Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 349
Arq. bras. med. vet. zootec. (Online) ; 73(2): 352-360, Mar.-Apr. 2021. tab, graf, ilus
Article in English | ID: biblio-1248941


In this study, the toxic effects of melittin on Madin-Darby Bovine Kidney cells (MDBK) were analyzed with respect to mitochondrial functionality by reduction of MTT and flow cytometry, apoptosis potential, necrosis, oxygen reactive species (ROS) production, lipid peroxidation, and DNA fragmentation using flow cytometry and cell membrane destabilization by confocal microscopy. The toxicity presented dose-dependent characteristics and mitochondrial activity was inhibited by up to 78.24 ±3.59% (P<0.01, n = 6) in MDBK cells exposed to melittin (10µg/mL). Flow cytometry analysis revealed that melittin at 2µg/mL had the highest necrosis rate (P<0.05) for the cells. The lipoperoxidation of the membranes was also higher at 2µg/mL of melittin (P<0.05), which was further confirmed by the microphotographs obtained by confocal microscopy. The highest ROS production occurred when the cells were exposed to 2.5µg/mL melittin (P<0.05), and this concentration also increased DNA fragmentation (P<0.05). There was a significative and positive correlation between the lipoperoxidation of membranes with ROS (R=0.4158), mitochondrial functionality (R=0.4149), and apoptosis (R=0.4978). Thus, the oxidative stress generated by melittin culminates in the elevation of intracellular ROS that initiates a cascade of toxic events in MDBK cells.(AU)

Neste estudo, os efeitos tóxicos da melitina em células Madin-Darby Bovine Kidney (MDBK) foram analisados quanto à funcionalidade mitocondrial, por redução de MTT e citometria de fluxo, potencial de apoptose, necrose, produção de espécies reativas de oxigênio (ROS), peroxidação lipídica e fragmentação de DNA, utilizando-se citometria de fluxo e desestabilização da membrana celular, por microscopia confocal. A toxicidade apresentou características dose-dependentes e a atividade mitocondrial foi inibida até 78,24±3,59% (P<0,01, n = 6) em células MDBK expostas à melitina (10µg/mL). Análises por citometria de fluxo revelaram que a melitina a 2µg/mL apresentou o maior índice necrótico celular (P<0,05). A maior lipoperoxidação de membranas também foi na concentração de 2µg/mL de melitina (P<0,05), o que foi posteriormente confirmado por microscopia confocal. A maior produção de ROS aconteceu quando as células foram expostas a 2,5µg/mL de melitina (P<0,05), e essa concentração também aumentou a fragmentação de DNA (P<0,05). Houve uma significativa correlação positiva entre a lipoperoxidação de membranas e a produção de ROS (R=0,4158), funcionalidade mitocondrial (R=0,4149) e apoptose (R=0,4978). Portanto, o estresse oxidativo gerado pela melitina culminou na elevação de ROS intracelular, que inicia uma cascata de eventos tóxicos nas células MDBK.(AU)

Reactive Oxygen Species/adverse effects , Apoptosis , Cytotoxins/analysis , Melitten/analysis , Bee Venoms/analysis , Microscopy, Confocal , Flow Cytometry
Braz. arch. biol. technol ; 64: e21190530, 2021. tab, graf
Article in English | LILACS | ID: biblio-1153299


HIGHLIGHTS The phenolic composition, antioxidant activity and cytotoxic potential of the extracts of C. solstitialis and U. picroides were investigated. Caffeic acid was found as the most abundant phenolic compound in the extracts. Both species showed promising antioxidant activity towards different assays. The highest cytotoxic potential was observed in the extract of C. solstitialis.

Abstract It is known that some genera of the Asteraceae family are commonly used in Turkish folk medicine. Several studies have investigated the biological effects of different extracts of Centaurea and Urospermum species, but studies involving the phenolic composition of C. solstitialis and U. picroides extracts are very limited. This study aimed to investigate the phenolic composition and antioxidant activity of C. solstitialis and U. picroides and evaluate their possible cytotoxic effect. RP-HPLC analysis was used to elucidate the phenolic profiles of the ethanolic extracts of flowering parts of C. solstitialis and U. picroides.The both ethanolic extracts were assessed for their antioxidant properties using DPPH, FRAP, phosphomolybdenum and metal chelating assays. Furthermore, the effect of the extracts on cell viability was evaluated against MCF-7 and PC-3 cancer cells and HEK293 cell line using the MTT assay. The most abundant phenolic compound in both extracts was determined to be caffeic acid, and the amount of this compound was 24078.03 and 14329.59 µg g-1 in the extracts of C. solstitialis and U. picroides, respectively. The antioxidant activity of the extracts was found similar. Compared with U. picroides extract, C. solstitialis extract had higher potential on the inhibition of cell viability. The IC50 value of C. solstitialis on MCF cells was found as 58.53 µg mL-1. These data suggest that the extracts of C. solstitialis and U. picroides may be considered as novel and alternative natural antioxidant and anticancer sources.

Humans , Asteraceae/chemistry , Cytotoxins/pharmacology , Centaurea/chemistry , Phenolic Compounds/analysis , Antioxidants/pharmacology , Phenols/pharmacology , Plants, Medicinal , Turkey , Caffeic Acids/pharmacology , Plant Extracts/pharmacology , Chromatography, High Pressure Liquid , HEK293 Cells
Braz. arch. biol. technol ; 64: e21190387, 2021. tab, graf
Article in English | LILACS | ID: biblio-1153290


HIGHLIGHTS Production of lipid nanoemulsions (<100 nm) of industrial interest with low energy demand. The antioxidant properties of babassu oil have been improved and the nanoemulsions are not cytotoxic. Babassu oil is a food and medicinal product. The nanoemulsion is strategic for the developed of new antioxidants phytotherapeutics.

Abstract Background: Babassu oil is an extract from a Brazilian native coconut (Orbignya phalerata Martius) and is used both as a food and a medicinal product. Methods: we produced two babassu oil nanoemulsions and evaluated them regarding their nanoscopic stability, antioxidant activity and cytotoxicity.The nanoemulsions were characterized by Dynamic Light Scattering, and their stability was investigated for 120 days. The antioxidant activity was assessed by Spectroscopy Electron Paramagnetic Resonance, and the cytotoxicity was assessed by a colorimetric method (MTT) with the NIH/3T3 cell lineage. Results: the results showed nanoemulsions with average hydrodynamic diameter lower than 100 nm (p(0.001).and a polydispersity index of less than 0.3 (p(0.001), indicating monodisperse systems and good stability at room temperature. The exposure of nanoemulsions at varying pH revealed that the isoelectric point was at 3.0, and the images obtained by Transmission Electron Microscopy showed spherical droplets with a size 27 nm. The antioxidant activity showed that the babassu nanoemulsions exposed to free radicals had a better response when compared to the oil free samples. The cell viability assays showed low toxicity of the formulation with viability over 92% (p(0.05). Conclusion: babassu oil nanoformulations showed low polydispersity and kinetic stability with effective antioxidant action. Therefore, they can be promising for application in the food industry or as antioxidant phytotherapeutics.

Palm Oil/chemistry , Nanotechnology , Antioxidants , Plant Extracts/chemistry , Food Industry , Cytotoxins , Microscopy, Electron, Transmission , Emulsions , Nanocomposites
J. venom. anim. toxins incl. trop. dis ; 26: e20190078, 2020. graf, ilus
Article in English | ID: biblio-1091025


Argenteohyla siemersi (red-spotted Argentina frog) is a casque-headed tree frog species belonging to the Hylidae family. This species has a complex combination of anti-predator defense mechanisms that include a highly lethal skin secretion. However, biochemical composition and biological effects of this secretion have not yet been studied. Methods: The A. siemersi skin secretion samples were analyzed by mass spectrometry and chromatographic analysis (MALDI-TOF/MS, RP-HPLC and GC-MS). Proteins were also studied by SDS-PAGE. Among the biological activities evaluated, several enzymatic activities (hemolytic, phospholipase A2, clotting, proteolytic and amidolytic) were assessed. Furthermore, the cytotoxic activity (cytolysis and fluorescence staining) was evaluated on myoblasts of the C2C12 cell line. Results: The MALDI-TOF/MS analysis identified polypeptides and proteins in the aqueous solution of A. siemersi skin secretion. SDS-PAGE revealed the presence of proteins with molecular masses from 15 to 55 kDa. Steroids, but no alkaloids or peptides (less than 5 KDa), were detected using mass spectrometry. Skin secretion revealed the presence of lipids in methanolic extract, as analyzed by CG-MS. This secretion showed hemolytic and phospholipase A2 activities, but was devoid of amidolytic, proteolytic or clotting activities. Moreover, dose-dependent cytotoxicity in cultured C2C12 myoblasts of the skin secretion was demonstrated. Morphological analysis, quantification of lactate dehydrogenase release and fluorescence staining indicated that the cell death triggered by this secretion involved necrosis. Conclusions: Results presented herein evidence the biochemical composition and biological effects of A. siemersi skin secretion and contribute to the knowledge on the defense mechanisms of casque-headed frogs.(AU)

Animals , Anura , Peptides , Mass Spectrometry , Biological Products , Electrophoresis, Polyacrylamide Gel , Phospholipases A2 , Biochemical Reactions/classification , Cytotoxins
Article in English | LILACS, MTYCI | ID: biblio-1145994


El presente estudio tiene como objetivo explorar las posibles aplicaciones de los extractos de corteza y hoja de Blepharocalyx cruckshanksii como agente citotóxico contra líneas celulares de cáncer in vitro ((MCF-7, PC-3 y HT-29) mediante el uso de ensayo de sulforhodamine B (SRB). El ensayo de citotoxicidad reveló que el extracto de acetato de etilo de la corteza exhibía una actividad anticancerígena marcada. El extracto activo se sometió a un reparto líquido-líquido usando hexano y acetato de etilo para obtener fracciones basadas en su polaridad. Sin embargo, la Fracción 4 (F4) fue identificado como el más efectivo de la serie al mostrar contra todas las líneas celulares de cáncer una citotoxicidad cercana a los agentes antineoplásicos ensayados. Luego, F4 se analizó por cromatografía de gasesespectrometría de masas (GC-MS) para identificar sus componentes principales y relacionar estos componentes con el efecto citotóxico. Los resultados obtenidos indicaron que la corteza de B. cruckshanksii tiene una excelente actividad citotóxica y amerita estudios adicionales para aislar nuevos compuestos para quimioterapia.

The present study aims to explore the potential applications of Blepharocalyx cruckshanksii bark and leaf extracts as a cytotoxic agent against in vitro cancer cell lines (MCF-7, PC-3 and HT-29) by using sulforhodamine B (SRB) assay. The cytotoxicity assay revealed that the ethyl acetate extract from the bark exhibited marked anticancer activity. The active extract was subjected to liquid-liquid partitioning by using hexane and ethyl acetate to obtain fractions based on their polarity. However, Fraction 4 (F4) was identified as the most effective of the series by displaying against all cancer cell lines a cytotoxicity close to antineoplastic agents assayed. Then, F4 was analyzed by gas chromatography­mass spectrometry (GC-MS) to identify their major components and to relate these components to the cytotoxic effect. The results obtained indicated that B. cruckshanksii bark have excellent cytotoxic activity and warrant further studies to isolate novel compounds for chemotherapeutic use.

Humans , Myrtaceae/chemistry , Cytotoxins , Antineoplastic Agents , In Vitro Techniques , Plant Extracts , Chile , Chromatography, Gas
Braz. j. oral sci ; 19: e200656, jan.-dez. 2020. ilus
Article in English | LILACS, BBO | ID: biblio-1152174


Composites have been proven to have a cytotoxic effect on a variety of tissues and cells. Aim: The aim of this study was to analyse the degree of conversion of resins and its correlation with the cell viability in primary gingival fibroblasts. Methods: Resin-based silorane (Filtek P90) and conventional methacrylate resins (Filtek Z100, Filtek Z250 and Filtek Z350XT) were used to evaluate cell viability and the degree of conversion. The resins were light-cured by a LED for 20 and 40 seconds. The degree of conversion was analysed by Fourier transform infrared spectroscopy. Cellular metabolism was evaluated after 24 hours by the MTT assay (n = 6) using the storage solution of composite resin for either 24 hours or 12 days. Variance analysis (ANOVA) with a Bonferroni correction (p < 0.05) was performed to compare the groups. Results: The composite Filtek P90 showed a higher degree of conversion when polymerised for 40 or 20 seconds, while the composites Filtek Z100, Filtek Z250 and Filtek Z350XT showed similar degree of conversion. Only the Filtek Z100 resin was cytotoxic. Conclusion: We found no statistically significant correlation between cell viability and the degree of conversion

Composite Resins , Cytotoxins , Fibroblasts
Pesqui. vet. bras ; 39(9): 744-756, Sept. 2019. tab, ilus
Article in English | ID: biblio-1040747


The objective of this study was to evaluate the hepatoprotective effect of the honey bee Apis mellifera ethanolic extract of the red propolis, obtained in four municipalities of the Rio Grande do Norte semi-arid region, through an in vitro evaluation of the antineoplastic potential in human hepatic carcinoma (HepG2) and normal cell lines (L929), and from the comet assay in hepatic cell lines (ZF-L hepatocytes) to evaluate the genoprotective potential of the extract. The hepatoprotective effect was also evaluated in vivo by the induction of chronic experimental hepatic lesions in rodents (Rattus norvegicus Berkenhout, 1769), Wistar line, by intraperitoneal administration of thioacetamide (TAA) at the dose of 0.2g/kg. The animals were distributed in the following experimental groups: G1 (control), G2 (treated with 500mg/kg ethanolic extract of propolis), G3 (treated with 500mg/kg of ethanolic extract and TAA) and G4 (treated with TAA). All rats were submitted to serum biochemical, macroscopic, histological and stereological biochemical exams of the liver. It was verified the genoprotective effect of red propolis since the mean damages promoted to DNA in cells tested with the extract were significantly lower than the mean of the positive control damage (hydrogen peroxide). The red propolis extract did not present cytotoxic activity to the tumor cells of human liver cancer, as well as to normal ones. The absence of cytotoxicity in normal cells may indicate safety in the use of the propolis extract. The results of the serum biochemical evaluation showed that the serum levels of the aminotransferase enzymes (AST) did not differ significantly between G1, G2 and G3 when compared to each other. G4 showed significant increase in levels compared to the other groups, indicating that the administration of the extract did not cause liver toxicity, as well as exerted hepatoprotective effect against the hepatic damage induced by TAA. The G3 and G4 animals developed cirrhosis, but in G3 the livers were characterized by the presence of small regenerative nodules and level with the surface of the organ, whereas in G4 the livers showed large regenerative nodules. The livers of the G1 and G2 animals presented normal histological appearance, whereas the livers of the G3 animals showed regenerative nodules surrounded by thin septa of connective tissue, and in G4 the regenerative nodules were surrounded by thick septa fibrous connective tissue. The analysis of the hepatic tissues by means of stereology showed that there was no statistical difference between the percentage of hepatocytes, sinusoids, and collagens in G1 and G2. In G3 the percentage of hepatocytes, sinusoids, and collagen did not differ significantly from the other groups. It was concluded that the ethanolic extract of the red propolis exerted a hepatoprotective effect, because it promoted in vitro reduction of the damage to the DNA of liver cells, antineoplastic activity in human hepatocellular carcinoma cell line (HepG2) and did not exert cytotoxic effect in normal cells or was able to reduce liver enzyme activity and the severity of cirrhosis induced by TAA in vivo.(AU)

Este estudo objetivou avaliar o efeito hepatoprotetor do extrato etanólico da própolis vermelha da abelha Apis mellifera, obtido em quatro municípios do semiárido do Rio Grande do Norte, mediante avaliação in vitro do potencial antineoplásico em linhagens de células de carcinoma hepático humano (HepG2) e em linhagens de células normais (L929), além do ensaio cometa em linhagens de células hepáticas (hepatócitos ZF-L) para avaliar o potencial genoprotetor do extrato. O efeito hepatoprotetor também foi avaliado in vivo através da indução de lesões hepática experimental crônica em roedores da espécie Rattus norvegicus (Berkenhout, 1769), linhagem Wistar, pela administração intraperitoneal de tioacetamida (TAA) na dose de 0,2g/kg. Os animais foram distribuídos nos seguintes grupos experimentais: G1 (controle), G2 (tratados com 500mg/kg de extrato etanólico da própolis), G3 (tratados com 500mg/kg de extrato etanólico e TAA) e G4 (tratados com TAA). Todos os ratos foram submetidos aos exames bioquímico sérico, anatomopatológico macroscópico, histológico e esteriológico do fígado. Foi constatado o efeito genoprotetor da própolis vermelha uma vez que as médias dos danos promovidos ao DNA em células testadas com o extrato foram significativamente inferiores à média dos danos do controle positivo (peróxido de hidrogênio). O extrato da própolis vermelha não apresentou atividade citotóxica para células tumorais de câncer de fígado humano, bem como para normais. A ausência de citotoxicidade em células normais, tal como constatado, pode indicar segurança no uso do extrato da própolis. Os resultados da avaliação bioquímica sérica demonstraram que os níveis séricos das enzimas aminotransferase (AST) não diferiram significativamente entre G1, G2 e G3, quando comparadas entre si. No G4 houve aumento significativo dos níveis em relação aos demais grupos, indicando que a administração do extrato não causou toxicidade hepática, bem como exerceu efeito hepatoprotetor frente ao dano hepático induzido pela TAA. Os animais dos G3 e G4 desenvolveram cirrose, porém no G3 os fígados caracterizaram-se pela presença de pequenos nódulos regenerativos e nivelados com a superfície do órgão, enquanto que no G4 os fígados apresentaram grandes nódulos regenerativos. Os fígados dos animais G1 e G2 apresentaram aspecto histológico normal, enquanto que os fígados dos animais do G3 apresentaram nódulos regenerativos circundados por finos septos de tecido conjuntivo, e nos do G4 os nódulos regenerativos foram circundados por espessos septos de tecido conjuntivo fibroso. A análise dos tecidos hepáticos por meio de estereologia mostrou que não houve diferença estatística entre o percentual de hepatócitos, sinusoides e colágenos nos G1 e G2. No G3 o percentual de hepatócitos, sinusoides e colágeno não diferiu significativamente dos demais grupos. Concluiu-se que o extrato etanólico da própolis vermelha exerceu efeito genoprotetor, por promover in vitro redução do dano ao DNA de células hepáticas, atividade antineoplásica em linhagem celular de carcinoma hepatocelular humano (HepG2) e não exerceu efeito citotóxico em células normais ou efeito hepatoprotetor in vivo com diminuição da gravidade da cirrose induzida por TAA.(AU)

Animals , Propolis/therapeutic use , Bees , Cytotoxins , Hepatoprotector Drugs , Antineoplastic Agents/analysis
Article in Korean | WPRIM | ID: wpr-760146


Autoimmune sensorineural hearing loss is a rare disease characterized by bilateral sensorineural hearing loss, some in a progressive pattern and others in idiopathic or fluctuating pattern, often accompanied by vestibular symptoms. This disease is also known as autoimmune inner ear disease (AIED), which primarily involves the vestibulo-cochlear system. However, in some cases, it occurs in the context of systemic autoimmune disorder such as wegner granulomatosis, or the Bechet disease. Response to steroids has been the requisite clinical criterion for diagnosis. Treatment usually includes corticosteroids and immunosuppressive drugs. However, after continuous steroid treatment development of corticosteroids, resistance is common in many AIED. To patients with AIED, response to steroids is not only a criterion for diagnosis but also a criterion to test steroid-sparing therapies such as methotrexate. A 10 year-old boy presenting a fluctuating pattern of bilateral sensorineural hearing loss was treated with a cytotoxic agent in suspicion of autoimmune sensorineural hearing loss. We reviewed this case with reference to relevant publications in the medical literature.

Adrenal Cortex Hormones , Cytotoxins , Diagnosis , Hearing Loss, Sensorineural , Humans , Labyrinth Diseases , Male , Methotrexate , Rare Diseases , Steroids
J. venom. anim. toxins incl. trop. dis ; 25: e20190009, 2019. graf, ilus
Article in English | ID: biblio-1040380


Several studies have pointed out that certain snake venoms contain compounds presenting cytotoxic activities that selectively interfere with cancer cell metabolism. In this study, Pseudocerastes persicus venom and its fractions were investigated for their anticancer potential on lung cancer cells. Methods: Lung cancer cells (A549) and normal fibroblast cells (Hu02) were treated with the P. persicus venom and its HPLC fractions and the cell cytotoxic effects were analyzed using MTT and lactate dehydrogenase release assays. Apoptosis was determined in venom-treated cell cultures using caspase-3 and caspase-9 assay kits. Results: The treatment of cells with HPLC fraction 21 (25-35 kDa) of P. persicus venom resulted in high LDH release in normal fibroblast cells and high caspase-3 and caspase-9 activities in lung cancer cells. These results indicate that fraction 21 induces apoptosis in cancer cells, whereas necrosis is predominantly caused by cell death in the normal cells. Fraction 21 at the final concentration of 10 μg/mL killed approximately 60% of lung cancer cells, while in normal fibroblast cells very low cell cytotoxic effect was observed. Conclusion: HPLC fraction 21 at low concentrations displayed promising anticancer properties with apoptosis induction in the lung cancer cells. This fraction may, therefore, be considered a promising candidate for further studies.(AU)

Animals , Snake Venoms/chemical synthesis , Apoptosis , Cell Culture Techniques , Cytotoxins/analysis , Lung Neoplasms
Laboratory Medicine Online ; : 249-253, 2019.
Article in Korean | WPRIM | ID: wpr-760509


A 22-year old female patient with systemic lupus erythematosus presenting microangiopathic hemolytic anemia was treated with therapeutic plasma exchange 23 times. The patient's condition and laboratory findings (aspartate aminotransferase, alanine aminotransferase, ferritin, total bilirubin, and lactate dehydrogenase) did not improve despite the initial 18 therapeutic plasma exchange treatments. Thrombotic thrombocytopenic purpura was ruled out due to normal ADAMTS-13 activity test result; hemophagocytic lymphohistiocytosis was diagnosed based on fever, splenomegaly, pancytopenia, hypertriglyceridemia, hyperferritinemia, and hemophagocytosis in bone marrow aspiration. The patient's condition improved rapidly upon treatment with a combination of immunosuppressants and cytotoxic agents, and more therapeutic plasma exchanges were performed five consecutive times with prolonged intervals in between. We observed that therapeutic plasma exchange treatment alone was not effective enough to treat hemophagocytic lymphohistiocytosis, unlike thrombotic thrombocytopenic purpura. Therefore, it is necessary to determine and start drug administration promptly in the treatment of hemophagocytic lymphohistiocytosis with thrombotic microangiopathy.

Alanine Transaminase , Anemia, Hemolytic , Bilirubin , Bone Marrow , Cytotoxins , Female , Ferritins , Fever , Humans , Hypertriglyceridemia , Immunosuppressive Agents , Lactic Acid , Lupus Erythematosus, Systemic , Lymphohistiocytosis, Hemophagocytic , Pancytopenia , Plasma Exchange , Plasma , Purpura, Thrombotic Thrombocytopenic , Splenomegaly , Thrombotic Microangiopathies
Braz. J. Pharm. Sci. (Online) ; 55: e18304, 2019. tab, graf
Article in English | LILACS | ID: biblio-1039081


Today, consumers are looking for functional foods that promote health and prevent certain diseases in addition to provide nutritional requirements. This study aimed to evaluate the antioxidant and cytotoxic properties of Liza klunzingeri protein hydrolysates. Fish protein hydrolysates (FPHs) were prepared from L. klunzingeri muscle using enzymatic hydrolysis with papain at enzyme/substrate ratios of 1:25 and 1:50 for 45, 90 and 180 min. The antioxidant activities of the FPHs were investigated through five antioxidant assays. The cytotoxic effects on 4T1 carcinoma cell line were also evaluated. The amino acid composition and molecular weight distribution of the hydrolysate with the highest antioxidant activity were determined by HPLC. All six FPHs exhibited good scavenging activity on ABTS (IC50=0.60-0.12 mg/mL), DPPH (IC50= 3.18-2.08 mg/mL), and hydroxyl (IC50=4.13-2.07 mg/mL) radicals. They also showed moderate Fe+2 chelating capacity (IC50=2.12-12.60 mg/mL) and relatively poor ferric reducing activity (absorbance at 70 nm= 0.01-0.15, 5 mg/mL). In addition, all hydrolysates showed cytotoxic activities against the 4T1 cells (IC50=1.62-2.61 mg/mL). 94.6% of peptide in hydrolysate with the highest antioxidant activity had molecular weight less than 1,000 Da. L. klunzingeri protein hydrolysates show significant antioxidant and anticancer activities in vitro and are suggested to be used in animal studies.

Smegmamorpha/anatomy & histology , Cytotoxins/adverse effects , Antioxidants/analysis , Protein Hydrolysates/pharmacokinetics , In Vitro Techniques/instrumentation
Braz. arch. biol. technol ; 62: e19180731, 2019. graf
Article in English | LILACS | ID: biblio-1055384


Abstract Metallic nanoparticles have great potential as a chemotherapeutic agent. The aim of this study was to develop and characterize silver and gold nanoparticles using a simple method, as well as evaluating the potential cytotoxic activity in relation to the K-562 cell line. For the synthesis, a solution containing the metallic ions was subjected to magnetic stirring with the aqueous extract of Lavandula dentata L. and a change of colour was observed. With the data obtained from the analyses we concluded that the nanoparticles were successfully obtained by a simple and green method using the aqueous extract of L. dentata. The obtained nanoparticles presented a reduced size, a low level of polydispersion, and a homogenous spherical shape. The nanoparticles presented intense and characteristic diffraction peaks, which could be correlated to the planes of the centred cubic structure of the silver and gold. The two formulations presented predominantly crystalline characteristics. The infrared analysis suggested that the amides and alcohols present in the samples may have been responsible for the reduction and limitation of the size and dispersion of the silver and gold nanoparticles. The cytotoxic assay showed that the nanoparticles demonstrated great potential to reduce the cell viability of the K-562 cell line, especially the gold nanoparticles.

Leukemia, Myeloid , Lamiaceae/toxicity , Cytotoxins , Metal Nanoparticles/analysis
Biosci. j. (Online) ; 34(4): 1017-1024, july/aug. 2018. tab
Article in English | LILACS | ID: biblio-967196


The toxic potential at the cellular level of industrialized Ginkgo biloba L. leaves was evaluated in meristematic cells of Allium cepa at concentrations of 0.1; 0.2 and 0.4 mg/ml. The industrialized products, from four pharmaceutical laboratories, were identified as A, B, C and D. Cell-level toxicity of dehydrated ginkgo leaf tea was also evaluated at concentrations of 0.15; 0.30 and 0.60 mg/ml. Dehydrated products were purchased from herbalists certified by ANVISA. The roots were exposed to teas and processed products for 24 and 48 hours. The results were submitted to the Chi-square test at 5%. However, industrialized ginkgo products at all concentrations caused antiproliferative effect. Also, the products purchased in pharmacies did not induce significant changes to root meristems. Therefore, industrialized ginkgo promoted cytotoxicity, however, they were not genotoxic to the bioassay used.

Avaliou-se, em células meristemáticas de raízes de Allium cepa, o potencial tóxico em nível celular de folhas de Ginkgo biloba L. industrializadas, nas concentrações 0,1; 0,2 e 0,4 mg/mL. Os produtos industrializados, oriundos de quatro laboratórios farmacêuticos, foram identificados como A, B, C e D. Também avaliou-se a toxicidade em nível celular de chás de folhas de ginkgo desidratadas, nas concentrações 0,15; 0,30 e 0,60 mg/mL. Os produtos desidratados foram adquiridos em ervanários certificados pela ANVISA. As raízes ficaram expostas aos chás e produtos industrializados por 24 e 48 horas. Os resultados obtidos foram submetidos ao teste Qui-quadrado, a 5%. No entanto, os produtos de ginkgo industrializados, em todas as concentrações, causaram efeito antiproliferativo. Ainda, os produto adquiridos em farmácias não induziram alterações em número significativo aos meristemas de raízes. Portanto, os ginkgos industrializados promoveram citotoxicidade, porém, não foram genotóxicos frente ao bioensaio utilizado.

Cell Division , Ginkgo biloba , Excipients , Cytotoxins
Braz. j. biol ; 78(2): 306-310, May-Aug. 2018. tab
Article in English | LILACS | ID: biblio-888877


Abstract The goal of this study was to analyze cytotoxicity, genotoxicity and mutagenicity to bone marrow cells of mice of nature identical synthetic flavorings, passion fruit and strawberry, and artificial synthetic flavorings, vanilla, chocolate, tutti-frutti and cookie, at doses 0.5; 1.0; 2.0; 5.0 and 10.0 mL/kg. The additives were given to the animals by gavage in a single daily application for seven days. Data were subjected to analysis of variance (ANOVA) followed by post Tukey's post hoc test, p <0.05. Animals treated with 2.0; 5.0 and 10.0 mL/Kg of flavorings chocolate, strawberry and cookie, and 5.0 and 10.0 mL/Kg of flavorings vanilla and passion fruit died on the fifth and sixth day of the experiment, respectively. The doses 0.5 and 1.0 mL/Kg of the six additives significantly reduced erythropoiesis in the examined tissue. Also, treatments 0.5 and 1.0 mL/Kg of chocolate, and 1.0 mL/Kg of strawberry and biscuit induced the formation of micronuclei in the bone marrow erythrocytes, at a significant frequency. Therefore, under the study conditions, the six microingredients analyzed were cytotoxic and genotoxic, and additives strawberry, chocolate and cookie were also mutagenic in at least one of the evaluated doses.

Resumo Os aromatizantes são essenciais para a indústria na confecção de alimentos industrializados. Porém, pouco se sabe sobre o potencial tóxico desses microingredientes alimentares. Dessa forma, objetivou-se neste trabalho analisar, em células de medula óssea de camundongos, a citotoxicidade, genotoxicidade e mutagenicidade de aromatizantes alimentares sintéticos idênticos ao natural, de maracujá e morango, e artificiais, de baunilha, chocolate, tutti-frutti e biscoito, nas doses 0,5; 1,0; 2,0; 5,0 e 10,0 mL/Kg. Os aditivos foram administrados aos animais via gavagem em aplicação diária única durante sete dias. Os dados obtidos foram submetidos ao procedimento estatístico ANOVA com pós teste de Tukey, com p < 0.05. Os animais tratados com 2,0; 5,0 e 10,0 mL/Kg dos aromatizantes de chocolate, morango e biscoito, e 5,0 e 10,0 mL/Kg dos aromatizantes de baunilha e maracujá vieram a óbito no quinto e sexto dia de experimento, respectivamente. As doses 0,5 e 1,0 mL/Kg dos seis aditivos reduziram significativamente a eritropoiese do tecido analisado. Ainda, os tratamentos 0,5 e 1,0 mL/kg de chocolate, e 1,0 mL/Kg de morango e biscoito induziram a formação de micronúcleos aos eritrócitos de medula em frequência significante. Portanto, nas condições de estudo estabelecidas, os seis microingredientes analisados foram citotóxico e genotóxicos, e os aditivos de morango, chocolate e biscoito também foram mutagênicos em pelo menos uma das doses avaliadas.

Animals , Mice , Bone Marrow Cells/cytology , Bone Marrow Cells/drug effects , Bone Marrow Cells/pathology , Flavoring Agents/toxicity , Cytotoxins/toxicity , Mutagens/toxicity
J. venom. anim. toxins incl. trop. dis ; 24: 40, 2018. tab, graf, ilus
Article in English | ID: biblio-984691


A leucemia mieloide crônica (LMC) é uma neoplasia mieloproliferativa BCR-ABL1 + marcada por aumento da mieloproliferação e presença de células leucêmicas resistentes à apoptose. A terapia de primeira linha atual para a LMC é a administração de inibidores da tirosina quinase, mesilato de imatinibe, dasatinibe ou nilotinibe. Embora eficaz no tratamento da LMC, alguns pacientes se tornaram resistentes a essa terapia, levando à progressão da doença e à morte. Assim, a descoberta de novos compostos para melhorar a terapia da LMC ainda é um desafio. Aqui, os destinatários se MjTX-I, uma fosfolipase A 2 isolado a partir de Bothrops moojeni de veneno de cobra, afecta a viabilidade de Bcr-Abl de mesilato de imatinib-resistente + linhas celulares. Métodos: Examinamos o efeito citotóxico e pró-apoptótico de MjTX-I em células K562-S e K562-R Bcr-Abl + e na linha de células HEK-293 não tumorais e células mononucleares de sangue periférico, usando o 3- (4, Brometo de 5-dimetiltiazol-2-il) -2,5-difeniltetrazólio e os métodos de solução fluorescente hipotônica, associados à detecção de ativação de caspases 3, 8 e 9 e clivagem de poli (ADP-ribose) polimerase (PARP). Também analisamos o potencial MjTX-I para modular a expressão de genes relacionados à apoptose em células K562-S e K562-R. Resultados: O MjTX-I diminuiu a viabilidade das células K562-S e K562-R em 60 a 65%, sem afetar a viabilidade das células não tumorais, ou seja, exerceu citotoxicidade seletiva para as linhagens celulares Bcr-Abl + . Em linhas de células leucêmicas, a toxina induziu apoptose, caspases 3, 8 e 9 ativadas, PARP clivada, expressão negativa do gene anti-apoptótico BCL-2 e expressão aumentada do gene pró-apoptótico BAD. Conclusão: O efeito antitumoral de MjTX-I está associado ao seu potencial para induzir apoptose e citotoxicidade em linhagens celulares positivas para Bcr-Abl sensíveis e resistentes ao mesilato de imatinibe, indicando que MjTX-I é um candidato promissor a fármaco para atualizar a terapia de LMC.(AU)

Animals , Snake Venoms , Leukemia, Myeloid/diagnosis , Bothrops , Cytotoxins/analysis , Phospholipases A2/isolation & purification , Neoplasms , Apoptosis
J. venom. anim. toxins incl. trop. dis ; 24: 33, 2018. tab, graf, ilus
Article in English | ID: biblio-976022


Snake venom phospholipases A2 (PLA2s) have been reported to induce myotoxic, neurotoxic, hemolytic, edematogenic, cytotoxic and proinflammatory effects. This work aimed at the isolation and functional characterization of a PLA2 isolated from Bothrops jararaca venom, named BJ-PLA2-I. Methods and Results: For its purification, three consecutive chromatographic steps were used (Sephacryl S-200, Source 15Q and Mono Q 5/50 GL). BJ-PLA2-I showed acidic characteristics, with pI~4.4 and molecular mass of 14. 2 kDa. Sequencing resulted in 60 amino acid residues that showed high similarity to other Bothrops PLA2s, including 100% identity with BJ-PLA2, an Asp49 PLA2 previously isolated from B. jararaca venom. Being an Asp49 PLA2, BJ-PLA2-I showed high catalytic activity, and also inhibitory effects on the ADP-induced platelet aggregation. Its inflammatory characterization showed that BJ-PLA2-I was able to promote leukocyte migration in mice at different concentrations (5, 10 and 20 µg/mL) and also at different response periods (2, 4 and 24 h), mainly by stimulating neutrophil infiltration. Furthermore, increased levels of total proteins, IL-6, IL-1 ß and PGE2 were observed in the inflammatory exudate induced by BJ-PLA2-I, while nitric oxide, TNF-α, IL-10 and LTB4 levels were not significantly altered. This toxin was also evaluated for its cytotoxic potential on normal (PBMC) and tumor cell lines (HL-60 and HepG2). Overall, BJ-PLA2-I (2.5-160 µg/mL) promoted low cytotoxicity, with cell viabilities mostly varying between 70 and 80% and significant values obtained for HL-60 and PBMC only at the highest concentrations of the toxin evaluated. Conclusions: BJ-PLA2-I was characterized as an acidic Asp49 PLA2 that induces acute local inflammation and low cytotoxicity. These results should contribute to elucidate the action mechanisms of snake venom PLA2s.(AU)

Animals , Bothrops , Crotalid Venoms/chemical synthesis , Cytotoxins , Cytotoxicity, Immunologic , Phospholipases A2/chemical synthesis
Article in English | WPRIM | ID: wpr-758795


Herein, we report the pathogenic and phylogenetic characteristics of seven Shiga toxin (Stx)-producing Escherichia coli (STEC) isolates from 434 retail meats collected in Korea during 2006 to 2012. The experimental analyses revealed that all isolates (i) were identified as non-O157 STEC, including O91:H14 (3 isolates), O121:H10 (2 isolates), O91:H21 (1 isolate), and O18:H20 (1 isolate), (ii) carried diverse Stx subtype genes (stx₁, stx(2c), stx(2e), or stx₁ + stx(2b)) whose expression levels varied strain by strain, and (iii) lacked the locus of enterocyte effacement (LEE) pathogenicity island, a major virulence factor of STEC, but they possessed one or more alternative virulence genes encoding cytotoxins (Cdt and SubAB) and/or adhesins (Saa, Iha, and EcpA). Notably, a significant heterogeneity in glutamate-induced acid resistance was observed among the STEC isolates (p < 0.05). In addition, phylogenetic analyses demonstrated that all three STEC O91:H14 isolates were categorized into sequence type (ST) 33, of which two beef isolates were identical in their pulsotypes. Similar results were observed with two O121:H10 pork isolates (ST641; 88.2% similarity). Interestingly, 96.0% of the 100 human STEC isolates collected in Korea during 2003 to 2014 were serotyped as O91:H14, and the ST33 lineage was confirmed in approximately 72.2% (13/18 isolates) of human STEC O91:H14 isolates from diarrheal patients.

Cytotoxins , Enterocytes , Escherichia coli , Genomic Islands , Humans , Korea , Meat , Population Characteristics , Red Meat , Shiga Toxin , Shiga-Toxigenic Escherichia coli , Virulence , Virulence Factors
Immune Network ; : e14-2018.
Article in English | WPRIM | ID: wpr-740198


T lymphocytes rely on several metabolic processes to produce the high amounts of energy and metabolites needed to drive clonal expansion and the development of effector functions. However, many of these pathways result in the production of reactive oxygen species (ROS), which have canonically been thought of as cytotoxic agents due to their ability to damage DNA and other subcellular structures. Interestingly, ROS has recently emerged as a critical second messenger for T cell receptor signaling and T cell activation, but the sensitivity of different T cell subsets to ROS varies. Therefore, the tight regulation of ROS production by cellular antioxidant pathways is critical to maintaining proper signal transduction without compromising the integrity of the cell. This review intends to detail the common metabolic sources of intracellular ROS and the mechanisms by which ROS contributes to the development of T cell-mediated immunity. The regulation of ROS levels by the glutathione pathway and the Nrf2-Keap1-Cul3 trimeric complex will be discussed. Finally, T cell-mediated autoimmune diseases exacerbated by defects in ROS regulation will be further examined in order to identify potential therapeutic interventions for these disorders.

Antioxidants , Autoimmune Diseases , Autoimmunity , Cytotoxins , DNA , Glutathione , Immunity, Cellular , Metabolism , Reactive Oxygen Species , Receptors, Antigen, T-Cell , Second Messenger Systems , Signal Transduction , T-Lymphocyte Subsets , T-Lymphocytes
Acta odontol. latinoam ; 31(1): 11-15, 2018. tab, graf
Article in English | LILACS | ID: biblio-909925


The aim of this study was to evaluate the cytotoxic effects of 2.5% sodium hypochlorite (NaOCl), 17% ethylenediamine tetraacetic acid (EDTA), and 1% peracetic acid (PAA) on human fibroblasts. FG11 and FG15 cell lines were cultured in 24well cell culture plates for cell proliferation assessment and 96well cell culture plates for the methylthiazolyldiphenyltetrazolium bromide (MTT) assay; Dulbecco's modified Eagle's medium (DMEM) was used as control data. The experimental solutions were used at 0.01%, 0.05%, and 0.1% dilutions and assessed at 1, 2, and 4hour intervals. Data were subjected to statistical analysis by twoway analysis of variance (ANOVA), followed by the Bonferroni test at a significance level of p <0.05. The assessment of cell proliferation in this study showed cytotoxicity to the fibroblasts with 2.5% NaOCl for all three dilutions at all time intervals, 17% EDTA for the 0.05% and 0.1% dilutions at the 2and 4hour intervals, and 1% PAA for all three dilutions at the 4hour interval. The cell viability assay (MTT assay) for fibroblasts showed 2.5% NaOCl to be cytotoxic at the 0.05% and 0.1% dilutions at all time intervals, 17% EDTA to be cytotoxic at the 0.1% dilution at the 2and 4hour intervals, and 1% PAA to be cytotoxic at the 0.1% dilution at the 2and 4hour intervals. In conclusion, 1% PAA was less cytotoxic than 2.5% NaOCl and 17% EDTA (AU)

O objetivo do presente estudo foi o de avaliar os efeitos citotóxicos de hipoclorito de sódio (NaOCl) a 2,5%, ácido etilenodiaminotetracético (EDTA) a 17% e ácido peracético (PAA) a 1% em fibroblastos humanos. As linhagens celulares FG11 e FG15 foram colonizadas em 24well cell plates para avaliação da proliferação celularr e em 96well cell plates para o ensaio de MTT; O médio modificado Dulbecco's Eagle's (DMEM) foi usado como controle. As soluções experimentais foram usadas com diluições de 0,01%, 0.05%, e 0,1% e avaliadas com 1, 2 e 4 horas de intervalo. Os dados foram submetidos à análise estatística pelo twoway ANOVA, seguido do teste de Bonferroni com nível de significância de p <0.05. A avaliação da proliferação celular neste estudo mostrou o NaOCL a 2,5% como citotóxico nas 3 diluições e 3 intervalos de tempo, o EDTA a 17% nas diluições de 0,05% e 0,1% nos intervalos de 2 e 4 horas, e o PAA a 1% em todas as diluições no intervalo de 4 horas. O teste de viabilidade cellular (MTT) mostrou o NaOCl a 2,5% citotóxico a 0,05% e 0,1% em todos os intervalos, o EDTA a 17% citotóxico nas diluições de 0,1% nos intervalos de 2 e 4 horas e o PAA a 1% citotóxico na diluição de 0,1% nos intervalos de 2 e 4 horas. Como conclusão o PAA a 1% mostrouse menos citotóxico que o NaOCl a 2,5% e o EDTA a 17% (AU)

Humans , Peracetic Acid , Sodium Hypochlorite , Edetic Acid , Cytotoxins , Fibroblasts , Time Factors , Cell Survival , Statistical Analysis , Analysis of Variance , Culture Media
Braz. J. Pharm. Sci. (Online) ; 54(3): e18028, 2018. tab, graf
Article in English | LILACS | ID: biblio-974417


Several studies have revealed that certain naturally occurring medicinal plants inhibit the growth of various cancers. The present study was conducted to evaluate cytotoxicity and apoptotic induction potential of Myristica fragrans Houtt mace extract. The cytotoxic activity of the Myristica fragrans Houtt mace acetone extract was assayed by MTT assay on human oral epidermal carcinoma KB cell lines. KB cells were incubated with different concentration of mace extract ranging from 25 to 125 µg/mL for 24hrs. The apoptotic induction potential was also studied by the analysis of Bcl-2 protein and gene expression in mace extract incubated KB cell lines using western blotting technique and real-time polymerase chain reaction. The mace extract exhibited cytotoxicity and anticancer effect against KB cell lines and it also suppressed the growth of cancer cells, therefore growth inhibitory effect was noted in extract treated cell lines. The apoptotic potential of mace extract was accompanied by reduced gene expression of Bcl-2 compared to the untreated KB cells. The mace extract shows the cytotoxic activity and induced the apoptosis through the modulation of its target genes Bcl-2 in the KB cell lines, suggesting the potential of mace as a candidate for oral cancer chemoprevention. This can be further investigated in vivo for its anticancer potential.

Plant Extracts/analysis , KB Cells , Myristica/anatomy & histology , Cytotoxins/analysis , Plants, Medicinal/classification , Pharmaceutical Preparations , Apoptosis , Genes, bcl-2/physiology