Lifetime toxicity/carcinogenicity studies of FD & C red no. 40 (allura red) in mice

Microglia in Alzheimer's disease: pathogenesis, mechanisms, and therapeutic potentials

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by protein aggregation in the brain. Recent studies have revealed the critical role of microglia in AD pathogenesis. This review provides a comprehensive summary of the current understanding of microglial involvement in AD, focusing on genetic determinants, phenotypic state, phagocytic capacity, neuroinflammatory response, and impact on synaptic plasticity and neuronal regulation. Furthermore, recent developments in drug discovery targeting microglia in AD are reviewed, highlighting potential avenues for therapeutic intervention. This review emphasizes the essential role of microglia in AD and provides insights into potential treatments.

Development of Three-Dimensional Nickel-Cobalt Oxide Nanoflowers for Superior Photocatalytic Degradation of Food Colorant Dyes: Catalyst Properties and Reaction Kinetic Study

In this work, we present three-dimensional flower-like nickel-cobalt oxide (F-NCO) nanosheets developed in a facile, eco-friendly hydrothermal route to apply as photocatalysts for food colorant Allura Red AC dye removal under light illumination. Using Brunauer-Emmett-Teller analysis, it was found that the F-NCO nanosheets displayed a surface area of ∼53.65 m²/g and a Barrett-Joyner-Halenda pore size of ∼14 nm, which was also confirmed by the calculated crystallite size of ∼15 nm using powder X-ray diffraction (XRD) analysis. From Williamson-Hall analysis of XRD spectra, F-NCO nanosheets revealed a crystal-lattice strain of ∼3.42 × 10^-3 and a dislocation density of ∼4.397 × 10¹⁵ lines/m² in the crystal structure. Transmission electron microscopy analysis revealed that F-NCO nanosheets accumulated to form flower-like nanostructures of <100 nm length with a d-spacing of ∼2.6 Å, which is attributed to the (311) crystallographic plane (α = γ = β = 90°, a = b = c = 8.110 Å, JCPDS No. 00-020-0781) of the cubic phase. The F-NCO nanosheets exhibited an excellent photocatalytic efficiency of ∼94.75% in ∼10 min with sodium borohydride under UV light. The Langmuir-Hinshelwood model determined pseudo-first-order reaction kinetics of dye degradation using the ln[AtA0]versus time plot. The kinetic study produced a first-order rate constant (k) of ∼0.219 min^-1, resulting in ∼3.16 min half-life (t_1/2) for the F-NCO-catalyzed degradation reaction. Thus outstanding photocatalytic performance of F-NCO nanosheets would display their huge potential for organic-pollutant removal from water with exceptional recyclability for wide research applications in the future.

Assessment of the exposure to Allura Red colour from the consumption of red juice-based and red soft drinks in Italy

This article reports the results of a survey and an exposure study, based on a probabilistic approach, concerning red juice-based and red soft drink products in Italy. It highlights the fact that the estimates of both the consumption rates and colorant intakes are related to the hypotheses of scenarios. In fact, the study estimates that, on average, consumers of red soft drinks consume 53.1 L year(-1), ranging from 39.1 to 70.7 L of soft drink products under one scenario, or 21.3 L, and from 12.7 and 35.9 L under another hypothesis; while 9.5 L of red juice-based drinks are consumed per year, ranging from 7.0 to 12.5 L, under one scenario, or on average 6.9 L, and ranging from 3.2 to 17.7 L under another scenario. The amount of colorant in a red beverage ranged from 10.9 mg l(-1) in a red soft drink up to 55.9 mg l(-1) in a red juice-based product. The risk evaluation process showed that in all cases the intake of E129 was always lower than the acceptable daily intake. The exposure assessment showed high average intakes of Allura Red in the worst-case scenario, on average, 6.5 and 13.9 mg day(-1), up to 25.0 and 33.0 mg day(-1) at the 95th percentile, for juice-based and soft drinks respectively. The most realistic scenario estimated a weighted average daily intake of Allura Red, on average from about 0.3 to 0.5 mg day(-1) at the 95th percentile, and from 0.4 to 0.6 mg day(-1) for the 95th percentile, from juice-based and soft drinks, respectively. Actually, the highest colorant intake was estimated in a 'health' juice-based drink. The intake of E129 significantly increased with a high level of colorant (>40 mg l(-1)).

Differential colon DNA damage induced by azo food additives between rats and mice

Azo dyes, amaranth, allura red and new coccine, which are currently used as food color additives in Japan, have been reported to cause colon specific DNA damage in mice. To examine species difference in the DNA damage between rats and mice, each of dyes was administered to male mice (1 and 10 mg/kg) and male rats (10, 100 and 1,000 mg/kg) by gavage. Brain, lung, liver, kidney, glandular stomach, colon, urinary bladder and bone marrow were sampled 3 hr (for mice) and 3, 6, 12 and 24 hr (for rats) after the treatment. The alkaline comet assay showed DNA damage in the mouse colon 3 hr after the administration of all of the dyes at 10 mg/kg. In rats, however, none of the dyes damaged DNA. Azo dyes should undergo metabolic reduction in the colon to be adducted to DNA. To determine transit time of the dyes to the colon after their administration, gastric emptying and intestinal transport in mice and rats were examined using brilliant blue FCF (BB) as an indicator. The half times of gastric emptying were 70 and 80 min for mice and rats, respectively; and about 60% of the BB was removed from the stomach 1 hr after the gastric intubation in both mice and rats. BB reached the mouse and rat colon 1 and 3 hr after the administration, respectively. Considering the wide dose range and sampling times well covering the transit time to the colon, rats may be insensitive to these azo dye-induced DNA damage.

High-throughput laser-mediated in situ cell purification with high purity and yield

BACKGROUND

Technologies for purification of living cells have significantly advanced basic and applied research in many settings. Nevertheless, certain challenges remain, including the robust and efficient purification (e.g., high purity, yield, and sterility) of adherent and/or fragile cells and small cell samples, efficient cell cloning, and safe purification of biohazardous cells. In addition, existing purification methods are generally open loop and exhibit an inverse relation between cell purity and yield.

METHODS

An automated closed-loop (i.e., employing feedback control) cell purification technology was developed by building upon medical laser applications and laser-based semiconductor manufacturing equipment. Laser-enabled analysis and processing has combined high-throughput in situ cell imaging with laser-mediated cell manipulation via large field-of-view optics and galvanometer steering. Laser parameters were determined for cell purification using three mechanisms (photothermal, photochemical, and photomechanical), followed by demonstration of system performance and utility.

RESULTS

Photothermal purification required approximately 10(8) W/cm(2) at 523 nm in the presence of Allura Red, resulting in immediate protein coagulation and cell necrosis. Photochemical purification required approximately 10(9) W/cm(2) at 355 nm, resulting in apoptosis induction over 4 to 24 h. Photomechanical purification required more than 10(10) W/cm(2) independent of wavelength, resulting in immediate cell lysis. Each approach resulted in high efficiency purification (>99%) after a single operation, as demonstrated with eight cell types. An automated closed-loop process to re-image and irradiate remaining targets in situ was implemented, resulting in improved purification (99.5-100%) without decreasing cell yield or affecting sterility in this closed system. Efficient purification was demonstrated with B- and T-cell mixtures over a wide range of contaminating cell percentages (0.1-99%) and cell densities (10(4)-10(6)/cm(2)). Efficient cloning of 293T cells based on fluorescence with green fluorescent protein after plasmid transfection was also demonstrated.

CONCLUSIONS

In situ laser-mediated purification was achieved with nonadherent and adherent cells on the automated laser-enabled analysis and processing platform. Closed-loop processing routinely enabled greater than 99.5% purity with a greater than 90% cell yield in sample sizes ranging from 10(1) to 10(8) cells. Throughput ranged from approximately 10(3) to 10(5) total cells/s for contaminating percentages ranging from 99% to 0.1%, respectively.

The comet assay with 8 mouse organs: results with 39 currently used food additives

We determined the genotoxicity of 39 chemicals currently in use as food additives. They fell into six categories-dyes, color fixatives and preservatives, preservatives, antioxidants, fungicides, and sweeteners. We tested groups of four male ddY mice once orally with each additive at up to 0.5xLD(50) or the limit dose (2000mg/kg) and performed the comet assay on the glandular stomach, colon, liver, kidney, urinary bladder, lung, brain, and bone marrow 3 and 24h after treatment. Of all the additives, dyes were the most genotoxic. Amaranth, Allura Red, New Coccine, Tartrazine, Erythrosine, Phloxine, and Rose Bengal induced dose-related DNA damage in the glandular stomach, colon, and/or urinary bladder. All seven dyes induced DNA damage in the gastrointestinal organs at a low dose (10 or 100mg/kg). Among them, Amaranth, Allura Red, New Coccine, and Tartrazine induced DNA damage in the colon at close to the acceptable daily intakes (ADIs). Two antioxidants (butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT)), three fungicides (biphenyl, sodium o-phenylphenol, and thiabendazole), and four sweeteners (sodium cyclamate, saccharin, sodium saccharin, and sucralose) also induced DNA damage in gastrointestinal organs. Based on these results, we believe that more extensive assessment of food additives in current use is warranted.

Reproductive and neurobehavioral effects of Allura Red AC administered to mice in the diet

The color additive, Allura Red AC, was given in the diet to provide levels of 0.42, 0.84, and 1.68% (control, 0%), from 5 weeks of age of the F0 generation to 9 weeks of age of the F1 generation in mice, and selected reproductive and neurobehavioral parameters were measured. There were few adverse effects of Allura Red AC on either litter size or weight, and ratio of male to female was significantly reduced in the lowest dosed group. Average body weight of offspring during the lactation period was significantly increased in the lower dosed groups of each sex. As regards the neurobehavioral parameters, no adverse effect was observed in the behavioral development during lactation period. There were few adverse effects of Allura Red AC on either movement activity or maze learning in F1 generation mice, compared with controls in each sex. The dose levels of Allura Red AC in the present study (approximately 86-1430 times greater than human ADI) produced few adverse effects in reproductive and neurobehavioral parameters in mice.