Oxidative balance in lymphocytes from patients with nonalcoholic steatohepatitis

A Decreased Response to Resistin in Mononuclear Leukocytes Contributes to Oxidative Stress in Nonalcoholic Fatty Liver Disease

BACKGROUND

Deregulation of immune response and oxidative stress contribute to nonalcoholic fatty liver disease (NAFLD) pathogenesis. Resistin is a physiological modulator of inflammation and redox homeostasis of different cell types. Increased resistin serum concentration and the direct association between resistin hepatic expression and NAFLD severity suggest that resistin participates in NAFLD pathogenesis.

AIMS

To evaluate resistin-induced regulation of redox homeostasis in mononuclear leukocytes from NAFLD patients and controls.

METHODS

We evaluated basal and resistin-mediated modulation of reactive oxygen species (ROS) and glutathione content by flow cytometry, and antioxidant enzyme activities by spectrophotometry.

RESULTS

Peripheral blood mononuclear cells (PBMC) from NAFLD patients showed higher ROS content and glutathione peroxidase activity and lower glutathione content, superoxide dismutase and glutathione reductase activities than control PBMC. Resistin decreased ROS levels and superoxide dismutase activity and increased glutathione reductase and catalase activities in PBMC from controls but not from patients. Resistin decreased glutathione content in PBMC from control and NAFLD patients, with greater effect on patient cells. Basal and resistin-modulated ROS levels were directly associated with obesity-related risk factors for NAFLD. Hepatic myeloid cells and T-lymphocytes from NAFLD patients showed higher basal ROS content than cells from controls. Resistin decreased ROS levels in hepatic T-lymphocytes from controls but not from patients.

CONCLUSIONS

Resistin regulates redox homeostasis in mononuclear leukocytes. A decreased response to resistin in leukocytes from NAFLD patients is associated with an impaired redox homeostasis.

Effects of red wine on postprandial stress: potential implication in non-alcoholic fatty liver disease development

INTRODUCTION

Red wine consumption is considered to be protective against oxidative stress. Diet strongly influences non-alcoholic fatty liver disease, which is associated with oxidative stress and is considered the hepatic manifestation of the metabolic syndrome.

METHODS

We reviewed the available evidence that investigated the effects of red wine on the postprandial-induced metabolic and oxidative stress in humans.

RESULTS

After red wine consumption with meal, despite the improvement in non-enzymatic antioxidant capacity and lipoperoxidation markers, the influence of confounding factors such as uric acid should be taken into account. Both uric acid and triglycerides increases, induced by ethanol, could cause liver damage. On the other hand, further researches are required in order to understand the meaning of the induction of antioxidant enzymes by red wine and red wine polyphenols in the context of non-alcoholic fatty liver disease.

CONCLUSION

In conclusion, inconsistent and contrasting findings exist regarding the potential benefits of red wine consumption against postprandial stress.