Biochemical and molecular assessment of oxidative stress in fruit fly exposed to azo dye Brilliant Black PN

BACKGROUND

Azo dyes are widely used in the food industry to prevent color loss during processing and storage of products. This study aimed to investigate the effect of a diazo dye Brilliant Black PN (E151) on oxidative stress-related parameters in fruit flies (Drosophila melanogaster) at biochemical and molecular levels.

METHODS AND RESULTS

Third instar larvae were transferred to a medium containing the dye at different doses (1, 2.5, and 5 mg/mL). Gene expression and activity of superoxide dismutase, catalase (CAT), glutathione peroxidase (GPX), and acetylcholinesterase (AChE) enzymes were determined in the heads of adult flies obtained from these larvae. In addition, the glutathione (GSH) and malondialdehyde levels were measured using spectrophotometric analysis. Mitochondrial DNA (mtDNA) copy number was also detected by real-time PCR. The results showed that treatment with 5 mg/mL of the dye caused a decrease in both gene expression and enzyme activity of CAT and GPx. Moreover, the same dose of dye treatment decreased AChE activity, GSH level, and mtDNA copy number.

CONCLUSIONS

As a result, Brilliant Black PN dye can trigger toxicity by altering the level and activity of oxidative stress-related biomarkers in a dose-dependent manner. Therefore, more comprehensive studies are needed to elucidate the side effect mechanism and toxicity of this dye.

Interaction of barley β-glucan with food dye molecules - An insight from pulse dipolar EPR spectroscopy

The interactions between dietary fibers (DFs) and small molecules are of great interest to food chemistry and nutrition science. However, the corresponding interaction mechanisms and structural rearrangements of DFs at the molecular level are still opaque due to the usually weak binding and the lack of appropriate techniques to determine details of conformational distributions in such weakly organized systems. By combining our previously established methodology on stochastic spin-labelling of DFs with the appropriately revised set of pulse electron paramagnetic resonance techniques, we present here a toolkit to determine the interactions between DFs and small molecules, using barley β-glucan as an example for neutral DF and a selection of food dye molecules as examples for small molecules. The proposed here methodology allowed us to observe subtle conformational changes of β-glucan by detecting multiple details of the local environment of the spin labels. Substantial variations of binding propensities were detected for different food dyes.

Magnetic Fe3O4 embedded chitosan-crosslinked-polyacrylamide composites with enhanced removal of food dye: Characterization, adsorption and mechanism

The water solubility in acid solution, relative low adsorption capacities and unsatisfactory separation performance limit application of traditional chitosan-based adsorbents in wastewater treatment. To break the limitation, a hydrophilic magnetic Fe₃O₄ embedded chitosan-crosslinked-polyacrylamide composites (abbreviated as m-CS-c-PAM) were prepared by a two-step method. The m-CS-c-PAM composites were systematically characterized using SEM, XRD, FTIR, VSM, TGA and BET. Sunset yellow (SY) was selected as model food dye to investigate adsorption kinetics and thermodynamic parameters of food dye adsorption onto m-CS-c-PAM. Compared with magnetic Fe₃O₄/chitosan, m-CS-c-PAM can adapt to a wider range of pH (2-10) and resist the presence of inorganic salts. m-CS-c-PAM was proved to have high adsorption capacity (359.71 mg g^-1) for SY dye at 298 K, much higher than magnetic Fe₃O₄/chitosan and many reported adsorbents. Moreover, m-CS-c-PAM could be rapidly and efficiently separated from treated solution within 15 s by an external magnet and regenerated by NaOH solution. With its excellent adsorption capacity, pH-independent adsorption capability for food dye, easy and convenient separation ability, satisfactory reusability, m-CS-c-PAM can be a promising material for food wastewater treatment.

A simple and affordable method for estimating the fluid volume a mosquito sucks using food dyes

BACKGROUND

Blood-sucking by mosquitoes is an inevitable behavior when pathogens are transmitted among humans. Adenine nucleotides such as ATP are known as phagostimulants for mosquitoes and are widely used to induce and enhance the blood-sucking activity in an artificial manner. Although using ATP solution is convenient to introduce a variety of substances (for example chemicals and pathogens) into the mosquito body via sucking, establishing an easy and cost-effective method to quantify the amount of solution ingested has yet to be reported.

RESULTS

A set of commercial food dyes (green, blue, yellow, and red) was employed in this study. Each dye was added to ATP solution used to colorize the abdomen of Ae. aegypti female mosquitoes after ingestion. The intake of food dyes did not show any toxicity to the mosquitoes, affecting neither ATP-sucking behavior nor survival of the mosquitoes. We observed that quantifying the color intensity of green dye in the mosquito abdomen by spectral analysis, as well as distinguishing the size of the colored abdomen using the naked eye, allowed the estimation of the amount of ingested solution. Using this method, capsaicin, a pungent component of chili peppers, was identified as an aversive tastant that can discourage mosquitoes from sucking the ATP solution.

CONCLUSIONS

Employing commercially available, non-toxic food dyes converted ATP-driven membrane feeding into an easy-to-use method to estimate the amount of solution ingested by mosquitoes. This method can be further applied for a variety of experiments such as introducing a certain quantity of chemical compounds or microbes into the mosquito body.

Food dyes as P-glycoprotein modulators

The drug transporter P-glycoprotein (P-gp) is often investigated in drug-interaction studies because the activity is modulated by a wide variety of xenobiotics including drugs, herbal products, and food components. In this study, we tested six common arylsulfonate food dyes-allura red, carmoisine, ponceau 4R, quinolone yellow, sunset yellow, and tartrazine-as activators and inhibitors of P-gp activity in vitro. The dyes were studied as P-gp activators by measuring ATPase activity in P-gp-expressing membranes. Compared to verapamil, a known activator of P-gp, the six food dyes showed no stimulatory activity. The potential for these six food dyes to act as P-gp inhibitors was tested in an intracellular efflux assay with P-gp-expressing cells. Compared to GF120918, a known P-gp inhibitor, there was no inhibitory activity for these six food dyes. The six food dyes tested do not interact with P-gp in vitro and, therefore, are unlikely cause clinical drug-food dye interactions. Further investigation is necessary to determine whether these food dyes could interact with other drug transporters.

Chitosan-coated sand and its application in a fixed-bed column to remove dyes in simple, binary, and real systems

Adsorption of tartrazine yellow food dye, in a fixed-bed column, was carried out using a single system, a binary system (in the presence of sunset yellow food dye), and in a real effluent provides from an ice cream industry. Chitosan was used to coat sand particles by the dip-coating technique, and these particles were applied in fixed-bed adsorption. The assays were performed in flow rates of 3 mL min^-1 and 5 mL min^-1. The best performance was reached at 3 mL min^-1. In this flow rate, for single and binary systems, the breakthrough time was 95 min and 65 min, and the maximum capacity of the column was around 595 mg g^-1 and 497 mg g^-1, respectively. In the assay conducted with the real effluent, the breakthrough time was 10 min, and the maximum adsorption capacity of the column was reduced to 191 mg g^-1 for tartrazine dye. The dynamic models of Thomas and Yoon-Nelson were used, and both were suitable to represent the breakthrough curves.

Adverse reactions to food additives in children: A retrospective study and a prospective survey

BACKGROUND

Allergic reactions to food additives are often suspected by families. The aim of this study was to describe oral food challenge (OFC) outcomes in a pediatric cohort with a suspected diagnosis of allergy to food additives (food dyes or sodium benzoate).

METHODS

All patients who underwent an open OFC to carmine red, cochineal red, erythrosine, patent blue V, tartrazine, yellow sunset S, and/or sodium benzoate were included. A survey was sent to families after testing to evaluate whether the OFC results had altered feeding behaviors with food additives.

RESULTS

Twenty-three patients were included. The main suspected food was candy (n=11/23; 48%). Only one OFC out of 45 was formally positive for the carmine and cochineal red. Subsequently, most OFCs were negative (44/45; 97.8%). Despite the negativity of the challenge, four families out of 14 reported occurrences of supposed allergic reactions to food additives and six out of 15 continued to completely avoid the additive of concern in their children's diet.

CONCLUSIONS

Allergies to food additives remain rare. Even if an IgE-mediated allergy was excluded with a negative OFC, families remained suspicious about ready-made products. Health professionals and parents should be reassured about the low risk of food dye intolerance or allergies.

Vibrational and electronic spectroscopic detection and quantification of carminic acid in candies

Carminic acid (CA) contained in one kind of gummy candy was detected and quantified by using vibrational and electronic spectroscopy, respectively; the proposed methodology in solution is simple and rapid without sample pretreatment as usually used and reported. The identification of CA in candies was performed through the Raman and surface enhanced Raman scattering (SERS) spectra along with the equivalent spectral data from the natural CA dye. A modified silver colloidal solution was used in order to obtain SERS activity of CA at very low concentration in colloidal aqueous solution. Theoretical calculations allow infer about both the CA/silver surface interaction nature and on the orientation of CA on the surface. The electronic spectroscopic (UV-Vis) data allowed quantify CA in candies; the amount resulted nearly identical to that determined from HPLC traditional measurements. The present results should contribute to the health of children consumers.

Dyeing but not dying: Colourful dyes as a non-lethal method of food labelling for in vitro-reared honey bee (Apis mellifera) larvae

Several environmental factors (e.g. food source, pesticides, toxins, parasites and pathogens) influence development and maturation of honey bees (Apis mellifera). Therefore, controlled experimental conditions are mandatory when studying the impact of environmental factors: particularly food quality and nutrient consumption. In vitro larval rearing is a standard approach for monitoring food intake of larvae and the labelling of food is necessary to quantify intake in controlled feeding experiments. Here, we tested the suitability of two food dyes, Allura Red and Brilliant Blue, in an experimental set up using in vitro reared honey bee larvae and freshly hatched adult workers. Absorbance of both dyes was measured, in food and dye-fed larvae, to determine the optimal dye concentrations for accurate detection and quantification. By quantifying relative dye concentrations in dye mixtures, relative concentrations of mixed dyes can be estimated independent of the total food consumed by the larvae. Survival assays were conducted to test the impact of both dyes on larval and worker bee survival. Worker bees showed no increase in adult mortality, when fed with dyed honey. Larval survival was not significantly different until the late pupal stage. The physiological impact of dye feeding was tested by measuring larval immune response. No changes in innate immune gene expression were detectable for larvae fed with dyed and non-dyed food. In conclusion, we established a non-invasive food labelling protocol for food intake quantification in in vitro reared honey bee larvae, using non-toxic, inexpensive, and easy to apply food dyes.

Visible light assisted Fenton oxidation of tartrazine using metal doped bismuth oxyhalides as novel photocatalysts

This research focused on the abatement of the model food dye, tartrazine, using visible light photo-Fenton oxidation with novel bismuth oxyhalide catalysts. Bismuth-oxyhalide and metal doped bismuth oxyhalide catalysts (BiOCl, Cu-BiOCl, and Fe-BiOCl) were synthesized via the facile co-precipitation method. The catalysts were characterized by SEM-EDX, XRD, BET, and DRS analyses and the results showed that Cu-BiOCl possess a unique flower-like nanostructure with narrow band gap (2.53 eV) which enhanced its visible light photocatalytic activity remarkably which was proven by catalyst screening experiments. A detailed experimental study was carried out to investigate the effects of operating parameters on the degradation and decolorization of the dye and from this the optimum values were determined as 0.25 g/L for photocatalyst loading, 100 W for visible light power, 6 for initial pH, 6 mM for initial H₂O₂ concentration, and temperature of 70 °C. Approximately 91% degradation, 95% decolorization, and 59% TOC reduction were obtained at optimum conditions. The results for the kinetic study showed that the degradation and decolorization reactions are in the pseudo-first order and obey the simplified Langmuir-Hinselwood kinetic model. The activation energies were calculated as 86.54 and 69.39 kJ/mol for degradation and decolorization, respectively.

Fixed Drug Eruption due to Achiote Dye

Fixed drug eruption (FDE) is a localized type IV sensitivity reaction to a systemically introduced allergen. It usually occurs as a result of new medication, making identification and avoidance of the trigger medication straightforward; however, in a rare subset of cases no pharmacological source is identified. In such cases, the causative agent is often a food or food additive. In this report we describe a case of a FDE in a 12-year-old girl recently immigrated to the United States from Ecuador who had no medication exposure over the course of her illness. Through an exhaustive patient history and literature review, we were able to hypothesize that her presentation was caused by a dietary change of the natural achiote dye used in the preparation of yellow rice to a locally available commercial dye mix containing tartrazine, or Yellow 5, which has previously been implicated in both systemic hypersensitivity reactions and specifically in FDE. This report adds to the small body of available literature on non-pharmacological fixed hypersensitivity eruptions and illustrates an effective approach to the management of such a presentation when history is not immediately revealing.

Effects on DNA repair in human lymphocytes exposed to the food dye tartrazine yellow

Tartrazine is a food additive that belongs to a class of artificial dyes and contains an azo group. Studies about its genotoxic, cytotoxic and mutagenic effects are controversial and, in some cases, unsatisfactory. This work evaluated the potential in vitro cytotoxicity, genotoxicity and effects on DNA repair of human lymphocytes exposed to the dye. We assessed the cytotoxicity of tartrazine by 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide test and the response of DNA repair through comet assay (alkaline version). We used different concentrations of the dye, ranging from 0.25-64.0 mM. The results demonstrated that tartrazine has no cytotoxic effects. However, this dye had a significant genotoxic effect at all concentrations tested. Although most of the damage was amenable to repair, some damage remained higher than positive control after 24 h of repair. These data demonstrate that tartrazine may be harmful to health and its prolonged use could trigger carcinogenesis.