Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Toxins (Basel) ; 16(1)2024 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-38276533

RESUMEN

(1) Background: Safety problems associated with aflatoxin B1 (AFB1) contamination have always been a major threat to human health. Removing AFB1 through adsorption is considered an attractive remediation technique. (2) Methods: To produce an adsorbent with a high AFB1 adsorption efficiency, a magnetic reduced graphene oxide composite (Fe3O4@rGO) was synthesized using one-step hydrothermal fabrication. Then, the adsorbent was characterized using a series of techniques, such as SEM, TEM, XRD, FT-IR, VSM, and nitrogen adsorption-desorption analysis. Finally, the effects of this nanocomposite on the nutritional components of treated foods, such as vegetable oil and peanut milk, were also examined. (3) Results: The optimal synthesis conditions for Fe3O4@rGO were determined to be 200 °C for 6 h. The synthesis temperature significantly affected the adsorption properties of the prepared material due to its effect on the layered structure of graphene and the loading of Fe3O4 nanoparticles. The results of various characterizations illustrated that the surface of Fe3O4@rGO had a two-dimensional layered nanostructure with many folds and that Fe3O4 nanoparticles were distributed uniformly on the surface of the composite material. Moreover, the results of isotherm, kinetic, and thermodynamic analyses indicated that the adsorption of AFB1 by Fe3O4@rGO conformed to the Langmuir model, with a maximum adsorption capacity of 82.64 mg·g-1; the rapid and efficient adsorption of AFB1 occurred mainly through chemical adsorption via a spontaneous endothermic process. When applied to treat vegetable oil and peanut milk, the prepared material minimized the loss of nutrients and thus preserved food quality. (4) Conclusions: The above findings reveal a promising adsorbent, Fe3O4@rGO, with favorable properties for AFB1 adsorption and potential for food safety applications.


Asunto(s)
Grafito , Nanocompuestos , Contaminantes Químicos del Agua , Humanos , Grafito/química , Aflatoxina B1/química , Espectroscopía Infrarroja por Transformada de Fourier , Adsorción , Aceites de Plantas , Fenómenos Magnéticos , Nanocompuestos/química , Cinética
2.
Food Chem ; 428: 136779, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37413832

RESUMEN

Physical adsorbents for detoxification are widely used in vegetable oil industry. So far, the high-efficiency and low-cost adsorbents have not been well explored. Here, a hierarchical fungal mycelia@graphene oxide@Fe3O4 (FM@GO@Fe3O4) was fabricated as an efficient adsorbent for simultaneous removal of aflatoxin B1 (AFB1) and zearalenone (ZEN). The morphological, functional and structural characteristics of the prepared adsorbents were systematic investigated. Batch adsorption experiments in both single and binary systems were conducted, and the adsorption behaviours and mechanism were explored. The results indicated that the adsorption process occurred spontaneously and the mycotoxin adsorption could be described as physisorption through hydrogen bonding, π-π stacking, electrostatic and hydrophobic interactions. Due to good biological safety, magnetic manipulability, scalability, recyclability and easy regeneration, FM@GO@Fe3O4 performance is suitable for application as a detoxification adsorbent in vegetable oil industry. Our study addresses a novel green strategy for removing multiple mycotoxins by integrating the toxigenic isolates with advanced nanomaterials.


Asunto(s)
Micotoxinas , Zearalenona , Zearalenona/química , Aflatoxina B1/química , Aceites de Plantas , Adsorción
3.
Anal Methods ; 15(1): 99-108, 2022 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-36484245

RESUMEN

Aflatoxin B1 (AFB1) is a highly toxic mycotoxin, which causes severe acute or cumulative poisoning. Therefore, it is important to develop sensitive and selective detection methods for AFB1 for the safety of food and medicinal herbs. Herein, we have developed a "signal-on" electrochemical aptasensor based on the high specificity of the aptamer and hybridization chain reaction (HCR) biological amplification for AFB1 detection. In this work, thiol-modified complementary DNA (cDNA) immobilized on the surface of a gold electrode (GE) served as an initiator DNA. When AFB1 was present, it competed with the cDNA for binding to the aptamers, which resulted in the detaching of aptamers from the cDNA-aptamer duplexes. Then, the single-stranded cDNA acted as an initiator to trigger the HCR signal amplification. Therefore, long double-stranded DNA (dsDNA) products were produced, which could load large amounts of methylene blue (MB) molecules to generate a distinct electrochemical signal. Under the optimized conditions, the proposed electrochemical aptasensor achieved the ultrasensitive detection of AFB1 with a linear detection range of 0.01-100 pg mL-1, and a limit of detection (LOD) down to 2.84 fg mL-1. Furthermore, the electrochemical aptasensor was successfully applied for detecting AFB1 in corn and two kinds of traditional Chinese medicine samples, indicating the potential value for AFB1 detection in practical samples.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , ADN Complementario/química , Aflatoxina B1/análisis , Aflatoxina B1/química , Aptámeros de Nucleótidos/química , Contaminación de Alimentos/análisis , Técnicas Electroquímicas/métodos , ADN/química , Técnicas Biosensibles/métodos
4.
J Food Sci ; 86(1): 149-160, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33314161

RESUMEN

The present study envisages the potential application of chitosan-coated Zingiber zerumbet essential oil nanoemulsion (ZEO-CsNE) as green antimicrobial preservative against Aspergillus flavus, aflatoxin B1 (AFB1 ), and lipid peroxidation of stored functional foods. GC-MS analysis of ZEO exhibited the abundance of cis-geraniol (15.53%) as the major component. ZEO-CsNE showed biphasic release profile during in vitro release study conducted for 10 days. The ZEO-CsNE inhibited the growth of A. flavus (strain AF-LHP-SH1) and AFB1 production at 1.0 and 0.8 µL/mL, respectively. Interestingly, considerable reduction in ergosterol biosynthesis followed by enhanced leakage of vital cellular contents and methylglyoxal inhibition represents novel antifungal and antiaflatoxigenic mechanism of action, respectively. Further, ZEO-CsNE inhibited lipid peroxidation and AFB1 production in postharvest Salvia hispanica seeds during in situ trial and presented favorable safety profile (median lethal dose [LD50 ] = 29,114 µL/kg) for male mice. Based on overall observations, ZEO-CsNE could be recommended as a green antimicrobial substitute of synthetic preservatives for in vitro and in situ protection of functional food samples. PRACTICAL APPLICATION: Food industries are facing enormous amount of burden coming from fungal and aflatoxin contamination that can cause severe adverse effects to humans. Essential oils (EOs) are well known for their food preservative efficacy; however, some limitations such as oxidative instability in open system may limit their application directly into food system. The encapsulation of the EOs into polymeric matrix could provide a barrier that will protect the EOs from degradation. This research could provide a basis for utilization of EO after encapsulation into chitosan nanoemulsion for industrial-scale application for preservation of stored functional foods from fungal and aflatoxin contamination.


Asunto(s)
Aflatoxina B1/química , Antifúngicos/farmacología , Quitosano/química , Aceites Volátiles/farmacología , Aceites de Plantas/farmacología , Zingiberaceae/química , Aflatoxina B1/toxicidad , Animales , Antifúngicos/química , Quitosano/farmacología , Emulsiones , Conservantes de Alimentos/farmacología , Hongos/efectos de los fármacos , Tecnología Química Verde , Peroxidación de Lípido/efectos de los fármacos , Ratones , Nanoestructuras/química , Aceites Volátiles/química , Aceites de Plantas/química
5.
Food Chem ; 343: 128521, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33162254

RESUMEN

Magnetic graphene oxide/TiO2(MGO/TiO2) nanocomposite was synthesized for the reduction of aflatoxin B1 (AFB1) in corn oil. The photodegradation of synthesized nanocomposites on AFB1 in corn oil under different treatment conditions and its effect on the quality of corn oil were investigated. The doping of magnetic GO effectively enhanced the photocatalytic activity of TiO2 both under UV light and visible light. The reduction of AFB1 in corn oil reached 96.4% after illumination for 120 min under UV-Vis light. Holes (h+) and the hydroxyl radicals (OH) were found to play important roles in the reduction of AFB1, and three transformation products were confirmed by electrospray ionization mass spectrometry (ESI/MS) analysis. In addition, the quality of the treated corn oil was still acceptable after storage for 180 days. This study provides an effective, environmental-friendly and practical approach for reduction of AFB1 in oil products.


Asunto(s)
Aflatoxina B1/química , Aceite de Maíz/química , Nanocompuestos/química , Contaminación de Alimentos , Calidad de los Alimentos , Grafito/química , Radical Hidroxilo , Luz , Fotólisis , Espectrometría de Masa por Ionización de Electrospray , Titanio/química , Rayos Ultravioleta
6.
Food Chem ; 339: 128072, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33152867

RESUMEN

The efficient magnetic adsorbent (Fe3O4@ATP) was prepared by precipitation through the dispersion of Fe3O4 nanoparticles on the natural attapulgite (ATP) and then tested as an adsorbent for aflatoxin B1 (AFB1) removal from contaminated oils. The adsorbent characterization results revealed that the Fe3O4 were incorporated into the ATP, affording the Fe3O4@ATP composite. This magnetic composite displayed a good ability to eliminate AFB1 from contaminated oils with a removal efficiency of 86.82% using a 0.3% dosage. The Fe3O4@ATP possessed paramagnetic character with a saturation magnetization of 50.86 emu/g, enabling its easy separation from the medium using an external magnet. The adsorption process followed the pseudo-second-order model and fitted the Freundlich isotherm well. Moreover, the thermodynamic studies showed that AFB1 adsorption onto Fe3O4@ATP was exothermic and spontaneous. The novelty of this study lies in the fabrication of magnetic composite adsorbents for AFB1 elimination from oils.


Asunto(s)
Aflatoxina B1/aislamiento & purificación , Arachis/química , Contaminación de Alimentos , Compuestos de Magnesio/química , Imanes/química , Aceites de Plantas/química , Compuestos de Silicona/química , Adsorción , Aflatoxina B1/química , Cinética , Termodinámica
7.
Sci Rep ; 10(1): 11265, 2020 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-32647290

RESUMEN

Microbial detoxification has been proposed as a new alternative for removing toxins and pollutants. In this study, the biodetoxification activities of yeasts against aflatoxin B1 and zinc were evaluated by HPLC and voltammetric techniques. The strains with the best activity were also subjected to complementary assays, namely biocontrol capability and heavy-metal resistance. The results indicate that the detoxification capability is toxin- and strain-dependent and is not directly related to cell growth. Therefore, we can assume that there are some other mechanisms involved in the process, which must be studied in the future. Only 33 of the 213 strains studied were capable of removing over 50% of aflatoxin B1, Rhodotrorula mucilaginosa being the best-performing species detected. As for zinc, there were 39 strains that eliminated over 50% of the heavy metal, with Diutina rugosa showing the best results. Complementary experiments were carried out on the strains with the best detoxification activity. Biocontrol tests against mycotoxigenic moulds showed that almost 50% of strains had an inhibitory effect on growth. Additionally, 53% of the strains grew in the presence of 100 mg/L of zinc. It has been proven that yeasts can be useful tools for biodetoxification, although further experiments must be carried out in order to ascertain the mechanisms involved.


Asunto(s)
Biodegradación Ambiental , Contaminantes Ambientales/química , Metales Pesados/química , Levaduras/metabolismo , Aflatoxina B1/química , Cromatografía Líquida de Alta Presión , Inocuidad de los Alimentos , Pichia/metabolismo , Rhodotorula/metabolismo , Saccharomyces cerevisiae/metabolismo , Saccharomycetales/metabolismo , Aguas Residuales , Zinc/química
8.
Toxins (Basel) ; 12(3)2020 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-32168976

RESUMEN

In this study, we investigated a novel aflatoxin biosensor based on acetylcholinesterase (AChE) inhibition by aflatoxin B1 (AFB1) and developed electrochemical biosensors based on a sodium alginate biopolymer as a new matrix for acetylcholinesterase immobilization. Electrochemical impedance spectroscopy was performed as a convenient transduction method to evaluate the AChE activity through the oxidation of the metabolic product, thiocholine. Satisfactory analytical performances in terms of high sensitivity, good repeatability, and long-term storage stability were obtained with a linear dynamic range from 0.1 to 100 ng/mL and a low detection limit of 0.1 ng/mL, which is below the recommended level of AFB1 (2 µg/L). The suitability of the proposed method was evaluated using the samples of rice supplemented with AFB1 (0.5 ng/mL). The selectivity of the AChE-biosensor for aflatoxins relative to other sets of toxic substances (OTA, AFM 1) was also investigated.


Asunto(s)
Acetilcolinesterasa/química , Aflatoxina B1/análisis , Alginatos/química , Técnicas Biosensibles , Inhibidores de la Colinesterasa/análisis , Acetiltiocolina/química , Aflatoxina B1/química , Inhibidores de la Colinesterasa/química , Espectroscopía Dieléctrica , Contaminación de Alimentos/análisis , Oryza/química
9.
J Hazard Mater ; 381: 120915, 2020 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-31352149

RESUMEN

Safety concerns pertaining towards fungal occurrence in oil commodities have been a significant threat to human health. In this research, magnetic composite adsorbents were fabricated for the removal of aflatoxin B1 (AFB1) from contaminated oils. To this goal, graphene oxides (GO) were synthesized using Hummer's method, and graphenes (rGO) were obtained by the reduction of GO by sodium borohydride. Thereafter, magnetic graphene oxides (MGO) and magnetic graphenes (MrGO) were prepared by coprecipitation of iron oxides on GO and rGO nanosheets, respectively. The as-prepared MGO and MrGO were characterized by SEM, TEM, FT-IR, XRD, VSM, and nitrogen adsorption-desorption techniques. Results showed that MGO had two-dimensional layered nanostructure with many wrinkles on its surface, and the Fe3O4 nanoparticles were essentially encapsulated onto the composite. The adsorption behaviors for the composite adsorbents especially for the removal of AFB1 from contaminated oils were systematically explored by varying adsorbent dosage, contact time, adsorption temperature and initial AFB1 concentration. The MGO adsorbent could have great potential in the application of AFB1 removal from contaminated oils, with the merits of facile magnetic separation and high removal efficiency. However, the removal process also causes a loss of the triglyceride, pigment, and beneficial micronutrients in the oil feedstocks.


Asunto(s)
Aflatoxina B1/química , Grafito/química , Nanopartículas de Magnetita/química , Nanocompuestos/química , Aceite de Salvado de Arroz/química , Adsorción , Inocuidad de los Alimentos , Fenómenos Magnéticos
10.
Toxins (Basel) ; 11(10)2019 10 22.
Artículo en Inglés | MEDLINE | ID: mdl-31652557

RESUMEN

Aflatoxin B1 (AFB1) and zearalenone (ZEN) exert deleterious effects to human and animal health. In this study, the ability of a CotA laccase from Bacillus subtilis (BsCotA) to degrade these two mycotoxins was first investigated. Among the nine structurally defined chemical compounds, methyl syringate was the most efficient mediator assisting BsCotA to degrade AFB1 (98.0%) and ZEN (100.0%). BsCotA could also use plant extracts, including the Epimedium brevicornu, Cucumis sativus L., Lavandula angustifolia, and Schizonepeta tenuifolia extracts to degrade AFB1 and ZEN. Using hydra and BLYES as indicators, it was demonstrated that the degraded products of AFB1 and ZEN using the laccase/mediator systems were detoxified. Finally, a laccase of fungal origin was also able to degrade AFB1 and ZEN in the presence of the discovered mediators. The findings shed light on the possibility of using laccases and a mediator, particularly a natural plant-derived complex mediator, to simultaneously degrade AFB1 and ZEN contaminants in food and feed.


Asunto(s)
Aflatoxina B1/química , Bacillus subtilis/enzimología , Proteínas Bacterianas/química , Proteínas Fúngicas/química , Ganoderma/enzimología , Lacasa/química , Extractos Vegetales/química , Zearalenona/química , Contaminación de Alimentos/prevención & control , Magnoliopsida
11.
Food Chem ; 301: 125281, 2019 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-31382109

RESUMEN

The need for safe and quality food, free from the presence of hazardous contaminants such as mycotoxins is an on-going and complex challenge. Cold atmospheric pressure plasma (CAPP) has the potential to contribute to achieving this goal. Decontamination efficacy of CAPP against six of the most common mycotoxins found in foods and feedstuffs was assessed herein. Concentration reduction of up to 66% was achieved in maize for both aflatoxin B1 and fumonisin B1. Degradation products were detected only in the case of aflatoxin B1 and zearalenone and were tested on human hepatocarcinoma cells with no increase in cytotoxicity observed. Analysis of treated maize revealed substantial changes to small molecular mass components of the matrix. While CAPP shows promise in terms of mycotoxin detoxification important questions concerning potential changes to the nutritional and safety status of the food matrix require further investigations.


Asunto(s)
Descontaminación/métodos , Contaminación de Alimentos/análisis , Micotoxinas/química , Gases em Plasma/química , Aflatoxina B1/análisis , Aflatoxina B1/química , Aflatoxina B1/toxicidad , Fumonisinas/análisis , Fumonisinas/química , Fumonisinas/toxicidad , Células Hep G2 , Hepatocitos/efectos de los fármacos , Humanos , Micotoxinas/análisis , Micotoxinas/toxicidad , Zea mays/química , Zearalenona/análisis , Zearalenona/química , Zearalenona/toxicidad
12.
Anal Chem ; 91(4): 2615-2619, 2019 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-30675773

RESUMEN

Detection of small molecules with good sensitivity, high throughput, simplicity, and generality using aptamers is desired but still remains challenging. We described an aptamer-structure-switch assay coupled with horseradish peroxidase (HRP) labeling on microplates for sensitive absorbance and chemiluminescence detection of small molecules. This assay relies on competition for affinity binding to a limited HRP-labeled aptamer between small-molecule targets and immobilized short DNA strands complementary to the aptamer (cDNA) on a microplate. In the absence of targets, the HRP-labeled aptamer hybridizes with the cDNA on the microplate, and HRP catalyzes substrate into product, generating absorbance or chemiluminescence signals. The binding of small-molecule targets to aptamers causes displacement of HRP-labeled aptamers from the cDNA and signal decrease. In chemiluminescence-analysis mode, the assay achieved detection of aflatoxin B1 (AFB1), ochratoxin A (OTA), and adenosine triphosphate (ATP) with detection limits of 10 pM, 20 pM, and 20 nM, respectively. This assay does not require enzyme-labeled small molecules or the conjugation of small molecules on solid phase. HRP, as an enzyme label, here allows for easily obtainable and highly active signal amplification. This microplate assay is rapid and promising for high-throughput analysis. It shows potential for wide applications in the detection of small molecules.


Asunto(s)
Adenosina Trifosfato/análisis , Aflatoxina B1/análisis , Aptámeros de Nucleótidos/química , Peroxidasa de Rábano Silvestre/química , Ocratoxinas/análisis , Adenosina Trifosfato/química , Aflatoxina B1/química , Aptámeros de Nucleótidos/genética , Bencidinas/química , Compuestos Cromogénicos/química , Colorimetría/métodos , ADN/química , ADN/genética , Ácidos Nucleicos Inmovilizados/química , Ácidos Nucleicos Inmovilizados/genética , Límite de Detección , Mediciones Luminiscentes/métodos , Hibridación de Ácido Nucleico , Ocratoxinas/química , Prueba de Estudio Conceptual
13.
Biol Trace Elem Res ; 190(1): 273-280, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30267312

RESUMEN

Animal feed is prone to becoming infected with molds during production and storage, resulting in secondary metabolite mycotoxins, such as aflatoxin B1 (AFB1), T-2 toxins, deoxynivalenol (DON), and ochratoxin A (OTA), which are harmful to humans and animals. Selenium is an essential trace element for humans and animals, and it is also an effective antioxidant. Many studies have shown that selenium can reduce the damage caused by mycotoxins in animals. This article reviews the current literature on the antagonistic effects of selenium on AFB1, T-2, DON, and OTA toxicity.


Asunto(s)
Alimentación Animal/análisis , Micotoxinas/química , Selenio/química , Aflatoxina B1/química , Ocratoxinas/química , Tricotecenos/química
14.
Toxins (Basel) ; 10(11)2018 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-30469366

RESUMEN

Experiments were carried out to evaluate the effectiveness of three different biosorbents (banana peel, Pyracantha leaves, and Aloe powder) in removing aflatoxin B1 (AFB1). A noncommercial mycotoxin binder (zeolite) was used as a reference material. A laboratory model that simulated the in vivo conditions of the poultry gastrointestinal tract was utilized to prove the removal efficiency of the biosorbents when added to AFB1-contaminated diet (100 µg/kg). The concentration of AFB1 was determined using antibody-based immunoaffinity column and spectrofluorometry methodologies. Z potential (ζ), point of zero charge (pHpzc), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR), and UV-Vis diffuse reflectance spectroscopy (DRS) techniques were used to further characterize the biosorbents. The addition of the biosorbents (1.5%, w/w) to the diet significantly reduced the bioavailability of AFB1 in the intestinal section. The highest aflatoxin adsorption values were 69% and 70% using Aloe powder and zeolite, respectively. A moderate biosorption uptake of 46% was achieved using Pyracantha leaves. The biomaterial with the lowest removal capacity was banana peel (28%). In conclusion, Aloe powder could be used as an alternative to conventional systems for AFB1 removal.


Asunto(s)
Aflatoxina B1/química , Aloe , Modelos Biológicos , Preparaciones de Plantas/química , Adsorción , Alimentación Animal , Animales , Disponibilidad Biológica , Dieta/veterinaria , Contaminación de Alimentos , Tracto Gastrointestinal/química , Musa , Hojas de la Planta , Aves de Corral , Pyracantha , Zeolitas/química
15.
Toxicon ; 150: 144-150, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29800608

RESUMEN

A rapid screening of the most toxic aflatoxin B1 (AFB1) in medicinal materials of radix and rhizome was performed by an immune chromatography method for the first time. The colloidal gold immunochromatographic strip was prepared after optimization of the conjugation of gold particles with monoclonal antibody, the test line and the control line. Under optimized conditions, the detection limit of the constructed test strip was as low as 0.1 ng mL-1 and the total analysis was conducted within 15 min by naked eyes. Four kinds of medicinal materials (Gastrodia elata, Poria cocos, Bletilla striata and Radix Angelicae Dahuricae) were investigated by the strip. Various complex matrixes pay a significant influence on the feasibility and effectiveness of the strip screening in medicinal materials. Aiming to the characteristics of selected medicinal materials, the screening was successfully proceeded with extraction by 70% methanol-water as well as three-fold dilution in Gastrodia elata and Radix Angelicae Dahuricae, 70% methanol-PBS as well as four-fold dilution in Poria cocos., and 60% methanol-water as well as four-fold dilution in Bletilla striata. Among the collected 40 samples, one was found to be positive of AFB1 with level above 5 µg kg-1. The result was in a good agreement with those obtained from LC-MS/MS determination (6.12 µg kg-1). The gold immunochromatographic strip was demonstrated as a rapid, cost-effective, reliable and on-site screening technique for mycotoxins in starch and polysaccharides-rich herbal medicines.


Asunto(s)
Aflatoxina B1/química , Cromatografía de Afinidad/métodos , Oro/química , Raíces de Plantas/química , Plantas Medicinales/química , Rizoma/química , Medicamentos Herbarios Chinos/química , Concentración de Iones de Hidrógeno , Nanopartículas/química , Tiras Reactivas , Sensibilidad y Especificidad
16.
Toxins (Basel) ; 10(3)2018 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-29495577

RESUMEN

Aflatoxin B1 (AFB1) is a very hazardous carcinogen, readily contaminating foodstuffs and traditional Chinese medicines (TCMs) that has inspired increasing health concerns due to dietary exposure. Colloidal nanocrystals have been proposed as optical labels for aptasensor assembly, but these typically require tedious multistep conjugation and suffer from unsatisfactory robustness when used for complex matrices. In the present study, we report a rapid and sensitive method for screening for trace AFB1 levels in TCMs using a label-free fluorescent aptasensor PicoGreen dye-based strategy. Using PicoGreen to selectively measure complementary double-stranded DNA, fluorescence enhancement due to dsDNA is 'turned off' in the presence of AFB1 due binding of aptamer target over complementary sequence. Self-assembly of a label-free fluorescent aptasensor based on AFB1 aptamer and PicoGreen dye was performed. Due to competition between the complementary sequence and AFB1 target, this rapid method was capable of highly sensitive and selective screening for AFB1 in five types of TCMs. This proposed approach had a limit of detection as low as 0.1 µg·L-1 and good linearity with a range of 0.1-10 µg·L-1 (0.1-10 ppb). Among the 20 samples tested, 6 batches were found to be contaminated with AFB1 using this method, which was confirmed using sophisticated liquid chromatography-electrospray ionization-tandem mass spectrometry/mass spectrometry analysis. The results of this study indicate the developed method has the potential to be a simple, quick, and sensitive tool for detecting AFB1 in TCMs.


Asunto(s)
Aflatoxina B1/análisis , Aptámeros de Nucleótidos/química , Técnicas Biosensibles , Contaminación de Medicamentos , Medicina Tradicional China , Aflatoxina B1/química , ADN/química , Colorantes Fluorescentes/química , Compuestos Orgánicos/química
17.
J Hazard Mater ; 344: 249-257, 2018 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-29055198

RESUMEN

A novel dual-competitive lateral flow aptasensor (LFA) benefited from aptamer and lateral flow strips was first designed by using aflatoxin B1 (AFB1) as the model target. In this LFA assay, the target AFB1 competed with AFB1-hapten at T line for binding to Cy5-labeled AFB1 aptamer and the complementary strand competed with the target AFB1 for binding to Cy5-labeled AFB1 aptamer at C line. The ratio of their fluorescent intensities at the T line and C line (ST/SC ratio) was employed in order to increase the sensitivity for target AFB1 detection. This technique has the limit of detection (LOD) of 0.1ng/mL for AFB1 within the linear range from 0.1ng/mL to 1000ng/mL. Subsequently, the LFA approach was validated using 11 kinds of food and feedstuff samples with a simple aqueous extraction protocol. The test results with different naturally contaminated feedstuffs indicated a good correlation between this LFA and a commercial ELISA kit. The assay can be completed within 20min and its sensitivity, specificity and reproducibility are highly satisfactory. This is the first LFA that has been rigorously validated, which will be greatly beneficial to development of commercial aptamer-based biosensors for food safety, environmental analysis, particularly in clinical diagnosis.


Asunto(s)
Aflatoxina B1/análisis , Técnicas Biosensibles , Contaminantes Ambientales/análisis , Contaminación de Alimentos/análisis , Aflatoxina B1/química , Alimentación Animal/análisis , Aptámeros de Nucleótidos , Biotina/química , ADN/química , Contaminantes Ambientales/química , Albúmina Sérica Bovina/química , Estreptavidina/química
18.
Food Chem Toxicol ; 111: 102-113, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29126800

RESUMEN

The study reports efficacy of Illicium verum essential oil (IvEO) against food borne moudls and its nanoencapsulation for enhancing antifungal and antiaflatoxigenic potency. Chemical characterization of the IvEO showed anethole (89.12%) as major compound followed by estragole (4.859%). The IvEO showed broad fungitoxic spectrum against common food borne moulds. It's minimum inhibitory concentration (MIC) and minimum aflatoxin B1 inhibitory concentration (MAIC) against aflatoxigenic strain Aspergillus flavus LHP-PV-1 were 0.7, and 0.5 µL/mL respectively. Morphological observations of treatment sets by SEM and TEM along with decrease in ergosterol content and enhanced leakage of Ca2+, K+ and Mg2+ ions denoted fungal cell membrane as site of action. The IvEO showed promising free radical scavenging activity and favourable safety profile with high LD50 value on mice. The IvEO also exhibited considerable protection of Pistacia vera from fungal contamination and complete protection from aflatoxin B1 contamination in storage containers. Nanoencapsulated IvEO in gel form and lyophilized form exhibited enhanced efficacy as fungal inhibitor and aflatoxin suppressor. The chemically characterised IvEO may be recommended as plant based preservative having favourable safety and its nanocapsules may be of industrial significance as shelf life enhancer of food items. This is the first report on in situ antiaflatoxigenic efficacy and nanoencapsulation of IvEO.


Asunto(s)
Aflatoxina B1/química , Conservantes de Alimentos/farmacología , Illicium/química , Aceites de Plantas/farmacología , Animales , Antifúngicos/química , Antifúngicos/farmacología , Aspergillus flavus/efectos de los fármacos , Aspergillus flavus/ultraestructura , Conservantes de Alimentos/química , Radicales Libres , Hongos/efectos de los fármacos , Ratones , Aceites Volátiles/química , Aceites Volátiles/farmacología , Pistacia/microbiología , Extractos Vegetales/farmacología , Aceites de Plantas/química
19.
Chem Res Toxicol ; 30(9): 1694-1701, 2017 09 18.
Artículo en Inglés | MEDLINE | ID: mdl-28768106

RESUMEN

Previously, a calcium montmorillonite clay (NovaSil) included in the diet of animals has been shown to bind aflatoxin B1 (AfB1) and reduce the symptoms of aflatoxicosis. To investigate and improve the capacity and efficacy of clay-based materials as aflatoxin sorbents, we developed and tested calcium and sodium montmorillonite clays amended with nutrients including l-carnitine and choline. Also, we determined the sorption of AfB1 by isothermal analysis and tested the ability of these amended sorbents to protect adult hydra from AfB1 toxicity. The results showed that exchanging montmorillonite clays with l-carnitine and choline inhibited swelling of the clays and increased the sorption capacity and efficacy of clay surfaces for AfB1. Results from dehydroxylated and heat-collapsed clays suggested that AfB1 was primarily adsorbed in the clay interlayer, as predicted from thermodynamic calculations and computational modeling. The hydra bioassay further indicated that the modified clays can significantly protect adult hydra from AfB1 with as low as 0.005% clay inclusion. This enterosorbent therapy may also be applied to screen hazardous chemicals such as pesticides and PAHs based on similar sorption mechanisms. Taken together, enterosorbent therapy could be delivered in nutritional supplements, foods that are vulnerable to aflatoxin contamination, flavored liquids and animal feeds during emergencies and outbreaks of acute aflatoxicosis, and as a screening model for hazardous environmental chemicals.


Asunto(s)
Aflatoxina B1/química , Silicatos de Aluminio/química , Sustancias Peligrosas/química , Adsorción , Animales , Bentonita/química , Carnitina/química , Colina/química , Arcilla , Dieta , Contaminación de Alimentos/análisis , Modelos Moleculares , Termodinámica
20.
Toxins (Basel) ; 8(11)2016 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-27845743

RESUMEN

Aflatoxins, a group of extremely hazardous compounds because of their genotoxicity and carcinogenicity to human and animals, are commonly found in many tropical and subtropical regions. Ultraviolet (UV) irradiation is proven to be an effective method to reduce or detoxify aflatoxins. However, the degradation products of aflatoxins under UV irradiation and their safety or toxicity have not been clear in practical production such as edible oil industry. In this study, the degradation products of aflatoxin B1 (AFB1) in peanut oil were analyzed by Ultra Performance Liquid Chromatograph-Thermo Quadrupole Exactive Focus mass spectrometry/mass spectrometry (UPLC-TQEF-MS/MS). The high-resolution mass spectra reflected that two main products were formed after the modification of a double bond in the terminal furan ring and the fracture of the lactone ring, while the small molecules especially nitrogen-containing compound may have participated in the photochemical reaction. According to the above results, the possible photodegradation pathway of AFB1 in peanut oil is proposed. Moreover, the human embryo hepatocytes viability assay indicated that the cell toxicity of degradation products after UV irradiation was much lower than that of AFB1, which could be attributed to the breakage of toxicological sites. These findings can provide new information for metabolic pathways and the hazard assessment of AFB1 using UV detoxification.


Asunto(s)
Aflatoxina B1/efectos de la radiación , Aceites de Plantas/efectos de la radiación , Rayos Ultravioleta , Aflatoxina B1/química , Línea Celular , Supervivencia Celular/efectos de los fármacos , Contaminación de Alimentos , Hepatocitos/efectos de los fármacos , Humanos , Aceite de Cacahuete , Fotólisis
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA