Chronic caffeine treatment attenuates experimental autoimmune encephalomyelitis induced by guinea pig spinal cord homogenates in Wistar rats

Dysfunction of adenosinergic systems has been implicated in the development of multiple sclerosis in humans and experimental autoimmune encephalomyelitis (EAE) in animals. Caffeine, a non-selective antagonist of adenosine receptors, has been shown to provide protection against myelin oligodendroglia glycoprotein (MOG)-induced EAE in mice. In this study, we showed that chronic caffeine similarly imparts neuroprotection against EAE induced in rats by guinea pig spinal cord homogenates (GPSCH). GPSCH-induced EAE is characterized by extensive tissue inflammation with a typical chronic disease course. We showed that caffeine decreases the incidence of EAE and attenuates EAE pathology at behavioral, histological (inflammatory cell infiltration and demyelination) and neurochemical (expression of inflammatory cytokines) levels. The attenuation of GPSCH-induced pathology by chronic caffeine treatment was observed at doses of 10 and 30 mg/kg and during both peak and recovery phases of EAE. Furthermore, it was showed that chronic treatment with caffeine up-regulated A1 receptor and TGF-β mRNAs and suppressed interferon-γ mRNA in EAE rats. Together with previous reports, our data demonstrates that chronic treatment with caffeine exerts a neuroprotective effect against EAE, possibly through an A1 receptor-mediated shift from Th1 to Th2 cell function, and provides a neurobiological basis for epidemiological investigation into the possible relationship between caffeine consumption and development of multiple sclerosis in humans.