RESUMEN
The present study examined the effects of mesoporous silica nanoparticles (MSNs) on its adsorption capacity of aflatoxin B1 (AFB1). Moreover, the study evaluated the toxicity of MSNs with AFB1 using NIH3T3 cells and hemolysis test. The obtained MSNs were spherical, irregular-like in shape, having a mean size of 39.97 ± 7.85 nm and a BET surface area of 1195 m2/g. At 0.1 mg mL-1 concentration of MSN, the AFB1 adsorption capacity was 30%, which reached 70% when the MSN concentration increased to 2.0 mg mL-1. Our findings showed that AFB1 was adsorbed (â¼67%) in the first few minutes on being in contact with MSNs, reaching an adsorption capacity of â¼70% after 15 min. Thereafter, the adsorption capacity remained constant in solution, demonstrating that the MSNs adsorbed toxins even beyond overnight. MSN treatment (0.5-2.0 mg mL-1) using NIH3T3 cells did not result in any reduction in cell viability. In addition, MSN treatment completely reversed the cytotoxic effect of AFB1 at all concentrations. Hemolysis test also revealed no hemolysis in MSNs evaluated alone and in those combined with AFB1. To the best of our knowledge, this study is the first to demonstrate that MSN can reduce cell toxicity produced by AFB1 due to its potential to adsorb mycotoxins.
Asunto(s)
Micotoxinas , Nanopartículas , Animales , Ratones , Aflatoxina B1 , Dióxido de Silicio , Células 3T3 NIHRESUMEN
Abstract Schizophrenia is an illness that affects 26 million people worldwide. However, conventional antipsychotics present side effects and toxicity, highlighting the need for new antipsychotics. We aimed to evaluate the cytotoxicity of haloperidol (HAL), clozapine (CLO), and a new molecule with antipsychotic potential, PT-31, in NIH-3T3 cells. The neutral red uptake assay and the MTT assay were performed to evaluate cell viability and mitochondrial activity, morphological changes were assessed, and intracellular reactive oxygen species (ROS) detection was performed. HAL and CLO (0.1 µM) showed a decrease in cell viability in the neutral red uptake assay and in the MTT assay. In addition, cell detachment, content decrease, rounding and cell death were also observed at 0.1 µM for both antipsychotics. An increase in ROS was observed for HAL (0.001, 0.01 and 1 µM) and CLO (0.01 and 1 µM). PT-31 did not alter cell viability in any of the assays, although it increased ROS at 0.01 and 1 µM. HAL and CLO present cytotoxicity at 0.1 µM, possibly through apoptosis and necrosis. In contrast, PT-31 does not present cytotoxicity to NIH-3T3 cells. Further studies must be performed for a better understanding of these mechanisms and the potential risk of conventional antipsychotics
Asunto(s)
Esquizofrenia/patología , Antipsicóticos/efectos adversos , Clozapina/análisis , Haloperidol/análisis , Células 3T3 NIH/clasificación , Rojo Neutro/farmacologíaRESUMEN
Valproic acid (VPA) and trichostatin A (TSA) are known histone deacetylase inhibitors (HDACIs) with epigenetic activity that affect chromatin supra-organization, nuclear architecture, and cellular proliferation, particularly in tumor cells. In this study, chromatin remodeling with effects extending to heterochromatic areas was investigated by image analysis in non-transformed NIH 3T3 cells treated for different periods with different doses of VPA and TSA under conditions that indicated no loss of cell viability. Image analysis revealed chromatin decondensation that affected not only euchromatin but also heterochromatin, concomitant with a decreased activity of histone deacetylases and a general increase in histone H3 acetylation. Heterochromatin protein 1-α (HP1-α), identified immunocytochemically, was depleted from the pericentromeric heterochromatin following exposure to both HDACIs. Drastic changes affecting cell proliferation and micronucleation but not alteration in CCND2 expression and in ratios of Bcl-2/Bax expression and cell death occurred following a 48-h exposure of the NIH 3T3 cells particularly in response to higher doses of VPA. Our results demonstrated that even low doses of VPA (0.05 mM) and TSA (10 ng/ml) treatments for 1 h can affect chromatin structure, including that of the heterochromatin areas, in non-transformed cells. HP1-α depletion, probably related to histone demethylation at H3K9me3, in addition to the effect of VPA and TSA on histone H3 acetylation, is induced on NIH 3T3 cells. Despite these facts, alterations in cell proliferation and micronucleation, possibly depending on mitotic spindle defects, require a longer exposure to higher doses of VPA and TSA.