Shaofeng Xu

l-3-n-Butylphthalide Improves Cognitive Impairment Induced by Chronic Cerebral Hypoperfusion in Rats

3-n-Butylphthalide (NBP) may be beneficial for the treatment of ischemic stroke with multiple actions on different pathophysiological processes. In the present study, we investigated the effect of NBP isomers on learning and memory impairment induced by chronic cerebral hypoperfusion in rats. Male Wistar rats were orally administered 10 and 30 mg/kg l-, d-, or dl-NBP daily for 23 days after bilateral permanent occlusion of the common carotid arteries. Rats receiving 10 mg/kg l-NBP performed significantly better in tests for spatial learning and memory, and they had attenuated cerebral pathology, including neuronal damage, white matter rarefaction, and glial activation compared with controls. Furthermore, 10 mg/kg l-NBP-treated rats had significantly higher choline acetyltransferase activity, decreased cortical lipid peroxide, and reduced hippocampal superoxide dismutase activity, compared with vehicle controls. However, d- and dl-NBP did not show significant beneficial effects. The present findings demonstrate that the beneficial effects of l-NBP on hypoperfusion-induced cognitive deficits may be due to preventing neuropathological alterations, inhibiting oxidative damage and increasing acetylcholine synthesis. Our results strongly suggest that l-NBP has therapeutic potential for the treatment of dementia caused by decreased cerebral blood flow.

L-3-n-butylphthalide improves cognitive impairment induced by intracerebroventricular infusion of amyloid-β peptide in rats

Alzheimers disease is the most common form of dementia. Amyloid-beta protein is considered as a key factor of pathogenesis of Alzheimers disease. l-3-n-butylphthalide (L-NBP), an anti-cerebral ischemia drug, has been shown to have therapeutic effects in vascular dementia animal models. In the present study, we investigated the potential of L-NBP to protect against cognitive impairment, oxidative damage and neuropathological changes induced by intracerebroventricular infusion of amyloid-beta peptide in rats. Daily treatments of 10 and 30 mg/kg L-NBP significantly improved spatial learning deficits and attenuated working memory deficits in Morris water maze task. L-NBP partially reversed the reduction of glutathione peroxidase activities and decreased malondialdehyde levels in the cortex and hippocampus. Furthermore, L-NBP markedly inhibited amyloid-beta-induced neuronal apoptosis, possibly by blocking caspase-3 activation. In addition, L-NBP reduced activation of glycogen synthase kinase-3beta and tau protein phosphorylation. Our results demonstrate that L-NBP protects against amyloid-beta-induced neurodegeneration and cognitive decline in a rat model, suggesting that it may have potential as a therapy for Alzheimers disease.

L-3-n-butylphthalide reduces tau phosphorylation and improves cognitive deficits in AβPP/PS1-Alzheimer's transgenic mice.

L-3-n-butylphthalide (L-NBP), an extract from seeds of Apium graveolens Linn (Chinese celery), has been shown to have neuroprotective effects on cerebral ischemic, vascular dementia and amyloid-β (Aβ)-induced animal models by inhibiting oxidative injury, neuronal apoptosis and glial activation, regulating amyloid-β protein precursor (AβPP) processing and reducing Aβ generation. The aim of the present study was to examine the effect of L-NBP on learning and memory in AβPP and presenilin 1 (PS1) double-transgenic AD mouse model (AβPP/PS1) and the mechanisms of L-NBP in reducing Aβ accumulation and tau phosphorylation. Twelve-month old AβPP/PS1 mice were given 15 mg/kg L-NBP by oral gavage for 3 months. L-NBP treatment significantly improved the spatial learning and memory deficits compared to the vehicle-treated AβPP/PS1 mice, whereas L-NBP treatment had no effect on cerebral Aβ plaque deposition and Aβ levels in brain homogenates. However, we found an L-NBP-induced reduction of tau hyperphosphorylation at Ser199, Thr205, Ser396, and Ser404 sites in AβPP/PS1 mice. Additionally, the expressions of cyclin-dependent kinase and glycogen synthase kinase 3β, the most important kinases involved in tau phosphorylation, were markedly decreased by L-NBP treatment. The effects of L-NBP on decreasing tau phosphorylation and kinases activations were further confirmed in neuroblastoma SK-N-SH cells overexpressing wild-type human AβPP695 (SK-N-SH AβPPwt). L-NBP shows promising candidate of multi-target neuronal protective agent for the treatment of Alzheimers disease.

L‐3‐n‐butylphthalide Promotes Neurogenesis and Neuroplasticity in Cerebral Ischemic Rats

This study investigated whether anticerebral ischemia new drug, l‐3‐n‐butylphthalide (l‐NBP), improved behavioral recovery and enhanced hippocampal neurogenesis after cerebral ischemia in rats.

Potassium 2-(1-hydroxypentyl)-benzoate improves learning and memory deficits in chronic cerebral hypoperfused rats.

Potassium 2-(1-hydroxypentyl)-benzoate (dl-PHPB), the pre-drug of 3-n-butylphthalide (dl-NBP), had the significantly therapeutic effect on the acute cerebral ischemia. The present study was to investigate the effect of dl-PHPB on the cognitive deficits induced by chronic cerebral hypoperfusion. Rats were orally administered three doses of dl-PHPB (13, 39 and 129mg/kg), dl-NBP 100mg/kg, and piracetam 600mg/kg daily for 21 days after the bilateral permanent occlusion of the common carotid arteries. The results showed that dl-PHPB, dl-NBP and piracetam significantly improved the spatial learning and memory deficits, and the effectiveness of dl-PHPB at dose of 39mg/kg was strongest. Meanwhile, the drugs decreased superoxide dismutase activity, reduced lipid peroxide and astrocyte activation in the cortex of the hypoperfused rats. Furthermore, dl-PHPB markedly reduced white matter rarefaction. The results indicated that preventing neuropathological alterations, inhibiting oxidative damage and inflammatory reaction might contribute to the improvement of dl-PHPB on hypoperfusion-induced cognitive deficits. Therefore, dl-PHPB has therapeutic potential for the treatment of dementia caused by decrease of cerebral blood flow.

L-3-n-butylphthalide regulates amyloid precursor protein processing by PKC and MAPK pathways in SK-N-SH cells over-expressing wild type human APP695.

Amyloid precursor protein (APP) is cleaved by α-secretase, within the amyloid-β (Aβ) sequence, resulting in the release of a secreted fragment (αAPPs) and precluding Aβ production. We investigated the effects of a promising anti-AD new drug, l-3-n-butylphthalide (L-NBP), on APP processing and Aβ generation in neuroblastoma SK-N-SH cells overexpressing wild-type human APP695. L-NBP significantly increased αAPPs release, and reduced Aβ generation. The steady-state full-length APP levels were unaffected by L-NBP. It suggested that L-NBP regulated APP processing towards to the non-amyloidogenic α-secretase pathway. Protein kinase C (PKC) and mitogen activated protein (MAP) kinase might be involved in L-NBP-induced αAPPs secretion. L-NBP significantly increased PKCα and ɛ activations, lowered PKCγ activation and increased the phosphorylation of p44/p42 MAPK. Furthermore, PKC and MAPK inhibitors partially reduced L-NBP-induced αAPPs secretion. The results suggested alternative pharmacological mechanisms of L-NBP regarding the treatment of Alzheimers disease (AD).

Strain- and age-related alteration of proteins in the brain of SAMP8 and SAMR1 mice.

In order to discover and identify the key protein biomarkers in the aging process, we performed a differential proteomic analysis of hippocampus and cortex in 5- and 15-month old senescence-accelerated mouse prone 8 (SAMP8) as well as in control strain SAM/resistant 1 (SAMR1). Using 2-DE combined with MALDI TOF/TOF mass spectrometry, about 1700 protein spots were isolated, and three groups of differentially expressed proteins were identified. The first group contained the strain-specific and non-age-related differential proteins that were differentially expressed in SAMP8 compared with SAMR1 mice. The changes might be implicated in the genetic difference between SAMP8 and SAMR1 mice; specifically, the proteins ubiquitin carboxyl-terminal esterase L3, mitofilin, adenylate kinase 4, and an unnamed protein product (gi|12847201). The proteins in the second group were age-specific, which were differentially expressed between 5- and 15-month old SAM mice. Those proteins are particularly interesting since the changes were aging-related and some of them were previously reported to be expressed in Alzheimers disease patients. These proteins included N-myc downstream regulated gene 2, enolase 2, Cu/Zn superoxide dismutase, myosin, and two unnamed protein products (gi|74214304 and gi|74178239). The protein in the third group was SAMP8 specific-age-related protein, which was identified as heme binding protein 1. The present study provides new information about SAMP8 specific and aging-related protein changes in brain. Further investigations will be performed to reveal the significance of these proteins in brain aging process and the potential roles as biomarkers for effective diagnosis and therapy.

Potassium 2-(1-hydroxypentyl)-benzoate attenuated hydrogen peroxide-induced apoptosis in neuroblastoma SK-N-SH cells.

Potassium 2-(1-hydroxypentyl)-benzoate (dl-PHPB) has been shown to have potent neuroprotective effects, such as reducing the infarct volume and improving neurobehavioral deficits in the transient focal cerebral ischemic rat model. The present study is to evaluate the neuroprotective effect of dl-PHPB on hydrogen peroxide (H(2)O(2))-induced apoptosis and the possible mechanism in the human neuroblastoma SK-N-SH cells. Our results showed that dl-PHPB significantly attenuated H(2)O(2)-induced cell death, and reduced neuronal apoptosis. Dl-PHPB partially reversed the decrease of B-cell CLL/lymphoma 2 (Bcl-2) protein level induced by H(2)O(2). Furthermore, dl-PHPB inhibited the elevation of pro-apoptotic Bcl-2-associated X protein (Bax) and caspase3, and alleviated the down-regulation of protein kinase C alpha (PKCα). The PKC inhibitor, Calphostin C significantly attenuated the protective effects of dl-PHPB. The findings suggest that dl-PHPB may protect neurons against H(2)O(2)-induced apoptosis by modulating apoptosis-related proteins, and PKC signaling pathway may be involved in the neuroprotection of dl-PHPB.

L-3-n-butylphthalide Rescues Hippocampal Synaptic Failure and Attenuates Neuropathology in Aged APP/PS1 Mouse Model of Alzheimer's Disease.

Our previous studies showed that L‐3‐n‐butylphthalide (L‐NBP), an extract from seeds of Apium graveolens Linn (Chinese celery), improved cognitive ability in animal models of cerebral ischemia, vascular dementia, and Alzheimers disease (AD). It is well known that cognitive deficit of AD is caused by synaptic dysfunction. In this study, we investigated the effect of L‐NBP on hippocampal synaptic function in APP/PS1 AD transgenic mice and related mechanisms.

Potassium 2-(1-Hydroxypentyl)-Benzoate Improves Memory Deficits and Attenuates Amyloid and τ Pathologies in a Mouse Model of Alzheimer's Disease

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by amyloid-β (Aβ) deposition and neurofibrillary tangles. Dl-PHPB [potassium 2-(1-hydroxypentyl)-benzoate], has been shown to have neuroprotective effects on cerebral ischemic, vascular dementia, and Aβ-induced animal models by inhibiting oxidative injury, neuronal apoptosis, and glial activation. The aim of the present study was to examine the effect of dl-PHPB on learning and memory in amyloid precursor protein (APP) and presenilin 1 (PS1) double-transgenic AD mouse models (APP/PS1) and the mechanisms of dl-PHPB in reducing Aβ accumulation and τ phosphorylation. Twelve-month-old APP/PS1 mice were given 30 mg/kg dl-PHPB by oral gavage for 3 months. Dl-PHPB treatment significantly improved the spatial learning and memory deficits compared with the vehicle-treated APP/PS1 mice. In the meantime, dl-PHPB obviously reduced τ hyperphosphorylation at Ser199, Thr205, and Ser396 sites in APP/PS1 mice. This reduction was accompanied by APP phosphorylation reduction and protein kinase C activation. In addition, expression of cyclin-dependent kinase and glycogen synthase kinase 3β, the most important kinases involved in τ phosphorylation, was markedly decreased by dl-PHPB treatment. Phosphorylated protein kinase B and phosphoinositide 3-kinase levels of APP/PS1 mice were significantly reduced compared with levels in wild-type mice, and dl-PHPB reversed the reduction. The effects of dl-PHPB effecting a decrease in τ phosphorylation and kinase activation were further confirmed in neuroblastoma SK-N-SH cells overexpressing wild-type human APP695. These data raised the possibility that dl-PHPB might be a promising multitarget neuronal protective agent for the treatment of AD.