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

Dl-3-n-butylphthalide promotes microglial phagocytosis and inhibits microglial inflammation via regulating AGE-RAGE pathway in APP/PS1 mice

Alzheimer's disease (AD) stands as the most prevalent neurodegenerative condition worldwide, and its correlation with microglial function is notably significant. Dl-3-n-butylphthalide (NBP), derived from the seeds of Apium graveolens L. (Chinese celery), has demonstrated the capacity to diminish Aβ levels in the brain tissue of Alzheimer's transgenic mice. Despite this, its connection to neuroinflammation and microglial phagocytosis, along with the specific molecular mechanism involved, remains undefined. In this study, NBP treatment exhibited a substantial improvement in learning deficits observed in AD transgenic mice (APP/PS1 transgenic mice). Furthermore, NBP treatment significantly mitigated the total cerebral Aβ plaque deposition. This effect was attributed to the heightened presence of activated microglia surrounding Aβ plaques and an increase in microglial phagocytosis of Aβ plaques. Transcriptome sequencing analysis unveiled the potential involvement of the AGE (advanced glycation end products) -RAGE (receptor for AGE) signaling pathway in NBP's impact on APP/PS1 mice. Subsequent investigation disclosed a reduction in the secretion of AGEs, RAGE, and proinflammatory factors within the hippocampus and cortex of NBP-treated APP/PS1 mice. In summary, NBP alleviates cognitive impairment by augmenting the number of activated microglia around Aβ plaques and ameliorating AGE-RAGE-mediated neuroinflammation. These findings underscore the related mechanism of the crucial neuroprotective roles of microglial phagocytosis and anti-inflammation in NBP treatment for AD, offering a potential therapeutic target for the disease.

Cdk8/CDK19 promotes mitochondrial fission through Drp1 phosphorylation and can phenotypically suppress pink1 deficiency in Drosophila

Cdk8 in Drosophila is the orthologue of vertebrate CDK8 and CDK19. These proteins have been shown to modulate transcriptional control by RNA polymerase II. We found that neuronal loss of Cdk8 severely reduces fly lifespan and causes bang sensitivity. Remarkably, these defects can be rescued by expression of human CDK19, found in the cytoplasm of neurons, suggesting a non-nuclear function of CDK19/Cdk8. Here we show that Cdk8 plays a critical role in the cytoplasm, with its loss causing elongated mitochondria in both muscles and neurons. We find that endogenous GFP-tagged Cdk8 can be found in both the cytoplasm and nucleus. We show that Cdk8 promotes the phosphorylation of Drp1 at S616, a protein required for mitochondrial fission. Interestingly, Pink1, a mitochondrial kinase implicated in Parkinson's disease, also phosphorylates Drp1 at the same residue. Indeed, overexpression of Cdk8 significantly suppresses the phenotypes observed in flies with low levels of Pink1, including elevated levels of ROS, mitochondrial dysmorphology, and behavioral defects. In summary, we propose that Pink1 and Cdk8 perform similar functions to promote Drp1-mediated fission.

Synthesis and evaluation of butylphthalide-scutellarein hybrids as multifunctional agents for the treatment of Alzheimer's disease

A series of butylphthalide and scutellarein hybrids 3-(alkyl/alkenyl) hydroxyphthalide derivatives were designed, synthesized and evaluated as multifunctional agents against Alzheimer's disease. In vitro bioactivity assays indicated that most of the compounds displayed excellent antioxidant activity and moderate to good inhibition activities of self-induced Aβ1-42 aggregation. Among them, compound 7c was demonstrated as a potential and balanced multifunctional candidate displaying the best inhibitory effects on self- and Cu2+-induced Aβ1-42 aggregation (90.2 % and 35.4 %, respectively) and moderate activity for disaggregation of Aβ1-42 aggregation (42.5 %). In addition, 7c also displayed excellent antioxidant (2.42 Trolox equivalents), metal ions chelating, oxidative stress alleviation, neuroprotective and anti-neuroinflammatory activities. Furthermore, in vivo study demonstrated that 7c could ameliorate the learning and memory impairment induced by sodium nitrite and Aβ1-42 in the step-down passive avoidance test. These balanced multifunctional profiles supporting compound 7c as a novel potential candidate for the treatment of AD.

Regulation of mitochondrial dysfunction induced cell apoptosis is a potential therapeutic strategy for herbal medicine to treat neurodegenerative diseases

Neurodegenerative disease is a progressive neurodegeneration caused by genetic and environmental factors. Alzheimer’s disease (AD), Parkinson’s disease (PD), and Huntington’s disease (HD) are the three most common neurodegenerative diseases clinically. Unfortunately, the incidence of neurodegenerative diseases is increasing year by year. However, the current available drugs have poor efficacy and large side effects, which brings a great burden to the patients and the society. Increasing evidence suggests that occurrence and development of the neurodegenerative diseases is closely related to the mitochondrial dysfunction, which can affect mitochondrial biogenesis, mitochondrial dynamics, as well as mitochondrial mitophagy. Through the disruption of mitochondrial homeostasis, nerve cells undergo varying degrees of apoptosis. Interestingly, it has been shown in recent years that the natural agents derived from herbal medicines are beneficial for prevention/treatment of neurodegenerative diseases via regulation of mitochondrial dysfunction. Therefore, in this review, we will focus on the potential therapeutic agents from herbal medicines for treating neurodegenerative diseases via suppressing apoptosis through regulation of mitochondrial dysfunction, in order to provide a foundation for the development of more candidate drugs for neurodegenerative diseases from herbal medicine.

Efficacy of sequential N-butylphthalide therapy on psychiatric and behavioral functions in acute ischemic stroke

BACKGROUND

Stroke can cause physical and mental problems. This study examined how the sequential therapy of N-butylphthalide (NBP) could effectively improve physical movement, life activities, and psychological disorders in stroke patients.

METHODS

This double-blind, randomized controlled trial included middle-aged or elderly patients with acute ischemic stroke that had commenced within 48 hours before enrolment in the study. The experimental group was administered 100 mL NBP injections twice a day in the first 14 days, and a sequential 200 mg NBP soft capsule 3 times a day for the next 76 days. The control group was administered 100 mL NBP placebo injections twice a day in the first 14 days and 200 mg sequential NBP placebo soft capsule 3 times a day for the next 76 days. Primary outcomes were the National Institutes of Health Stroke Scale, the Barthel Index of activities of daily living, and Modified Rankin Scale which were evaluated at day 0, day 14, and month 1 or at day 14, month 3, and month 6. Secondary outcomes included the Hamilton Anxiety Scale and the Hamilton Depression Scale, all were evaluated on day 0, month 3, and month 6. Moreover, the adverse reaction of NBP or other serious adverse events were evaluated at each time.

RESULTS

Our therapy significantly increased the Barthel Index of activities of daily living scores, decreased the National Institutes of Health Stroke Scale and Modified Rankin Scale scores, and the incidence of the Hamilton Anxiety Scale and the Hamilton Depression Scale of ischemic stroke patients (P < .05).

CONCLUSION

Our results indicated that 90 days' sequential therapy with NBP as an additional therapy in the treatment of ischemic stroke can better improve patients' psychological and behavioral functions without significant side effects.

Novel 3-benzylidene/benzylphthalide Mannich base derivatives as potential multifunctional agents for the treatment of Alzheimer's disease

To discover novel multifunctional agents for the treatment of Alzheimer's disease, a series of 3-benzylidene/benzylphthalide Mannich base derivatives were designed, synthesized and evaluated. The biological screening results indicated that most of these derivatives exhibited good multifunctional activities. Among them, compound (Z)-13c raised particular interest because of its excellent multifunctional bioactivities. It displayed excellent EeAChE and HuAChE inhibition (IC₅₀ = 9.18 × 10^-5 and 6.16 × 10^-4 μM, respectively), good MAO-B inhibitory activity (IC₅₀ = 5.88 μM) and high antioxidant activity (ORAC = 2.05 Trolox equivalents). Additionally, it also exhibited good antiplatelet aggregation activity, moderate self- and Cu²⁺-induced Aβ_1-42 aggregation inhibitory potency, disaggregation ability on Aβ_1-42 fibrils, biometal chelating ability, appropriate BBB permeability and significant neuroprotective effect. Furthermore, (Z)-13c can also ameliorate the learning and memory impairment induced by scopolamine in mice. These multifunctional properties highlight compound (Z)-13c as a promising candidate for further development of multifunctional drug against AD.

Natural products as pharmacological modulators of mitochondrial dysfunctions for the treatments of Alzheimer's disease: A comprehensive review

Alzheimer's disease (AD) is the most common progressive neurodegenerative disorder characterized by neuronal loss and cognitive impairment that harshly affect the elderly individuals. Currently, the available anti-AD pharmacological approaches are purely symptomatic to alleviate AD symptoms, and the curative effects of novel anti-AD drugs focused on Aβ target are disappointing. Hence, there is a tremendous need to adjust AD therapeutic targets and discover novel anti-AD agents. In AD, mitochondrial dysfunction gradually triggers neuronal death from different aspects and worsens the occurrence and progress of AD. Consequently, it has been proposed that the intervention of impaired mitochondria represents an attractive breakthrough point for AD treatments. Due to chemical diversity, poly-pharmacological activities, few adverse effects and multiple targeting, natural products (NPs) have been identified as a valuable treasure for drug discovery and development. Multiple lines of studies have scientifically proven that NPs display ameliorative benefits in AD treatment in relation to mitochondrial dysfunction. This review surveys the complicated implications for mitochondrial dysregulation and AD, and then summarizes the potentials of NPs and their underlying molecular mechanisms against AD via reducing or improving mitochondrial dysfunction. It is expected that this work may open the window to speed up the development of innovative anti-AD drugs originated from NPs and improve upcoming AD therapeutics.

Herb-target virtual screening and network pharmacology for prediction of molecular mechanism of Danggui Beimu Kushen Wan for prostate cancer

Prostate cancer (PCa) is a cancer that occurs in the prostate with high morbidity and mortality. Danggui Beimu Kushen Wan (DBKW) is a classic formula for patients with difficult urination including PCa. This study aimed to investigate the molecular mechanisms of DBKW for PCa. We obtained DBKW compounds from our previous reviews. We identified potential targets for PCa from literature search, currently approved drugs and Open Targets database and filtered them by protein-protein interaction network analysis. We selected 26 targets to predict three cancer-related pathways. A total of 621 compounds were screened via molecular docking using PyRx and AutoDock Vina against 21 targets for PCa, producing 13041 docking results. The binding patterns and positions showed that a relatively small number of tight-binding compounds from DBKW were predicted to interact strongly and selectively with three targets. The top five high-binding-affinity compounds were selected to generate a network, indicating that compounds from all three herbs had high binding affinity against the 21 targets and may have potential biological activities with the targets. DBKW contains multi-targeting agents that could act on more than one pathway of PCa simultaneously. Further studies could focus on validating the computational results via experimental studies.

Dl-3-n-Butylphthalide Reduces Cognitive Deficits and Alleviates Neuropathology in P301S Tau Transgenic Mice

Alzheimer's disease (AD) is a destructive and burdensome neurodegenerative disease, one of the most common characteristics of which are neurofibrillary tangles (NFTs) that are composed of abnormal tau protein. Animal studies have suggested that dl-3-n-butylphthalide (dl-NBP) alleviates cognitive impairment in mouse models of APP/PS1 and SAMP8. However, the underlying mechanisms related to this remain unclear. In this study, we examined the effects of dl-NBP on learning and memory in P301S transgenic mice, which carry the human tau gene with the P301S mutation. We found that dl-NBP supplementation effectively improved behavioral deficits and rescued synaptic loss in P301S tau transgenic mice, compared with vehicle-treated P301S mice. Furthermore, we also found that it markedly inhibited the hyperphosphorylated tau at the Ser262 site and decreased the activity of MARK4, which was associated with tau at the Ser262 site. Finally, dl-NBP treatment exerted anti-inflammatory effects and reduced inflammatory responses in P301S mice. In conclusion, our results provide evidence that dl-NBP has a promising potential for the therapy of tauopathies, including AD.

Improvement of cerebral ischemia-reperfusion injury by L-3-n-butylphthalide through promoting angiogenesis

Cerebral ischemia/reperfusion (I/R) injury may lead to a poor prognosis for ischemic stroke patients after reperfusion therapy, and currently, lacks effective therapeutic intervention. This study aimed to investigate the effects of L-3-n-butylphthalide (L-NBP) on cerebral I/R injury in rats. Rat models of cerebral I/R injury were established using the middle cerebral artery occlusion/refusion (MACO/R) surgery and were administrated intragastrically with L-NBP or vehicle. We found that L-NBP attenuated the histological damages and reduced the brain hematoma in MACO/R rats. L-NBP also significantly improved the neurological function, alleviated the brain edema, and reduced the permeability of blood-brain barrier of MACO/R rats. Moreover, we detected that L-NBP considerably facilitated microvessel formation in the lesion area of brain in MACO/R rats. Finally, we found that L-NBP significantly increased the protein and mRNA expression levels of Nrf2, HIF-1α, and VEGF in the brain of MACO/R rats. In conclusion, our results demonstrated that L-NBP exerted significant beneficial effects on cerebral I/R injury in rats through promoting angiogenesis, which may be associated with the activation of Nrf2/HIF-1α/VEGF signaling pathway. Our results suggested that L-NBP could be a potential therapeutic drug for cerebral I/R injury.

L-3-n-Butylphthalide improves synaptic and dendritic spine plasticity and ameliorates neurite pathology in Alzheimer's disease mouse model and cultured hippocampal neurons

Alzheimer's disease (AD) is the most common cause of dementia among elderly people. Despite enormous efforts, the pathogenesis of AD still remains unclear and no drug has yet been proved to be disease-modifying. As the basis of learning and memory, the plasticity of synapse and dendritic spine has been impaired during AD progression. Previous studies have showed a protective effect of L-3-n-butylphthalide (L-NBP) on cognitive deficits in AD, we wonder whether this protective effect is associated with positive alterations on synapse and dendritic spines. In this study, we first of all confirmed the anti-dementia effect of L-NBP in 13-month-old APP/PS1 mice, and then investigated the alterations in synaptic and dendritic spine plasticity due to L-NBP treatment both in vivo and in vitro. We also conducted preliminary studies and found the possible mechanisms related to the inhibition of over-activated complement cascade and the remodeling of actin cytoskeleton. Besides, we also found extra benefits of L-NBP on presynaptic dystrophic neurites and attempted to give explanations from the view of autophagy regulation. Taken together, our study added some new evidence to the application of L-NBP in AD treatment and provided deeper insight into the relevant mechanisms for future study.

From Seeds of Apium graveolens Linn. to a Cerebral Ischemia Medicine: The Long Journey of 3-n-Butylphthalide

3-n-Butylphthalide (NBP) as well as its derivatives and analogues (NBPs), in racemic or enantiomerically pure forms, possess potent and diverse pharmacological properties and have shown a great potential therapeutic interest for many human conditions, especially for cerebral ischemia. This Perspective outlines the synthesis and therapeutic applications of NBPs.

The Efficacy of N-Butylphthalide and Dexamethasone Combined with Hyperbaric Oxygen on Delayed Encephalopathy After Acute Carbon Monoxide Poisoning

Background

Carbon monoxide (CO) poisoning is a common health problem among people in many countries, primarily because of its severe clinical effects and high toxicological morbidity and mortality. Acute brain injury and delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) are the most common neurological complications. This study was performed to assess the efficacy of N-butylphthalide (NBP) and dexamethasone (DXM) combined with hyperbaric oxygen (HBO) in patients with DEACMP.

Patients and Methods

A total of 171 patients with DEACMP were recruited and assigned to the combined therapy group (receiving NBP and DXM 5 mg/day plus HBO therapy) or the control group (HBO therapy as monotherapy). Conventional treatments were provided for all patients. The cognition and movement changes in patients were evaluated by the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA) scale and the Barthel index of activities of daily living (ADL) before and after the treatment at 1 month, 3 months, and 1 year, respectively.

Results

At 1 month, 3 months, and 1 year after the treatment, the MMSE, MoCA and ADL scores were all significantly higher in the combined therapy group than those in the control group. There were no significant alterations in blood glucose, blood lipids, or liver and kidney function during the whole treatment session. Some patients experienced loss of appetite, mild headache and minor skin irritations. However, these patients recovered by themselves and needed no additional medications or special treatment.

Conclusion

These results indicated that NBP and DXM combined with HBO for the treatment of DEACMP can significantly improve the cognitive and motor functions of patients and is very safe.

Comparative study on neuroprotective activities of fucoidans from Fucus vesiculosus and Undaria pinnatifida

This study investigated the neuroprotective activities of five different fucoidan samples with different chemical compositions prepared from Fucus vesiculosus (FE, FF, and S) and Undaria pinnatifida (UE and UF) to determine if they reduced aggregation or cytotoxicity of Aβ1-42 in neuronal PC-12 cells. Only fucoidans S, UE, and UF showed anti-aggregation effects against Aβ1-42, as determined using Thioflavin T (ThT) fluorometric fibrillisation kinetics and transmission electron microscopy (TEM) of fibril morphology. However, all five fucoidan samples reduced the cytotoxicity of both Aβ1-42 and hydrogen peroxide in neuronal PC-12 cells and demonstrated inhibition of apoptosis induced by Aβ1-42. Three fucoidan samples (FF, UE and UF) showed significant activity in enhancing neurite outgrowth. Fucoidan from different seaweed sources and with varying chemical compositions demonstrate a range of neuroprotective activities that may have potential to alter Aβ1-42 neurotoxicity in Alzheimer's disease.

Long-Term DL-3-n-Butylphthalide Treatment Alleviates Cognitive Impairment Correlate With Improving Synaptic Plasticity in SAMP8 Mice

Alzheimer’s disease (AD) is the most prevalent form of dementia worldwide. AD is characterized by mild cognitive impairment at onset, irreversibly progressing with age to severe neurodegeneration and cognitive deficits in the late stages. Unfortunately, no effective treatments exist to prevent or delay the cognitive symptoms of AD. Studies have shown that DL-3-n-butylphthalide (DL-NBP) alleviates cognitive impairment induced by amyloid-β in mice by reducing oxidative stress, inhibiting apoptosis, and decreasing tau phosphorylation. In this study, we examined the effects of DL-NBP administration on cognitive function in the senescence-accelerated mouse prone 8 (SAMP8) model of age-related dementia. DL-NBP treatment for 3 months alleviated cognitive impairment in SAMP8 mice as assessed by performance in the Morris water maze test. Moreover, DL-NBP significantly increased the expression of synaptophysin and postsynaptic density protein 95 in the hippocampus of SAMP8 mice, indicative of a protective effect on hippocampal structural synaptic plasticity. In addition, brain-derived neurotrophic factor/tropomyosin receptor kinase B signaling, previously shown to promote synaptic plasticity, was significantly enhanced by the DL-NBP administration. Our findings suggest that DL-NBP is a potential drug candidate for the treatment of cognitive impairment in AD and may serve as the foundation for further research into the development of AD drugs.

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

AIMS

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 Alzheimer's 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.

METHODS

Eighteen-month-old APP/PS1 transgenic (Tg) mice were administrated 15 mg/kg L-NBP by oral gavage for 3 months. Synaptic morphology and the thickness of postsynaptic density (PSD) in hippocampal neurons were investigated by electron microscope. The dendritic spines, Aβ plaques, and glial activation were detected by staining. The expressions of synapse-related proteins were observed by Western blotting.

RESULTS

L-NBP treatment significantly increased the number of synapses and apical dendritic thorns and the thickness of PSD, increased the expression levels of synapse-associated proteins including PSD95, synaptophysin (SYN), β-catenin, and GSK-3β, and attenuated Aβ plaques and neuroinflammatory responses in aged APP/PS1 Tg mice.

CONCLUSION

L-NBP may restore synaptic and spine function in aged APP Tg mice through inhibiting Aβ plaques deposition and neuroinflammatory response. Wnt/β-catenin signaling pathway may be involved in L-NBP-related restoration of synaptic function.

Recent progress towards an effective treatment of amyotrophic lateral sclerosis using the SOD1 mouse model in a preclinical setting

Amyotrophic lateral sclerosis (ALS) is a progressive, fatal and incurable neurodegenerative disorder. Motor neurone degeneration can be caused by genetic mutation but the exact etiology of the disease, particularly for sporadic illness, still remains unclear. Therapeutics which target known pathogenic mechanisms involved in ALS, such as protein aggregation, oxidative stress, apoptosis, inflammation, endoplasmic reticulum stress and mitochondria dysfunction, are currently being pursued in order to provide neuroprotection which may be able to slow down, or perhaps even halt, disease progression. This present review focuses on the compounds which have been recently evaluated using the SOD1 mouse model, the most widely used preclinical model for ALS research.

L-3-n-Butylphthalide attenuates neuroinflammatory responses by downregulating JNK activation and upregulating Heme oxygenase-1 in lipopolysaccharide-treated mice

Microglia activation-induced neuroinflammation contributes to neuronal damage in neurodegenerative diseases. Inhibition of microglia activation and reduction of major neurotoxic cytokines have been becoming a therapeutic strategy for neurodegenerative diseases. L-3-n-Butylphthalide (L-NBP) has shown the potent neuroprotective effects in stroke and Alzheimer's disease animal models. The present study investigated the immune modulatory effects of L-NBP on pro-inflammatory cytokines and microglia activation in brain tissue induced by systemic lipopolysaccharide (LPS) treatment in C57BL/6 mice. Our results showed that systemic LPS treatment induced microglia activation in the brain. L-NBP treatment significantly suppressed the expression of proinflammatory cytokines, such as tumor necrosis factor (TNFα), interlukin-1β (IL-1β), interlukin-6 (IL-6), and interlukin-10 (IL-10) in LPS-treated mice. At the meantime, L-NBP treatment decreased the morphological activation of microglia. In addition, the phosphorylation level of JNK MAP kinase-signaling pathway was also inhibited by L-NBP in LPS-treated mice. Furthermore, L-NBP upregulated the expression of heme oxygenase (HO)-1, a key element in the anti-inflammation and anti-oxidative stress. These results suggested that L-NBP might be a promising candidate in delaying and reversing the progress of neurodegenerative diseases by inhibiting microglia activation.

Pharmacokinetics, safety and tolerability of L-3-n-butylphthalide tablet after single and multiple oral administrations in healthy Chinese volunteers

L-3-n-butylphthalide (L-NBP) is a naturally occurring antioxidant, which can be used for the treatment of acute ischemic stroke and vascular dementia. This study evaluated the safety, tolerability and pharmacokinetics of L-NBP tablets in healthy Chinese volunteers. This was a single-center, randomized, double-blind, placebo-controlled, single- and multiple-dose study. Subjects were assigned to receive a single dose of L-NBP tablet at either 80, 160, 320, or 480 mg (n=40), or multiple doses of 160 mg twice daily for 7 days (n=12). Plasma samples were analyzed with LC-MS/MS. Pharmacokinetic parameters of L-NBP were calculated using non-compartmental analysis with WinNonlin software. Statistical analysis was performed using SPSS software. All adverse events (AEs) were mild and of limited duration; AEs in this study occurred less frequently and more mildly than AEs listed for the DL-NBP soft capsule. No serious adverse event (SAE), death or withdrawal from the study was observed. In the single-dose study, Cmax was reached at about 1 h, and the mean t1/2 was approximately 13.76 h. Area under curve (AUC) and Cmax increased with dose escalation, but dose proportionality was not observed over the range of 160 to 480 mg. In the multiple-dose study, the steady-state was reached within 3 days with slight accumulation. In summary, the L-NBP tablet was well tolerated in healthy Chinese subjects. Slight accumulation appeared after repeated doses.

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

AIMS

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.

METHODS AND RESULTS

The middle cerebral artery of rats was blocked for 2 h. The daily oral administrations of 30 mg/kg l-NBP or vehicle were begun from the second day until the rats were sacrificed. L-NBP treatment markedly increased 5-bromo-2'-deoxyuridine (BrdU)-positive cells in the hippocampal dentate gyrus (DG) of injured hemisphere on day 28 after ischemia. The amount of newborn cells and newly mature neurons was also increased. The expressions of growth-associated protein-43 and synaptophysin were significantly elevated in l-NBP-treated rats. However, l-NBP markedly reduced the percentage of BrdU(+) /GFAP(+) cells. Additionally, the levels of catalytical subunit of protein kinase A (PKA), protein kinase B (Akt), and cAMP response element-binding protein (CREB) were significantly increased, and the activation of the signal transducer and activation of transcription 3 (STAT3) and the expressions of cleaved caspase-3 and Bax were obviously inhibited by l-NBP. Consequently, l-NBP attenuated the behavioral dysfunction.

CONCLUSIONS

It first demonstrates that l-NBP may improve the behavioral outcome of cerebral ischemia by promoting neurogenesis and neuroplasticity. Activation of CREB and Akt and inhibition of STAT3 signaling might be involved in.

Synthesis, recognition characteristics and properties of l-3-n-butylphthalide molecularly imprinted polymers as sorbent for solid-phase extraction through precipitation polymerization

L-3-n-butylphthalide molecularly imprinted polymers (MIPs) were synthesized using l-3-n-butylphthalide as template molecule, acrylamide as functional monomer, ethylene glycol dimethacrylate as cross-linking agent, and acetone as the porogenic solvent through precipitation polymerization. The non-imprinted polymers (NIPs) were prepared with the same procedure, but with the absence of template molecule. The optimum preparation conditions of the MIPs such as the functional monomer, the porogenic solvent, the molar ratio of the template to the functional monomer and the molar ratio of the template to the cross-linker were investigated in detail. Prior to the polymerization, the molecular simulation with the computer-aided design was used to help choose a suitable polymerization porogen for the molecularly imprinted pre-assembled system and study the interactions between l-NBP and the functional monomers. The synthesized polymers were characterized with FTIR and SEM to observe their structures as well as the morphologies, and their adsorption properties were respectively evaluated by static and dynamic adsorption as well as selectivity experiments. Scatchard analyses revealed that there were high and low affinity sites formed in the MIPs, which elucidated good affinity to l-NBP in the ethanol system. The adsorption capacity of the MIPs for l-NBP was 3.561 mg g(-1), with an imprinting factor (α) of 2.321 when compared with that of the NIPs. Scatchard analysis illustrated that the binding sites with affinity for l-3-n-butylphthalide molecules were formed in the prepared MIPs.

Effects of N-Butylphthalide on the expressions of Nogo/NgR in rat brain tissue after carbon monoxide poisoning

Carbon monoxide (CO) intoxication is one of the most common types of poisoning worldwide, and may result in neuropathologic sequelae, yet its pathogenesis is not clear and there is no optimal management strategy for patients with CO poisoning. In this study, the rat model of CO poisoning was established in a hyperbaric chamber by CO exposure. Rats were administered orally N-Butylphthalide (NBP) at a dose of 1 ml/100g. Neuronal apoptosis was assessed by TUNEL stain and flow cytometry. The expressions of neurite outgrowth inhibitor (Nogo), myelin-associated glycoprotein (MAG) and Nogo receptor-1 (NgR1) were observed in rat brain tissue by immunohistochemistry and double immunofluorescence staining. As we expected, CO poisoning could start the mechanism of apoptosis. The number of apoptotic cells and the early neuronal apoptosis percentage (EAR) were significantly increased at 1 day, 3 day after CO exposure. NBP treatment obviously reduce neuronal apoptosis and the EAR (P<0.05). CO poisoning could induce Nogo, MAG and NgR1 expressions. The increased Nogo, MAG and NgR1 proteins were still observed at 4 week after CO poisoning. NBP could significantly reduce the levels of Nogo and NgR1 proteins. Then we suspected that the expressions of Nogo, MAG and NGR1 proteins might be associated with brain injury and demyelination induced by CO poisoning. NBP might inhibit neuronal apoptosis and the EAR, down-regulate the expressions of Nogo and NgR1 proteins (but not MAG), and play a neuro-protective role in brain damage after acute CO poisoning.

L-3-n-butylphthalide protects against vascular dementia via activation of the Akt kinase pathway

As a neuroprotective drug for the treatment of ischemic stroke, 3-n-butylphthalide, a celery seed extract, has been approved by the State Food and Drug Administration of China as a clinical therapeutic drug for ischemic stroke patients. L-3-n-butylphthalide possesses significant efficacy in the treatment of acute ischemic stroke. The activated Akt kinase pathway can prevent the death of nerve cells and exhibit neuroprotective effects in the brain after stroke. This study provides the hypothesis that l-3-n-butylphthalide has a certain therapeutic effect on vascular dementia, and its mechanism depends on the activation of the Akt kinase pathway. A vascular dementia mouse model was established by cerebral repetitive ischemia/reperfusion, and intragastrically administered l-3-n-butylphthalide daily for 28 consecutive days after ischemia/reperfusion, or 7 consecutive days before ischemia/reperfusion. The Morris water maze test showed significant impairment of spatial learning and memory at 4 weeks after operation, but intragastric administration of l-3-n-butylphthalide, especially pretreatment with l-3-n-butylphthalide, significantly reversed these changes. Thionine staining and western blot analylsis showed that preventive and therapeutic application of l-3-n-butylphthalide can reduce loss of pyramidal neurons in the hippocampal CA1 region and alleviate nerve damage in mice with vascular dementia. In addition, phosphorylated Akt expression in hippocampal tissue increased significantly after l-3-n- butylphthalide treatment. Experimental findings demonstrate that l-3-n-butylphthalide has preventive and therapeutic effects on vascular dementia, and its mechanism may be mediated by upregulation of phosphorylated Akt in the hippocampus.

l-3-n-Butylphthalide attenuates β-amyloid-induced toxicity in neuroblastoma SH-SY5Y cells through regulating mitochondrion-mediated apoptosis and MAPK signaling

Alzheimer's disease (AD) is a progressive neurodegenerative disease. Amyloid-β protein (Aβ), the hallmark of AD, invokes a cascade of mitochondrial dysfunction and eventually leads to neuronal death. l-3-n-Butylphthalide (l-NBP) has shown the potent neuroprotective effects in stroke and AD animal models. The present study is to evaluate the neuroprotective effect of l-NBP on Aβ25-35-induced neuronal injury and the possible mechanism in the human neuroblastoma SH-SY5Y cells. Our results showed that l-NBP significantly attenuated Aβ25-35-induced cell death and reduced neuronal apoptosis. l-NBP significantly inhibited Aβ25-35-induced mitochondrial dysfunction, including mitochondrial membrane potential reduction, and reactive oxygen species production. Furthermore, l-NBP could partially reverse the elevations of Aβ25-35-induced active caspase-3, caspase-9, and cytochrome c expressions, and the downregulation of anti-apoptosis protein Bcl-2. Moreover, l-NBP markedly inhibited the activations of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase/stress-activated protein kinase signaling pathway. These results demonstrated that l-NBP was capable of protecting neuronal cells from Aβ25-35-induced toxicity through a mitochondrial-dependent apoptotic pathway. Thus, l-NBP shows promising candidate of multi-target neuronal protective agent for the treatment of AD.

Protective effect of Bajijiasu against β-amyloid-induced neurotoxicity in PC12 cells

Beta-amyloid peptide (Aβ), a major protein component of senile plaques associated with Alzheimer's disease (AD), is also directly neurotoxic. Mitigation of Aβ-induced neurotoxicity is thus a possible therapeutic approach to delay or prevent onset and progression of AD. This study evaluated the protective effect of Bajijiasu (β- D-fructofuranosyl (2-2) β- D-fructofuranosyl), a dimeric fructose isolated from the Chinese herb Radix Morinda officinalis, on Aβ-induced neurotoxicity in pheochromocytoma (PC12) cells. Bajijiasu alone had no endogenous neurotoxicity up to 200 μM. Brief pretreatment with 10-40 μM Bajijiasu (2 h) significantly reversed the reduction in cell viability induced by subsequent 24 h exposure to Aβ25-35 (21 μM) as measured by MTT and LDH assays, and reduced Aβ25-35-induced apoptosis as indicated by reduced annexin V-EGFP staining. Bajijiasu also decreased the accumulation of intracellular reactive oxygen species and the lipid peroxidation product malondialdehyde in PC12 cells, upregulated expression of glutathione reductase and superoxide dismutase, prevented depolarization of the mitochondrial membrane potential (Ψm), and blocked Aβ25-35-induced increases in [Ca(2+)] i . Furthermore, Bajijiasu reversed Aβ25-35-induced changes in the expression levels of p21, CDK4, E2F1, Bax, NF-κB p65, and caspase-3. Bajijiasu is neuroprotective against Aβ25-35-induced neurotoxicity in PC12 cells, likely by protecting against oxidative stress and ensuing apoptosis.

Bioassay-Guided Isolation of Neuroprotective Compounds from Uncaria rhynchophylla against Beta-Amyloid-Induced Neurotoxicity

Uncaria rhynchophylla is a component herb of many Chinese herbal formulae for the treatment of neurodegenerative diseases. Previous study in our laboratory has demonstrated that an ethanol extract of Uncaria rhynchophylla ameliorated cognitive deficits in a mouse model of Alzheimer's disease induced by D-galactose. However, the active ingredients of Uncaria rhynchophylla responsible for the anti-Alzheimer's disease activity have not been identified. This study aims to identify the active ingredients of Uncaria rhynchophylla by a bioassay-guided fractionation approach and explore the acting mechanism of these active ingredients by using a well-established cellular model of Alzheimer's disease, beta-amyloid- (Aβ-) induced neurotoxicity in PC12 cells. The results showed that six alkaloids, namely, corynoxine, corynoxine B, corynoxeine, isorhynchophylline, isocorynoxeine, and rhynchophylline were isolated from the extract of Uncaria rhynchophylla. Among them, rhynchophylline and isorhynchophylline significantly decreased Aβ-induced cell death, intracellular calcium overloading, and tau protein hyperphosphorylation in PC12 cells. These results suggest that rhynchophylline and isorhynchophylline are the major active ingredients responsible for the protective action of Uncaria rhynchophylla against Aβ-induced neuronal toxicity, and their neuroprotective effect may be mediated, at least in part, by inhibiting intracellular calcium overloading and tau protein hyperphosphorylation.

Therapeutic Effect of Yi-Chi-Tsung-Ming-Tang on Amyloid β-Induced Alzheimer's Disease-Like Phenotype via an Increase of Acetylcholine and Decrease of Amyloid β

Alzheimer's disease (AD) is an irreversible neurodegenerative disorder characterized by amyloid accumulation, neuronal death, and cognitive impairments. Yi-Chi-Tsung-Ming-Tang (YCTMT) is a traditional Chinese medicine and has never been used to enhance cognitive function and treat neurodegenerative disorders such as senile dementia. Whether YCTMT has a beneficial role in improving learning and memory in AD patients remains unclear. The present study showed that oral administration of YCTMT ameliorated amyloid-β- (Aβ₁₋₄₀) injection-induced learning and memory impairments in rats, examined using passive avoidance and Morris water-maze tests. Immunostaining and Western Blot results showed that continuous Aβ₁₋₄₀ infusion caused amyloid accumulation and decreased acetylcholine level in hippocampus. Oral administration of medium and high dose of YCTMT 7 days after the Aβ₁₋₄₀ infusion decreased amyloid accumulation area and reversed acetylcholine decline in the Aβ₁₋₄₀-injected hippocampus, suggesting that YCTMT might inhibit Aβ plague accumulation and rescue reduced acetylcholine expression. This study has provided evidence on the beneficial role of YCTMT in ameliorating amyloid-induced AD-like symptom, indicating that YCTMT may offer an alternative strategy for treating AD.

The emergence of designed multiple ligands for neurodegenerative disorders

The incidence of neurodegenerative diseases has seen a constant increase in the global population, and is likely to be the result of extended life expectancy brought about by better health care. Despite this increase in the incidence of neurodegenerative diseases, there has been a dearth in the introduction of new disease-modifying therapies that are approved to prevent or delay the onset of these diseases, or reverse the degenerative processes in brain. Mounting evidence in the peer-reviewed literature shows that the etiopathology of these diseases is extremely complex and heterogeneous, resulting in significant comorbidity and therefore unlikely to be mitigated by any drug acting on a single pathway or target. A recent trend in drug design and discovery is the rational design or serendipitous discovery of novel drug entities with the ability to address multiple drug targets that form part of the complex pathophysiology of a particular disease state. In this review we discuss the rationale for developing such multifunctional drugs (also called designed multiple ligands or DMLs), and why these drug candidates seem to offer better outcomes in many cases compared to single-targeted drugs in pre-clinical studies for neurodegenerative diseases such as Alzheimer's and Parkinson's disease. Examples are drawn from the literature of drug candidates that have already reached the market, some unsuccessful attempts, and others that are still in the drug development pipeline.