Combining nitric oxide release with anti-inflammatory activity preserves nigrostriatal dopaminergic innervation and prevents motor impairment in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine model of Parkinson's disease

Current evidence suggests a role of neuroinflammation in the pathogenesis of parkinson's disease (pd) and in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (mptp) model of basal ganglia injury. reportedly,nonsteroidal anti-inflammatory drugs (nsaids) mitigate daergic neurotoxicity in rodent models of pd. consistent with these findings,epidemiological analysis indicated that certain nsaids may prevent or delay the progression of pd. however,a serious impediment of chronic nsaid therapy,particularly in the elderly,is gastric,renal and cardiac toxicity. nitric oxide (no)-donating nsaids,have a safer profile while maintaining anti-inflammatory activity of parent compounds. we have investigated the oral activity of the no-donating derivative of flurbiprofen,[2-fluoro-α-methyl (1,1'-biphenyl)-4-acetic-4-(nitrooxy)butyl ester],hct1026 (30 mg kg-1daily in rodent chow) in mice exposed to the parkinsonian neurotoxin mptp.methods: ageing mice were fed with a control,flurbiprofen,or hct1026 diet starting ten days before mptp administration and continuing for all the experimental period. striatal high affinity synaptosomial dopamine up-take,motor coordination assessed with the rotarod,tyrosine hydroxylase (th)- and dopamine transporter (dat) fiber staining,stereological cell counts,immunoblotting and gene expression analyses were used to assess mptp-induced nigrostriatal daergic toxicity and glial activation 1-40 days post-mptp.results: hct1026 was well tolerated and did not cause any measurable toxic effect,whereas flurbiprofen fed mice showed severe gastrointestinal side-effects. hct1026 efficiently counteracted motor impairment and reversed mptp-induced decreased synaptosomal [3h]dopamine uptake,th- and dat-stained fibers in striatum and th+neuron loss in subtantia nigra pars compacta (snpc),as opposed to age-matched mice fed with a control diet. these effects were associated to a significant decrease in reactive macrophage antigen-1 (mac-1)-positive microglial cells within the striatum and ventral midbrain,decreased expression of inos,mac-1 and nadph oxidase (phox),and downregulation of 3-nitrotyrosine,a peroxynitrite finger print,in snpc daergic neurons.conclusions: oral treatment with hct1026 has a safe profile and a significant efficacy in counteracting mptp-induced dopaminergic (daergic) neurotoxicity,motor impairment and microglia activation in ageing mice. hct1026 provides a novel promising approach towards the development of effective pharmacological neuroprotective strategies against pd. © 2010 l'episcopo et al; licensee biomed central ltd.