Potent Antioxidant and Genoprotective Effects of Boeravinone G, a Rotenoid Isolated from Boerhaavia diffusa

Background and Aims: Free radicals are implicated in the aetiology of some gastrointestinal disorders such as gastric ulcer, colorectal cancer and inflammatory bowel disease. In the present study we investigated the antioxidant and genoprotective activity of some rotenoids (i.e. boeravinones) isolated from the roots of Boerhaavia diffusa, a plant used in the Ayurvedic medicine for the treatment of diseases affecting the gastrointestinal tract. Methods/Principal Findings: Antioxidant activity has been evaluated using both chemical (Electron Spin Resonance spectroscopy, ESR) and Caco-2 cells-based (TBARS and ROS) assays. DNA damage was evaluated by Comet assay, while pERK 1/2 and phospho-NF-kB p65 levels were estimated by western blot. Boeravinones G, D and H significantly reduced the signal intensity of ESR induced by hydroxyl radicals, suggesting a scavenging activity. Among rotenoids tested, boeravinone G exerted the most potent effect. Boeravinone G inhibited both TBARS and ROS formation induced by Fenton's reagent, increased SOD activity and reduced H 2O 2-induced DNA damage. Finally, boeravinone G reduced the levels of pERK 1 and phospho-NF-kB p65 (but not of pERK 2) increased by Fenton's reagent. Conclusions: It is concluded that boeravinone G exhibits an extraordinary potent antioxidant activity (significant effect in the nanomolar range). The MAP kinase and NF-kB pathways seem to be involved in the antioxidant effect of boeravinone G. Boeravinone G might be considered as lead compound for the development of drugs potentially useful against those pathologies whose aetiology is related to ROS-mediated injuries

Infections after liver transplantation in adults: data from a university hospital in southern Brazil (1996-2000) Infecções em pacientes transplantados hepáticos adultos no Hospital de Clínicas de Porto Alegre, Rio Grande do Sul, Brasil, no período de 1996-2000

BACKGROUND: Infections after liver transplantations are the most important cause of morbi-mortality. In this study, we assessed the main characteristics of these infections in a southern Brazilian university hospital. METHODS: We conducted a retrospective cohort with 55 patients who underwent orthotopic liver transplantation between 1996 and 2000 in the "Hospital de Clínicas de Porto Alegre", Porto Alegre, RS, Brazil, to characterize the infections that occurred in the group. RESULTS: One or more infections (average 2.10) were diagnosed in 47 patients, especially during the first month after transplantation. The most common were bacteremia, intra-abdominal infections and pneumonia, predominantly with bacteria, especially Staphylococcus sp (and particularly S. aureus) and E. coli. The mortality rate attributed to infections was high: 17 cases of all deaths (total 27 deaths). Significant risk factors for infections included reoperation, diabetes, biliary stenosis and higher Child-Pugh scores. CONCLUSION: Infections remain a severe threat in liver transplant patients, and special efforts should be made to prevent and manage them correctly.<br>RACIONAL: Infecções são a causa principal de morbimortalidade em pacientes submetidos a transplantes hepáticos. OBJETIVO: Avaliar as principais características destas infecções em pacientes de um hospital universitário do sul do Brasil. MÉTODO: Uma coorte retrospectiva foi conduzida com os 55 pacientes transplantados hepáticos adultos cuja cirurgia foi realizada entre 1996 e 2000 no Hospital de Clínicas de Porto Alegre, RS, todos aos eventos infecciosos que ocorreram nesta população foram registrados. RESULTADOS: Uma ou mais infecções (média 2,1 episódios) foram diagnosticadas em 47 pacientes, o período de maior ocorrência destas foi o primeiro mês após a cirurgia. As infecções mais comuns foram: bacteremias, infecções intra-abdominais e pneumonias, a etiologia mais freqüente foi bacteriana, sendo os germes mais comuns os estafilicocos (em particular o S. aureus) e a E. coli. A taxa de mortalidade associada a infecções foi elevada: 17 óbitos de todos observados na coorte (27 no total). Os fatores de risco para infecção estatisticamente significantes foram: reoperação, diabetes, estenose de via biliar e classificação de Child-Pugh elevada. CONCLUSÃO: As infecções continuam sendo grave ameaça aos pacientes transplantados hepáticos e intenso esforço, que envolve o conhecimento da epidemiologia microbiológica, pesquisa e acompanhamento dos pacientes deve ser empregado, para prevenir e tratar de forma adequada estas complicações

Effect of sibutramine on cardiovascular outcomes in overweight and obese subjects.

BACKGROUND: The long-term effects of sibutramine treatment on the rates of cardiovascular events and cardiovascular death among subjects at high cardiovascular risk have not been established. METHODS: We enrolled in our study 10,744 overweight or obese subjects, 55 years of age or older, with preexisting cardiovascular disease, type 2 diabetes mellitus, or both to assess the cardiovascular consequences of weight management with and without sibutramine in subjects at high risk for cardiovascular events. All the subjects received sibutramine in addition to participating in a weight-management program during a 6-week, single-blind, lead-in period, after which 9804 subjects underwent random assignment in a double-blind fashion to sibutramine (4906 subjects) or placebo (4898 subjects). The primary end point was the time from randomization to the first occurrence of a primary outcome event (nonfatal myocardial infarction, nonfatal stroke, resuscitation after cardiac arrest, or cardiovascular death). RESULTS: The mean duration of treatment was 3.4 years. The mean weight loss during the lead-in period was 2.6 kg; after randomization, the subjects in the sibutramine group achieved and maintained further weight reduction (mean, 1.7 kg). The mean blood pressure decreased in both groups, with greater reductions in the placebo group than in the sibutramine group (mean difference, 1.2/1.4 mm Hg). The risk of a primary outcome event was 11.4% in the sibutramine group as compared with 10.0% in the placebo group (hazard ratio, 1.16; 95% confidence interval [CI], 1.03 to 1.31; P=0.02). The rates of nonfatal myocardial infarction and nonfatal stroke were 4.1% and 2.6% in the sibutramine group and 3.2% and 1.9% in the placebo group, respectively (hazard ratio for nonfatal myocardial infarction, 1.28; 95% CI, 1.04 to 1.57; P=0.02; hazard ratio for nonfatal stroke, 1.36; 95% CI, 1.04 to 1.77; P=0.03). The rates of cardiovascular death and death from any cause were not increased. CONCLUSIONS: Subjects with preexisting cardiovascular conditions who were receiving long-term sibutramine treatment had an increased risk of nonfatal myocardial infarction and nonfatal stroke but not of cardiovascular death or death from any cause. (Funded by Abbott; ClinicalTrials.gov number, NCT00234832.

Enteral Glutamine Infusion Modulates Ubiquitination of Heat Shock Proteins, Grp-75 and Apg-2, in the Human Duodenal Mucosa

Glutamine, the most abundant amino acid in the human body, plays several important roles in the intestine. Previous studies showed that glutamine may affect protein expression by regulating ubiquitin-proteasome system. We thus aimed to evaluate the effects of glutamine on ubiquitinated proteins in human duodenal mucosa. Five healthy male volunteers were included and received during 5 h, on two occasions and in a random order, either an enteral infusion of maltodextrins alone (0.25 g kg(-1) h(-1), control), mimicking carbohydrate-fed state, or maltodextrins with glutamine (0.117 g kg(-1) h(-1), glutamine). Endoscopic duodenal biopsies were then taken. Total cellular protein extracts were separated by 2D gel electrophoresis and analyzed by an immunodetection using anti-ubiquitin antibody. Differentially ubiquitinated proteins were then identified by liquid chromatography-electrospray ionization MS/MS. Five proteins were differentially ubiquitinated between control and glutamine conditions. Among these proteins, we identified two chaperone proteins, Grp75 and hsp74. Grp75 was less ubiquitinated after glutamine infusion compared with control. In contrast, hsp74, also called Apg-2, was more ubiquitinated after glutamine. In conclusion, we provide evidence that glutamine may regulate ubiquitination processes of specific proteins, i.e., Grp75 and Apg-2. Grp75 has protective and anti-inflammatory properties, while Apg-2 indirectly regulates stress-induced cell survival and proliferation through interaction with ZO-1. Further studies should confirm these results in stress conditions