Obesity, bariatric surgery and oxidative stress / Obesidade, cirurgia bariátrica e estresse oxidativo

Summary Introduction: Obesity refers to the accumulation of fatty tissues and it favors the occurrence of oxidative stress. Alternatives that can contribute to body weight reduction have been investigated in order to reduce the production of reactive oxygen species responsible for tissue damage. The aim of the current study was to assess whether the oxidant and antioxidant markers of obese women before and after bariatric surgery were able to reduce oxidative damage. Method: We have assessed 16 morbidly obese women five days before and 180 days after the surgery. The control group comprised 16 non-obese women. Levels of thiobarbituric acid-reactive substances, carbonylated proteins, reduced glutathione and ascorbic acid were assessed in the patients' plasma. Results: Levels of lipid peroxidation and protein carbonylation in the pre-surgical obese women were higher than those of the controls and post-surgical obese women. Levels of reduced glutathione in the pre-surgical obese women were high compared to the controls, and declined after surgery. Levels of ascorbic acid fell in the pre--surgical obese women compared to the control and post-surgical obese women. Conclusion: Body weight influences the production of reactive oxygen species. Bariatric surgery, combined with weight loss and vitamin supplementation, reduces cellular oxidation, thus reducing tissue damage.

Resumo Introdução: Na obesidade, verifica-se um acúmulo de tecido adiposo, o que favorece a ocorrência de estresse oxidativo. A fim de diminuir a produção das espécies reativas que levam a danos teciduais, buscam-se alternativas que contribuam para a redução do peso corporal. Este estudo avaliou se os marcadores oxidantes e antioxidantes de obesas antes e após cirurgia bariátrica reduziram o dano oxidativo. Método: Foram avaliadas 16 mulheres obesas mórbidas cinco dias antes e 180 dias após o procedimento cirúrgico. O grupo controle constituiu-se de 16 mulheres não obesas. Os níveis das substâncias reativas ao ácido tiobarbitúrico, das proteínas carboniladas, da glutationa reduzida e do ácido ascórbico foram avaliados no plasma dessas pacientes. Resultados: Os níveis de lipoperoxidação e da carbonilação de proteínas nas obesas pré-cirúrgicas eram mais elevados quando comparados ao controle e às obesas pós-cirúrgicas; os níveis de glutationa reduzida eram maiores nas obesas pré-cirúrgicas em comparação ao controle e diminuíram após a cirurgia; os níveis de ácido ascórbico eram menores nas obesas pré-cirúrgicas em relação ao controle e às obesas pós-cirúrgicas. Conclusão: Observou-se que a massa corporal influenciou na produção das espécies reativas. A cirurgia bariátrica, somada à perda de peso e à suplementação vitamínica, diminui a oxidação celular e, com isso, reduz os danos teciduais.

Protein carbonyl content: a novel biomarker for aging in HIV/AIDS patients

Abstract Background: The major complications of “treated” Human Immunodeficiency Virus (HIV) infection are cardiovascular disease, malignancy, renal disease, liver disease, bone disease, and perhaps neurological complications, which are phenomena of the normal aging process occurring at an earlier age in the HIV-infected population. The present study is aimed to explore protein carbonyl content as a biomarker for detecting oxidative DNA damage induced ART toxicity and/or accelerated aging in HIV/AIDS patients. Objective: To investigate the potential of carbonyl content as a biomarker for detecting oxidative Deoxyribonucleic acid (DNA) damage induced Antiretroviral Theraphy (ART) toxicity and/or accelerated aging in HIV/AIDS patients. Methods: In this case–control study a total 600 subjects were included. All subjects were randomly selected and grouped as HIV-negative (control group) (n = 300), HIV-infected ART naive (n = 100), HIV-infected on first line ART (n = 100), and HIV-infected on second line ART (n = 100). Seronegative control subjects were age- and sex-matched with the ART naive patients and the two other groups. Carbonyl protein was determined by the method described in Levine et al. DNA damage marker 8-OH-dG was determined using 8-hydroxy-2-deoxy Guanosine StressXpress ELA Kit by StressMarq Biosciences. Results: Protein carbonyl content levels and oxidative DNA damage were significantly higher (p < 0.05) in HIV-infected patients on second line ART and HIV-infected patients on first line ART than ART naive patients and controls. In a linear regression analysis, increased protein carbonyl content was positively associated with increased DNA damage (OR: 0.356; 95% CI: 0.287–0.426) p < 0.05. Conclusions: Carbonyl content may has a role as a biomarker for detecting oxidative DNA damage induced ART toxicity and/or accelerated aging in HIV/AIDS patients. Larger studies are warranted to elucidate the role of carbonyl content as a biomarker for premature aging in HIV/AIDS patients.

Gingival crevicular fluid oxidative stress level in patients with periodontal disease and hyperlipidemia

Abstract: This study aimed to assess the impact of hyperlipidemia on healthy and diseased periodontal tissue by evaluating oxidative stress biomarkers in gingival crevicular fluid (GCF). Clinical periodontal parameters and blood serum lipid, GCF malondialdehyde (MDA), protein carbonyl (PC), and total antioxidant capacity (TAOC) levels were evaluated in six age and sex-matched groups (n = 15 each) of normolipidemic and hyperlipidemic individuals as follows: normolipidemic + periodontally healthy (H), normolipidemic + gingivitis (G), normolipidemic + chronic periodontitis (CP), hyperlipidemic + periodontally healthy (HH), hyperlipidemic + gingivitis (HG), and hyperlipidemic + CP (HCP). GCF MDA, and PC levels varied among groups, with patients with periodontitis having the highest MDA and PC levels [CP > G > H (p < 0.01) and HCP > HG > HH (p < 0.01)] and the lowest TAOC levels [CP < G < H (p < 0.01) and HCP < HG < HH (p < 0.01)]. Furthermore, paired comparisons showed MDA and PC levels to be higher and TAOC levels to be lower in HCP compared with NCP (p < 0.01). In patients with hyperlipidemia, GCF, MDA, and PC levels positively correlated with clinical assessments and serum triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL) levels and negatively correlated with serum high-density lipoprotein cholesterol (HDL) levels, whereas GCF TAOC levels negatively correlated with clinical assessments and serum TG, TC, and LDL levels, but positively correlated with serum HDL levels (p < 0.01). In normolipidemic patients, GCF, MDA, and PC levels positively correlated with clinical assessments and serum TG levels and negatively correlated with serum HDL levels, whereas GCF TAOC levels negatively correlated with clinical assessments and serum TG levels and positively correlated with serum HDL levels (p < 0.01). In conclusion, abnormal serum lipid subfractions could be considered a risk factor for enhancing oxidative stress in GCF in the presence of periodontal disease.

Can protein carbonyl / glutathione ratio be used as a potential biomarker to assess oxidative stress in alcoholic hepatitis.

Context: Oxidative stress plays a crucial role in the pathogenesis of alcoholic liver disease (ALD). Aim: The present study was undertaken to evaluate the significance of protein carbonyl / glutathione ratio as a biomarker to assess the oxidative stress in alcoholic hepatitis. Settings and Design: The study included 30 patients with alcoholic hepatitis and 30 age-sex- matched controls. Protein carbonyl (PCO) levels was estimated by modified levine's method, malondialdehyde (MDA) by thiobarbituric acid method, reduced glutathione (GSH) by dithiobis-2-nitrobenzoic acid method, total sialic acid (TSA) by modified aminoff's method, plasma transferases (GGT, AST, and ALT), total protein and albumin using commercial kits adapted to autoanalyzer respectively. Statistical Analysis Used: All data were expressed as mean ± SEM. Spearman's correlation analysis and receiver operating characteristic curve were performed using SPSS version 16 for Microsoft. A P value < 0.05 was considered as significant. Results: Alcoholic hepatitis patients showed significantly higher levels of PCO, MDA, GGT, AST, AST/ALT, TSA, and significantly lower GSH, total protein and albumin levels. PCO/GSH ratio in these patients showed a significant positive correlation with GGT (r = 0.594, P = 0.000), AST/ALT (r = 0.443 P = 0.000), MDA (r = 0.727, P = 0.000), TSA (r = 0.729, P = 0.000), and a significant negative correlation with total protein (r = -0.683, P = 0.000) and albumin (r = -0.544, P = 0.000). ROC curve showed a cut off value of 2.735, indicating 100% sensitivity and 90% specificity of PCO/GSH at this value. Conclusions: Alcohol intake regularly for long duration leads to oxidative stress. We suggest that PCO/GSH ratio can be used as a potential biomarker to assess oxidative stress in alcoholic hepatitis.

Propofol and N-Acetylcysteine attenuate oxidative stress induced by intestinal ischemia/reperfusion in rats: Protein carbonyl detection by immunoblotting / Propofol e N-Acetilcisteína atenuam o estresse oxidativo induzido pela isquemia/reperfusão intestinal em ratos: Detecção de proteína carbonilada por immunoblotting

PURPOSE: To evaluate the antioxidant effect of Propofol and N-Acetylcysteine (NAC) on intestinal ischemia/reperfusion (I/R) in rats by determining carbonyl protein level. METHODS: Forty Wistar rats were randomly assigned into the following groups: Control; Sham; I/R with Propofol; I/R with Propofol and NAC; I/R with Ketamine and Xylazine. The I/R groups underwent 60 minutes of ischemia and an equal period of reperfusion. Blood samples, collected by cardiac punction, were centrifuged for plasma obtainment. Protein carbonyl level in plasma samples was determined by immunoblotting. RESULTS: No significant difference in protein carbonyl level was found between Control and Sham groups (P>0.05). The highest reduction in protein carbonyl level (P<0.05) was obtained with the administration of Propofol and NAC (Group 4) in intestinal I/R procedure. CONCLUSION: The administration of Propofol and NAC showed the best antioxidant effect on oxidative stress in rats that underwent intestinal I/R procedure, suggesting a synergistic interaction.

OBJETIVO: Avaliar o efeito antioxidante do Propofol e N-Acetilcisteína (NAC) na isquemia/reperfusão (I/R) intestinal em ratos através da determinação do nível de proteína carbonilada. MÉTODOS: 40 ratos Wistar foram aleatoriamente distribuídos nos seguintes grupos: Controle; Sham; I/R com Propofol; I/R com Propofol e NAC; I/R com Ketamina e Xilazina. Os grupos I/R foram submetidos à isquemia durante 60 minutos e à reperfusão por igual período de tempo. Amostras de sangue, coletadas por punção cardíaca, foram centrifugadas para a obtenção de plasma. O nível de proteína carbonilada nas amostras de plasma foi determinado por imunoblotting. RESULTADOS: Nenhuma diferença significativa foi encontrada entre os grupos Controle e Sham (P>0.05). Uma redução marcante no nível de proteína carbonilada (P<0.05) foi obtida com a administração combinada de Propofol e NAC (Grupo 4) durante o procedimento de I/R intestinal, comparando-se com os demais grupos I/R testados. CONCLUSÃO: A administração de Propofol e NAC apresentou o melhor efeito antioxidante sobre o estresse oxidativo em ratos submetidos ao procedimento de I/R intestinal, sugerindo-se uma interação sinergística.