In Silico Study and Bioprospection of the Antibacterial and Antioxidant Effects of Flavone and Its Hydroxylated Derivatives.

Flavonoid compounds are widely used as natural protective species, which can act as anti-inflammatory, antioxidant, anticoagulant, antihypertensive and antitumor agents. This study set out to investigate the probable pharmacological activities, along with the antibacterial and antioxidant effects, of flavone and its hydroxy derivatives: 3-hydroxyflavone, 5-hydroxyflavone and 6-hydroxyflavone. To do so, we investigated their pharmacological characteristics, using in silico tests that indicate likelihood of activity or inactivity, with the PASS online software, and the antimicrobial potential against Gram positive and Gram negative bacteria was also analyzed, including bacteria of clinical importance. We also tested for oxidant and antioxidant potential in these molecules in the presence of reactive oxygen species (ROS) and phenylhydrazine (Ph). The results revealed the following characteristics: pharmacological activities for the flavonoids as agonists of cell membrane integrity and as permeability inhibitors, as antagonists of anaphylatoxin receptors, as inhibitors of both kinase and peroxidase, and as having both antimutagenic capacity and vaso-protective potential. All of the flavonoids exhibited moderate antibacterial activity against Gram positive and Gram negative strains, with the flavones being bactericidal at 200 µg/mL for the strains of P. aeruginosa ATCC 8027, S. aureus ATCC 25619 and E. coli 104; the other flavonoids revealed bacteriostatic action. The substances did not promote erythrocyte oxidation and behaved as sequestrators and antioxidants of hydrogen peroxide (H2O2) and phenylhydrazine (Ph). It was concluded that the analyzed compounds have various pharmacological activities in accordance with the predictions of PASS online, as their antibacterial and antioxidant activities were confirmed. The study also helps to consolidate the use of computational chemistry in silico tools to guide new drug search and discovery protocols.

Antibacterial and hemolytic activity of a new lectin purified from the seeds of Sterculia foetida L.

The aim of this study was to isolate, characterize, and verify possible antibacterial and hemolytic activity for a lectin found in the seeds of Sterculia foetida L. Purification of the lectin from S. foetida (SFL) was realized with ion exchange chromatography DEAE-Sephacel coupled to HPLC. The purity and the molecular weight was determined by SDS-PAGE. The isolated SFL was characterized as to its glycoprotein nature, and sugar specificity, as well as resistance to pH, temperature, denaturing agents, reduction, oxidation, and chelation. A microdilution method was used to determine antibacterial activity, and hemolytic activity was observed in human erythrocytes. The SFL has a molecular weight of 17 kDa, and a carbohydrate content of 53 µg/mL, specific for arabinose and xylose, and is resistant to treatment with urea, sensitive to treatment with sodium metaperiodate and ß-mercaptoethanol, and in the presence of EDTA lost its hemagglutinating activity (HA). However, in the presence of divalent cations (Ca(2 +) and Mn(2 +)) the HA was increased. The SFL remained active even after incubation at 80 °C, and, within pH values of between 5 and 11. The SFL inhibited the bacterial growth of all the tested strains and caused little hemolysis in human erythrocytes when compared to the positive control Triton X-100.

Molecular ageing in progeroid syndromes: Hutchinson-Gilford progeria syndrome as a model.

Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disorder that belongs to a group of conditions called laminopathies which affect nuclear lamins. Mutations in two genes, LMNA and ZMPSTE24, have been found in patients with HGPS. The p.G608G LMNA mutation is the most commonly reported mutation. The aim of this work was to compile a comprehensive literature review of the clinical features and genetic mutations and mechanisms of this syndrome as a contribution to health care workers. This review shows the necessity of a more detailed clinical identification of Hutchinson-Gilford progeria syndrome and the need for more studies on the pharmacologic and pharmacogenomic approach to this syndrome.

Pulmonary bacterial pathogens in cystic fibrosis patients and antibiotic therapy: a tool for the health workers.

Cystic fibrosis is the most common and best known genetic disease involving a defect in transepithelial Cl- transport by mutations in the CF gene on chromosome 7, which codes for the cystic fibrosis transmembrane conductance regulator protein (CFTR). The most serious symptoms are observed in the lungs, augmenting the risk of bacterial infection. The objective of this review was to describe the bacterial pathogens colonizing patients with cystic fibrosis. A systematic search was conducted using the international bibliographic databanks SCIELO, HIGHWIRE, PUBMED, SCIRUS and LILACS to provide a useful and practical review for healthcare workers to make them aware of these microorganisms. Today, B. cepacia, P. aeruginosa and S. aureus are the most important infectious agents in cystic fibrosis patients. However, healthcare professionals must pay attention to emerging infectious agents in these patients, because they represent a potentially serious future problem. Therefore, these pathogens should be pointed out as a risk to these patients, and hospitals all over the world must be prepared to detect and combat these bacteria.