Atorvastatin inhibits oxidative stress via adiponectin-mediated NADPH oxidase down-regulation in hypercholesterolemic patients

Background: Interventional treatment with atorvastatin lowered the circulating levels of the catalytic core of NADPH oxidase, namely sgp91(phox), but the underlying mechanism is still undefined. Aim: To test the hypothesis that the inhibitory effect on oxidative stress, induced by Atorvastatin, could be mediated by adiponectin. Methods and results: We compared 36 patients with polygenic hypercholesterolemia and 18 healthy subjects. Patients were randomized to either a low-fat diet (Group A) or low-fat diet plus atorvastatin 10 mg/day (Group B) for 30 days. Lower serum adiponectin levels and higher lipid profile, gp91(phox) serum levels, urinary isoprostanes, platelet oxygen free radicals, characterized patients. After 30 days of treatment, group B showed higher levels of adiponectin which is inversely correlated to reduced levels of sgp91(phox), urinary isoprostanes and platelet oxygen free radicals (p < 0.001). In in vitro model, adiponectin dosages between 5 and 10 ng/ml inhibited p47(phox) translocation to gp91(phox) and soluble gp91(phox) cleavage indicating its ability in inhibiting the assembly of NADPH oxidase subunits on cell membrane and in turn the enzymatic system activation. Conclusion: This study provides the first evidence that in patients higher APN serum levels are associated with gp91(phox) down-regulation. APN-mediated gp91(phox) reduction could be one of the mechanisms involved in atorvastatin's antioxidant effect. (C) 2010 Elsevier Ireland Ltd. All rights reserved.