Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
1.
Bioelectromagnetics ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862415

RESUMO

Human cytogenetic biomonitoring (HCB) has long been used to evaluate the potential effects of work environments on the DNA integrity of workers. However, HCB studies on the genotoxic effects of occupational exposure to extremely low-frequency electromagnetic fields (ELF-MFs) were limited by the quality of the exposure assessment. More specifically, concerns were raised regarding the method of exposure assessment, the selection of exposure metrics, and the definition of exposure group. In this study, genotoxic effects of occupational exposure to ELF-MFs were assessed on peripheral blood lymphocytes of 88 workers from the electrical sector using the comet and cytokinesis-block micronucleus assay, considering workers' actual exposure over three consecutive days. Different methods were applied to define exposure groups. Overall, the summarized ELF-MF data indicated a low exposure level in the whole study population. It also showed that relying solely on job titles might misclassify 12 workers into exposure groups. We proposed combining hierarchical agglomerative clustering on personal exposure data and job titles to define exposure groups. The final results showed that occupational MF exposure did not significantly induce more genetic damage. Other factors such as age or past smoking rather than ELF-MF exposure could affect the cytogenetic test outcomes.

2.
Onderstepoort J Vet Res ; 91(1): e1-e6, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38572889

RESUMO

Global aflatoxin contamination of agricultural commodities is of the most concern in food safety and quality. This study investigated the hepatoprotective effect of 80% methanolic leaf extract of Annona senegalensis against aflatoxin B1 (AFB1)-induced toxicity in rats. A. senegalensis has shown to inhibit genotoxicity of aflatoxin B1 in vitro. The rats were divided into six groups including untreated control, aflatoxin B1 only (negative control); curcumin (positive control; 10 mg/kg); and three groups receiving different doses (100 mg/kg, 200 mg/kg, and 300 mg/kg) of A. senegalensis extract. The rats received treatment (with the exception of untreated group) for 7 days prior to intoxication with aflatoxin B1. Serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, and creatinine were measured. Hepatic tissues were analysed for histological alterations. Administration of A. senegalensis extract demonstrated hepatoprotective effects against aflatoxin B1-induced toxicity in vivo by significantly reducing the level of serum aspartate aminotransferase and alanine aminotransferase and regenerating the hepatocytes. No significant changes were observed in the levels of alkaline phosphatase, lactate dehydrogenase, and creatinine for the AFB1 intoxicated group, curcumin+AFB1 and Annona senegalensis leaf extract (ASLE)+AFB1 (100 mg/kg, 200 mg/kg, and 300 mg/kg body weight [b.w.]) treated groups. Annona senegalensis is a good candidate for hepatoprotective agents and thus its use in traditional medicine may at least in part be justified.Contribution: The plant extract investigated in this study can be used in animal health to protect the organism from toxicity caused by mycotoxins.


Assuntos
Annona , Curcumina , Ratos , Animais , Aflatoxina B1/toxicidade , Curcumina/farmacologia , Alanina Transaminase/farmacologia , Fosfatase Alcalina/farmacologia , Creatinina/farmacologia , Fígado , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Aspartato Aminotransferases/farmacologia , Lactato Desidrogenases
3.
Heliyon ; 9(3): e14097, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36923833

RESUMO

Until today, it remains controversial whether long-term exposure to extremely low-frequency magnetic fields (ELF-MF) below the legislative exposure limits could result in adverse human health effects. In the present study, the effects of long-term in vitro MF exposure on three different study endpoints (cell viability, genetic damage, and sensitivity to damage induced by known mutagens) were investigated in the human B lymphoblastoid (TK6) cell line. Cells were exposed to 50 Hz MF at three selected magnetic flux densities (i.e., 10, 100, and 500 µT) for different exposure periods ranging from 96h up to 6 weeks. Cell viability following MF exposure was assessed using the ATP-based cell viability assay. Effects of MF exposure on cell genetic damage and cell sensitivity to mutagen-induced damage were evaluated using the in vitro alkaline comet assay and the in vitro cytokinesis block micronucleus assay. The results showed that long-term exposure up to 96h to 50 Hz MF at all tested flux densities could significantly increase TK6 cell viability. In contrast, long-term MF exposure did not affect cell genetic damage, and long-term pre-exposure to MF did not change cell sensitivity to damage induced by known mutagens. At certain time points, statistically significant difference in genotoxicity test results were observed between the MF-exposed cells and the control cells. However, these observations could not be confirmed in the repeat experiments, indicating that they are probably not biologically significant.

4.
Onderstepoort J Vet Res ; 89(1): e1-e6, 2022 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-35384682

RESUMO

Aflatoxins are potent hepatotoxic and carcinogenic secondary metabolites produced by toxigenic fungi. The present study investigated the protective effect of methanolic leaf extracts of Monanthotaxis caffra (MLEMC) against aflatoxin B1-induced toxicity in male Sprague-Dawley rats. The rats were randomly divided into 6 groups of 8 animals each. Five groups were administered orally for seven days with three different concentrations of MLEMC (100 mg/kg, 200 mg/kg and 300 mg/kg), curcumin (10 mg/kg) or vehicle (25% propylene glycol). The following day, these groups were administered 1 mg/kg b.w. of aflatoxin B1 (AFB1). The experiment was terminated three days after administration of AFB1. Group 6 represented untreated healthy control. Serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, creatinine and liver histopathology were evaluated. Methanolic leaf extracts of M. caffra decreased the levels of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase and creatinine in the sera of rats as compared with the AFB1 intoxicated group. Co-administration of MLEMC improved the histological characteristics of the hepatocytes in contrast to the AFB1 treated group, which had mild to severe hepatocellular injuries including bile duct proliferation, bile duct hyperplasia, lymphoplasmacytic infiltrate and fibrosis. Extracts of M. caffra were beneficial in mitigating the hepatotoxic effects of AFB1 in rats by reducing the levels of liver enzymes and preventing hepatic injury.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Doenças dos Roedores , Aflatoxina B1/metabolismo , Aflatoxina B1/toxicidade , Alanina Transaminase/metabolismo , Alanina Transaminase/farmacologia , Animais , Aspartato Aminotransferases/metabolismo , Aspartato Aminotransferases/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Doença Hepática Induzida por Substâncias e Drogas/veterinária , Creatinina/metabolismo , Creatinina/farmacologia , Lactato Desidrogenases/metabolismo , Fígado , Masculino , Metanol/metabolismo , Metanol/farmacologia , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-Dawley , Doenças dos Roedores/metabolismo , Doenças dos Roedores/patologia
5.
J Ethnopharmacol ; 285: 114868, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34826541

RESUMO

ETHNOBOTANICAL RELEVANCE: Smoke from the wood of Acacia seyal Delile has been used by Sudanese women for making a smoke bath locally called Dukhan. The ritual is performed to relieve rheumatic pain, smooth skin, heal wounds and achieve general body relaxation. AIM OF THE STUDY: The present study was designed to investigate the in vitro anti-inflammatory effect of the smoke condensate using cyclooxygenase -1 (COX-1) and -2 (COX-2) as well as its potential genotoxic effects using the bacterial-based Ames test and the mammalian cells-based micronucleus/cytome and comet assays. MATERIAL AND METHODS: The smoke was prepared in a similar way to that commonly used traditionally by Sudanese women then condensed using a funnel. Cyclooxygenase assay was used to evaluate its in vitro anti-inflammatory activity. The neutral red uptake assay was conducted to determine the range of concentrations in the mammalian cells-based assays. The Ames, cytome and comet assays were used to assess its potential adverse (long-term) effects. RESULTS: The smoke condensate did not inhibit the cyclooxygenases at the highest concentration tested. All smoke condensate concentrations tested in the Salmonella/microsome assay induced mutation in both TA98 and TA100 in a dose dependent manner. A significant increase in the frequency of micronucleated cells, nucleoplasmic bridges and nuclear buds was observed in the cytome assay as well as in the % DNA damage in the comet assay. CONCLUSIONS: The findings indicated a dose dependent genotoxic potential of the smoke condensate in the bacterial and human C3A cells and may pose a health risk to women since the smoke bath is frequently practised. The study highlighted the need for further rigorous assessment of the risks associated with the smoke bath practice.


Assuntos
Acacia/química , Medicinas Tradicionais Africanas , Fumaça , Madeira/química , Adulto , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Feminino , Humanos , Testes de Mutagenicidade , Sudão
6.
Environ Toxicol Pharmacol ; 82: 103550, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33227413

RESUMO

Persistent organic and inorganic contaminants generated by industrial effluent wastes poses a threat to the maintenance of aquatic ecosystems and public health. The Khniss and Hamdoun rivers, located in the central-east of Tunisia, receive regularly domestic and textile wastewater load. The present study aimed to survey the water quality of these rivers using physicochemical, analytical and toxicological approaches. In the physicochemical analysis, the recorded levels of COD and TSS in both samples exceed the Tunisian standards. Using the analytical approach, several metals and some textile dyes were detected. Indeed, 17 metals were detected in both samples in varying concentrations, which do not exceed the Tunisian standards. The sources of metals pollution can be of natural and anthropogenic origin. Three textile disperse dyes were detected with high levels compared to other studies: the disperse orange 37 was detected in the Khniss river with a concentration of 6.438 µg/L and the disperse red 1 and the disperse yellow 3 were detected in the Hamdoun river with concentrations of 3.873 µg/L and 1895 µg/L, respectively. Textile activities were the major sources of disperse dyes. For both samples, acute and chronic ecotoxicity was observed in all the studied organisms, however, no genotoxic activity was detected. The presence of metals and textile disperse dyes could be associated with the ecotoxicological effects observed in the river waters, in particular due to the industrial activity, a fact that could deteriorate the ecosystem and therefore threaten the human health of the population living in the study areas. Combining chemical and biological approaches, allowed the detection of water ecotoxicity in testing organisms and the identification of possible contributors to the toxicity observed in these multi-stressed water reservoirs.


Assuntos
Poluentes Químicos da Água/toxicidade , Aliivibrio fischeri/efeitos dos fármacos , Aliivibrio fischeri/metabolismo , Animais , Arsênio/análise , Arsênio/toxicidade , Clorofíceas/efeitos dos fármacos , Clorofíceas/crescimento & desenvolvimento , Corantes/análise , Corantes/toxicidade , Daphnia , Disruptores Endócrinos/análise , Disruptores Endócrinos/toxicidade , Monitoramento Ambiental , Resíduos Industriais , Lepidium sativum/efeitos dos fármacos , Lepidium sativum/crescimento & desenvolvimento , Metais/análise , Metais/toxicidade , Parabenos/análise , Parabenos/toxicidade , Praguicidas/análise , Praguicidas/toxicidade , Fenóis/análise , Fenóis/toxicidade , Rios , Testes de Toxicidade , Tunísia , Águas Residuárias , Poluentes Químicos da Água/análise
7.
MethodsX ; 7: 101071, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33088726

RESUMO

Potential health effects of extremely low-frequency (electro)magnetic fields (ELF-(E)MFs) have long been investigated, but the results are still inconclusive. With respect to genotoxicity, sound data related to the effects of long-term exposure to ELF-(E)MFs on the genetic material and the impact of long-term pre-exposure to ELF-(E)MFs on the sensitivity of cells to the damage induced by known mutagens are needed. In this manuscript, an optimized protocol for a combined in vitro comet/micronucleus study to investigate these effects in a human lymphoblastoid cell line (TK6) is provided including the description of a well-validated exposure system. Furthermore, the use of a shielding system to limit background ELF-MFs inside the incubator is described as well.•Optimized protocols for cytogenetic tests with ELF-MFs on TK6 cells ensure the reproducibility of test results.•Validation of exposure environment and exposure system are needed prior to performing tests with ELF-MFs.•A simple, but effective method to shield cells and reduce unintentional ELF-MF exposure consists of using the mu-metal cylinder. This is of particular interest when studying the effects of low exposure levels.

8.
Environ Sci Pollut Res Int ; 27(32): 40088-40100, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32656751

RESUMO

Due to the complexity and variability of textile wastewater composition, a constant search for new treatment strategies that are efficient, eco-friendly, and cost-effective is mandatory. In the present study, the efficiency of coagulation-flocculation using biocoagulants derived from cactus Opuntia ficus indica and eggplant Solanum melongena to remove toxic compounds from Tunisian textile wastewater samples was evaluated by combining assays to investigate physicochemical properties and in vitro (geno)toxicity with analytical chemistry. Both natural coagulants could significantly improve the physicochemical properties of the textile wastewater samples compared to the traditionally used chemical coagulant. The highest rate of decolorization was achieved after treatment with the cactus-derived coagulant. The analytical study revealed the presence of only crystal violet dye (CV) in only one sample. Both natural coagulants were able to remove CV, which may (partially) explain the decolorization of the treated samples. Only one untreated textile effluent induced a genotoxic response in the VITOTOX® assay. The genotoxic effect was not linked to the presence of CV and was no longer observed after treatment with each of the natural coagulants, suggesting the effectiveness of the remediation treatments to remove potentially genotoxic compound(s). However, in the other genotoxicity tests, no biologically relevant effects were observed for any of the tested samples. In conclusion, although the physicochemical data indicate that the use of natural coagulants (cactus and eggplant) could be an interesting alternative treatment process to the chemical coagulant for detoxifying textile effluents, these results were only partially supported by the toxicological and analytical data.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Floculação , Resíduos Industriais/análise , Indústria Têxtil , Têxteis , Eliminação de Resíduos Líquidos , Águas Residuárias/análise , Poluentes Químicos da Água/análise
9.
Bioelectromagnetics ; 41(6): 425-437, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32602188

RESUMO

The hypothesis of an electromagnetic origin of idiopathic environmental intolerance (IEI) attributed to electromagnetic fields (EMF) has been widely investigated by provocation studies, which consist of deliberately exposing people with IEI-EMF in laboratory settings to particular EMF to observe volunteers' reactions. In the majority of these studies, reactions have been found to be independent of exposure. However, most of these studies suffer from design and methodological limitations that might bias their findings or reduce their precision. As provocation studies are best suited for isolating the effects of EMF, innovative protocols should be applied. In the ExpoComm project (PNREST Anses, EST/2017/2 RF/19), several innovations have been introduced: the involvement of people with IEI-EMF in the development of the protocol, the attenuation of the anxiogenic nature of the tests, the individualization of the protocol, the validation of the neutral or normal reactivity state before the test, and the use of a cocktail of real, rather than artificially generated, sources. The objective of involving people with IEI-EMF was to increase the relevance and acceptability of the protocol, while respecting technical constraints and scientific quality requirements. This paper describes the protocol resulting from the collaborative process. Bioelectromagnetics. 2020;41:425-437. © 2020 Bioelectromagnetics Society.


Assuntos
Bioensaio/métodos , Campos Eletromagnéticos/efeitos adversos , Sensibilidade Química Múltipla/etiologia , Telefone Celular , Humanos , Invenções
10.
Environ Res ; 184: 109387, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32182484

RESUMO

Biological effects have been reproducibly reported in rodents exposed to radiofrequency fields (RF) without significant change of the body temperature. These observations relaunch the controversial question of non-thermal effects of RF. If true, such effects would imply to consider RF energy absorption/interaction in tissues, not as volume-averaged, but locally down to the microscale, which is of potential consequence in particular at frequencies beyond 3 GHz. We propose study protocols to explore that question.


Assuntos
Telefone Celular , Campos Eletromagnéticos , Ondas de Rádio/efeitos adversos , Radiometria
12.
Food Chem Toxicol ; 135: 110768, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31479712

RESUMO

Stem bark of Erythrina latissima E. Mey (Leguminosae) contains a wide range of prenylated flavonoids able to counteract the genotoxic properties of aflatoxin B1 (AFB1). Thus, the hypothesis was raised that E. latissima stem bark extracts (ELBE) may counteract the in vivo hepatotoxic effects of aflatoxins, contaminants in food and feed. An HPLC-DAD method was developed and validated to determine the level of flavonoid aglycones (11.82%) and glycosides (16.17%). ADME, pharmacokinetic and drug-likeness assessment of major flavonoids of ELBE, using the web tool SwissADME, showed good oral bioavailability. The protective effect of ELBE against AFB1 induced genotoxicity in the Vitotox assay after metabolic activation was confirmed (IC50 of 44.32 µg/ml), followed by evaluation of its inhibitory effect on hepatotoxicity in rats induced by the same agent. Male Wistar rats were orally treated with ELBE (20 mg/kg, 50 mg/kg and 100 mg/kg) or curcumin (500 mg/kg) combined with piperine (20 mg/kg) - positive control, for 8 days prior to AFB1 exposure (1 mg/kg). The ELBE group showed a decreased activity of ALP and γ-GT compared to the AFB1 group. Histopathological examination of the liver demonstrated ameliorative effects of ELBE. Thus, ELBE could have a protective effect against hepatotoxins such as AFB1.


Assuntos
Aflatoxina B1/toxicidade , Antimutagênicos/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Erythrina/química , Casca de Planta/química , Extratos Vegetais/farmacologia , Caules de Planta/química , Animais , Antimutagênicos/farmacocinética , Cromatografia Líquida de Alta Pressão , Simulação por Computador , Flavonoides/análise , Masculino , Extratos Vegetais/química , Ratos , Ratos Wistar , Reprodutibilidade dos Testes
14.
Heliyon ; 5(5): e01604, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31193420

RESUMO

Olea europaea L. is one of the most important fruit trees in Tunisia because of its content of many potentially bioactive compounds. The aim of this study was to evaluate the chemical composition, antibiofilm, antiradical and acethylcholinesterase inhibitory activities from four Tunisian cultivars of Olea europaea L., i.e. 'Chetoui', 'Meski', 'Oueslati' and 'Jarboui'. By means of standardized methods, total phenols were determined and some of them characterized by HPLC. The total phenols and flavonoids contents were found to be the highest in the leaves of Chetoui cultivar. The Chetoui cultivar exhibited an important antioxidant and anticholinesterasic activity and an important anti-biofilm activity against Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Candida albicans, Enterococcus faecalis and Escherichia coli, with percentages of inhibition comprised between 83 and 93% at 2xMIC values. Olive leaves extracts could be used in the control of bacterial biofilms in food and food-related environments.

15.
J Pharm Pharmacol ; 70(7): 976-984, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29633259

RESUMO

OBJECTIVES: Monanthotaxis caffra (Sond.) Verdc. (Annonaceae) has been reported to possess antitumoural properties. Preliminary screening showed that the crude methanolic leaf extract had strong antimutagenic effects against aflatoxin B1 -induced mutagenicity. The aim of this study was to isolate and evaluate the antimutagenic properties of the active constituents from M. caffra. METHODS: Different chromatographic, spectroscopic and spectrometric techniques were used for the isolation and identification of the antimutagenic constituents. The antimutagenic effect of the extract and compounds was evaluated using Ames, Vitotox and Comet assays. KEY FINDINGS: Bioassay-guided fractionation of the methanolic leaf extract yielded two antimutagenic compounds identified as (+)-crotepoxide and 5,6-diacetoxy1-benzoyloxymethyl-1,3-cyclohexadiene. Crotepoxide had strong antimutagenicity in the Vitotox assay with an IC50 value of 131 µg/ml. 5,6-Diacetoxy-1-benzoyloxymethyl-1,3-cyclohexadiene showed strong antimutagenic activity in the Ames assay with an IC50 value of 348.9 µg/plate and no antimutagenic activity in the Vitotox test. Furthermore, the compound was able to inhibit, block or prevent biotransformation of aflatoxin B1 by repressing the proteins involved in transcription. CONCLUSIONS: Crotepoxide and 5,6-diacetoxy-1-benzoyloxymethyl-1,3-cyclohexadiene have the potential to mitigate the risks arising from consumption of aflatoxin B1 -contaminated food and feed.


Assuntos
Annonaceae/química , Antimutagênicos/farmacologia , Cicloexenos/farmacologia , Compostos de Epóxi/farmacologia , Extratos Vegetais/farmacologia , Aflatoxina B1/efeitos adversos , Aflatoxina B1/antagonistas & inibidores , Biotransformação/efeitos dos fármacos , Relação Dose-Resposta a Droga , Compostos de Epóxi/isolamento & purificação , Humanos , Estrutura Molecular , Testes de Mutagenicidade , Extratos Vegetais/química , Folhas de Planta/química , Células Tumorais Cultivadas
16.
Arch Toxicol ; 92(4): 1593-1608, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29411056

RESUMO

Although the value of the regulatory accepted batteries for in vitro genotoxicity testing is recognized, they result in a high number of false positives. This has a major impact on society and industries developing novel compounds for pharmaceutical, chemical, and consumer products, as afflicted compounds have to be (prematurely) abandoned or further tested on animals. Using the metabolically competent human HepaRG™ cell line and toxicogenomics approaches, we have developed an upgraded, innovative, and proprietary gene classifier. This gene classifier is based on transcriptomic changes induced by 12 genotoxic and 12 non-genotoxic reference compounds tested at sub-cytotoxic concentrations, i.e., IC10 concentrations as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The resulting gene classifier was translated into an easy-to-handle qPCR array that, as shown by pathway analysis, covers several different cellular processes related to genotoxicity. To further assess the predictivity of the tool, a set of 5 known positive and 5 known negative test compounds for genotoxicity was evaluated. In addition, 2 compounds with debatable genotoxicity data were tested to explore how the qPCR array would classify these. With an accuracy of 100%, when equivocal results were considered positive, the results showed that combining HepaRG™ cells with a genotoxin-specific qPCR array can improve (geno)toxicological hazard assessment. In addition, the developed qPCR array was able to provide additional information on compounds for which so far debatable genotoxicity data are available. The results indicate that the new in vitro tool can improve human safety assessment of chemicals in general by basing predictions on mechanistic toxicogenomics information.


Assuntos
Dano ao DNA , Testes de Mutagenicidade/métodos , Mutagênicos/toxicidade , Reação em Cadeia da Polimerase em Tempo Real/métodos , Linhagem Celular , Humanos , Toxicogenética
17.
Chem Biol Drug Des ; 91(2): 631-640, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28845550

RESUMO

The diverse pharmacological properties of the diaryltriazenes have sparked the interest to investigate their potential to be repurposed as antitubercular drug candidates. In an attempt to improve the antitubercular activity of a previously constructed diaryltriazene library, eight new halogenated nitroaromatic triazenides were synthesized and underwent biological evaluation. The potency of the series was confirmed against the Mycobacterium tuberculosis lab strain H37Ra, and for the most potent derivative, we observed a minimal inhibitory concentration of 0.85 µm. The potency of the triazenide derivatives against M. tuberculosis H37Ra was found to be highly dependent on the nature of the halogenated phenyl substituent and less dependent on cationic species used for the preparation of the salts. Although the inhibitory concentration against J774A.1 macrophages was observed at 3.08 µm, the cellular toxicity was not mediated by the generation of nitroxide intermediate as confirmed by electron paramagnetic resonance spectroscopy, whereas no in vitro mutagenicity could be observed for the new halogenated nitroaromatic triazenides when a trifluoromethyl substituent was present on both the aryl moieties.


Assuntos
Antituberculosos/química , Triazenos/química , Animais , Antituberculosos/síntese química , Antituberculosos/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Espectroscopia de Ressonância de Spin Eletrônica , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Halogenação , Camundongos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/efeitos dos fármacos , Nitrofenóis/química , Relação Estrutura-Atividade , Triazenos/síntese química , Triazenos/farmacologia
18.
Arch Microbiol ; 200(4): 553-565, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29230492

RESUMO

The UPLC MS/MS analysis showed the presence of the two antibiotics in the pharmaceutical industry discharges during 3 months; norfloxacin and spiramycin which were quantified with the mean concentrations of 226.7 and 84.2 ng mL-1, respectively. Sixteen resistant isolates were obtained from the pharmaceutical effluent and identified by sequencing. These isolates belong to different genera, namely Citrobacter, Acinetobacter, Pseudomonas, Delftia, Shewanella, and Rheinheimera. The antibiotic resistance phenotypes of these isolates were determined (27 tested antibiotics-discs). All the studied isolates were found resistant to amoxicillin and gentamicin, and 83.33% of isolates were resistant to ciprofloxacin. Multiple antibiotic resistances were revealed against ß-lactams, quinolones, and aminoglycosides families. Our overall results suggest that the obtained bacterial isolates may constitute potential candidates for bioremediation and can be useful for biotechnological applications. Genotoxic effects were assessed by a battery of biotests; the pharmaceutical wastewater was genotoxic according to the bacterial Vitotox test and micronuclei test. Genotoxicity was also evaluated by the comet test; the tail DNA damages reached 38 and 22% for concentrated sample (10×) and non-concentrated sample (1×), respectively. However, the histological sections of kidney and liver's mice treated by pharmaceutical effluent showed normal histology and no visible structural effects or alterations as cytolysis, edema, or ulcerative necrosis were observed. Residual antibiotics can reach water environment through wastewater and provoke dissemination of the antibiotics resistance and induce genotoxic effects.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Águas Residuárias/microbiologia , Poluentes Químicos da Água/farmacologia , Animais , Antibacterianos/análise , Bactérias/genética , Biodegradação Ambiental , Linhagem Celular Tumoral , Cromatografia Líquida , Dano ao DNA , Indústria Farmacêutica , Farmacorresistência Bacteriana Múltipla , Feminino , Humanos , Resíduos Industriais , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Espectrometria de Massas em Tandem , Tunísia , Águas Residuárias/análise , Águas Residuárias/toxicidade , Microbiologia da Água , Poluentes Químicos da Água/análise
19.
Water Sci Technol ; 76(11-12): 3000-3021, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29210687

RESUMO

In the following study, we came up with and validated a prompt, sensitive and precise method for the simultaneous determination of 56 antimicrobial drugs (tetracyclines, sulfonamides, ß-lactams, macrolides and quinolones) using the ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). This method was implemented with success to determine antibiotics in samples collected from four wastewater treatment plants and five coasts in Tunisia. Results showed the presence of high concentrations of antibiotics that ranged from 0.1 to 646 ng mL-1, which can induce many negative impacts on health and the environment. For this reason, we have opted to evaluate toxicity of wastewater samples using a battery of biotests. In fact, genotoxicity was assessed using three tests: Vitotox, comet and micronucleus assays. The input and output of wastewater treatment plants induced a strongly genotoxic effect on the Salmonella typhimurium TA104 prokaryotic Vitotox assay. This result was confirmed using the comet and the micronucleus assays performed on the human liver hepatocellular carcinoma cells. The genotoxic power of the tested wastewater treatment plants' samples could be attributed to the presence of the higher quantities of antibiotics that are detected in these samples and to the antibiotic and organic compound cocktails.


Assuntos
Antibacterianos/química , Instalações de Eliminação de Resíduos , Águas Residuárias/análise , Poluentes Químicos da Água/química , Animais , Cromatografia Líquida/métodos , Humanos , Mar Mediterrâneo , Medição de Risco , Espectrometria de Massas em Tandem/métodos , Tunísia , Drogas Veterinárias , Eliminação de Resíduos Líquidos
20.
BMC Complement Altern Med ; 17(1): 446, 2017 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-28874162

RESUMO

BACKGROUND: Mutations play a major role in the pathogenesis and development of several chronic degenerative diseases including cancer. It follows, therefore that antimutagenic compound may inhibit the pathological process resulting from exposure to mutagens. Investigation of the antimutagenic potential of traditional medicinal plants and compounds isolated from plant extracts provides one of the tools that can be used to identify compounds with potential cancer chemopreventive properties. The aim of this study was to isolate and characterise the compounds responsible for the antimutagenic activity of Combretum microphyllum. METHODS: The methanol leaf extract of C. microphyllum was evaluated for antimutagenicity in the Ames/microsome assay using Salmonella typhimurium TA98. TA100 and TA102. Solvent-solvent fractionation was used to partition the extracts and by using bioassay-guided fractionation, three compounds were isolated. The antimutagenic activity of the three compounds were determined in the Ames test using Salmonella typhimurium TA98, TA100 and TA102. The antioxidant activity of the three compounds were determined by the quantitative 2,2-diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging method. The cytotoxicity was determined in the MTT assay using human hepatocytes. RESULTS: A bioassay-guided fractionation of the crude extracts for antimutagenic activity led to the isolation of three compounds; n-tetracosanol, eicosanoic acid and arjunolic acid. Arjunolic acid was the most active in all three tested strains with a antimutagenicity of 42 ± 9.6%, 36 ± 1.5% and 44 ± 0.18% in S. typhimurium TA98, TA100 and TA102 respectively at the highest concentration (500 µg/ml) tested, followed by eicosanoic acid and n-tetracosanol. The antioxidant activity of the compounds were determined using the quantitative 2,2 diphenyl-1-picryhydrazyl (DPPH)-free radical scavenging method. Only arjunolic acid had pronounced antioxidant activity (measured as DPPH-free scavenging activity) with an EC50 value of 0.51 µg/ml. The cytotoxicity of the isolated compounds were determined in the MTT assay using human hepatocytes. The compounds had low cytotoxicity at the highest concentration tested with LC50 values >200 µg/ml for n-tetracosanol and eicosanoic acid and 106.39 µg/ml for arjunolic acid. CONCLUSIONS: Based on findings from this study, compounds in leaf extracts of C. microphyllum protected against 4-NQO and MMC induced mutations as evident in the Ames test. The antimutagenic activity of arjunolic acid may, at least in part, be attributed to its antioxidant activity resulting in the detoxification of reactive oxygen species produced during mutagenesis.


Assuntos
Antimutagênicos/farmacologia , Combretum/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Antimutagênicos/análise , Antimutagênicos/química , Compostos de Bifenilo/análise , Compostos de Bifenilo/metabolismo , Linhagem Celular , Ácidos Eicosanoicos , Humanos , Testes de Mutagenicidade , Picratos/análise , Picratos/metabolismo , Extratos Vegetais/análise , Extratos Vegetais/química , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Triterpenos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA