Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
Toxicol Ind Health ; 37(3): 164-172, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33506746

RESUMO

Air pollution is a worldwide public health issue and it is associated with millions of premature deaths due to cancer, thrombosis, and pulmonary and cardiovascular diseases. Thrombosis is the excessive clotting that blocks a blood vessel, and its etiology is multifactorial. In recent years, growing evidence has linked air pollution, especially particulate matter (PM) and metals, to the development of thrombosis. PM and metals induce lung and systemic inflammation and oxidative stress that are frequent mechanisms in thrombosis. Platelets are important effectors of physiological hemostasis and pathological thrombosis. They are responsible for the formation of the initial plug and are important in the cellular model of coagulation. Therefore, any changes in their morphology or function or an increase in activation could be extremely relevant in thrombosis. Megakaryocytes (MKs) in the bone marrow and in the lungs are the precursor cells of platelets, and the latter is the first organ injured by air pollution. There is substantial evidence of the effect that PM and metals have on platelets, but there is almost no research about the effect of PM and metals on MKs. It is very likely that the alterations produced by air pollution originate in these cells. In this article, we review the biology of MKs and platelets and their role in particulate air pollution-related thrombosis to emphasize the need for further research in this field.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Plaquetas/efeitos dos fármacos , Megacariócitos/efeitos dos fármacos , Material Particulado/efeitos adversos , Trombose/etiologia , Plaquetas/metabolismo , Humanos , Trombose/induzido quimicamente
2.
Int J Toxicol ; 39(1): 20-29, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31884850

RESUMO

Vanadium is a metal present in particulate matter and its reprotoxic effects have been demonstrated in males and pregnant females in animal models. However, the effects of this metal on the reproductive organs of nonpregnant females have not been sufficiently studied. In a vanadium inhalation model in nonpregnant female mice, we found anestrous and estrous cycle irregularity, as well as low serum concentrations of 17ß-estradiol and progesterone. A decrease in the diameter of secondary and preovulatory follicles, as well as a thickening of the myometrium and endometrial stroma, was observed in the vanadium-treated mice. There was no difference against the control group with respect to the presence of the estrogen receptor α in the uterus of the animals during the estrous stage. Our results indicate that when vanadium is administered by inhalation, effects are observed on the female reproductive organs and the production of female sex hormones.


Assuntos
Ciclo Estral/efeitos dos fármacos , Ovário/efeitos dos fármacos , Útero/efeitos dos fármacos , Vanádio/toxicidade , Administração por Inalação , Animais , Estradiol/sangue , Receptor alfa de Estrogênio/metabolismo , Feminino , Camundongos , Ovário/patologia , Progesterona/sangue , Útero/metabolismo , Útero/patologia
3.
Int J Toxicol ; 37(1): 45-52, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29254395

RESUMO

Kidney diseases have notably increased in the last few years. This is partially explained by the increase in metabolic syndrome, diabetes, and systemic blood hypertension. However, there is a segment of the population that has neither of the previous risk factors, yet suffers kidney damage. Exposure to atmospheric pollutants has been suggested as a possible risk factor. Air-suspended particles carry on their surface a variety of fuel combustion-related residues such as metals, and vanadium is one of these. Vanadium might produce oxidative stress resulting in the damage of some organs such as the kidney. Additionally, in countries like Mexico, the ingestion of sweetened beverages is a major issue; whether these beverages alone are responsible for direct kidney damage or whether their ingestion promotes the progression of an existing renal damage generates controversy. In this study, we report the combined effect of vanadium inhalation and sweetened beverages ingestion in a mouse model. Forty CD-1 male mice were distributed in 4 groups: control, vanadium inhalation, 30% sucrose in drinking water, and vanadium inhalation plus sucrose 30% in drinking water. Our results support that vanadium inhalation and the ingestion of 30% sucrose induce functional and histological kidney damage and an increase in oxidative stress biomarkers, which were higher in the combined effect of vanadium plus 30% sucrose. The results also support that the ingestion of 30% sucrose alone without hyperglycemia also produces kidney damage.


Assuntos
Bebidas/efeitos adversos , Nefropatias/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacos , Sacarose/efeitos adversos , Vanádio/toxicidade , Administração Oral , Animais , Bebidas/análise , Glicemia , Interações Medicamentosas , Rim/efeitos dos fármacos , Rim/patologia , Masculino , Camundongos , Distribuição Aleatória , Sacarose/administração & dosagem , Sacarose/química , Sacarose/farmacocinética , Edulcorantes/administração & dosagem , Edulcorantes/efeitos adversos , Edulcorantes/análise , Edulcorantes/farmacocinética , Urinálise , Vanádio/farmacocinética
4.
Toxicol Ind Health ; 32(5): 908-18, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-24442345

RESUMO

Vanadium (V) is an air pollutant released into the atmosphere by burning fossil fuels. Also, it has been recently evaluated for their carcinogenic potential to establish permissible limits of exposure at workplaces. We previously reported an increase in the number and size of platelets and their precursor cells and megakaryocytes in bone marrow and spleen. The aim of this study was to identify the involvement of Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway and thrombopoietin (TPO) receptor, and myeloproliferative leukemia virus oncogene (Mpl), in megakaryocyte proliferation induced by this compound. Mice were exposed twice a week to vanadium pentoxide inhalation (0.02 M) and were killed at 4th, 6th, and 8th week of exposure. Phosphorylated JAK2 (JAK2 ph), STAT3 (STAT3 ph), STAT5, and Mpl were identified in mice spleen megakaryocytes by cytofluorometry and immunohistochemistry. An increase in JAK2 ph and STAT3 ph, but a decrease in Mpl at 8-week exposure was identified in our findings. Taking together, we propose that the morphological findings, JAK/STAT activation, and decreased Mpl receptor induced by V leads to a condition comparable to essential thrombocythemia, so the effect on megakaryocytes caused by different mechanisms is similar. We also suggest that the decrease in Mpl is a negative feedback mechanism after the JAK/STAT activation. Since megakaryocytes are platelet precursors, their alteration affects platelet morphology and function, which might have implications in hemostasis as demonstrated previously, so it is important to continue evaluating the effects of toxics and pollutants on megakaryocytes and platelets.


Assuntos
Proliferação de Células/efeitos dos fármacos , Janus Quinases/metabolismo , Megacariócitos/efeitos dos fármacos , Trombocitemia Essencial/genética , Vanádio/toxicidade , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Relação Dose-Resposta a Droga , Janus Quinases/genética , Masculino , Megacariócitos/citologia , Camundongos , Fosforilação , Receptores de Trombopoetina/genética , Receptores de Trombopoetina/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Trombocitemia Essencial/induzido quimicamente , Trombocitemia Essencial/diagnóstico
5.
Toxicol Pathol ; 43(2): 282-91, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25492423

RESUMO

Neurodegenerative disorders, such as Parkinson's and Alzheimer's diseases, have olfaction impairment. These pathologies have also been linked to environmental pollutants. Vanadium is a pollutant, and its toxic mechanisms are related to the production of oxidative stress. In this study, we evaluated the effects of inhaled vanadium on olfaction, the olfactory bulb antioxidant, through histological and ultrastructural changes in granule cells. Mice in control group were made to inhale saline; the experimental group inhaled 0.02-M vanadium pentoxide (V2O5) for 1 hr twice a week for 4 weeks. Animals were sacrificed at 1, 2, 3, and 4 weeks after inhalation. Olfactory function was evaluated by the odorant test. The activity of glutathione peroxidase (GPx) and glutathione reductase (GR) was assayed in olfactory bulbs and processed for rapid Golgi method and ultrastructural analysis. Results show that olfactory function decreased at 4-week vanadium exposure; granule cells showed a decrease in dendritic spine density and increased lipofuscin, Golgi apparatus vacuolation, apoptosis, and necrosis. The activity of GPx and GR in the olfactory bulb was increased compared to that of the controls. Our results demonstrate that vanadium inhalation disturbs olfaction, histology, and the ultrastructure of the granule cells that might be associated with oxidative stress, a risk factor in neurodegenerative diseases.


Assuntos
Poluentes Ambientais/toxicidade , Bulbo Olfatório/metabolismo , Bulbo Olfatório/patologia , Compostos de Vanádio/administração & dosagem , Compostos de Vanádio/toxicidade , Administração por Inalação , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Espinhas Dendríticas/efeitos dos fármacos , Espinhas Dendríticas/patologia , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Masculino , Camundongos , Necrose , Bulbo Olfatório/efeitos dos fármacos , Olfato/efeitos dos fármacos
6.
J Appl Toxicol ; 34(3): 258-64, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23620078

RESUMO

Vanadium is an environmental pollutant attached to the smallest air suspended particles that enters into the respiratory tract reaching the systemic circulation. The oxidative state of this element and sex are factors related to its toxicity. In this study, we explored sex-associated genotoxic and cytotoxic differences in a mouse experimental model. Mice inhaled V2O5 (0.02 M) 2 h/twice a week; blood samples were obtained at 24 h and every week until the end of the 4-week exposure. Samples were processed for fluorochrome-mediated viability and a micronucleus assay in slides pre-covered with acridine orange (AO). The results showed that males were more susceptible to genotoxicity during the exposure in contrast to the females. In peripheral blood leukocytes, no cytotoxic differences were observed in both, females or males, but the decrease in circulating reticulocytes provides evidence of the metal's cytotoxic effect on the bone marrow (BM). A significant decrease in reticulocytes was observed during the experiment independent of the animal's sex. The present findings might be explained by the interaction of the metal with the enzymes that control erythropoiesis or a direct effect on erythropoietin production might explain our findings; however, an absence of the genotoxic effects in females could be a consequence of the protective effect against oxidative stress by their higher estrogen levels. This study contributes to a better understanding of the mechanisms by which vanadium induces adverse effects in biological systems.


Assuntos
Poluentes Ambientais/toxicidade , Exposição por Inalação/efeitos adversos , Leucócitos/efeitos dos fármacos , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Reticulócitos/efeitos dos fármacos , Caracteres Sexuais , Compostos de Vanádio/toxicidade , Animais , Sobrevivência Celular/efeitos dos fármacos , Feminino , Leucócitos/citologia , Masculino , Camundongos , Micronúcleos com Defeito Cromossômico/estatística & dados numéricos , Testes para Micronúcleos , Reticulócitos/citologia
7.
Environ Toxicol Pharmacol ; 108: 104465, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38734396

RESUMO

Malaria represents the greatest global health burden among all parasitic diseases, with drug resistance representing the primary obstacle to control efforts. Sodium metavanadate (NaVO3) exhibits antimalarial activity against the Plasmodium yoelii yoelii (Pyy), yet its precise antimalarial mechanism remains elusive. This study aimed to assess the antimalarial potential of NaVO3, evaluate its genotoxicity, and determine the production of reactive oxygen and nitrogen species (ROS/RNS) in Pyy. CD-1 mice were infected and divided into two groups: one treated orally with NaVO3 (10 mg/kg/day for 4 days) and the other untreated. A 50% decrease in parasitemia was observed in treated mice. All experimental days demonstrated DNA damage in exposed parasites, along with an increase in ROS and RNS on the fifth day, suggesting a possible parasitostatic effect. The results indicate that DNA is a target of NaVO3, but further studies are necessary to fully elucidate the mechanisms underlying its antimalarial activity.


Assuntos
Antimaláricos , Dano ao DNA , Plasmodium yoelii , Espécies Reativas de Nitrogênio , Espécies Reativas de Oxigênio , Vanadatos , Animais , Plasmodium yoelii/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Antimaláricos/toxicidade , Antimaláricos/farmacologia , Espécies Reativas de Nitrogênio/metabolismo , Vanadatos/toxicidade , Vanadatos/farmacologia , Malária/tratamento farmacológico , Masculino , Parasitemia , Feminino
8.
Histol Histopathol ; 39(8): 969-982, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38329181

RESUMO

The non-ciliated bronchiolar cell, also referred to as "club cell", serves as a significant multifunctional component of the airway epithelium. While the club cell is a prominent epithelial type found in rodents, it is restricted to the bronchioles in humans. Despite these differences, the club cell's importance remains undisputed in both species due to its multifunctionality as a regulatory cell in lung inflammation and a stem cell in lung epithelial regeneration. The objective of this review is to examine different aspects of club cell morphology and physiology in the lung epithelium, under both normal and pathological conditions, to provide a comprehensive understanding of its importance in the respiratory system.


Assuntos
Pulmão , Mucosa Respiratória , Humanos , Animais , Mucosa Respiratória/patologia , Mucosa Respiratória/citologia , Pulmão/patologia , Pulmão/citologia , Bronquíolos/patologia , Células Epiteliais/fisiologia , Células Epiteliais/patologia , Células-Tronco
9.
Antibiotics (Basel) ; 12(5)2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37237792

RESUMO

Pleopeltis crassinervata (Pc) is a fern that, according to ethnobotanical records, is used in Mexican traditional medicine to treat gastrointestinal ailments. Recent reports indicate that the hexane fraction (Hf) obtained from Pc methanolic frond extract affects Toxoplasma gondii tachyzoite viability in vitro; therefore, in the present study, the activity of different Pc hexane subfractions (Hsf) obtained by chromatographic methods was evaluated in the same biological model. Gas chromatography/mass spectrometry (GC/MS) analysis was carried out for hexane subfraction number one (Hsf1), as it showed the highest anti-Toxoplasma activity with a half-maximal inhibitory concentration (IC50) of 23.6 µg/mL, a 50% cytotoxic concentration (CC50) of 398.7 µg/mL in Vero cells, and a selective index (SI) of 16.89. Eighteen compounds were identified by Hsf1 GC/MS analysis, with the majority being fatty acids and terpenes. Hexadecanoic acid, methyl ester was the most commonly found compound (18.05%) followed by olean-13(18)-ene, 2,2,4a,8a,9,12b,14a-octamethyl-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,12,12a,12b,13,14,14a,14b-eicosahydropicene, and 8-octadecenoid acid, methyl ester, which were detected at 16.19%, 12.53%, and 12.99%, respectively. Based on the mechanisms of action reported for these molecules, Hsf1 could exert its anti-Toxoplasma activity mainly on T. gondii lipidomes and membranes.

10.
Histol Histopathol ; 38(7): 765-777, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36524411

RESUMO

The non-ciliated bronchiolar cell (NCBC) is responsible for the defense of the lung and responds to negative stimuli such as exposure to toxic pro-oxidant substances, which triggers the hyperproduction and hypersecretion of mucins and CC16 protein. The literature demonstrates that physiological and pathological responses in the lung can be influenced by the organism's sex. The objective of this report was to evaluate response differences to vanadium (V) inhalation in male and female CD-1 mice. Mice were exposed to V for four weeks. Hyperplasia of bronchiolar epithelium, small inflammatory foci and sloughing of the NCBC were observed, without changes between sexes and throughout the exposure time. Mucosecretory metaplasia was found in both males and females, however it was more drastic in males. The expression of CC16 increased in both sexes. This study demonstrated a different susceptibility between male and female mice exposed to V inhalation regarding mucosecretory metaplasia.


Assuntos
Caracteres Sexuais , Vanádio , Ratos , Camundongos , Masculino , Feminino , Animais , Camundongos Endogâmicos , Ratos Endogâmicos F344 , Vanádio/toxicidade , Pulmão
11.
Antibiotics (Basel) ; 11(11)2022 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-36421302

RESUMO

Apicomplexan parasites are the causal agents of different medically important diseases, such as toxoplasmosis, cryptosporidiosis, and malaria. Toxoplasmosis is considered a neglected parasitosis, even though it can cause severe cerebral complications and death in immunocompromised patients, including children and pregnant women. Drugs against Toxoplasma gondii, the etiological agent of toxoplasmosis, are highly toxic and lack efficacy in eradicating tissue cysts, promoting the establishment of latent infection and acute relapsing disease. Cryptosporidiosis has been recognized as the most frequent waterborne parasitosis in US outbreaks; anti-cryptosporidium drug discovery still faces a major obstacle: drugs that can act on the epicellular parasite. Severe malaria is most commonly caused by the progression of infection with Plasmodium falciparum. In recent years, great progress has been made in the field of antimalarial drugs and vaccines, although the resistance of P. falciparum to artemisinin has recently gained a foothold in Africa. As seen, the search for new drugs against these parasites remains a challenge. Peptide-based drugs seem to be attractive alternative therapeutic agents recently recognized by the pharmaceutical industry, as they can kill different infectious agents and modulate the immune response. A review of the experimental effects of bioactive peptides on these parasites follows, along with comments. In addition, some biological and metabolomic generalities of the parasites are reviewed to elucidate peptide mechanisms of action on Apicomplexan targets.

12.
Artigo em Inglês | MEDLINE | ID: mdl-34444206

RESUMO

Environmental pollution is a worldwide problem recognized by the World Health Organization as a major health risk factor that affects low-, middle- and high-income countries. Suspended particulate matter is among the most dangerous pollutants, since it contains toxicologically relevant agents, such as metals, including vanadium. Vanadium is a transition metal that is emitted into the atmosphere especially by the burning of fossil fuels to which dwellers are exposed. The objective of this literature review is to describe the toxic effects of vanadium and its compounds when they enter the body by inhalation, based especially on the results of a murine experimental model that elucidates the systemic effects that vanadium has on living organisms. To achieve this goal, we reviewed 85 articles on the relevance of vanadium as a component of particulate matter and its toxic effects. Throughout several years of research with the murine experimental model, we have shown that this element generates adverse effects in all the systems evaluated, because it causes immunotoxicity, hematotoxicity, neurotoxicity, nephrotoxicity and reprotoxicity, among other noxious effects. The results with this experimental model add evidence of the effects generated by environmental pollutants and increase the body of evidence that can lead us to make more intelligent environmental decisions for the welfare of all living beings.


Assuntos
Poluentes Atmosféricos , Síndromes Neurotóxicas , Administração por Inalação , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Animais , Combustíveis Fósseis , Camundongos , Material Particulado/análise , Material Particulado/toxicidade , Vanádio/toxicidade
13.
Toxicol Rep ; 7: 1001-1007, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32874923

RESUMO

Malaria is a parasitic disease with the highest morbidity and mortality worldwide and antimalarial drug resistance has increased in last two decades. Chloroquine and artemisinin which were usedfor the treatment of malaria are also reported with resistances. Recently, some metallic compounds of ruthenium and iridium have been used as possible therapeutic agents against other parasites such as Leishmania and Trypanosoma cruzi. Organic and inorganic compounds of vanadium such as metavanadate, have been used lately because its therapeutic properties as antineoplastic and hypoglycemic agents. In this study we evaluated the genotoxicity and cytotoxicity of metavanadate per os and its working dose, as a previous step for the future use of metavanadate as anti-parasitic agent in a Plasmodium yoelii yoelii malarial lethal model. Our findings suggest that 10 mg/kg is a safe dose that decreases parasitemia and increases the survival of the Plasmodium yoelii yoelii infected mice with no evidence of genotoxicity, cytotoxicity with the dose selected.

14.
Histol Histopathol ; 35(5): 497-508, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31531844

RESUMO

The Non-Ciliated Bronchiolar Cell (NCBC) is responsible for the defense and maintenance of the bronchiolar epithelium. Several cellular defense mechanisms have been associated with an increase in the secretion of CC16 and changes in the phenotype of the cell; these mechanisms could be linked to tolerance to the damage due to exposure to inhaled Particulate Matter (PM) of the epithelium. These defense mechanisms have not been sufficiently explored. In this article, we studied the response of the NCBC to inhaled vanadium, an element which adheres to PM. This response was measured by the changes in the phenotype of the NCBC and the secretion of CC16 in a mouse model. Mice were exposed in two phases to different vanadium concentrations; 1.27 mg/m³ in the first phase and 2.56 mg/m³ in the second phase. Mice were sacrificed on the 2nd, 4th, 5th, 6th and 8th weeks. In the second phase, we observed the following: sloughing of the NCBC, hyperplasia and small inflammatory foci remained without changes and that the expression of CC16 was higher in this phase than in phase I. We also observed a change in the phenotype with a slow decrease in both phases. The increase in the secretion of CC16 and the phenotype reversion could be due to the anti-inflammatory activity of CC16. The changes observed in the second phase could be attributed to the tolerance to inhaled vanadium.


Assuntos
Bronquíolos , Células Epiteliais , Uteroglobina/metabolismo , Vanádio/toxicidade , Poluentes Atmosféricos/toxicidade , Animais , Anti-Inflamatórios/metabolismo , Bronquíolos/citologia , Bronquíolos/metabolismo , Bronquíolos/patologia , Tolerância a Medicamentos/fisiologia , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Epitélio/metabolismo , Epitélio/patologia , Inflamação , Inalação , Pulmão/metabolismo , Camundongos , Material Particulado/toxicidade
15.
Rev. Fac. Med. UNAM ; 67(3): 41-51, may.-jun. 2024. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1569545

RESUMO

Resumen El sentido del gusto tiene un papel importante porque ha permitido discriminar entre lo que puede ser alimento y lo que no, e incluso en lo que puede ser tóxico o peligroso al ingerirlo. La búsqueda de nuevos sabores está presente en toda la historia de la humanidad. Desde la antigüedad, las especias aportaron nuevas experiencias gustativas para hacer más palatables los alimentos o incluso para conservarlos durante más tiempo. La búsqueda de especias fue una motivación para realizar viajes que llevaron a descubrimiento de nuevas tierras y continentes. Más recientemente, la pandemia por un virus que altera los sentidos del olfato y del gusto, nos ha hecho recordar la importancia de estos sentidos. El sentido del gusto está determinado por unas pequeñas estructuras que se ubican en las papilas linguales. Hay cuatro tipos que definen cinco sabores y uno que aún está en duda. Las alteraciones de este sentido tienen varios posibles orígenes que se comentan en esta revisión.


Abstract Taste is relevant because it has allowed us to discriminate between what is food and what is not, and even what can be toxic or dangerous when ingested. The search for new flavors is present in history of mankind. Since ancient times, the spices provided new taste experiences to make meals more palatable or as a means of preserving food; the search for spices was a motivation to make voyages that led to the discovery of new lands and continents. More recently, a viral pandemic that damages the olfaction and taste senses made us to remember the relevance of the senses. Small structures, called taste buds, located in the papillae of the tongue are responsible of the sense of taste. There are four types of taste buds that identify five tastes and one whose existence has not yet been fully proven. Taste alterations have different etiologies which will be commented on this review.

16.
J Immunotoxicol ; 16(1): 54-62, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30938211

RESUMO

Silver nanoparticles (AgNP) are one of the most studied nanoparticles due to their anti-bacterial, -fungal, -viral, -parasitic, and -inflammatory properties. This raises the need to evaluate the toxicity and biological effects of AgNP in the immune system in order to develop new safer biomedical products. In this study, an AgNP formulation currently approved for veterinary applications was applied to mouse bone marrow-derived dendritic cells (BMDC), considered important antigen-presenting cells of the immune system, to evaluate cytotoxicity, genotoxicity, and any significant influence on expression of cellular markers associated with BMDC phenotype and maturation status. The results showed that after 12 h of AgNP exposure, a significant decrease in BMDC viability occurred at the highest concentration tested (1.0 µg AgNP/ml) and at lower doses, the cells maintained membrane integrity and metabolic activity. DNA damage was not significant with any AgNP level aside from the 1.0 µg AgNP/ml level. Regarding phenotype, no differences in expression of CD40 (co-stimulatory molecule highly present in mature BMDC) or in CD273 (a marker for inhibitory T-cell response) were observed. The current results showed that the toxicity of this AgNP formulation was dose-related. The findings also suggest BMDC could maintain structural conservation of co-stimulatory/co-inhibitory surface molecules after 12 h of exposure to this AgNP. This work represents the first step in identifying the toxic effects of this AgNP formulation on dendritic cells.


Assuntos
Células da Medula Óssea/imunologia , Células Dendríticas/imunologia , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Animais , Células da Medula Óssea/patologia , Antígenos CD40 , Dano ao DNA/imunologia , Células Dendríticas/patologia , Masculino , Camundongos , Proteína 2 Ligante de Morte Celular Programada 1/imunologia
17.
Rev. Fac. Med. UNAM ; 67(1): 8-16, ene.-feb. 2024. graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1559095

RESUMO

Resumen Se calcula que el cuerpo humano está conformado por billones de células, las cuales sufren cientos de miles de lesiones al día en su DNA. Aunque el DNA no es la única biomolécula que sufre daños, su importancia radica en que es la única que no puede ser sustituida por la célula, así que, cuando esta sufre daños, la célula debe repararlos, tolerarlos o, en el caso extremo, activar las vías que la llevarán a la muerte, ya que lo importante es mantener la integridad celular y la homeostasis del organismo. Hay miles de agentes que pueden dañar al DNA, algunos los produce la misma célula y se les denomina 'agentes endógenos', mientras que otros son agentes externos y se les conoce como 'agentes exógenos'. La célula no puede evitar el daño causado por los agentes endógenos, ya que son productos de la actividad metabólica, por ejemplo; así que, cuando suceden se activan de forma inmediata los mecanismos celulares para mitigarlos. Lo mismo pasa con los daños causados por agentes exógenos, ya que la célula hará todo lo posible por disminuir los efectos adversos que pueden causar. El problema se pone de manifiesto cuando la célula no puede reparar los daños o los repara mal o son tantos que los mecanismos de reparación se ven rebasados, es entonces cuando el daño permanece en el DNA y se genera un estado de inestabilidad cromosómica que puede conducir a la célula a la disfunción y a la malignización. Este estado de inestabilidad cromosómica se puede ver reflejado en el aumento de rompimientos de DNA o de micronúcleos en las células expuestas, lo que se puede cuantificar por medio de métodos especiales como el 'Ensayo Cometa' y el 'Ensayo de Micronúcleos', ya que identificar el daño en el DNA es una forma de evaluar el potencial tóxico que tienen los agentes a los que están expuestas las poblaciones, permite conocer los mecanismos de acción que tienen y, además, ayuda a comprender los factores que influyen en el detrimento de la salud poblacional.


Abstract It is estimated that the human body is made of trillions of cells, which suffer hundreds of thousands of DNA lesions every day. Although DNA is not the only biomolecule that suffers damage, its importance lies in the fact that it is the only biomolecule that cannot be replaced by the cell, so when it suffers damage, the cell must repair it, tolerate or, in a extreme case, activate pathways that will lead to death, since the objective is to maintain cell integrity and the homeostasis of the organism.There are thousands of agents that can damage DNA, some are produced by the cell and are called 'endogenous, while others are external agents and are known as 'exogenous. The cell cannot avoid the damage caused by endogenous agents, since they are products of its metabolic activity, for example, so when they occur, cellular mechanisms are immediately activated to mitigate them. The same happens with the damage caused by exogenous agents, since the cell will do everything possible to diminish the adverse effects they can cause. The problem becomes apparent when the cell is unable to repair the damage or poorly repairs it, or repairs so much that the mechanisms are overwhelmed, when the damage remains in the DNA and a state of chromosomal instability is generated that can lead the cell to dysfunction and malignization. This state of chromosomal instability can be reflected in increased DNA breaks or micronuclei in exposed cells, which can be quantified by special methods such as the 'Comet Assay' and the 'Micronucleus Assay'. Since identifying DNA damage is a way of evaluating the toxic potential of the agents to which populations are exposed, it allows us to know their mechanisms of action and helps to understand the factors that influence the detriment in population's health.

18.
Histol Histopathol ; 33(12): 1299-1309, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29923593

RESUMO

The indiscriminate use of herbal products is increasingly growing worldwide; nonetheless consumers are not warned about the potential health risks that these products may cause. Hintonia latiflora (Hl) is a tree native to the American continent belonging to the Rubiaceae family and its stem bark is empirically used mainly to treat diabetes and malaria; supplements containing Hl are sold in America and Europe without medical prescription, thus scientific information regarding its toxicity as a consequence of a regular consumption is needed. In the present study, the histopathological effect of 200 and 1000 mg/kg of HI methanolic stem bark extract (HlMeOHe) was evaluated in the small bowel, liver, pancreas, kidneys and brain of CD-1 male mice after oral sub-acute treatment for 28 days. No histopathological alterations were observed in the brain and small bowel of the treated animals; however, mice presented diarrhea from day 2 of treatment with both doses. No histological changes were observed in the tissues collected from the animals treated with 200 mg/kg, except for the liver that depicted periportal hepatitis. Animals treated with the higher dose showed in the liver sections hydropic degeneration, hepatitis and necrosis, kidney sections depicted tubular necrosis and in pancreas sections, hydropic degeneration of the pancreatic islets was observed. In conclusion, HlMeOHe damaged the liver with an oral dose of 200 mg/kg, and at 1000 mg/kg injured the kidneys and pancreas of the CD-1 male mice.


Assuntos
Suplementos Nutricionais/toxicidade , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Pâncreas/efeitos dos fármacos , Extratos Vegetais/toxicidade , Animais , Rim/patologia , Fígado/patologia , Masculino , Camundongos , Pâncreas/patologia , Casca de Planta/toxicidade , Rubiaceae
19.
Rev. Fac. Med. UNAM ; 66(6): 37-52, nov.-dic. 2023. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1535225

RESUMO

Resumen El endotelio es una monocapa formada por células aplanadas llamadas w, que revisten la parte más interna del corazón, los vasos sanguíneos y los linfáticos. Es considerado un órgano que tiene una función de barrera, pero además se encarga de regular la permeabilidad y tono vascular, hemostasia, inflamación y angiogénesis. Esta revisión se centra sobre todo en las generalidades del endotelio vascular sano y su disfunción. Se analizan los conceptos de activación y disfunción, en donde la activación se considera como un proceso autolimitado, indispensable para la hemostasia y la inflamación. La disfunción endotelial, en cambio, es un proceso patológico, de mayor duración y que se presenta cuando el endotelio ya no puede autorregularse y cambia a un fenotipo proinflamatorio y protrombótico permanente. Esta disfunción es el primer cambio que lleva a la ateroesclerosis y al aumento del riesgo cardiovascular, por esta razón se revisan los principales biomarcadores de disfunción endotelial y riesgo cardiovascular. A medida que se avance en el conocimiento básico del endotelio y su disfunción, será posible diseñar nuevas medidas preventivas o terapéuticas que puedan disminuir dicho riesgo.


Abstract The endothelium is a monolayer of flatten cells named endothelial cells that form the inner layer of the heart, blood, and lymphatic vessels. Its function is not just as a barrier, but it is a regulator of vascular permeability and tone, hemostasis, inflammation, and angiogenesis. This review is about the general aspects of vascular endothelium and endothelial dysfunction that leads to increased vascular risk. Activation and dysfunction are discussed, considering the endothelial activation as a self-limiting process, necessary to promote inflammation and hemostasis. Endothelial dysfunction is a pathological process in which the endothelium loses its ability for self-regulation and acquires a prothrombotic and proinflammation phenotype. Endothelial dysfunction is the initial step for atherosclerosis and increased cardiovascular risk, so the main biomarkers of endothelial dysfunction are reviewed. As basic knowledge about endothelium increases, preventive or therapeutic measures can be designed as treatment or prevention the risk of its dysfunction.

20.
Rev. Fac. Med. UNAM ; 65(5): 20-29, sep.-oct. 2022. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1431339

RESUMO

Resumen Se estima que el 80% de la población mundial utiliza diversas plantas medicinales para el tratamiento o control de diversas enfermedades, ya sean agudas o crónicas, debido a su accesibilidad y bajo costo, observándose en los últimos años un aumento en el consumo sin una observación médica adecuada. México es considerado como el segundo país más importante del mundo en cuanto al conocimiento de la medicina tradicional, solo después de china. El uso de las plantas medicinales se ha reportado desde tiempos prehispánicos como una opción terapéutica, sin embargo, el único enfoque que se tiene es la parte curativa y no se ha reflexionado en que las plantas poseen metabolitos secundarios (compuestos químicos producidos por las plantas con actividad biológica en los seres vivos) que, además de tener efectos terapéuticos poseen efectos tóxicos en las personas que las consumen, observándose en algunos casos efectos reversibles después de suspender su consumo. El copalchi o palo amargo es una planta medicinal que proviene de la corteza del árbol de Hintonia latiflora (sin. Coutarea latiflora), la cual ha sido utilizada principalmente como tratamiento alternativo para pacientes con diabetes tipo 2, ya que se ha demostrado que tiene efecto hipoglucemiante. Sin embargo, se han reportado casos de hepatotoxicidad aguda con un incremento en las transaminasas hepáticas (ALT y AST) por el consumo continuo de dicha corteza, no obstante el procesamiento de las plantas medicinales utilizando medios físicos (calentar o hervir) puede alterar la actividad farmacológica de los constituyentes orgánicos, los cuales pueden verse también afectados en su concentración dependiendo de los factores ambientales de cultivo, localización del suelo, humedad y temperatura ambiental, así como la temporada de cosecha (tallos, hojas, flores, raíces, semillas). El consumo de esta planta medicinal es por medio de infusiones calientes o en cápsulas con extracto.


Abstract Approximately 80% of the world's population uses various medicinal plants for the treatment or control of various diseases, whether acute or chronic, due to their accessibility and low cost, observing in recent years an increase in consumption without proper medical observation. Mexico is considered the second most important country in the world in terms of traditional medicine knowledge, only after China. The use of medicinal plants has been reported since pre-Hispanic times as a therapeutic option; however, the only focus is on the curative part and it has not been considered that plants have secondary metabolites (chemical compounds produced by plants with biological activity in living beings) that, besides having therapeutic effects, have toxic effects in people who consume them, and in some cases reversible effects are observed after suspending their consumption. Copalchi or palo amargo is a medicinal plant obtained from the bark of the Hintonia latiflora tree (syn. Coutarea latiflora), which has been used mainly as an alternative treatment for patients with type 2 diabetes, since it has been shown to have a hypoglycemic effect. However, cases of acute hepatotoxicity have been reported with an increase in hepatic transaminases (ALT and AST) by the continuous consumption of this bark. However, the processing of medicinal plants using physical means (heating or boiling) can alter the pharmacological activity of the organic constituents, which can also be affected in their concentration depending on the environmental factors of cultivation, soil location, humidity, and environmental temperature, as well as the harvesting season (stems, leaves, flowers, roots, seeds). The consumption of this medicinal plant is by means of hot infusions or in capsules with extract.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA