From stroke to neurodegenerative diseases: The multi-target neuroprotective effects of 3-n-butylphthalide and its derivatives.

Discovering effective agents to slow or stop neurodegeneration is a challenging task. Over decades, only a few drugs were approved by Food and Drug Administration (FDA) and most ended in failure. The lessons learned have switched the strategy of drug discovery from designing highly selective ligands to a network pharmacology approach. This enables many natural products like butylphthalide (NBP) once again to be regarded as a valuable source of leads for drug discovery. In this review, we first start with the neuroprotective effects of NBPs on acute ischemic stroke, and later spread to their applications in major neurodegenerative diseases. The underlying mechanisms are also discussed in order to provide a direction for further study. Hopefully, this review could bring some new insights for drug development in this struggling field.

Dl-3-n-Butylphthalide (NBP): A Promising Therapeutic Agent for Ischemic Stroke.

BACKGROUND AND OBJECTIVE: Stroke is a leading cause of morbidity and mortality in both developed and developing countries all over the world. The only drug for ischemic stroke approved by FDA is recombinant tissue plasminogen activator (rtPA). However, only 2-5% stroke patients receive rtPAs treatment due to its strict therapeutic time window. As ischemic stroke is a complex disease involving multiple mechanisms, medications with multi-targets may be more powerful compared with single-target drugs. Dl-3-n-Butylphthalide (NBP) is a synthetic compound based on l-3-n- Butylphthalide that is isolated from seeds of Apium graveolens. The racemic 3-n-butylphthalide (dl- NBP) was approved by Food and Drug Administration of China for the treatment of ischemic stroke in 2002. A number of clinical studies indicated that NBP not only improved the symptoms of ischemic stroke, but also contributed to the long-term recovery. The potential mechanisms of NBP for ischemic stroke treatment may target different pathophysiological processes, including anti-oxidant, antiinflammation, anti-apoptosis, anti-thrombosis, and protection of mitochondria et al. Conclusion: In this review, we have summarized the research progress of NBP for the treatment of ischemic stroke during the past two decades.

L-3-n-butylphthalide improves cognitive impairment and reduces amyloid-beta in a transgenic model of Alzheimer's disease.

Alzheimer's disease (AD) is an age-related, progressive neurodegenerative disorder that occurs gradually and results in memory, behavior, and personality changes. L-3-n-butylphthalide (L-NBP), an extract from seeds of Apium graveolens Linn (Chinese celery), has been demonstrated to have neuroprotective effects on ischemic, vascular dementia, and amyloid-beta (Abeta)-infused animal models. In the current study, we examined the effects of L-NBP on learning and memory in a triple-transgenic AD mouse model (3xTg-AD) that develops both plaques and tangles with aging, as well as cognitive deficits. Ten-month-old 3xTg-AD mice were given 15 mg/kg L-NBP by oral gavage for 18 weeks. L-NBP treatment significantly improved learning deficits, as well as long-term spatial memory, compared with vehicle control treatment. L-NBP treatment significantly reduced total cerebral Abeta plaque deposition and lowered Abeta levels in brain homogenates but had no effect on fibrillar Abeta plaques, suggesting preferential removal of diffuse Abeta deposits. Furthermore, we found that L-NBP markedly enhanced soluble amyloid precursor protein secretion (alphaAPPs), alpha-secretase, and PKCalpha expression but had no effect on steady-state full-length APP. Thus, L-NBP may direct APP processing toward a non-amyloidogenic pathway and preclude Abeta formation in the 3xTg-AD mice. The effect of l-NBP on regulating APP processing was further confirmed in neuroblastoma SK-N-SH cells overexpressing wild-type human APP(695) (SK-N-SH APPwt). L-NBP treatment in 3xTg-AD mice also reduced glial activation and oxidative stress compared with control treatment. L-NBP shows promising preclinical potential as a multitarget drug for the prevention and/or treatment of Alzheimer's disease.

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

Alzheimer's disease is the most common form of dementia. Amyloid-beta protein is considered as a key factor of pathogenesis of Alzheimer's 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 Alzheimer's disease.

l-3-n-Butylphthalide ameliorates beta-amyloid-induced neuronal toxicity in cultured neuronal cells.

l-3-n-Butylphthalide (l-NBP), as an anti-cerebral ischemia agent, has been shown to have therapeutic effects on learning and memory deficits induced by chronic cerebral hypoperfusion and Abeta intracerebroventricular infusion in rats. In the present study, we investigated the neuroprotective effects of l-NBP on beta-amyloid (Abeta)25-35-induced neuronal death/apoptosis and potential mechanisms in rat hippocampal neurons and human neuroblastoma SH-SY5Y cells. Abeta25-35 significantly reduced cell viability and increased the number of apoptotic-like cells, indicating that Abeta25-35-induced neurotoxicity. In addition, tau protein hyperphosphorylation was found to increase after Abeta exposure. All of these phenotypes induced by Abeta25-35 were markedly reversed by l-NBP. Pretreatment with l-NBP prior to Abeta25-35 exposure significantly elevated cell viability, and reduced Abeta25-35-induced nuclear fragmentation and early apoptosis. Furthermore, immunoreactivity for hyperphosphorylation tau protein was significantly decreased by l-NBP treatment. Our results suggest that l-NBP may protect neurons against Abeta-induced neurotoxicity via inhibiting tau protein hyperphosphorylation.

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.

Antiplatelet and antithrombotic activity of L-3-n-butylphthalide in rats.

3-n-butylphthalide (NBP) is a potentially beneficial drug for the treatment of ischemic stroke with multiple actions on different pathophysiological processes. In the present study, the effect of l-, d-, and dl-NBP was investigated on ADP-, collagen-, and AA-induced platelet aggregation. l-NBP was the most potent among l-, d-, and dl-NBP. At higher concentration the effect of dl-NBP on platelet aggregation was greater than that of l- or d-NBP alone. The ex vivo antiaggregatory activity of l-NBP 100mg/kg declined gradually after 2 hours, but a considerable antiplatelet activity was still observed 4h after l-NBP administration. NBP was given orally and resulted in a dose-dependent inhibition of thrombus formation. Of the two isomers, l-NBP was the most potent. It significantly protected mice from a mixture of collagen and epinephrine induced thromboembolic death. When 100 mg/kg of l-NBP were administered orally to rats, the bleeding time increased 2.1-fold compared with the control group. At the same dose, ex vivo platelet aggregation induced by ADP, collagen, and AA was inhibited by l-NBP and the antithrombotic effects of the compound were also observed. Thus, NBP exerts oral anti-platelet and anti-thrombotic efficacy without perturbing systemic hemostasis in rats. l-NBP is more potent than d- and dl-NBP as antiplatelet agent.

[Effects of NBP on ATPase and anti-oxidant enzymes activities and lipid peroxidation in transient focal cerebral ischemic rats].

OBJECTIVE: The aim of the present study was designed to explore the effect of (+/-) -3-n-butylphthalide (NBP) on ATPase, anti-oxidant enzymes activities and lipid peroxidation of mitochondria and cerebral cortex in rats subjected to 24 hours of reperfusion following 2 hours of cerebral ischemia (tMCAO). METHODS: Activities of SOD (Superoxide Dismutase), GSH-Px (glutathione Peroxidase,) and CAT (Catalase), and MDA level of mitochondria or cortex were measured by using biochemical methods in tMCAO rats. RESULTS: (1) The activities of mitochondrial Na+K(+)-ATPase, Ca(2+)-ATPase and Mg2+ ATPase were found to decrease significantly in the vehicle group (ischemia + saline). Pre-treatment with NBP (5, 10, 20 mg/kg, i.p.) 10 min before tMCAO markedly enhanced the activities of Na+K(+)-ATPase and Ca(2+)-ATPase, compared with vehicle group. (2) The activities of SOD and mitochondrial GSH-Px were decreased and MDA level increased in vehicle groups as compared with that in sham group (non-ischemia + saline). NBP (20 mg/kg, i.p.) significantly enhanced total mitochondrial SOD activity, and also enhanced cerebral cortex total SOD activity (in 5, 10, 20 mg/kg groups). However, it had no obvious effect on CuZn-SOD activity. NBP (20 mg/kg i.p.) markedly increased mitochondrial (but not in cerebral cortex) GSH-Px activity; NBP 10, 20 mg/kg markedly decreased mitochondrial MDA level compared with that in vehicle group (P < 0.05). (3) The action of raceme NBP on the increase of the activities of ATPase and antioxidative enzymes seemed to be beneficial than that of (-) -NBP or (+) NBP. CONCLUSION: The results suggest that NBP improves energy pump and subsides oxidative injury which may contribute to its anti-neuronal apoptotic effect.