The protective effect of rifampicin on behavioral deficits, biochemical, and neuropathological changes in a cuprizone model of demyelination.

Multiple sclerosis (MS) is a disease of the central nervous system (CNS) in which both neuroinflammation and neurodegeneration play critical roles in the pathogenesis of the disease. A growing body of evidence indicates that some antibiotics have anti-inflammatory and neuroprotective properties. Rifampicin, commonly used for the treatment of mycobacteria, has been shown to exert neuroprotective activities in neurodegenerative diseases. In this study, we examined the efficacy of rifampicin on demyelination, gliosis, apoptosis, inflammation, behavioral dysfunction, and biochemical alterations in the cuprizone model of demyelination. For this aim, male C57BL/6J mice were fed a chow containing 0.2% cuprizone (w/w) for 6 weeks to induce reversible demyelination in the corpus callosum. Mice intraperitoneally received serial doses of rifampicin (10, 20, or 40 mg/kg body weight) in the last 7 days of a 6-week period of cuprizone treatment. The results showed that the administration of rifampicin led to the improvement in motor behavioral deficits. In line with this, rifampicin decreased the number of apoptotic cells in the corpus callosum thereby diminishing the expression of cleaved caspase-3 and Bax, as well as increasing Bcl-2. Moreover, rifampicin significantly lowered the levels of interleukin-6, interleukin-1β, caspase-12 activity, heme oxygenase-1(HO-1), nitric oxide (NO), and malondialdehyde (MDA) in mice treated with cuprizone. Conversely, the activity of glutathione peroxidase (GPx) and the level of ferric reducing ability of plasma (FRAP) were increased in response to the treatment with rifampicin. Histopathological findings demonstrated that rifampicin statistically promoted remyelination and mitigated microgliosis and astrogliosis. It seems that rifampicin is able to be added to the armamentarium of therapies for multiple sclerosis.