Avaliação da citotoxicidade in vitro e genotoxicidade ex-vivo em compostos da Pavonia glazioviana Gürke (Malvaceae)

Introduction: Alternative therapies using medicinal plants and herbal medicines are quite common in Brazil. Among several Brazilian plant species used in therapies, the species of the Malvaceae family stand out. Objetctives: The present study aimed to evaluate the in vitro cytotoxicity and ex-vivo genotoxicity in compounds of the Brazilian Pavonia glazioviana Gürke belonging to the Malvaceae family. Methodology: In vitro methods were used to verify the cytotoxic potential through hemolytic and antihemolytic assays and the ex-vivo genotoxic analysis. The Crude Etanolic Extract (CEE) and Cloroformic Fraction (CF) was obtained in vegetal sample used on this study. Results: The CEE-Pg and CF-Pg products only showed a low cytotoxic effect at the concentrations of 50 and 100 µg/mL. The exposure to the concentrations of 500 and 1000 µg/mL showed a high to moderate hemolytic index with lysis higher than 60%. A moderate anti-hemolytic effect was described in all samples treated with 500 and 1000 µg/mL, with hemolysis <60%. In addition, the compounds showed low ex-vivo genotoxic effect with a general index of normal cells greater than 84% at all concentrations. Conclusion: The results suggest a low toxic profile of the compounds obtained from the Pavonia glazioviana Gürke species belonging to the Malvaceae family, indicating safe limits for the use of these natural products.Introdução: as terapias alternativas que utilizam plantas medicinais e fitoterápicos são bastante comuns no Brasil. Dentre várias espécies vegetais brasileiras utilizadas em terapias destacam-se as espécies da família Malvaceae. Objetivos: o presente estudo teve como objetivo avaliar a citotoxicidade in vitro e a genotoxicidade ex-vivo em compostos da Pavonia glazioviana Gürke espécie brasileira pertencente à família Malvaceae. Metodologia: métodos in vitro foram utilizados para verificar o potencial citotóxico por meio de ensaios hemolíticos e anti-hemolíticos e da análise genotóxica ex-vivo. O Extrato Etanólico Bruto (EEB) e Fração Clorofórmico (FC) foram obtidos na amostra vegetal utilizada neste estudo. Resultados: os produtos EEB-Pg e FC-Pg apresentaram baixo efeito citotóxico apenas nas concentrações de 50 e 100 µg / mL. As amostras expostas às concentrações de 500 e 1000 µg / mL apresentaram índice hemolítico alto a moderado com lise superior a 60%. Foi descrito efeito anti-hemolítico moderado em todas as amostras tratadas com 500 e 1000 µg / mL, com hemólise < 60%. Além disso, os compostos mostraram baixo efeito genotóxico ex-vivo, com um índice geral de células normais superior a 84% em todas as concentrações. Conclusões: os resultados sugerem um baixo perfil tóxico dos compostos obtidos da espécie Pavonia glazioviana, indicando limites seguros para o uso desses produtos naturais

Selenoglicolicamidas: síntese, caracterização e avaliações das atividades antimicrobiana, leishmanicida e citotóxica em células tumorais

In the search for new synthetic compounds and the development of new drugs, organoselenium compounds have been prominent in the last decades, mainly because they present a wide range of biological activities such as: antibacterial, antiviral, antifungal, anticancer, anti-inflammatory, antinociceptive, etc. In this work, we describe the synthesis of selenoglicolicamides, the antimicrobial, leishmanicide and cytotoxicity studies of the compounds. Selenoglycolicamides were obtained in yields between 70-80% and were characterized by IR, 1H and 13C NMR spectroscopic techniques. In the in vitro antimicrobial evaluation, the selenoglycolicamides presented activities against the different strains of Staphylococcus aureus with minimum inhibitory concentration (MIC) in the range of 16-256 µg/mL, highlighting the compounds HSe-01, HSe-06, HSe-09 that presented an MIC between 16-64 µg/mL. In the antibacterial evaluation against tetracycline resistant Staphylococcus aureus by modulating efflux pump resistance, selenoglycolicamides presented a potential adjuvant for the antibiotic, presenting a reduction factor of tetracycline MIC up to 512 times. In the antifungal activity, only HSe-01 and HSe-09 compounds exhibited inhibitory activity against Candida strains with MIC between 512-1024 µg/mL. The leishmanicidal evaluation in L. amazonensis promastigote cells shows that selenoglycolicamides with halogens in their structures showed IC 50 of less than 10 µM, especially for compound HSe-05 with an IC50 of 5.46 µM. In the cytotoxic evaluation against tumor cells, the selenoglycolicamides that stood out the most in the inhibition of cell growth (IC%) were: HSe-02 and HSe-07 with 49% inhibition against the MCF-7 lineage; HSe-02 and HSe-05 with 100% inhibition against the HEp-2 lineage and HSe-05 with 99.56% inhibition in the HL60 lineage. In the determination of the IC50 in the HL-60 tumoral lineage, selenoglicolicamide HSe-02 presented an IC50 of 3.42 µg/mL.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESNa busca de novos compostos sintéticos e o desenvolvimento de novos fármacos, os compostos de organoselênio vem se destacando bastante nas últimas décadas, principalmente pelo fato de apresentar uma larga gama de atividades biológicas tais como: antibacteriana, antiviral, antifúngica, anticâncer, anti-inflamatória, antinociceptivo, etc. Neste trabalho, se descreve a síntese das selenoglicolicamidas, os estudos antimicrobiano, leishmanicida e de citotoxicidade dos compostos. As selenoglicolicamidas foram obtidas com rendimentos entre 70-80% e foram caraterizadas pelas técnicas espectroscópicas de IV, RMN 1H e 13C. Na avaliação antimicrobiana in vitro, as selenoglicolicamidas apresentaram atividades frente às diversas linhagens de Staphylococcus aureus com concentração inibitória mínima (CIM) na faixa de 16-256 µg/mL, se destacando os compostos HSe-01, HSe-06, HSe-09 que apresentaram uma CIM entre 16-64 µg/mL. Na avaliação antibacteriana frente ao Staphylococcus aureus resistente à tetraciclina pela modulação de resistência via bomba de efluxo, as selenoglicolicamidas apresentaram um potencial adjuvante para o antibiótico, apresentando um fator de redução da CIM da tetraciclina em até 512 vezes. Na atividade antifúngica, apenas os compostos HSe-01 e Hse-09 exibiram atividade inibidora contra as cepas de Candida com CIM entre 512 – 1024 µg/mL. A avaliação leishmanicida, em células promastigostas de L. amazonensis, mostra que as selenoglicolicamidas com halogênios em suas estruturas apresentaram CI50 inferiores a 10 µM, destacando-se para o composto HSe-05 com uma CI50 de 5,46 µM. Na avaliação citotóxica contra células tumorais, as selenoglicolicamidas que mais se destacaram na inibiçãodo crescimento celular (IC%) foram: HSe-02 e HSe-07 com 49% de inibição contra a linhagem MCF-7; HSe-02 e HSe-05 com 100% de inibição contra a linhagem HEp-2 e o HSe-05 com inibição de 99,56% na linhagem HL60. Na determinação da CI50 na linhagem tumoral HL-60, a selenoglicolicamida HSe2 apresentou uma CI50 de 3,42 µg/mL

ANTIFUNGAL AND ANTIBIOFILM ACTIVITY OF 2-BROMO-N-PHENYLCETAMIDE AGAINST CRYPTOCOCCUS NEOFORMANS

Objective: This study aimed to evaluate the antifungal and antibiofilm of 2-bromo-N-phenylacetamide (A1Br) against Cryptococcus neoformans in vitro. Methods: The compound was characterized by infrared and 1H-nuclear magnetic resonance spectrometry data. Minimum inhibitory concentration (MIC) was determined using the plate dilution method and biofilm formation inhibition of the crystal violet assay. Results: A1Br inhibited the growth of C. neoformans with MIC of 0.25 and 0.5 μg/ml and has good antibiofilm activity MIC ×4, with ≥80% inhibition growth. Conclusions: Thus, A1Br shows potential antifungal and antibiofilm agents for the treatment of infections caused by C. neoformans, as well as the eradication of cryptococcal colonization of medical prosthetic devices

Mechanistic studies of cytotoxic activity of the mesoionic compound MIH 2.4Bl in MCF-7 breast cancer cells

In the present study, the cytotoxic effects of a 1,3-thiazolium-5-thiolate derivative of a mesoionic compound, MIH 2.4Bl, were assessed in the MCF-7 breast cancer cell line. The cytotoxic effects of MIH 2.4Bl were determined using a crystal violet assay. Using a dose-response curve, the IC value of MIH 2.4Bl was determined to be 45.8±0.8 µM. Additionally, the effects of MIH 2.4Bl on mitochondrial respiration were characterized using oxygen consumption rate analysis. Treating MCF-7 cells with increasing concentrations of MIH 2.4Bl resulted in a significant reduction in all mitochondrial respiratory parameters compared with the control cells, indicative of an overall decrease in mitochondrial membrane potential. The induction of autophagy by MIH 2.4Bl was also examined by measuring changes in the expression of protein markers of autophagy. As shown by western blot analysis, treatment of MCF-7 cells with MIH 2.4Bl resulted in increased protein expression levels of Beclin-1 and ATG5, as well as an increase in the microtubule-associated protein 1A/1B light chain 3B (LC3B)-II to LC3B-I ratio compared with the control cells. Microarray analysis of changes in gene expression following MIH 2.4Bl treatment demonstrated 3,659 genes exhibited a fold-change ≥2. Among these genes, 779 were up-regulated, and 2,880 were down-regulated in cells treated with MIH 2.4Bl compared with the control cells. Based on the identity of the transcripts and fold-change of expression, six genes were selected for verification by reverse transcription-quantitative (RT-q)PCR; activating transcription factor 3, acidic repeat-containing protein, heparin-binding EGF-like growth factor, regulator of G-protein signaling 2, Dickkopf WNT signaling pathway inhibitor 1 and adhesion molecule with Ig like domain 2. The results of RT-qPCR analysis of RNA isolated from control and MIH 2.4Bl treated cells were consistent with the expression changes identified by microarray analysis. Together, these results suggest that MIH 2.4Bl may be a promising candidate for treating breast cancer and warrants further and investigation

Selene-Ethylenelacticamides and <i>N</i>-Aryl-Propanamides as Broad-Spectrum Leishmanicidal Agents

The World Health Organization classifies Leishmania as one of the 17 “neglected diseases” that burden tropical and sub-tropical climate regions with over half a million diagnosed cases each year. Despite this, currently available anti-leishmania drugs have high toxicity and the potential to be made obsolete by parasite drug resistance. We chose to analyze organoselenides for leishmanicidal potential given the reduced toxicity inherent to selenium and the displayed biological activity of organoselenides against Leishmania. Thus, the biological activities of 77 selenoesters and their N-aryl-propanamide derivatives were predicted using robust in silico models of Leishmania infantum, Leishmania amazonensis, Leishmania major, and Leishmania (Viannia) braziliensis. The models identified 28 compounds with >60% probability of demonstrating leishmanicidal activity against L. infantum, and likewise, 26 for L. amazonesis, 25 for L. braziliensis, and 23 for L. major. The in silico prediction of ADMET properties suggests high rates of oral absorption and good bioavailability for these compounds. In the in silico toxicity evaluation, only seven compounds showed signs of toxicity in up to one or two parameters. The methodology was corroborated with the ensuing experimental validation, which evaluated the inhibition of the Promastigote form of the Leishmania species under study. The activity of the molecules was determined by the IC50 value (µM); IC50 values 50 values Leishmania species under study, with compound NC34 presenting the strongest parasite inhibition profile. Furthermore, the methodology used was effective, as many of the compounds with the highest probability of activity were confirmed by the in vitro tests performed

Cytotoxic Activity of the Mesoionic Compound MIH 2.4Bl in Breast Cancer Cell Lines

In this work, we report the synthesis of a new 1,3-thiazolium-5-thiolate derivative of a mesoionic compound (MIH 2.4Bl) and the characterization of its selective cytotoxicity on a panel of breast cancer cells lines. The cytotoxic effect of MIH 2.4Bl on breast cancer cell lines was determined by XTT and crystal violet assays, flow cytometry analysis, electron microscopy characterization, and terminal deoxynucleotidyl transferase (TdT) deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) apoptosis assays. As determined using XTT cell growth and survival assays, MIH 2.4Bl exhibited growth inhibition activity on most breast cancer cell lines tested, compared with normal human mammary epithelial cells. Three breast cancer cell lines (MCF-7, T-47D, and ZR-75-1) showed a more potent sensitivity index to growth inhibition by MIH 2.4Bl than the other breast cancer cell lines. Interestingly, these 3 cell lines were derived from tumors of Luminal A origin and have ER (estrogen receptor), PR (progesterone receptor), and HER2 (human epidermal growth factor receptor 2) positive expression. Additional analysis of cytotoxicity mediated by MIH 2.4Bl was performed using the MCF-7 cell line. MCF-7 cells displayed both time- and dose-dependent decreases in cell growth and survival, with a maximum cytotoxic effect observed at 72 and 96 hours. The MCF-7 cells were also characterized for cell cycle changes upon treatment with MIH 2.4Bl. Using flow cytometry analysis of cell cycle distribution, a treatment-dependent effect was observed; treatment of cells with MIH 2.4Bl increased the G2/M population to 34.2% compared with 0.1% in untreated (control) cells. Ultrastructural analysis of MFC-7 cells treated with MIH 2.4Bl at 2 different concentrations (37.5 and 75 μM) was performed by transmission electron microscopy. Cells treated with 37.5 μM MIH 2.4Bl showed morphologic changes beginning at 6 hours after treatment, while cells treated with 75 μM showed changes beginning at 3 hours after treatment. These changes were characterized by an alteration of nuclear morphology and mitochondrial degeneration consistent with apoptotic cell death. Results of a TUNEL assay performed on cells treated for 96 hours with MIH 2.4Bl supported the observation of apoptosis. Together, these results suggest that MIH 2.4Bl is a promising candidate for treating breast cancer and support further in vitro and in vivo investigation