Antibiotic resistance is a serious global threat to public health. This has promoted the research for new drug targets, and the use of other approaches, such as antimicrobial combined therapy. The present study evaluated the antibacterial activity of 88 extracts from Brazilian Atlantic Forest trees. The organic extract from leaves of Miconia latecrenata (EMl) was the most promising for inhibiting the growth of Staphylococcus aureus (0.3 mg/mL) and Pseudomonas aeruginosa (2.5 mg/mL). After the bioguided fractionation of EMl and metabolite profiling performed by UPLC-DAD-MS/MS, the ethyl acetate (AFMl) and aqueous (WFMl) fractions showed a mixture of phenolic compounds derived from ellagic acid and quercetin. The MIC value of AFMl was twotimes lower than EMl for P. aeruginosa, suggesting that these phenolic compounds can perform bioactivity. Furthermore, EMI and AFMl showed synergism with ampicillin and tetracycline for S. aureus and P. aeruginosa, respectively. These findings suggest that extract and fractions of the Miconia latecrenata leaves can be used as therapeutic antibacterial agents.
Background The Atlantic Forest biome extends along the entire Brazilian coast and is home to approximately 20,000 plant species, many of which are endemic; it is considered one of the hotspot regions of the planet. Several of these species are sources of natural products with biological activities that are still unknown. In this study, we evaluated the antimicrobial activity of 90 extracts derived from native Atlantic Forest tree species against Staphylococcus aureus , an important human and veterinary pathogen. Methods Extracts from native Atlantic Forest tree species were evaluated for their antimicrobial activity against S. aureus by in vitro standard methods. Phytochemical fractionation of the extract from Maclura tinctoria was performed by liquid-liquid partitioning. LC-DAD-ESI-MS was used for identification of constituents in the most active fraction. Damage of cells and alterations in the permeability of cell membrane were determined by atomic force microscopy (AFM) and crystal violet uptake assay, respectively. In vivo antimicrobial activity was evaluated using Galleria mellonella larvae infected with S. aureus with survival data collected using the Kaplan-Meier method. Results Among the organic or aqueous extracts tested here, 26 showed biological activity. Eight species showed relevant results, with a minimum inhibitory concentration (MIC) below 1 mg/mL. Antibacterial activity was registered for three species for the first time. An organic extract from Maclura tinctoria leaves showed the lowest MIC (0.08 mg/mL). Fractionation of this extract by liquid-liquid partitioning led to obtaining fraction 11FO d with a MIC of 0.04 mg/mL. This fraction showed strong activity against veterinary S. aureus isolates and contributed to the increased survival of Galleria mellonella larvae infected with S. aureus ATCC 29213. The bacterial surface was not altered by the presence of 11FO d, and no cell membrane damage was detected. The LC-DAD-ESI/MS analyses identified prenylated flavonoids as the major constituents responsible for the antibacterial activity of this active extract. Conclusion A fraction enriched in prenylated isoflavones and flavanones from M. tinctoria showed in vitro and in vivo efficacy as antistaphylococcal agents. These findings justify the need for further research to elucidate the mechanisms of action of these compounds.
Athenaea velutina is a promising Brazilian shrub with cytotoxic and antimigratory properties against cancer cells. However, the mechanism of induction of cancer cell death and the compounds involved remain unknown. To ascertain these bioactive compounds, bioassay-guided fractionation was performed, alongside the appropriate in vitro tests. A withanolide-rich fraction (FAv_5) from the dichloromethane extract increased cytotoxic activity by 1.5-fold (IC50 = 2.1 µg/mL). Fourteen withanolide steroids were tentatively identified for the first time for this species by mass spectrometry coupled to liquid chromatography (LC MS/MS), including withanolide A, aurelianolide A, and aurelianolide B. FAv_5 significantly decreased cell proliferation, migration, and invasion with a selectivity index greater than 8 for B16F10 cells. Furthermore, flow cytometry with annexin V fluorescein isothiocyanate/propidium iodide (V-FITC/PI) staining showed FAv_5 to promote cell cycle arrest at the G0/G1-phase as well as apoptotic cell death. Overall, these findings highlight A. velutina as a source of withanolide-steroids that inhibit cancer cell proliferation through apoptosis and cell cycle blockade mechanisms. Details on the geographic distribution of A. velutina and species conservation strategies have also been highlighted.
Gestational diabetes mellitus (GDM), is characterized by glucose intolerance from the second trimester of pregnancy. Risk factors such as advanced maternal age, obesity, Polycystic Ovary Syndrome, Gestational hypertension, among others, are associated with its development. The disease has an important impact on maternal and fetal health, and therefore, it is recommended that from the 24th week of gestation, the oral glucose tolerance test be performed. Regarding its treatment, one of the most recommended options is metformin, an oral hypoglycemic agent. Although the drug is shown to be safe in pregnancy, there is no evidence in the medical literature of an increase in the rate of congenital malformations, fetal death or trauma during childbirth, and controversy remains over the long-term metabolic implications of fetal exposure to the drug. To analyze the risks and benefits associated with the use of metformin in the treatment of GDM. Methods: An analysis of publications indexed in the database of MEDLINE/PubMed ® (National Library of Medicine), SciELO (Scientific Eletronic Library Online) and Google Scholar between January 1, 2011 and December 31, 2019, was carried out. Twenty studies were found who's summary, or full access available, was validated by correlation with the topic. The study suggests that further evidence about the use of RESUMO O Diabetes mellitus gestacional (DMG), caracteriza-se por intolerância à glicose a partir do segundo trimestre da gestação. Fatores de risco como idade materna avançada, obesidade, Síndrome dos Ovários Policísticos, Hipertensão gestacional, entre outros, encontram-se associados a seu desenvolvimento. A doença causa um importante impacto na saúde materna e fetal, e desse modo, recomenda-se que a partir da 24ª semana de gestação, seja realizado o teste oral de tolerância a glicose. Em relação a seu tratamento, uma das opções mais indicadas é a metformina, um hipoglicemiante oral. Embora o fármaco se mostre seguro na gravidez, não há na literatura médica evidência do aumento da taxa de malformações congênitas, morte fetal ou trauma durante o parto, permanecendo a controvérsia sobre as implicações metabólicas a longo prazo da exposição fetal ao fármaco. Analisar os riscos e benefícios associados ao uso da metformina no tratamento do DMG. Efetuou-se uma análise das publicações indexadas na base de dados do MEDLINE/PubMed ® (National Library of Medicine), da SciELO (Scientific Eletronic Library Online) e do Google Acadêmico entre 1º de janeiro de 2011 a 31 de dezembro de 2019. Foram encontrados vinte estudos cujo resumo, ou acesso completo disponíveis foram validados pela correlação com o tema. O estudo sugere que maiores evidências acerca da utilização do fármaco durante a gestação e de suas implicações metabólicas de longo prazo sobre o desenvolvimento fetal sejam investigadas, por meio de estudos clínicos randomizados que abranjam um grande número de gestantes.
A bioprospecção de produtos naturais a partir de coleções de extratos vegetais tem sido uma estratégia eficiente e promissora para a descoberta de novos fármacos antitumorais. O objetivo dessa pesquisa foi bioprospectar produtos naturais com potencial antitumoral de espécies vegetais nativas do bioma Mata Atlântica. Foi avaliado o potencial citotóxico de 282 extratos provenientes de 72 espécies em linhagens celulares B16F10 (melanoma), SW480 (adenocarcinoma de cólon), Jurkat (leucemia) e Vero (células epiteliais de rim de macaco). Os extratos promissores foram submetidos ao fracionamento biomonitorado e determinada a concentração inibitória do crescimento celular em 50% (IC 50 ). As espécies que apresentaram maior citotoxicidade foram Sorocea hilarii (Moraceae), espécie até então com escasso estudo fitoquímico e farmacológico e Casearia arborea (Salicaceae). Após fracionamento biomonitorado, foi realizado para as frações ativas um estudo de desreplicação, empregando-se dados de cromatografia líquida de alta eficiência acoplada ao espectrômetro de massas de alta resolução, em associação com a plataforma GNPS (Global Natural Product Social Molecular Networking). Para S. hilarii foram identificadas clusters moleculares referentes às classes megastigmanos, lignanas e saponinas esteroidais, enquanto para C. arborea foram identificados diterpenos clerodânicos e flavonoides. Na tentativa de isolar e identificar os compostos com atividade antitumoral, diferentes extratos de folhas de C. arborea foram obtidos. O extrato em diclorometano se mostrou mais citotóxico frente às linhagens SW480, MDA-MB-231 (câncer de mama) e Hep G2 (câncer de fígado). O fracionamento biomonitorado desse extrato levou a frações contendo diterpenos clerodânicos, sendo purificados e elucidados estruturalmente três diterpenos clerodânicos, dois deles inéditos: casearborina F e casearborina G. As estruturas químicas foram elucidadas empregando técnicas de espectroscopia de massas de alta resolução e por experimentos de Ressonância Magnética Nuclear unidimensional (RMN de 1 H, 13 C, DEPT 135) e bidimensional (HMBC, HSQC e NOESY). Frações contendo estes compostos induziram a morte celular por apoptose, e apresentam as propriedades antimigratórias e anticlonogênicas, assim como atuam em G0/G1 no ciclo celular de células SW480. Essa pesquisa mostra que espécies vegetais nativas da Mata Atlântica brasileira são potenciais fontes de compostos antitumorais, inclusive de novas moléculas bioativas. Palavras-chave: Bioprospecção. Mata Atlântica. Antitumoral. Sorocea hilarii. Casearia arborea. Diterpenos clerodânicos. Casearborina
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.