Correlation of cognitive function with acetylcholinesterase activity and P300 event-related potential of patients with type 2 diabetes mellitus

BACKGROUND： At present, central cholinergic neuron system is regarded the most major structural basis of cognitive function. Changes in structure of cholinergic neuron system of brain and receptor expression after brain injury can cause cognitive impairment. OBJECTIVE＂ To comparatively observe the intelligence quotient （IQ）, latent period and wave amplitude of P300 event-related potential and the difference of activity of acetylcholinesterase （ACHE） in blood and cerebrospinal fluid between patients with type 2 diabetes mellitus and with non-diabetes mellitus, and analyze the correlation of IQ of cognitive impairment patients with diabetes mellitus with AChE activity, latent period and wave amplitude of P300 event-related potential in cerebrospinal fluid. DESIGN： Correlation analysis of contrast observation SETTING： Department of Endocrinology, Affiliated Hospital of Binzhou Medical College PARTICIPANTS： Totally 32 patients with type 2 diabetes mellitus who received the treatment in the Department of Endocrinology, Affiliated Hospital of Binzhou Medical College between April 2004 and April 2005 were recruited, serving as diabetes mellitus group. They, including 19 male and 13 female, aged 49 to 73 years, with disease course of 4 to 11 years, all met the diagnostic criteria of diabetes mellitus revised by World Health Organization in 1999. Another 30 patients with non-diabetes mellitus who homeochronously underwent lumbar anesthesia in the Department of Surgery and Department of Gynecology were recruited, serving as non-diabetes mellitus group. The 30 patients included 18 male and 12 female, and their age ranged from 46 to 71 years. Informed consents of detected items were obtained from the involved patients. METHODS： ① Evaluation,on IQ： The IQ of involved subjects was evaluated with Chinese Version of the Wechsler Adult Intelligence Scale revised by Gong Yao-xian （WAIS-RC）. WAIS-RC included 6 verbal subscales and 5 performance subscales. The test scores of the 11 subscales integrated into the scores of the whole scale, and the scores on the WAIS-RC included verbal IQ （VlQ）, performance IQ （PIQ） and full scale IQ （FIQ）. FIQ ≤79 scores indicated low IQ and FIQ≤69 indicated intelligence impairment. ② Detection of P300 wave： P300 wave was detected with evoked potential instrument （MYTOPRO, Italian）, and data of latent period and amplitude of P300 event-related potential were automatically shown by computer. ③ Detection of AChE activity in blood and cerebrospinal fluid： Activity of AChE of blood and cerebrospinal fluid was measured with biochemical methods by using CORNING-560 autoanalyzer.④Correlation analysis： Correlation of FIQ with AChE of cerebrospinal fluid and P300 wave of patients with type 2 diabetes mellitus was analyzed, t test was used in intergroup comparison and linear correlation analysis for relevant treatment. MAIN OUTCOME MEASURES： ① Comparison of IQ, latent period and wave amplitude of P300 wave as well as the activity of AChE between two groups. ② Analysis on the correlation of FIQ of patients with type 2 diabetes mellitus with AChE of cerebrospinal fluid and P300 wave. RESULTS： Thirty-two patients with diabetes mellitus and 30 non-diabetes mellitus participated in the result analysis. ①Comparison of IQ, latent period and wave amplitude of P300 wave as well as the activity of AChE between two groups： The scores of VIP, PIQ and FIQ of patients with type 2 diabetes mellitus were （97.4±10.4）. （92.6±8.4） and （95.2±9.7） scores, respectively; and those of patients with non-diabetes mellitus were （104.7±9.6）, （102.5±8.5）and（102.7±8.9） scores, respectively, and P 〈 0.05-0.01 was set in intergroup comparison. The latent period of P300 wave at points Fz , Cz and Pz of patients with type 2 diabetes mellitus was （370.8±41.8）.（371.5±39.1）and （375.1±43.1） ms, respectively, and that of patients with non-diabetes mellitus was （ 332.1 ±28.3 ）, （335.7 ±29.4）and （339.7 ±27.3） ms, respectively, and P 〈 0.01 was set in intergroup comparison; Wave amplitude of P300 of patients with type 2 diabetes mellitus was （8.6±4.1）,（8.6±4.0） and （7.7±4.0） μV, respectively and that of patients with non-diabetes mellitus was （11.9±4.1）,（11.5±4.4） and （10.9±5.0） μV, respectively , and P 〈 0.05-0.01 was set in intergroup comparison; The level of AChE in blood and cerebrospinal fluid of patients with type 2 diabetes mellitus was （235.61 ±50.34）and （17.89±4.46） μkat/L, respectively, which was significantly higher than that of patients with non-diabetes mellitus [（205.03±44.15）and （14.63±0.48） μkat /L, respectively], and P 〈 0.05-0.01 was set in the intergroup comparison. ② Correlation of FIQ value of patients with type 2 diabetes mellitus with AChE of cerebrospinal fluid and P300 wave： The value of FIQ was significantly negatively correlated with the AChE activity of cerebrospinal fluid （r=-0.588 1, P 〈 0.01 ）, significantly negatively correlated with the latent period at points Fz. C and Pz of P300 wave （r= -0.700 5, -0.689 4, -0.688 5, P 〈 0.01 ）, and significantly positively correlated with the amplitude at points Fz . Cz and Pz of P300 wave（r= 0.607 4,0.616 1,0.592 0,P 〈 0.01 ）. CONCLUSION： ① Cognitive impairment of patients with type 2 diabetes mellitus might be related to the increase of activity of AChE in cerebrospinal fluid. ②Combined application of examination of P300 wave and evaluation of IQ is more useful in deciding the state of cognitive function of patients with type 2 diabetes mellitus.

Effects of Dimethoate Exposure on Locomotor Activity and Anxiety-Like Behavior in Female Wistar Rat

Developmental exposure to organophosphate insecticide is well known to induce neurobehavioral impairments, at late period. The present study aims to investigate the effects of subchronic exposure to Dimethoate, on locomotors skills and anxiety like behavior among wistar rat. Two groups of female’s rats are used. The intoxicated group receives daily, during five weeks, by intragastric gavage, a dose of Dimethoate dissolved in corn oil (100 mg/kg body weight). The control group receives only the corn oil. Spontaneous locomotors activity is evaluated using the Open Field test (OF) and anxiety-like behavior is measured using Elevated Plus-Maze (EPM). Dimethoate induced significant impairment of spontaneous locomotors activities, which is reflected by high decrease of number of squares crossed (SC) in OF. Females exposed to Dimethoate develop further anxiety-like response, expressed by significant reductions of the time spent in open arm of Elevated Plus-Maze.

Actions of Sodium Fluoride on Acetylcholinesterase Activities in Rats

This study was carried out to observe the effects of sodium fluoride on acetylcholinesterase (AChE) activities in the cerebral synaptic membranes (SPM) and the peripheral red blood cells (RBC) of rats by in vivo and in vitro experiments. In the in vivo study,pregnant rats ingested ad libitum fluorinated drinking water (5, 15, 50 ppm F ) during their gestation and lactation. It was shown that the AChE activities of the SPM and peripheral RBCs in maternal rats exposed 5 ~ 50 ppm F for 60 days were elevated significantly by 30. 0 ~ 67. 6 % and 12. 5 ~ 31. 9 % in a dose-dependent manner, respectively. The AChE activities of their offspring 80 days after birth were also increaased (8. 7 ~ 28. 7 % for SPM and20. 6 ~ 32. 4 % for RBC). In contrast, the AChE activities of SPM in vitro were inhibited by 5. 0~ 50 .0 mmol F /L treatment in a time-and dose dependent manner. Analaysis with the Hanes plots suggested that the enzymesubstrate kinetics are consistent with a mixed type ofinhibition.

Enzyme-digested Colla Corii Asini(E’jiao) prevents hydrogen peroxide-induced cell death and accelerates amyloid beta clearance in neuronal-like PC12 cells

As an aging-associated degenerative disease,Alzheimer’s disease is characterized by the deposition of amyloid beta(Aβ),oxidative stress,inflammation,dysfunction and loss of cholinergic neurons.Colla Corii Asini(CCA)is a traditional Chinese medicine which has been used for feebleness-related diseases and anti-aging.CCA might delay aging-induced degenerative changes in neurons.In the present study,we evaluated antioxidant activity,cytoprotective effects,and Aβremovability of enzyme-digested Colla Corii Asini(CCAD).Oxygen radical absorbance capacity(ORAC)activity assay showed that,as compared to gelatins from the skin of porcine,bovine and cold water fish,CCA exhibited the highest ORAC activity.The ORAC activity of CCA and CCAD was increased gradually by the length of time in storage.Ultrastructure analysis by scanning electron microscopy showed that among CCA manufactured in 2008,2013,2017 and gelatin from cold water fish skin,CCA manufactured in 2008 presented the smoothest surface structure.We further tested the protective effects of CCAD(manufactured in 2008)and enzyme-digested gelatin from cold water fish skin(FGD)on hydrogen peroxide(H2O2)-induced cell death in nerve growth factor-differentiated neuronal-like PC12 cells.Presto blue assay showed that both FGD and CCAD at 0.5 mg/m L increased cell viability in H2O2-treated neuronal-like PC12 cells.The protection of CCAD was significantly superior to that of FGD.Acetylcholinesterase(Ach E)assay showed that both FGD and CCAD inhibited Ach E activity in nerve growth factor-differentiated neuronal-like PC12 cells to 89.1%and 74.5%of that in non-treated cells,respectively.The data suggest that CCAD might be able to increase the neurotransmitter acetylcholine.Although CCAD inhibited Ach E activity in neuronal-like PC12 cells,CCAD prevented H2O2-induced abnormal deterioration of Ach E.ELISA and neprilysin activity assay results indicated that CCAD reduced amyloid beta accumulation and increased neprilysin activity in Aβ1–42-treated neuronal-like PC12 cells,suggesting that CCAD can enhance Aβclearance.Our results suggest that CCA might be useful for preventing and treating Alzheimer’s disease.

Neuroprotective Effect of Phyllanthus acidus L. on Learning and Memory Impairment in Scopolamine-Induced Animal Model of Dementia and Oxidative Stress: Natural Wonder for Regulating the Development and Progression of Alzheimer’s Disease

Nature is the best source of complementary and alternative medicine. The plant Phyllanthus acidus (PA) L. has been used traditionally in pain, inflammatory and oxidative stress related disorders. In this consequence, methanolic extract of PA (MEPA) was selected to explore the ability of this plant to enhance cognitive function, brain antioxidant enzymes and anti-acetylcholinesterase activity which can be used for the treatment of oxidative stress related disorders like Alzheimer’s disease (AD). The purpose of this study was to investigate the neuroprotective effect of MEPA on learning and memory impairment in scopolamine-induced rats of dementia and oxidative stress. Treatment with MEPA (i.e., 100 and 200 mg/kg b.w.) was investigated in scopolamine-treated Swiss albino male rats for 14 days and its neuroprotective effects were examined using Elevated Plus Maze (EPM) test, Passive Avoidance (PA) test, Novel Object Recognition (NOR) test, Morris Water Maze (MWM) test as well as level of antioxidant enzymes such as catalase (CAT), super oxide dismutase (SOD), glutathione reductase (GSR), glutathione-S-transferase (GST), reduced glutathione (GSH), glutathione peroxidase (GSH-Px), lipid peroxidation (TBARS) contents and acetylcholinesterase (AChE) activity in rat brain tissue homogenates. Administration of MEPA significantly (P < 0.05, P < 0.01;P < 0.01) decreased RTL (retention transfer latency) in rats on 7th and 14th day compared to the disease control and control group in the EPM test. In PA test the doses of MEPA suggestively (P < 0.05, P < 0.001;P < 0.05, P < 0.01) increased STL (step-through latency) in rats on 7th and 14th day with respect to disease control and control group. For NOR test administration of MEPA considerably (P < 0.01, P < 0.001;P < 0.01) increased the DI (discrimination index) in rats with respect to that of disease control and control group. The doses of MEPA markedly (P < 0.05, P < 0.01;P < 0.01) decreased EL (escape latency) and significantly (P < 0.01, P < 0.001;P < 0.05, P < 0.01) increased TSTQ (time spent in the target quadrant) on successive days as compared to that of disease control and control group in the acquisition trial of MWM test. In case of probe trial of MWM test MEPA administration considerably (P < 0.01;P < 0.05, P < 0.01) increased TSTQ and significantly (P < 0.05, P < 0.01;P < 0.05, P < 0.01) increased TSA (time spent in the annuli) in rats on successive days as compared to that of disease control and control group. MEPA administration significantly (P < 0.05, P < 0.01, P < 0.001;P < 0.05, P < 0.01) increased the level of CAT, SOD, GSR, GST GSH, GSH-Px and markedly (P < 0.01;P < 0.01, P < 0.001) decreased TBARS level through inhibiting lipid peroxidation as well as significantly (P < 0.01, P < 0.001;P < 0.05, P < 0.01, P < 0.001) decreasing AChE activity in rats brain compared to the disease control and control group. The present study demonstrates that MEPA showed the neuroprotective effect by improving cognitive functions and reduces oxidative stress by increasing the level of brain antioxidant enzymes as well as decreasing lipid peroxidation and acetylcholinesterase activity. Therefore, this plant extract can be used for enhancing learning, memory, antioxidant potentiality and anti-acetylcholinesterase activity in neurodegenerative disorders like AD.

Analyzing Nootropic Effect of Phyllanthus reticulatus Poir. on Cognitive Functions, Brain Antioxidant Enzymes and Acetylcholinesterase Activity against Aluminium-Induced Alzheimer’s Model in Rats: Applicable for Controlling the Risk Factors of Alzheimer’s Disease

Oxidative stress is intensely linked with neurodegenerative disorders, especially Alzheimer’s disease (AD). Searching for medicinal plant with the nootropic activity for controling the development and progression of AD has received extensive consideration. The plant Phyllanthus reticulatus (PR) Poir. is known in Bengali as Panjuli belongs to family Euphorbiaceae. Previous studies have shown the antioxidant, analgesic, anti-inflammatory, etc. activities of this plant. Therefore, the objective of this study was to examine the nootropic effect of ethanolic extracts of Phyllanthus reticulatus (EEPR) on cognitive functions, brain antioxidatant enzymes and acetylcholinesterase activity in aluminium-induced rats of cognitive impairment and oxidative stress. The effects of EEPR fruit (i.e., 100 and 200 mg/kg b.w.) were examined for 30 days and its nootropic effect was determined in aluminium treated Swiss albino male rats by behavioral studies such as Passive Avoidance (PA) test, Rewarded Alternation (RA) test and biochemical studies such as superoxide dismutase (SOD), catalase (CAT), contents of thiobarbituric acid reactive substances (TBARS) and acetylcholinesterase (AChE) activity in rats brain tissue homogenates. In PA test, administration of EEPR fruit (i.e., 100 and 200 mg/kg, b.w.) significantly (P < 0.05, P < 0.01) increased step-through latency (STL) in rats on 30th day with respect to disease control group. The percentage of memory retention (MR) for this test was pointedly (P < 0.05) increased in rats treated with EEPR fruit (i.e., 200 mg/kg b.w.) as compared with disease control group. For RA test, EEPR fruit (i.e., 200 mg/kg b.w.) markedly (P < 0.01) increased the correct responses (CR) in rats on 30th day related to disease control group. In case of this test the percentage of MR was significantly (P < 0.05, P < 0.01) increased in rats treated with EEPR fruit (i.e., 100 and 200 mg/kg b.w.) with respect to disease control group. Administration of EEPR fruit (i.e., 100 and 200 mg/kg b.w.) considerably (P < 0.05, P < 0.01) increased the level of SOD, CAT and expressively (P < 0.05) decreased TBARS level compared to disease control group. Treatment with EEPR fruit (i.e., 100 and 200 mg/kg b.w.) markedly (P < 0.05, P < 0.01) decreased the level of AChE activity to that of disease control group. The present study shows that EEPR fruit has excellent nootropic effect on cognitive performance and brain antioxidant markers in aluminium-induced rats of cognitive impairment and oxidative stress which could be developed in the management of neurodegenerative diseases especially AD.

New Lycopodium alkaloids from Lycopodium obscurum

Three new Lycopodium alkaloids,obscurumines C-E(1-3),along with nine known compounds,were isolated from the club moss Lycopodium obscurum L.Structures of the new compounds were determined on the basis of their spectroscopic analysis and the relative configurations of 1 were established by X-ray crystallographic analysis.All the new isolates were tested for the acetylcholinesterase(AChE)inhibitory activity.

Carinatines A and B,Lycopodium Alkaloids from Phlegmariurus carinatus

Carinatine A(1),a C16N2-type Lycopodium alkaloid possessing a 5/6/6/6 ring system formed by a new C-4/C-12 bond,and carinatine B(2),the first derivative of lycojaponicumin C,along 16 known compounds,were isolated from the whole plant of Phlegmariurus carinatus.Their structures were elucidated based on the spectroscopic data.The two new isolates were no inhibitory activity for the acetylcholinesterase(AChE).

Synthesis and Acetylcholinesterase Inhibitory Activity of Polymethoxyflavone Mannich Base Derivatives

A series of novel polymethoxyflavone Marmich base derivatives 1--8 was synthesized by Mannich reaction of 5-hydroxy-3,7,3＇,4＇-tetramethoxyflavone 9 with various secondary aliphatic amines and formaldehyde. Their acetylcholmesterase（AChE） inhibitory activities were evaluated. The results showed that most of them exhibited AChE inhibitory activity and especially piperidin-l-yl methyl substituent derivative 5（IC50=0.238 μmol/L） demon- strated stronger activity comparable with the positive control, neoeserinemethyl sulfate（IC50=1.39 μmol/L）, which is worthy of further development as an agent for Alzheimer＇s disease treatment.