018 is a newly developed iron-zinc complex supplement designed as a nanoformulation to improve the efficacy of iron and zinc supplementation. However, safety concerns have been raised, as there is no clear evaluation of ALP1018 toxicity. The goal of this study was to determine the potential mutagenicity and genotoxicity of ALP1018 through three standard screenings: the Ames test, which evaluates bacterial reverse mutations; the in vitro test of chromosomal aberration in Chinese hamster lung cells; and the in vivo micronucleus assay using ICR mice. ALP1018 showed no mutagenic effect, as no increase was observed in the presence or absence of metabolic activation (S9 mix) in revertant colonies on all the bacterial strains used in the Ames test. No structural chromosomal abnormalities were observed in the presence or absence of the S9 mix in mammalian cells used in the chromosomal aberration assay. In the micronucleus test, the frequency of micronucleated polychromatic erythrocytes was not significantly increased in mouse bone marrow cells. Based on these findings, we can conclude that ALP1018 is safe to use and has no mutagenic or genotoxic potential.

Effect of a phthalimide pesticide on human peripheral blood lymphocytes in vitro: induction of DNA damage

Introduction. Captan is a contact fungicide from the phthalimide class, used in agriculture to combat plant diseases. However, the question of its genotoxicity for humans remains open. Various studies examining the mutagenic activity of captan using different tests have yielded conflicting results. This study aims to investigate the potential of captan to induce DNA damage in human peripheral blood lymphocytes in vitro using single-cell alkaline gel electrophoresis.
 Material and methods. The DNA-damaging effect of captan (0; 2.5; 5.0; 10.0; 12.5 and 25 μg/ml) on lymphocytes of 26 donors was assessed with metabolic activation (+S9) and without it (–S9) using DNA comet analysis.
 Results. In the absence of metabolic activation, captan exhibited a pronounced genotoxic effect on cells. Statistically significant effects of captan was found on lymphocytes of all donors. The level of DNA-damaging effect on lymphocytes from 20 out of 26 donors depended on the concentration. The fold increase in the “%DNA in the tail of comets” indicator compared to the negative control at a concentration of 25 μg/ml varied in the range of 4,3–226 times. In the presence of the S9 mixture, weak but significant effects meeting the criteria for a positive response were detected only in three donors.
 Limitations. The genotoxicity of captan was studied only in vitro.
 Conclusion. Captan induces DNA damage in human peripheral blood lymphocytes in vitro in the absence of metabolic activation. Under conditions of metabolic activation, genotoxic effects were low. The levels of DNA damage in peripheral blood lymphocytes of different donors after exposure to captan varied markedly, indicating the necessity to consider individual sensitivity to genotoxicants when utilizing the DNA comet method to assess the potential mutagenic activity of chemicals.

Matrine and Oxymatrine: evaluating the gene mutation potential using in silico tools and the bacterial reverse mutation assay (Ames test).

The quinolizidine alkaloids matrine and its N-oxide oxymatrine occur in plants of the genus Sophora. Recently, matrine was sporadically detected in liquorice products. Morphological similarity of the liquorice plant Glycyrrhiza glabra with Sophora species and resulting confusion during harvesting may explain this contamination, but use of matrine as pesticide has also been reported. The detection of matrine in liquorice products raised concern as some studies suggested a genotoxic activity of matrine and oxymatrine. However, these studies are fraught with uncertainties, putting the reliability and robustness into question. Another issue was that Sophora root extracts were usually tested instead of pure matrine and oxymatrine. The aim of this work was therefore to determine whether matrine and oxymatrine have potential for causing gene mutations. In a first step and to support a weight-of-evidence analysis, in silico predictions were performed to improve the database using expert and statistical systems by VEGA, Leadscope (Instem®), and Nexus (Lhasa Limited). Unfortunately, the confidence levels of the predictions were insufficient to either identify or exclude a mutagenic potential. Thus, in order to obtain reliable results, the bacterial reverse mutation assay (Ames test) was carried out in accordance with OECD Test Guideline 471. The test set included the plate incorporation and the preincubation assay. It was performed with five different bacterial strains in the presence or absence of metabolic activation. Neither matrine nor oxymatrine induced a significant increase in the number of revertants under any of the selected experimental conditions. Overall, it can be concluded that matrine and oxymatrine are unlikely to have a gene mutation potential. Any positive findings with Sophora extracts in the Ames test may be related to other components. Notably, the results also indicated a need to extend the application domain of respective (Q)SAR tools to secondary plant metabolites.

Morphine decreases cytotoxicity and mutagenicity of doxorubicin in vitro: Implications for cancer chemotherapy

Morphine is the most common opioid analgesic administered to treat pain in patients undergoing cancer chemotherapy. This study aimed to evaluate the cytotoxic and mutagenic effects of morphine alone and in combination with doxorubicin (Dox), an antineoplastic agent largely used in patients with solid cancers. Cytotoxicity was evaluated in neuroblastoma (SH-SY5Y) and fibroblast (V79) cells using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay while mutagenicity was assessed using the Salmonella/microsome assay in the absence and in the presence of S9 mix. Morphine showed a cytotoxic effect mainly on SH-SY5Y cells and reduced the cytotoxic effects of Dox when evaluated in a co-treatment procedure. In the Salmonella/microsome assay, it was observed that morphine did not induce mutations and, in fact, decreased the mutagenic effects induced by Dox in TA98 and TA102 strains in the absence of metabolic activation. Furthermore, in the presence of metabolic activation, no induction of mutations was observed with morphine. In conclusion, morphine decreased Dox cytotoxicity in both neuronal and non-neuronal cells and showed antimutagenic effects in the TA102 strain which detects mutagens inducing DNA oxidative damages. However, morphine decreased frameshift mutations induced by Dox in non-cytotoxic concentrations, an effect suggesting interference of Dox intercalation activity that could decrease its chemotherapeutic efficacy. These compelling findings highlight the importance of conducting further studies to explore the potential implications of co-administering morphine and Dox during cancer chemotherapy.

In vitro micronucleus assay: Method for assessment of nanomaterials using cytochalasin B.

The in vitro micronucleus (MNvit) assay is used to evaluate the aneugenic and clastogenic potential of a test material based upon its ability to induce micronuclei in the cells. This protocol is provided for testing of nanomaterials (NM) with standard cell lines in the absence of metabolic activation. The use of cytochalasin B (CytoB) and the analysis of binucleated cells in the cytokinesis-block version of the micronucleus assay ensures that cells analyzed have undergone cell division, which is required for expression of DNA damage and micronucleus formation. Issues specific to NM that were problematic with standard test methods are addressed, including test system choice, dose selection, test material exposures, CytoB timing, cytotoxicity determination, and DNA damage expression time. A step-by-step protocol for in vitro micronucleus assessment of NM is provided.

New thieno[2,3-b]pyridine-fused pyrimidin-4(3H)-ones as potential thymidylate synthase inhibitors: Synthesis, SAR, in vitro and in silico study

Cancer is the second leading cause of death, following cardiovascular disease. Thymidylate synthase (TS) has long been identified as a significant target for chemotherapy due to its critical role in DNA biosynthesis. New thieno[2,3-b]pyridine-fused pyrimidinones were prepared utilizing a three-component tandem protocol. One equivalent of 3-aminothieno[2,3-b]pyridine-2-carboxylate and 1.5 equivalents of dimethylformamide-dimethylacetal in toluene was microwave irradiated at 110 °C for 15 min. Next, the crude enamine was dissolved in dioxane and one equivalent of the respective aromatic amines or 3-aryl-1H-pyrazol-5-amines was added. The mixture was irradiated by microwaves at 100 °C for 20–45 min to produce the desired pyrimidinones in 72–89% yields. Examination of the in vitro cytotoxicity of the new products revealed a wide range of activity. Pyrazole-linked pyrimidinones 2b and 2c, attached to p-Cl and p-NO2, demonstrated the best cytotoxicity with IC50 values up to 6.59 and 3.65 µM, respectively, against MCF-7, HEPG2, and Caco2. The in vitro TS inhibitory activity of 2b and 2c was also assessed. 2b demonstrated comparable activity to the standard pemetrexed with inhibition percentages up to 86.3, whereas 2c inhibited TS the best with inhibition percentages up to 91.5. The Ames test revealed that 2b and 2c had no or weakly mutagenic potential to the Salmonella TA 98 or TA 100 strain in the presence or absence of metabolic activation. Docking study predicted the promising TS inhibitory activity of pyrimidinones 2b and 2c. According to SwissADME and Lipinski's rule of five, all new pyrimidinones could be classified as drug-like.

A novel combination of immobilized Enterococcus casseliflavus sp. nov. with silver nanoparticles into a reusable matrix of Ca-Alg beads as a new strategy for biotreatment of Disperse Blue 183: Insights into metabolic characterization, biotoxicity, and mutagenic properties

Recent advances in immobilized biologic systems for decolorizing azo dyes are gaining great attention due to microorganisms like bacteria and nanoparticles that could stimulate decolorization. Enhanced decolorization performance was observed in this study, indicating the great potential of the immobilized complex of bacterial cells and AgNPs as an alternative to the traditional biological processes to improve the performance of biological systems. The biodegradation and decolorization of Disperse Blue183 (DB 183) were investigated utilizing a novel combination of Enterococcus casseliflavus strain A2 mediated by silver nanoparticles synthesized by Marinospirillum alkaliphilum strain N in three different conditions. Ⅰ: free bacterial strain A2 (100% dye removal in 72 h), Ⅱ: immobilized bacterial strain A2 in Ca-Alg beads (100% dye removal in 15 h), and Ⅲ: immobilized bacterial strain A2 with silver nanoparticles (AgNPs) as support in Ca-Alg beads (100% dye removal in 9 h). The presence of bacterial cells and nanoparticles in Ca-Alg beads was assessed and proved by scanning electron microscope (SEM) and X-ray energy diffraction (EDX) analysis. Moreover, DB 183 and its decolorization metabolites were evaluated by applying UV–Vis, infrared spectroscopy (FTIR), and GC/MS, and the results showed that the dye was degraded. The antimicrobial effect, brine shrimp toxicity (BST) test, and mutagenicity assay in the presence and absence of metabolic activation (+S9/-S9) were run to assess DB 183 and metabolite obtained from biodegradation. The antimicrobial activity of DB 183 disappeared after treatment. Further, the results of the BST test determined that the dye has moderate biotoxicity (LC50:0.064 mg/mL), and the after-treatment product was not toxic. According to the Ames test, DB 183 had mutagenicity effect (69–84%), and the metabolic activation increased the mutagenicity of the dye) 12–25%). However, the percentage mutagenicity of decolorization products decreased, ranging from 50 to 80% without activation (-S9) and 83–96% in present activation (+S9). This work used the immobilized bacterial cells and AgNPs Ca-Alg gel beads for the first time to introduce this kind of system as a suitable technique for rapid decolorization. Using this application enables a remarkable reduction in the time dedicated to the bioremediation of dyeing wastewater.

Preclinical safety evaluation of Lipase OF from Candida cylindracea.

Triacylglycerol lipases are enzymes commonly used to process foods and beverages such as oils, wines, and cheeses through catalyzation of long-chain triglyceride hydrolysis. Lipase OF derived from Candida cylindracea (strain MS-5-OF) is only intended for use as a processing aid in food production applications; however, it may be present at trace levels in some products. As such, the safety of Lipase OF was evaluated in this study that included a bacterial reverse mutation assay, an in vitro chromosome aberration test, and a 90-day subchronic toxicity study in rats. In the in vitro bacterial reverse mutation and chromosome aberration assays, Lipase OF was not observed to be mutagenic at concentrations up to 5000 μg/plate and 50 μg/ml, respectively, in the presence or absence of metabolic activation. Results from the 90-day subchronic toxicity study indicated only minimal adverse effects (i.e., increased platelet count and prothrombin time) in male rats from the high-dose group following administration of Lipase OF via the diet at levels of 0, 1.0, 2.5, and 5.0 w/w%. The no-observed-adverse-effect level (NOAEL) for Lipase OF was therefore considered 2.5 w/w% (1597.6mg/kg body weight/day [1027.3mg TOS/kg body weight/day]) in males and 5.0 w/w% (3700.4mg/kg body weight/day [2379.4mg TOS/kg body weight/day]) in females under the test conditions. Thus, the evidence presented within this study supports the safe use of Lipase OF as a processing aid in various food production applications for human consumption.

Preclinical toxicological assessment of levothyroxine and liothyronine Maillard impurities.

Following the introduction of new stability-indicating related substances methods, an unknown impurity was observed in levothyroxine (LeMI) and liothyronine (LiMI) tablets (ADVANZ PHARMA) in concentrations ≥1.0%, from 6months of storage onwards. The impurity was identified as a Maillard condensation product between lactose and LeMI/LiMI in the LeMI and LiMI tablets, respectively. To establish the toxicity profile of LeMI and LiMI in humans and to define appropriate shelf-life specification limits, a comprehensive nonclinical toxicological assessment was performed, including in silico (Leadscope and Derek Nexus analyses), in vitro (Ames test), and in vivo tests (7-day dose range finding and 90-day dose repeat studies in rats). In silico analyses indicated that potential LeMI and LiMI structures should not be considered bacterial mutagens or in vitro/in vivo clastogens, and that at the low oral exposure levels expected, the impurities are unlikely to cause harm. In vitro testing showed that neither LeMI nor LiMI were cytotoxic or mutagenic at up to 5000μg/plate, both in the presence and absence of metabolic activation. The 2 in vivo studies further confirmed that no systemic toxicity or other notable negative effects were evident at up to 200μg/kg/day for LeMI and 45μg/kg/day for LiMI, the highest doses tested. These doses represent 120-122 times the maximum daily exposures of LeMI and LiMI, based on body surface area (μg/m2). Based on these results, a proposal has been formulated to increase the limits of Maillard condensation products to ≤8.0% for LeMI and≤6.0% for LiMI at shelf life.

Toxicogenetic assessment of a pre-workout supplement: In vitro mutagenicity, cytotoxicity, genotoxicity and glutathione determination in liver cell lines and in silico ADMET approaches.

The benefits of practicing physical activity, such as weight loss and control, are commonly associated with caloric restriction diets and may be improved by the ingestion of thermogenic and ergogenic supplements. However, there is a lack of safety data on commonly marketed nutritional supplements. Therefore, this investigation aims to evaluate a pre-workout supplement for mutagenicity using the Ames test, hepatocytoxicity in HepG2 and F C3H cells after 24h, 48h and 72h, genotoxicity using the CBMN assay, determination of gluthatione activity and computational prediction of the three major isolated compounds present in the supplement. The mutagenicity test showed a mutagenic response in TA98 His+ revertants of 5mg/plate in the presence of metabolic activation, cytotoxicity in TA98 of 5mg/plate in the absence of metabolic conditions, and in TA102 of 0.5mg/plate both in the presence and absence of metabolic activation. In our in vitro eukaryotic cell viability, WST-1, LDH and alkaline phosphatase assays, the supplement showed hepatocytotoxicity both dose-dependently and time-dependently. In the cytokinesis blocking micronuclei assay, the supplement induced micronuclei, nuclear buds, nucleoplasmatic, bridge formation, and a decreased in nuclear division. In addition, the supplement decreased intra and extracellular GSH. Computational analysis showed that the three isolated compounds most present in the supplement have the potential to cause hepatotoxicity. In the present investigation, the pre-workout supplement induced mutagenic, genotoxic, and cytotoxic responses and GSH decrease. Thus, considering food safety and public health sanitary vigilance, the consumption of this pre-workout supplement may harm the health of its consumers.

Evaluation of genotoxicity of SUNACTIVE Zn-P240 in vitro and in vivo.

We evaluated the potential genotoxic effects of the nutrient supplement SUNACTIVE Zn-P240 in vitro and in vivo. Genotoxicity tests were performed at the Korea Testing and Research Institute, a GLP certification institution. A bacterial reverse mutation test was performed using the pre-incubation method, while the in vitro chromosome aberration test was performed using a cultured Chinese hamster lung cell line in the presence or absence of metabolic activation. The in vivo micronucleus test was performed using ICR mice. The bacterial reverse mutation test revealed that SUNACTIVE Zn-P240 did not induce genetic mutations at the tested doses in Salmonella typhimurium (TA98, TA100, TA1535, and TA1537) and Escherichia coli (WP2uvrA) tester strains. Meanwhile, the results of the in vitro chromosomal aberration and in vivo micronucleus tests revealed that SUNACTIVE Zn-P240 did not induce chromosomal aberrations. These results suggest that SUNACTIVE Zn-P240 did not exhibit mutagenic or clastogenic properties in vitro and in vivo.

Value of FDG-PET/MR in Oral Focus Assessment in Head and Neck Cancer Patients-A Feasibility Study.

FDG-PET/MR is a hybrid imaging modality used for the staging and restaging of advanced head & neck cancer (HNC) patients. Their treatment typically involves radiation therapy, which requires previous dental focus assessment. The aim of this study was to analyze if staging FDG-PET/MR is a valuable tool for oral focus assessment. For this purpose, FDG-PET/MR findings, such as metabolic activity of periapical radiolucencies and marginal periodontitis, were retrospectively compared with conventional standardized dental focus assessment, including dental radiographs and clinical assessment of 124 teeth in seven patients. Increased FDG uptake of periapical lesions was found in one out of 23 lesions. Increased FDG uptake of the marginal periodontium was recorded in one out of 34 lesions. In summary, standardized dental focus assessment by panoramic radiography and periapical radiographs may be enriched by information from FDG-PET/MR, showing active inflammation in dental foci. However, many dental foci have no correlate in FDG-PET/MR. The treatment decision for oral foci may benefit from the visualized presence or absence of metabolic activity on FDG-PET/MR.

Assessment of genotoxicity of Ssanghwa-tang, an herbal formula, by using bacterial reverse mutation, chromosome aberration, and in vivo micronucleus tests

Objectives: Ssanghwa-tang (SHT) is a traditional herbal formula comprising nine medicinal herbs, and it is used for reducing fatigue in Korea. SHT exerts various effects such as anti-inflammatory, antioxidant, and anti-aging activities, and protection against acute hepatotoxicity. However, the genotoxicity of SHT has not yet been established.Methods: Ten components were identified in SHT water extract by using high-performance liquid chromatography analysis. We assessed the genotoxicity of SHT by using bacterial reverse mutation (Ames test), chromosome aberration, and in vivo micronucleus tests.Results: The contents of paeoniflorin, glycyrrhizin, and liquiritin apioside in SHT were 15.57, 6.94, and 3.48 mg/g extract, respectively. SHT did not increase the revertant colonies of Salmonella typhimurium and Escherichia coli strains in the presence or absence of metabolic activity. Although SHT did not induce structurally abnormal chromosomes in Chinese hamster lung (CHL) cells in the presence of metabolic activity, the number of structurally aberrated chromosomes increased dose-dependently in the absence of metabolic activity. In the in vivo micronucleus test, SHT did not affect the formation of micronuclei compared with the vehicle control.Conclusions: Genotoxicity of SHT was not observed in the Ames test and in vivo micronucleus test. However, based on the results of chromosome aberration test, it can be presumed that SHT has the potential to induce genotoxicity because it induced structurally abnormal chromosomes in the absence of metabolic activity.

Subacute oral toxicity and bacterial mutagenicity of a mixture of Puerariae radix and Hizikia fusiforme extracts

The study aims to identify the safety profile of a mixed extract (KGC-02-PS) from two traditional medicinal herbs, Puerariae radix and Hizikia fusiforme. In a subacute oral toxicity study, KGC-02-PS was administered orally for 28 days by gavage to Sprague Dawley rats (both sexes) at a daily dose of 0, 500, 1000, and 2000 mg/kg body weight. Bodyweight, food consumption, and clinical signs were monitored during the experimental period. After administering the final dose, this study conducted hematology, serum biochemistry, and pathological evaluations. In addition, the study performed a bacterial reverse mutation test with varying concentrations of KGC-02-PS (312.5 μg − 5,000 μg/plate) following OECD guideline No. 471, before testing five bacterial strains (Salmonella typhimurium TA98, TA100, TA1535, TA1537, and Escherichia coli WP2) in the presence or absence of metabolic activation. The preclinical evaluation of KGC-02-PS’s subacute oral toxicity yielded no associated toxicological effects or any changes in clinical signs, body weight, and food consumption. Moreover, examining KGC-02-PS’s hematological and serum biochemical characteristics and pathology yielded no toxicological changes in terms of organ weight measurements and gross or histopathological findings. KGC-02-PS neither increased the number of revertant colonies in all bacterial strains used in the bacterial reverse mutation test, nor did it induce genotoxicity related to bacterial reverse mutations under the study’s conditions. Also, KGC-02-PS’s no-observed-adverse-effect level was greater than 2000 mg/kg.

STRUCTURE AND PROPERTIES OF THE DI- ((2S) -2 -AMINO-3 - (1H-INDOL-3-YL) PROPIONATE)-DIHYDRO-TETRAIODIDE

New organic iodine complex in the amino acid - alkali metal salt - iodine - water systemwas synthesized. The physico-chemical properties of complexdi- ((2S) -2-amino-3- (1H-indol-3-yl) propionate)-dihydro-tetraiodide were studied. Microscopic analysis shows that particles of complex have elongated needle-like linear stick-like shapes with average size 2.50-4.00 µm. The cytotoxicity test on MDCK cell culture, antimicrobial activity on S. aureus ATCC 6538-Р (museum susceptible strain); S. aureus ATCC-BAA-39 (museum multiresistant strain); E. coli ATCC 8739 (museum susceptible strain); E. coli ATCC-BAA-196 (museum multiresistant strain); P. aeruginosa ATCC 9027 (museum susceptible strain); P. aeruginosa TA2were observed. Complex has low cytotoxicity, direct antiviral effect, and antimicrobial activity against antibiotic-resistant strains of microorganisms. Di- ((2S) -2-amino-3- (1H-indol-3-yl) propionate)-dihydro-tetraiodide does not cause any mutagenic effect on mammalian cells of the L5178Y line, both in the presence and in the absence of metabolic activation.

Antigenotoxic Effects and Possible Mechanism of Red Yeast (Sporidiobolus pararoseus) on Aflatoxin B1-Induced Mutagenesis.

Red yeast (Sporidiobolus pararoseus), obtained from glycerol waste in the biodiesel process, has been used as a mycotoxin sorbent in some agricultural products. This study focused on the antigenotoxic effects of red yeast on aflatoxin B1 (AFB1)-induced mutagenesis, using a Salmonella mutation assay and a rat liver micronucleus test. Red yeast was sequentially extracted to obtain hexane, acetone, hot water, and residue fractions. Carbohydrates were mainly found in hot water extract (HWE), while proteins were observed in the residue fraction. The amount of lycopene in hexane extract (HE) was higher than the amount of β-carotene in HE. All red yeast extracts were not mutagenic in the Salmonella typhimurium strains TA98 and TA100 under the presence and absence of metabolic activation. Among the extracts obtained from red yeast, HE presented the strongest antimutagenicity against AFB1-induced mutagenesis in both strains, but HWE did not show any antimutagenicity. The oral administration of red yeast, HE, and HWE for 28 days was further investigated in rats. These extracts did not induce micronucleated hepatocytes. Furthermore, they modulated the activities of some detoxifying enzymes but did not alter the activities of various cytochrome P450 isozymes. Notably, they significantly decreased hepatic micronucleus formation in AFB1-initiated rats. HE altered the activity of hepatic glutathione-S-transferase but did not affect its protein expression. Taken together, the antigenotoxicity of red yeast against AFB1-induced mutagenesis might be partly due to the modulation of some detoxifying enzymes in AFB1 metabolism. β-Carotene and lycopene might be promising antigenotoxic compounds in red yeast.

Mutagenicity and genotoxicity assessments of some industrially processed meat products in Algeria

Processed meat products are presumptive sources of mutagens and genotoxins for consumers. Several epidemiological studies have reported that these products' high intakes have a positive link with cancer incidence. In Algeria, industrially processed meat products are widely consumed. However, there are no earlier studies involving their genotoxic activity. For this end, the current study aimed at evaluating the mutagenicity and the genotoxicity of some representative industrially processed meat products sold in popular supermarkets. All samples were extracted by established method, using both polar and non-polar solvents. The meat extracts mutagenicity was assessed by Ames test, using four strains of Salmonella typhimurium in the presence and absence of metabolic activation, and subsequently by treat and wash assay for extracts showing biologically significant results. The genotoxicity was determined in TK6 human lymphoblastoid cells using the in vitro micronucleus assay in micromethod. The results showed that all extracts analyzed induce no mutagenic activity. However, one of these extracts induced a biologically significant increase in the number of micronucleated cells. Our findings indicate the importance of the genetic damage detection for taking measures to suppress or reduce the exposure to harmful contaminants and encourage further research investigating genotoxic effects of industrially processed meat worldwide.

Evaluation of effect of hazardous contaminants in areas for the abstraction of drinking water

The lower portion of Taquari River is influenced by compounds from anthropic activities causing concern about the drinking water supplied to cities in the region. The study objective was to investigate the presence of contaminants at drinking water abstraction sites, defining the mutagenic effects of these stressors as an ecosystem quality parameter and its possible effects on human health. Geographic Information System techniques were used to investigate sources of contamination and it was found that agricultural activities predominated with a few medium and high potential pollutant agricultural activities, besides a soil area that was contaminated and undergoing an intervention process. Mutagenic effects were evaluated by Salmonella/microsome assay using TA98, TA97a, TA100, YG1041 and YG1042 strains in the presence and absence of metabolic activation (S9). Mutagenesis found in organic sediment extracts and surface water samples showed the prevalence of direct-acting mutagens at the drinking water abstraction sites. Taquari (Ta032, the sampling points were named according to the initial letters of the river (Ta), followed by the number of kilometers from the mouth) showed the highest mutagenic potency in sediment, while Ta063, at Bom Retiro do Sul, presented it in the water sample. In the Triunfo region (Ta011) there were significant responses in sediment and in water samples. The samples at General Câmara (Ta006) showed the least presence of contaminants. The Allium cepa test applied to sediments in natura showed significant micronucleus induction in Ta032 in accordance with the Salmonella/microssome assay. The test performed on Danio rerio embryos (FET) in the in natura water samples did not present significant responses. Chemical analyses of polycyclic aromatic hydrocarbons and metals already identified as chemical markers in the area indicated a small contribution to the mutagenic potency, calling attention to the fact that other direct-acting pollutants may be present at the drinking water abstraction sites.

Safety assessment of the substance benzophenone-3,3',4,4'-tetracarboxylic dianhydride, for use in food contact materials.

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of benzophenone‐3,3′,4,4′‐tetracarboxylic dianhydride (BTDA), FCM substance No 1083, as co‐monomer for the production of polyimides used in repeated use materials and articles that are in contact with acidic and fatty foods at temperatures up to 250°C. Migration of BTDA from a polyimide containing 43% BTDA, ■■■■■ into olive oil was below the limit of quantification of about 3 μg/kg food, and in 3% acetic acid it decreased from 30.3 μg/kg in the first test to 22.1 μg/kg in the third test (2 h/100°C). In a semi‐quantitative screening using acetonitrile and acetonitrile/water to extract the polymer powder, linear and cyclic oligomers were detected at levels below 1 mg/kg material. In thermal desorption of the polymer powder at 250°C, phenol, tentatively identified ■■■■■ were found, but the modelled migrations of these were far below a level of potential concern. ■■■■■. The substance did not induce gene mutations in bacterial and mammalian cells. In an in vitro chromosomal aberration test, the substance was found to be directly clastogenic in the absence of metabolic activation. In an in vivo follow‐up, the substance did not induce the formation of micronuclei in experimental conditions associated with evidence of systemic exposure and therefore the Panel considered that the substance does not raise concern for genotoxicity. The CEP Panel concluded that the use of the substance BTDA is not of safety concern for the consumer if it is applied at up to 43% as a co‐monomer in the production of polyimides for repeated use contact with acidic or fatty foods at temperatures up to 250°C. In addition, the migration of BTDA should not exceed 50 μg/kg.