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1.
Artigo em Inglês | MEDLINE | ID: mdl-38756090

RESUMO

Antibiotics are considered "wonder drugs" due to the fact that they are the most extensively utilised medication in the world. They are used to cure a broad spectrum of diseases and lethal infections. A variety of bacteria and fungi produce antibiotics as a result of secondary metabolism; however, their production is dominated by a special class of bacteria, namely Actinobacteria. Actinobacteria are gram-positive bacteria with high G+C content and unparalleled antibiotic-producing ability. They produce numerous polyenes, tetracyclines, ß-lactams, macrolides, and peptides. Actinobacteria are ubiquitous in nature and are isolated from various sources, such as marine and terrestrial endophytes of plants and air. They are studied for their relative antibiotic-producing ability along with the mechanism that the antibiotics follow to annihilate the pathogenic agents that include bacteria, fungi, protozoans, helminths, etc. Actinobacteria isolated from endophytes of medicinal plants have amassed significant attention as they interfere with the metabolism of medicinal plants and acquire enormous benefits from it in the form of conspicuous novel antibiotic-producing ability. Actinobacteria is not only an antibiotic but also a rich source of anticancer compounds that are widely used owing to its remarkable tumorigenic potential. Today, amongst Actinobacteria, class Streptomyces subjugates the area of antibiotic production, producing 70% of all known antibiotics. The uniqueness of bioactive Actinobacteria has turned the attention of scientists worldwide in order to explore its potentiality as effective "micronanofactories". This study provides a brief overview of the production of antibiotics from Actinobacteria inhabiting diverse environments and the methods involved in the screening of antibiotics.

2.
Cell Biochem Funct ; 42(3): e3988, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38532684

RESUMO

This article deals with the antibacterial and anticancer potential of secondary metabolites produced by actinomycetes also reported as actinobacteria, Microbacterium proteolyticum (MN560041), and Streptomycetes rochei, where preliminary studies were done with the well diffusion method. These actinobacteria's silver nanoparticles were synthesized and characterized using transmission electron microscopy (TEM) and UV-Visible spectroscopy. Anticancer was measured using the MTT test, reactive oxygen species (ROS) generation measured with DCFDA, mitochondrial membrane potential (MMP) measurement, and DAPI fluorescence intensity activity was measured in treated and non-treated cancerous cells. The IC50 value for 5-FU (a), LA2(O) (b), LA2(R) (c), LA2(ON) (d), and LA2(RN) (e) was obtained at 3.91 µg/mL (52.73% cell viability), 56.12 µg/mL (52.35% cell viability), 44.90 µg/mL (52.3% cell viability), 3.45 µg/mL (50.25% cell viability), and 8.05 µg/mL (48.72% cell viability), respectively. TEM micrographs revealed discrete, well-separated AgNPs particles of size 7.88 ± 2 to 12.86 ± 0.24 nm. Gas chromatography-mass spectrometry was also performed to detect the compounds in bioactive metabolites where n-hexadecanoic acid was obtained as the most significant one. MTT test showed a substantial decline in A549 cell viability (up to 48.72%), 2.75-fold increase in ROS generation was noticed in comparison to untreated A549 lung cancer cells when measured with DCFDA. A total of 0.31-fold decrease in MMP and 1.74-fold increase in DAPI fluorescence intensity compared to untreated A549 lung cancer cells suggests that the synthesized nanoparticles promote apoptosis in cancerous cells. Our findings suggests that the secondary metabolites of M. proteolyticum and S. rochei in nanoparticle form can be used as a significant compound against lung cancers.


Assuntos
Actinobacteria , Fluoresceínas , Neoplasias Pulmonares , Nanopartículas Metálicas , Humanos , Prata/química , Espécies Reativas de Oxigênio/metabolismo , Actinobacteria/metabolismo , Nanopartículas Metálicas/química , Células A549 , Extratos Vegetais/química
3.
Arch Gynecol Obstet ; 298(1): 159-169, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29728850

RESUMO

PURPOSE: Cervical cancer is the fourth most common cancer in women worldwide with very high incidence in India. Liquid-based cytology (LBC) provides the use of ancillary techniques in addition to a good morphology and detection of cytologic abnormalities. The current study was designed to assess the diagnostics of P16INK4a immunoexpression, p16 promoter hypermethylation, human papilloma virus (HPV), and DNA ploidy in LBC samples with cervical precancer and cancer. METHODS: A series of LBC samples categorised by Bethesda system including 22 atypical squamous cells of undetermined significance (ASC-US), 21 low-grade squamous intraepithelial lesion (LSIL), 41 high-grade squamous intraepithelial lesion (HSIL), 54 squamous cell carcinoma (SCC), and 26 controls with normal cytology were included. Ancillary techniques evaluated included P16INK4a immunoexpression, p16 promoter methylation DNA ploidy by flow cytometry, and HPV was detected using PGMY09/PGMY11 primers. RESULTS: The test positivity rate of p16 expression in women with ASC-US, LSIL, HSIL, and SCC was 21.1, 39.0, 67.7, and 85.4%. For the p16 methylation the corresponding test positivity rate was 36.4, 76.2, 92.7, and 92.6%. The test positive rate of HPV in women with ASC-US, LSIL, HSIL, and SCC was 45.5, 76.2, 87.8, and 92.6%. Diploid G1 and diploid S values significantly (p < 0.05 or p < 0.01) discriminate LSIL versus HSIL and LSIL versus. SCC. CONCLUSIONS: P16 gene promoter methylation and HPV seem more sensitive in detection of ASC-US and LSIL cytology with higher specificity. Diploid G1 and diploid S phase study provides progressive change in parameters with progression from LSIL to HSIL and SCC.


Assuntos
Citodiagnóstico/métodos , Displasia do Colo do Útero/patologia , Feminino , Humanos , Imuno-Histoquímica/métodos , Pessoa de Meia-Idade
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