Paraoxonase 1 activity in multiple sclerosis patients during mitoxantrone therapy.

It has been implicated in many studies that reactive oxygen species play a role in the development of demyelination in multiple sclerosis (MS). Paraoxonase 1 (PON1) is an antioxidant enzyme that protects cell membranes against oxidative modification. Mitoxantrone is a cytotoxic drug approved for the treatment of MS with adverse effects associated potentially with an increased level of oxidative stress. The aim of this study was to assess the influence of mitoxantrone therapy on PON1 activity in patients with MS.A studied group included 26 patients with secondary progressive MS, 16 women and 10 men. The blood was collected before the beginning of the therapy as well as after 6 and 12 months. Patients were receiving mitoxantrone every 12 weeks. Serum PON1 activity was assayed using two synthetic substrates: paraoxon and phenyl acetate.Paraoxonase 1 activity toward paraoxon and phenyl acetate and lipid profile did not change significantly in patients receiving mitoxantrone.Mitoxantrone therapy does not influence PON1 activity.