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1.
Braz. j. biol ; 83: e245753, 2023. tab
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1278536

RESUMO

Abstract The species Eugenia involucrata DC. is a plant native to Brazil and is traditionally used for intestinal problems, however, little research has documented about its biological potential and phytochemical profile. Thus, the objective of this study was to carry out preliminary phytochemical prospecting, antimicrobial and antioxidant potential of E. involucrata extracts. Using the E. involucrata leaves, aqueous and organic extracts were obtained using the following solvents (ethanol, methanol, hexane, acetone, dichloromethane and ethyl acetate). The phytochemical prospecting detected the presence of saponins, steroids, flavonoids and tannins in the extracts. Ethanolic and methanolic extracts presented antimicrobial activity for most of the bacterial strains tested, as well as for yeast Candida albicans, with concentrations between 3.12 and 50 mg/mL. The ethanolic and metanolic extract presented high free radical sequestration potential (>90%). The methanol extract showed an IC50 value statistically equal to that found for the commercial antioxidant BHT (p <0.05). The crude extracts obtained with ethanol and methanol were the most promising. These results suggest that methanolic, ethanolic and aqueous extracts are a promising source of natural bioactive.


Resumo A espécie Eugenia involucrata DC. é uma planta nativa do Brasil e tradicionalmente utilizada para problemas intestinais, porém, poucas pesquisas documentam sobre seu potencial biológico e perfil fitoquímico. Assim, o objetivo deste trabalho foi realizar uma prospecção fitoquímica preliminar, o potencial antimicrobiano e antioxidante dos extratos de E. involucrata. A partir das folhas de E. involucrata, foram obtidos extratos aquosos e orgânicos com os seguintes solventes (etanol, metanol, hexano, acetona, diclorometano e acetato de etila). A prospecção fitoquímica detectou a presença de saponinas, esteroides, flavonóides e taninos nos extratos. Os extratos etanólico e metanólico apresentaram atividade antimicrobiana para a maioria das cepas bacterianas testadas, assim como para a levedura Candida albicans, com concentrações entre 3,12 e 50 mg/mL. Os extratos etanólico e metanólico apresentaram alto potencial de sequestro de radicais livres (> 90%). O extrato metanólico apresentou IC50 estatisticamente igual ao encontrado para o antioxidante comercial BHT (p <0,05). Os extratos brutos obtidos com etanol e metanol foram os mais promissores. Esses resultados sugerem que os extratos metanólico, etanólico e aquoso são uma fonte promissora de bioativos naturais.

2.
Braz. j. biol ; 82: e233425, 2022. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1249266

RESUMO

Abstract The secondary metabolism products of plants have influenced great economic interest, given their chemical diversity and biological activities. Because of this, this study evaluates the phytochemical composition, antimicrobial activity, insecticidal, and antioxidant activity of plant extracts and oil of Myrcia oblongata. Saponins, steroids, triterpenoids, tannins, and flavonoids were detected. The extracts showed antimicrobial capacity on the tested microorganisms, except for the methanolic extract, which showed no activity for P. mirabilis and S. enteritidis. Regarding the analysis of antioxidant compounds, the hexanic, ethyl acetate and acetone extracts showed higher antioxidant activities and also higher insecticidal performance on Alphitobius diaperinus larvae, resulting in 80% adult mortality. The results reported here show that there may be a relationship between antioxidant potential and the insecticidal effect of Myrcia oblongata DC. The components present in both the extract and the oil can be used as natural alternative to synthetic compounds in the biological control of parasites and pathogenic microorganisms.


Resumo Os produtos do metabolismo secundário das plantas têm despertado grande interesse econômico, dada sua diversidade química e atividades biológicas. Neste sentido, o estudo objetivou avaliar a composição fitoquímica, atividade antimicrobiana, inseticida e antioxidante dos extratos vegetais e óleo de Myrcia oblongata. Foram detectados a presença de saponinas, esteróides, triterpenóides, taninos e flavonóides. Os extratos apresentaram capacidade antimicrobiana sobre os microrganismos testados, exceto o extrato metanólico que não demonstrou atividade para P. mirabilis e S. Enteritidis. Quanto a análise de compostos antioxidantes observou-se que os extratos hexânico, acetato de etila e acetona apresentaram maiores atividades antioxidantes e também maior performance inseticida sobre a larva Alphitobius diaperinus e exibindo mortalidade de 80% na fase adulta. Os resultados aqui reportados mostram que pode haver uma relação entre potencial antioxidante e efeito inseticida do óleo de Myrcia oblongata; os componentes presentes tanto no extrato como o oléo podem ser utilizados como alternativa natural aos compostos sintéticos no controle biológico de parasitas e microrganismos patogênicos.

3.
Braz J Biol ; 83: e245753, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34190760

RESUMO

The species Eugenia involucrata DC. is a plant native to Brazil and is traditionally used for intestinal problems, however, little research has documented about its biological potential and phytochemical profile. Thus, the objective of this study was to carry out preliminary phytochemical prospecting, antimicrobial and antioxidant potential of E. involucrata extracts. Using the E. involucrata leaves, aqueous and organic extracts were obtained using the following solvents (ethanol, methanol, hexane, acetone, dichloromethane and ethyl acetate). The phytochemical prospecting detected the presence of saponins, steroids, flavonoids and tannins in the extracts. Ethanolic and methanolic extracts presented antimicrobial activity for most of the bacterial strains tested, as well as for yeast Candida albicans, with concentrations between 3.12 and 50 mg/mL. The ethanolic and metanolic extract presented high free radical sequestration potential (>90%). The methanol extract showed an IC50 value statistically equal to that found for the commercial antioxidant BHT (p <0.05). The crude extracts obtained with ethanol and methanol were the most promising. These results suggest that methanolic, ethanolic and aqueous extracts are a promising source of natural bioactive.


Assuntos
Anti-Infecciosos , Eugenia , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Brasil , Compostos Fitoquímicos , Extratos Vegetais/farmacologia , Folhas de Planta
4.
Braz J Biol ; 82: e233425, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34105655

RESUMO

The secondary metabolism products of plants have influenced great economic interest, given their chemical diversity and biological activities. Because of this, this study evaluates the phytochemical composition, antimicrobial activity, insecticidal, and antioxidant activity of plant extracts and oil of Myrcia oblongata. Saponins, steroids, triterpenoids, tannins, and flavonoids were detected. The extracts showed antimicrobial capacity on the tested microorganisms, except for the methanolic extract, which showed no activity for P. mirabilis and S. enteritidis. Regarding the analysis of antioxidant compounds, the hexanic, ethyl acetate and acetone extracts showed higher antioxidant activities and also higher insecticidal performance on Alphitobius diaperinus larvae, resulting in 80% adult mortality. The results reported here show that there may be a relationship between antioxidant potential and the insecticidal effect of Myrcia oblongata DC. The components present in both the extract and the oil can be used as natural alternative to synthetic compounds in the biological control of parasites and pathogenic microorganisms.


Assuntos
Anti-Infecciosos , Inseticidas , Óleos Voláteis , Antioxidantes/farmacologia , Bactérias , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia
5.
BMJ Open Diabetes Res Care ; 4(1): e000179, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27547409

RESUMO

AIMS/HYPOTHESIS: In type 1 diabetes (T1D), most insulin-producing ß cells are destroyed, but the trigger is unknown. One of the possible triggers is a virus infection and the aim of this study was to test if enterovirus infection affects glucose stimulated insulin secretion and the effect of virus replication on cellular macromolecules and organelles involved in insulin secretion. METHODS: Isolated human islets were infected with different strains of coxsackievirus B (CVB) virus and the glucose-stimulated insulin release (GSIS) was measured in a dynamic perifusion system. Classical morphological electron microscopy, large-scale electron microscopy, so-called nanotomy, and immunohistochemistry were used to study to what extent virus-infected ß cells contained insulin, and real-time PCR was used to analyze virus induced changes of islet specific genes. RESULTS: In islets infected with CVB, GSIS was reduced in correlation with the degree of virus-induced islet disintegration. The expression of the gene encoding insulin was decreased in infected islets, whereas the expression of glucagon was not affected. Also, in islets that were somewhat disintegrated, there were uninfected ß cells. Ultrastructural analysis revealed that virus particles and virus replication complexes were only present in ß cells. There was a significant number of insulin granules remaining in the virus-infected ß cells, despite decreased expression of insulin mRNA. In addition, no typical Golgi apparatus was detected in these cells. Exposure of islets to synthetic dsRNA potentiated glucose-stimulated insulin secretion. CONCLUSIONS/INTERPRETATION: Glucose-stimulated insulin secretion; organelles involved in insulin secretion and gene expression were all affected by CVB replication in ß cells.

6.
Pituitary ; 18(4): 500-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25261979

RESUMO

UNLABELLED: Whether the preoperative use of somatostatin analogues (SA) improves surgical outcomes in acromegaly is still a matter of debate. OBJECTIVE: We conducted a systematic review of randomized, controlled trials that compared the short-term outcomes of preoperative use of SA (Pre-SA) with direct TSS (No-SA) for the treatment of newly diagnosed acromegaly. METHODS: Embase, Pubmed, Lilacs, and Central Cochrane were used as our data sources. The primary outcomes were no need for any adjuvant treatment 3 months after surgery, based on biochemical results (GH nadir after OGTT <1 µg/L and normal IGF-1 for age and gender), quality of life and mortality. The included trials were analyzed using the Grading of Recommendations Assessment, Development, and Evaluation approach. RESULTS: A total of 2.099 references were identified and two reviewers independently screened the titles and abstracts. From the 14 potentially eligible studies, four were included and ten were excluded due to lack of randomization or different outcomes. A pool of 261 patients was randomly assigned to Pre-SA or No-SA. Meta-analysis of IGF1 normalization showed a significant difference in favor of Pre-SA (RR 2.47; 95% CI 1.66, 3.77). Adding a GH nadir on OGTT ≤1 µg/L, we found a RR of 2.15 (95% CI 1.39, 3.33). Quality of evidence for no need of adjuvant postoperative treatment was moderate, but for improving quality of life was very low and for mortality was absent. CONCLUSION: Pre-SA increases the chance of biochemical control of acromegaly 3 months after TSS in patients harboring GH-secreting pituitary macroadenomas.


Assuntos
Adenoma/tratamento farmacológico , Antineoplásicos Hormonais/uso terapêutico , Adenoma Hipofisário Secretor de Hormônio do Crescimento/tratamento farmacológico , Terapia Neoadjuvante , Procedimentos Neurocirúrgicos , Octreotida/uso terapêutico , Peptídeos Cíclicos/uso terapêutico , Somatostatina/análogos & derivados , Adenoma/metabolismo , Adenoma/mortalidade , Quimioterapia Adjuvante , Teste de Tolerância a Glucose , Adenoma Hipofisário Secretor de Hormônio do Crescimento/metabolismo , Adenoma Hipofisário Secretor de Hormônio do Crescimento/mortalidade , Hormônio do Crescimento Humano/metabolismo , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Cuidados Pré-Operatórios , Qualidade de Vida , Somatostatina/uso terapêutico
7.
J Pediatr (Rio J) ; 77(6): 441-6, 2001.
Artigo em Português | MEDLINE | ID: mdl-14647822

RESUMO

OBJECTIVE: Given that the most common allergic manifestations (asthma, rhinitis, dermatitis, food allergies) occur during childhood, because the immune system can be induced into sensitization rather than into allergenic tolerance at the beginning of life, we analyzed the main immunological aspects of fetuses and infant in terms of allergic sensitization and response. METHODS: Detailed bibliographic revision concerning nonspecific immune response (physical and chemical barriers, myeloid cells) and specific immune response (T and B lymphocytes, cytokines) of the fetus and infant, with special attention to studies carried out in the last fifteen years. RESULTS: Various compartments of the immune system in fetuses and infants are different from those present in older children and adults. Thus, developmental aspects of nonspecific and specific immunity may contribute to atopic disease. CONCLUSIONS: Atopic predisposition is determined at the beginning of life and seems to originate not only from genetic factors, but also from intrauterine environment and initial stage of childhood, inducing the immune system to increase the synthesis of IgE.

8.
J Autom Methods Manag Chem ; 21(2): 39-43, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-18924842

RESUMO

A control system based on a combination of the gain-scheduling control method and an adaptive PID controller was designed for the production of xylose from hardwood hemicellulose using a stirring tank reactor. Different operating conditions have been considered for estimating the adjustable parameter (theta) to take into account the changes of energy of the system. The performance of the control system was studied first by numerical simulation, and after implementation in the stirred tank reactor where the controller actually works.

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