Protective effects of carotenoids from saffron on neuronal injury in vitro and in vivo.

Crocus sativus L. (saffron) has been used as a spice for flavoring and coloring food preparations, and in Chinese traditional medicine as an anodyne or tranquilizer. Our previous study demonstrated that crocin, a carotenoid pigment of saffron, can suppress the serum deprivation-induced death of PC12 cells by increasing glutathione (GSH) synthesis and thus inhibiting neutral sphingomyelinase (nSMase) activity and ceramide formation.

Inhibition of sphingomyelinase activity helps to prevent neuron death caused by ischemic stress.

Magnesium-dependent neutral sphingomyelinase (N-SMase) present in plasma membranes is an enzyme that can be activated by stress in the form of inflammatory cytokines, serum deprivation, and hypoxia. The design of small molecule N-SMase inhibitors may offer new therapies for the treatment of inflammation, ischemic injury, and cerebral infarction. Recently, we synthesized a series of difluoromethylene analogues (SMAs) of sphingomyelin.

[Synthesis of sphingomyelin analogues as a sphingomyelinase inhibitor and the application as a blocking agent of extracellular stress signaling].

Sphingomyelin (SM) pathway, where sphingomyelinase (SMase) hydrolyzes SM to produce ceramide, has recently been suggested to link to the signaling pathway that determines cell death. Therefore, elucidation of the mechanism by which SMase is activated and the regulation of SMase activity will be an important therapeutic strategy for various cytokine-related and ischemic diseases. We have synthesized nine difluoromethylene analogues of SM as SMase inhibitors and evaluated their inhibitory potencies.

Tau filament formation and associative memory deficit in aged mice expressing mutant (R406W) human tau.

The R406W tau mutation found in frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) causes a hereditary tauopathy clinically resembling Alzheimer's disease. Expression of modest levels of the longest human tau isoform with this mutation under the control of the alpha-calcium-calmodulin-dependent kinase-II promoter in transgenic (Tg) mice resulted in the development of congophilic hyperphosphorylated tau inclusions in forebrain neurons. These inclusions appeared as early as 18 months of age.