Browsing by Author "Parodi, J."

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    Effects of Tetrahydrohyperforin in Mouse Hippocampal Slices: Neuroprotection, Long-term Potentiation and TRPC Channels
    (2014) Montecinos-Oliva, C.; Schueller, A.; Parodi, J.; Melo, F.; Inestrosa, N. C.
    Tetrahydrohyperforin (IDN5706) is a semi-synthetic compound derived from hyperforin (IDN5522) and is the main active principle of St. John's Wort. IDN5706 has shown numerous beneficial effects when administered to wild-type and double transgenic (APPswe/PSEN1 Delta E9) mice that model Alzheimer's disease. However, its mechanism of action is currently unknown. Toward this end, we analysed field excitatory postsynaptic potentials (fEPSPs) in mouse hippocampal slices incubated with IDN5706 and in the presence of the TRPC3/6/7 activator 1-oleoyl-2-acetyl-sn-glycerol (OAG), the TRPC channel blocker SKF96365, and neurotoxic amyloid beta-protein (A beta) oligomers. To study spatial memory, Morris water maze (MWM) behavioural tests were conducted on wild-type mice treated with IDN5706 and SKF96365. In silico studies were conducted to predict a potential pharmacophore. IDN5706 and OAG had a similar stimulating effect on fEPSPs, which was inhibited by SKF96365. IDN5706 protected from reduced fEPSPs induced by A beta oligomers. IDN5706 improved spatial memory in wild-type mice, an effect that was counteracted by co-administration of SKF96365. Our in silico studies suggest strong pharmacophore similarity of IDN5706 and other reported TRPC6 activators (IDN5522, OAG and Hyp9). We propose that the effect of IDN5706 is mediated through activation of the TRPC3/6/7 channel subfamily. The unveiling of the drug's mechanism of action is a necessary step toward the clinical use of IDN5706 in Alzheimer's disease.
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    Tetrahydrohyperforin prevents cognitive deficit, Aβ deposition, tau phosphorylation and synaptotoxicity in the APPswe/PSEN1ΔE9 model of Alzheimer's disease: a possible effect on APP processing
    (2011) Inestrosa, N. C.; Tapia-Rojas, C.; Griffith, T. N.; Carvajal, F. J.; Benito, M. J.; Rivera-Dictter, A.; Alvarez, A. R.; Serrano, F. G.; Hancke, J. L.; Burgos, P. V.; Parodi, J.; Varela-Nallar, L.
    Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a progressive deterioration of cognitive abilities, amyloid-beta peptide (A beta) accumulation and synaptic alterations. Previous studies indicated that hyperforin, a component of the St John's Wort, prevents A beta neurotoxicity and some behavioral impairments in a rat model of AD. In this study we examined the ability of tetrahydrohyperforin (IDN5607), a stable hyperforin derivative, to prevent the cognitive deficit and synaptic impairment in an in vivo model of AD. In double transgenic APPswe/PSEN1DE9 mice, IDN5706 improves memory and prevents the impairment of synaptic plasticity in a dose-dependent manner, inducing a recovery of long-term potentiation. In agreement with these findings, IDN5706 prevented the decrease in synaptic proteins in hippocampus and cortex. In addition, decreased levels of tau hyperphosphorylation, astrogliosis, and total fibrillar and oligomeric forms of A beta were determined in double transgenic mice treated with IDN5706. In cultured cells, IDN5706 decreased the proteolytic processing of the amyloid precursor protein that leads to A beta peptide generation. These findings indicate that IDN5706 ameliorates AD neuropathology and could be considered of therapeutic relevance in AD treatment.
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