[Ginkgo leaves tablet improved the memory quotient of patients with mild cognitive impairment: a clinical observation].

OBJECTIVE: To observe the effect of Ginkgo Leaves Tablet (GLT) on memory quotient (MQ) of mild cognitive impairment (MCI) patients. METHODS: One hundred and thirteen patients were randomly assigned to the control group (55 cases) and the treatment group (58 cases). Patients in the control group received dietetic therapy and physical exercises, while those in the treatment group additionally took GLT, 19.2 mg each time, three times daily. The treatment course was 12 months for all. The MQ of all the patients was assessed by WMS-RC before treatment,at 6-month of treatment, and 12-month of treatment. RESULTS: Compared with the control group, the improvement of MQ increased in the treatment group 0.5 and 1 year after treatment (P < 0.05). The clinical efficiency of MQ obviously increased in the treatment group (48.28% and 50.00%), showing statistical difference when compared with the control group (30.91% and 27.27%, P < 0.05, P < 0.01). There was statistical difference in added scores of recognition, regeneration, understanding, and recitation test at 6-month of treatment and 12-month of treatment between the treatment group and the control group (P < 0.05, P < 0.01). CONCLUSION: GLT was effective in improving MQ of MCI patients, especially in improving recognition, regeneration, understanding, and recitation test.

[Effects of Ginkgo biloba extract in improving episodic memory of patients with mild cognitive impairment: a randomized controlled trial].

BACKGROUND: Mild cognitive impairment is a transitional stage between normal aging and dementia. It is important in terms of recognizing memory loss in older people as well as identifying a group of individuals at high risk of developing dementia and who may benefit from preventive strategies. Ginkgo biloba extract has been shown to possess polyvalent properties, such as anti-oxidation, anti-apoptosis and anti-inflammation. Ginkgo biloba extract appears to have a neuroprotective effect against neurodegenerative diseases. OBJECTIVE: To observe the efficacy of Ginkgo biloba leaf tablet in improving episodic memory of mild cognitive impairment. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: This is a multicenter, randomized, controlled trial. The authors enrolled generally healthy, ambulatory or ambulatory-aided amnestic subjects with MCI, 60 to 85 years old, who expressed a memory complaint from Huadong Hospital, seven Community Health Centers in Shanghai, and Shanghai First Welfare Institution. A total of 120 MCI patients were randomly assigned to the Ginkgo biloba leaf tablet group (treatment group, 60 cases) and control group (60 cases). The patients in the treatment group took Ginkgo biloba leaf tablets 3 times a day, 19.2 mg each dose. The control group did not receive any intelligence-promoting or vasodilator reflex treatment except some health care. MAIN OUTCOME MEASURES: The patients were tested with nonsense picture recognition of the clinical memory scale and the logical memory test based on the Wechsler memory scale before and after treatment. RESULTS: After 6 months of treatment, the scores of the logical memory test and nonsense picture recognition were increased significantly in the treatment group (P<0.01, P<0.05), while the scores of the two tests from the control group had no statistically significant difference (P>0.05). After treatment, the positive rate of nonsense picture recognition was 55.17% in the treatment group, which was significantly higher than that of the control group at 32.73% (P<0.05). The efficacy rate of logical memory was 58.62% in the treatment group, also higher than 38.18% in the control group (P<0.05). CONCLUSION: Ginkgo biloba leaf tablet showed good efficacy in promoting episodic memory function in MCI patients.

Bilobalide inhibits inflammation and promotes the expression of Aß degrading enzymes in astrocytes to rescue neuronal deficiency in AD models.

The pathogenesis of Alzheimer's disease (AD) involves multiple cell types including endothelial cells, glia, and neurons. It suggests that therapy against single target in single cell type may not be sufficient to treat AD and therapies with protective effects in multiple cell types may be more effective. Here, we comprehensively investigated the effects of bilobalide on neuroinflammation and Aß degrading enzymes in AD cell model and mouse model. We find that bilobalide inhibits Aß-induced and STAT3-dependent expression of TNF-α, IL-1ß, and IL-6 in primary astrocyte culture. Bilobalide also induces robust expression of Aß degrading enzymes like NEP, IDE, and MMP2 to facilitate astrocyte-mediated Aß clearance. Moreover, bilobalide treatment of astrocyte rescues neuronal deficiency in co-cultured APP/PS1 neurons. Most importantly, bilobalide reduces amyloid and inflammation in AD mouse brain. Taken together, the protective effects of bilobalide in in vitro cultures were fully recapitulated in in vivo AD mouse model. Our study supports that bilobalide has therapeutic potential for AD treatment.

Melatonin-induced ApoE expression in mouse astrocytes protects endothelial cells from OGD-R induced injuries.

Stroke is a leading reason of death and long-term disability, and most studies mainly focus on efforts to protect neurons. However, failed clinical trials suggest that therapies against single target in neurons may not be sufficient and the involvement of endothelial cells and glial cells have been underestimated. Astrocytes are the major source of ApoE in the brain and endothelial cells express high level of ApoE receptors. Thus, ApoE may mediate the interaction between astrocytes and endothelial cells. To address whether and how ApoE-mediated astrocytes-endothelial cells interaction contributes to the pathogenesis of stroke, we used oxygen and glucose deprivation-reoxygenation (OGD-R) as a stroke model and investigated the effects of OGD-R on astrocytes-endothelial cell co-cultures in the current study. We find that OGD-R leads to various damages to endothelial cells, including compromised cell viability, increased ROS level, enhanced caspase activity, and higher apoptotic rate. Meanwhile, mouse astrocytes could secrete ApoE to activate PI3K/eNOS signaling in endothelial cells to prevent OGD-R induced injuries. In addition, OGD-R induces down-regulation of ApoE in astrocyte-endothelial cell co-cultures while melatonin restores astrocytic ApoE expression via pCREB pathway and protects endothelial cell in OGD-R treated co-cultures. Our study provides evidence that astrocytes could protect endothelial cells via ApoE in OGD-R condition and Melatonin could induce ApoE expression to protect endothelial cells.

Correction: Melatonin-induced ApoE expression in mouse astrocytes protects endothelial cells from OGD-R induced injuries.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

DNA Aptamers Targeting BACE1 Reduce Amyloid Levels and Rescue Neuronal Deficiency in Cultured Cells.

ß-amyloid (Aß) plays an essential role in the pathogenesis of Alzheimer's disease (AD). Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) is indispensable for Aß production, and knockout of BACE1 has no overt phenotypes in mouse. Thus, fine modulation of BACE1 may be a safe and effective treatment for AD patients. However, the large active site of BACE1 makes it challenging to target BACE1 with classical small-molecule inhibitors. DNA aptamer can have high affinity and specificity against diverse targets, and it provides an alternative strategy to target BACE1. In this study, we used a novel cell-systematic evolution of ligands by exponential enrichment (SELEX) strategy to select specific DNA aptamers optimized to target BACE1 under physiological status. After 17 rounds of selection, we identified two DNA aptamers against BACE1: BI1 and BI2. The identified aptamers interacted with BACE1 in pull-down assay, inhibited BACE1 activity in in vitro fluorescence resonance energy transfer (FRET) assay and HEK293-APP stable cell line, reduced Aß in the culture medium of HEK293-amyloid protein precursor (APP) stable cell line and APP-PS1 primary cultured neurons, and rescued Aß-induced neuronal deficiency in APP-PS1 primary cultured neurons. In contrast, the identified aptamers had no effect on α- or γ-secretase. In addition, cholesteryl tetraetylene glycol (TEG) modification further improved the potency of the identified aptamers. Our study suggests that it is feasible and effective to target BACE1 with DNA aptamers, and the therapeutic potential of the identified aptamers deserves further investigation.

Subcutaneous rotenone rat model of Parkinson's disease: Dose exploration study.

Subcutaneous administration of rotenone has recently attracted attention because of its convenience, simplicity and efficacy in replicating features of Parkinson's disease (PD) in animal models. However, the wide range of doses reported in the literature makes it difficult to evaluate the effectiveness of this technique objectively. The aim of the present study was to identify the optimum dose of subcutaneous rotenone for establishing a model of PD. We injected male Wistar rats subcutaneously with one of three doses of rotenone (1.5, 2, or 2.5mg/kg) daily for 5 weeks. Rotenone caused a dose-dependent increase in α-synuclein in the substantia nigra. Furthermore, at 2 and 2.5mg/kg, rotenone caused a significant decrease in the number of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra, and dopamine in the striatum. However, mortality at 2.5mg/kg was 46.7%, compared with just 6.7% at 2mg/kg; the high mortality observed at 2.5mg/kg would limit its application. The 2mg/kg dose showed no detrimental effect on body weight after 5 weeks of daily injections. Furthermore, rats in the 2mg/kg group showed a longer latency to descend from a horizontal bar and a grid wall, decreased rearing, and shorter latency to fall from a rotarod than rats that received vehicle or saline. Mitochondrial damage, observed by transmission electron microscopy, was also evident at this dose. Together, our data indicate that daily subcutaneous injection of 2mg/kg rotenone in rats facilitates the formation of α-synuclein and reproduces the typical features of PD, while maintaining low mortality.

PI3K/Akt pathway contributes to neuroprotective effect of Tongxinluo against focal cerebral ischemia and reperfusion injury in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Tongxinluo (TXL), a compound prescription, is formulated according to the collateral disease doctrine of traditional Chinese medicine, and is widely used for the treatment of cardio-cerebrovascular diseases in China. AIM OF THE STUDY: We aimed to investigate the neuroprotective effect of TXL on focal cerebral ischemia and reperfusion injury in rats by attenuating its brain damage and neuronal apoptosis, and to assess the potential role of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in this protection. MATERIALS AND METHODS: Adult Male Sprague-Dawley rats (n=120) were randomly divided into 5 groups: sham, cerebral ischemia and reperfusion (I/R), cerebral ischemia and reperfusion plus TXL (1.6g/kg/day) (TXL1.6), TXL1.6 plus LY294002 and dimethyl sulfoxide (DMSO) (TXL1.6+LY294002), TXL1.6 plus DMSO (TXL1.6+vehicle). Prior to the grouping, TXL1.6 was selected to be the optimal dose of TXL by evaluating the neurological deficits score of five group rats (Sham, I/R, TXL0.4, TXL0.8 and TXL1.6, n=30) at 0, 1, 3, 5, and 7 days after reperfusion. Rats, being subjected to middle cerebral artery occlusion (MCAO) for 90min followed by 24h reperfusion, were the cerebral ischemia/reperfusion models. At 24h after reperfusion, cerebral infarct area was measured via tetrazolium staining and neuronal damage was showed by Nissl staining. The double staining of Terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick end labeling (TUNEL) staining and immunofluorescence labeling with NeuN, was performed to evaluate neuronal apoptosis. Proteins involved in PI3K/Akt pathway were detected by Western blot. RESULTS: The results showed that TXL markedly improved neurological function, reduced cerebral infarct area, decreased neuronal damage, and significantly attenuated neuronal apoptosis, while these effects were eliminated by inhibition of PI3K/Akt with LY294002. We also found that TXL up-regulated the expression levels of p-PDK1, p-Akt, p-c-Raf, p-BAD and down-regulated Cleaved caspase 3 expression notably, which were partially reversed by LY294002. Additionally, the increment of p-PTEN level on which LY294002 had little effect was also detected in response to TXL treatment. CONCLUSIONS: These findings demonstrated that TXL provided neuroprotection against cerebral ischemia/reperfusion injury and neuronal apoptosis, and this effect was mediated partly by activation of the PI3K/Akt pathway.