ABSTRACT
Inflammation has been associated with the two classic lesions in the Alzheimer's (AD) brain, amyloid deposits and neurofibrillary tangles. Recent data suggest that Triflusal, a compound with potent anti-inflammatory effects in the central nervous system in vivo, might delay the conversion from amnestic mild cognitive impairment to a fully established clinical picture of dementia. In the present study, we investigated the effect of Triflusal on brain Abeta accumulation, neuroinflammation, axonal curvature and cognition in an AD transgenic mouse model (Tg2576). Triflusal treatment did not alter the total brain Abeta accumulation but significantly reduced dense-cored plaque load and associated glial cell proliferation, proinflammatory cytokine levels and abnormal axonal curvature, and rescued cognitive deficits in Tg2576 mice. Behavioral benefit was found to involve increased expression of c-fos and BDNF, two of the genes regulated by CREB, as part of the signal transduction cascade underlying the molecular basis of long-term potentiation. These results add preclinical evidence of a potentially beneficial effect of Triflusal in AD.
Subject(s)
Alzheimer Disease/drug therapy , Alzheimer Disease/metabolism , Brain/drug effects , Brain/metabolism , Central Nervous System Agents/pharmacology , Salicylates/pharmacology , Alzheimer Disease/pathology , Amyloid beta-Peptides/genetics , Amyloid beta-Peptides/metabolism , Animals , Axons/drug effects , Axons/pathology , Brain/pathology , Brain-Derived Neurotrophic Factor/metabolism , Cognition Disorders/drug therapy , Cognition Disorders/metabolism , Cognition Disorders/pathology , Cytokines/metabolism , Disease Models, Animal , Humans , Mice , Mice, Inbred C57BL , Mice, Transgenic , Neuroglia/drug effects , Neuroglia/pathology , Plaque, Amyloid/drug effects , Plaque, Amyloid/metabolism , Plaque, Amyloid/pathology , Proto-Oncogene Proteins c-fos/metabolismABSTRACT
Alzheimer's disease (AD) is characterized by senile plaques and neurodegeneration although the neurotoxic mechanisms have not been completely elucidated. It is clear that both oxidative stress and inflammation play an important role in the illness. The compound curcumin, with a broad spectrum of anti-oxidant, anti-inflammatory, and anti-fibrilogenic activities may represent a promising approach for preventing or treating AD. Curcumin is a small fluorescent compound that binds to amyloid deposits. In the present work we used in vivo multiphoton microscopy (MPM) to demonstrate that curcumin crosses the blood-brain barrier and labels senile plaques and cerebrovascular amyloid angiopathy (CAA) in APPswe/PS1dE9 mice. Moreover, systemic treatment of mice with curcumin for 7 days clears and reduces existing plaques, as monitored with longitudinal imaging, suggesting a potent disaggregation effect. Curcumin also led to a limited, but significant reversal of structural changes in dystrophic dendrites, including abnormal curvature and dystrophy size. Together, these data suggest that curcumin reverses existing amyloid pathology and associated neurotoxicity in a mouse model of AD. This approach could lead to more effective clinical therapies for the prevention of oxidative stress, inflammation and neurotoxicity associated with AD.