Current Issue : July-September Volume : 2026 Issue Number : 3 Articles : 5 Articles
Amaranth (R2) is used as a color additive in cosmetics. In Korea, R2 is permitted only as a cosmetic colorant and is prohibited in products intended for infants and children under 13 years of age; in Europe, it is regulated solely as a cosmetic colorant rather than a hair dye ingredient. Despite its regulatory relevance, dermal absorption data for R2 are lacking. In this study, percutaneous absorption of R2 was evaluated using the Franz diffusion method with excised rat dorsal skin. Quantitative analysis of R2 was developed and validated using high-performance liquid chromatography (HPLC) in accordance with Korean Ministry of Food and Drug Safety guidelines, demonstrating acceptable linearity (r2 = 0.9996–0.9999), accuracy (95.5–104.4%), and precision (0.3–5.8%). Two formulations (skin lotion and cream), each containing 1% R2, were applied at 113 mg/cm2 for 24 h. Dermal absorption was assessed by analyzing receptor fluid, skin wash, stratum corneum, epidermis, and dermis. Total dermal absorption of R2 was 3.4 ± 2.7% for the lotion and 0% for the cream, corresponding to in vitro skin permeabilities of 34.5 ± 27.0 μg/cm2 and 0 μg/cm2, respectively. Total recovery ranged from 80.3 ± 8.2% to 91.4 ± 19.4%. These results provide essential data for cosmetic risk assessment of R2....
Background: Vulvovaginal candidiasis (VVC) is a significant public health concern characterized by increasing incidence and challenges in treatment. However, most studies investigating Candida spp. virulence factors and antifungal susceptibility predominantly rely on in vitro assays. While these assays are highly reproducible, they do not accurately replicate the complex vaginal microenvironment. To address this limitation, we developed an ex vivo model using porcine vaginal mucosa and a physiologically relevant volume of simulated vaginal fluid (SFV) to better mimic human vaginal conditions. Methods: Biofilm formation and fluconazole activity were assessed using the reference strain Candida albicans ATCC 90028 and two clinical isolates associated with VVC. Results were expressed as colony-forming units (CFU) and directly compared with in vitro assays conducted in Sabouraud dextrose broth (SDB) and SVF. Results: CFU analysis revealed that the ex vivo vaginal mucosa model supported more robust biofilm development, with counts ranging from 6.67 × 107 to 7.20 × 107 CFU/mL, compared to the in vitro SDB assay (3.58 × 107 to 4.5 × 107 CFU/mL). This suggests enhanced fungal growth under tissue-based conditions. Moreover, fluconazole achieved greater biofilm eradication in the ex vivo model (>70%) compared to the in vitro SDB assay (≤34.50%), which may indicate increased antifungal activity within a physiologically relevant environment. Conclusions: The ex vivo vaginal mucosa model offers a physiologically relevant platform for supporting C. albicans biofilm development and serves as a valuable alternative for preclinical screening of antifungal agents....
Background: Stroke is a major global risk to human health due to its high incidence, mortality, and prevalence of associated long-term disabilities. Recent studies have highlighted a significant impact of the gut–brain axis and metabolites derived from intestinal microbiota on modulating neurological disorders, including stroke. Methods: In this study, we investigated the effects of pre- and post-treatment with D-lactate, a lactate stereoisomer mainly produced by certain gut bacteria, on stroke outcome using a transient middle cerebral artery occlusion (MCAO) mouse model. For this purpose, male C57BL/6J mice received a single administration of D-lactate or vehicle (PBS) via the tail vein either before the MCAO surgery, as a preventive approach, or upon reperfusion, as a therapeutic paradigm. Functional outcome was assessed daily using a standard neuroscore and the adhesive removal test until day three post-surgery, when mice were sacrificed. Results: Our results indicated no significant difference in infarct size, measured using cresyl violet staining, between the D-lactate and PBS groups in both pre- and post-treatment experiments. In addition, evaluation of neurological deficits and sensorimotor function showed no statistically significant differences between the interventions throughout the experiment. Conclusions: The present data suggest that treatment with D-lactate does not show a beneficial effect in our C57BL/6J mouse MCAO model....
Background/Objectives: Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra (SN). Because current therapeutics have limited efficacy once PD is fully developed, it is crucial to start disease-modifying interventions during the prodromal stage of PD. In the present study, we aimed to evaluate whether intranasally delivered human umbilical cord mesenchymal stem cells (hUC-MSCs) have an efficacy in the rotenone-induced prodromal PD-like phenotype mouse model. Methods: To produce the prodromal PD mouse model, C57BL/6 mice were treated with intraperitoneal (i.p.) rotenone for 1 or 2 weeks. hUC-MSCs or PBS were delivered intranasally for 1 or 2 weeks with rotenone injection. We subsequently performed behavioral assessments to evaluate motor and non-motor features, followed by pathological analyses of the mouse brains. Results: Intranasal administration of hUCMSCs restored motor performance and protected dopaminergic neurons in the SN of mice treated with rotenone for 2 weeks. In the 1-week rotenone mice, hUC-MSCs treatment ameliorated depressive-like behaviors and attenuated olfactory dysfunction. Furthermore, intranasal hUC-MSC treatment suppressed the accumulation of protein aggregates in the brains of mice, which is associated with enhanced autophagic function, as indicated by increased LC3B and normalization of LAMP2A protein expression. Conclusions: Our data demonstrate that intranasal administration of hUC-MSCs improves non-motor symptoms at early time points and attenuates progression to nigrostriatal loss and motor deficits in the rotenone-induced PD mouse model. These findings support the potential of a non-invasive, prodromal-stage intervention to modulate early pathological progression in PD....
The purpose of this study was to investigate whether quercetin, a flavonoid abundantly found in onion leaves and other plant foods, induces the dilation of retinal blood vessels in rats. The time-course changes in retinal arteriolar diameter were measured using a retinal circulation evaluation system based on a high-resolution digital fundus camera developed in our laboratory. The intravenous administration of quercetin (10–100 μg/kg/min) increased the retinal arteriolar diameter in a dose-dependent manner. This vasodilatory effect of quercetin was almost completely suppressed through an intravitreal pretreatment with Nω-nitro-L-arginine methyl ester (L-NAME), a nitric oxide (NO) synthase inhibitor. In contrast, the systemic intravenous infusion of quercetin did not cause significant changes in the systemic blood pressure and heart rate. These results suggest that NO production plays an important role in the quercetin-induced dilation of retinal arterioles. Quercetin, which is abundantly present in several plant foods and possesses antioxidant properties, may be a useful agent for the prevention of various ocular diseases associated with visual impairment caused by reduced retinal blood flow....
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