Protective effect of huperzine A on phenytoin induced cognition impairment: Behavioral and biochemical study

Phenytoin, a drug of choice for Epilepsy is also known for its adverse effects. The most common adverse effect due to phenytoin is cognition impairment. Cognition impairment is a serious problem in society as it debars the person's social life. Thus to overcome such a problem demand for a solution arises. Huperzine, sesquiterpene alkaloids having immense neuroprotective properties. Thus in this study, it was aimed to evaluate the effectiveness of huperzine on Phenytoin- induced Cognition Impairment. The protective effect of huperzine on phenytoin-induced cognition impairment was evaluated in rats. The effect of Huperzine on phenytoin-induced cognitive impairment was evaluated by behavioral, biochemical, and histopathological studies. The co-administration of huperzine with phenytoin showed significant results. The treatment of Huperzine with phenytoin resulted in significant improvement in learning and memory. The oxidative stress induced by Phenytoin was reversed by huperzine. A significant decrease in cholinesterase activity was also observed. The histopathology showed damaged neuronal cells in periventricular regions and cortex due to phenytoin which was altered by Huperzine. Thus, the present study demonstrates the protective effect of huperzine on phenytoin-induced cognition impairment.

Expression of / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Acetylcholinesterase (AChE) is a key enzyme used to detect organophosphorus pesticide residues by the enzyme inhibition method. An accidental discovery of a mutant strain with AChE activity was made in our laboratory during the process of AChE expression by

Effect of Ultrafine Powder of Gastrodiae Rhizoma in Improving Learning and Memory Ability of Vascular Dementia Rats by Regulating Cholinergic System / 中国实验方剂学杂志

Objective:To investigate whether ultrafine powder of Gastrodiae Rhizoma （UPG） can alleviate the learning and memory impairment of vascular dementia rats and delay the process of VD， and whether this effect is related to the release of acetylcholine （Ach） through the regulation with acetylcholinesterase （AChE） and choline acetyltransferase （ChAT） and control of cholinergic system. Method:SD rats were randomly divided into sham operation group， UPG low dose group （0.45 g·kg-1）， UPG high dose group （1.8 g·kg-1） and Huperzine A group （80 μg·kg-1）， with 12 rats in each group. The drug administration groups were given orally drugs once a day for 8 weeks， and sham group and model group were given orally the same amount of distilled water. The learning and memory ability of the rats with VD were evaluated by the Morris water maze. Htoxylin eosin（HE） staining was used for pathomorphological observation of hippocampus CA1 area of the rats. The content of Ach was determined by enzyme-linked immunosorbent assay（ELISA）， AChE and ChAT protein expressions were detected by Western blot， and expression of ChAT in hippocampus CA1 area was observed by immunohistochemistry. Result:Compared with the sham operation group， the escape latency of the model group was significantly increased （P<0.01）， and the frequency of crossings platform and the time of staying in the target quadrant were reduced significantly （P<0.01）. HE staining of hippocampal tissues from VD rat showed neuron disorders， loss and degeneration and necrosis， pyknosis of the nucleus and light coloration of the cytoplasm. The level of acetylcholine in the hippocampus was significantly decreased by ELISA （P<0.05）， the expression level of AChE protein was significantly up-regulated， and the expression level of ChAT protein was significantly down-regulated （P<0.01）. Compared with model group， each administration group could significantly reduce the escape latency of the model rats， and significantly increase the frequency of crossing platform and the time of staying in the target quadrant （P<0.01）， the content of Ach was significantly increased （P<0.05）， the expression of AChE protein was significantly down-regulated （P<0.01）， while the expression of ChAT protein was significantly up-regulated （P<0.01）. Conclusion:UPG improves the learning and memory ability of vascular dementia rats， and its mechanism may be related to the increase of Ach， ChAT level and the decrease of AChE level.

Biological activity of synthesized 5-{1-[(4-chlorophenyl)sulfonyl]piperidin-4-yl}-2-mercapto-1, 3, 4-oxadiazole derivatives demonstrated by in silico and BSA binding studies

We synthesized a series of compounds bearing pharmacologically important 1,3,4-oxadiazole and piperidine moieties. Spectral data analysis by 1H-NMR, 13C-NMR, IR and EI-MS was used to elucidate the structures of the synthesized molecules. Docking studies explained the different types of interaction of the compounds with amino acids, while bovine serum albumin (BSA) binding interactions showed their pharmacological effectiveness. Antibacterial screening of these compounds demonstrated moderate to strong activity against Salmonella typhi and Bacillus subtilis but only weak to moderate activity against the other three bacterial strains tested. Seven compounds were the most active members as acetyl cholinesterase inhibitors. All the compounds presented displayed strong inhibitory activity against urease. Compounds 7l, 7m, 7n, 7o, 7p, 7r, 7u, 7v, 7x and 7v were highly active, with respective IC50 values of 2.14±0.003, 0.63±0.001, 2.17±0.006, 1.13±0.003, 1.21±0.005, 6.28±0.003, 2.39±0.005, 2.15±0.002, 2.26±0.003 and 2.14±0.002 µM, compared to thiourea, used as the reference standard (IC50 = 21.25±0.15 µM). These new urease inhibitors could replace existing drugs after their evaluation in comprehensive in vivo studies.

Donepezil: A review of the recent structural modifications and their impact on anti-Alzheimer activity

Alzheimer disease (AD) is characterized by a low level of acetylcholine, beta-amyloid (Aβ) aggregation and oxidative stress. Donepezil is the core medicine used for the treatment of AD. Various structural modifications of donepezil have been carried out. Benzylpiperidine part of donepezil has been replaced with benzylpyridine, pyridyl methylpiperidine, benzylpiperazine, pyrimidyl piperazine. These derived molecules showed promising activities as anti-Alzheimer agents. Replacement of indanone part by other heterocyclic rings such as pyridine resulted in the formation of compounds which exhibited monoamine oxidase (MAO) as well as acetylcholinesterase (AChE) inhibition. Propargylamine containing derivatives displayed AChE as well as MAO inhibition properties. Attachment of donepezil with natural compounds like ferulic acid, flavonoids, and curcumin showed antioxidant activities in addition to inhibition of the AChE. Benzylpiperidine and benzylpiperazine have also been combined with condensed heterocyclic rings and these compounds displayed promising anti-Alzheimer properties. This review highlights the important structural modifications of donepezil and their influence on biological activities as anti-Alzheimer agents.

Synthesis and DPPH scavenging assay of reserpine analogues, computational studies and in silico docking studies in AChE and BChE responsible for Alzheimer's disease

Alzheimer's disease (AD) is a fast growing neurodegenerative disorder of the central nervous system and anti-oxidants can be used to help suppress the oxidative stress caused by the free radicals that are responsible for AD. A series of selected synthetic indole derivatives were biologically evaluated to identify potent new antioxidants. Most of the evaluated compounds showed significant to modest antioxidant properties (IC50 value 399.07 140.0±50 µM). Density Functional Theory (DFT) studies were carried out on the compounds and their corresponding free radicals. Differences in the energy of the parent compounds and their corresponding free radicals provided a good justification for the trend found in their IC50 values. In silico, docking of compounds into the proteins acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), which are well known for contributing in AD disease, was also performed to predict anti-AD potential.

A doença de Alzheimer (DA) é uma doença neurodegenerativado sistema nervoso central, em rápido crescimento, e antioxidantes ajudam a suprimir o estresse oxidativo causado por radicais livres, responsávies pela DA. Avaliou-se, biologicamente, série de derivados sintéticos de indol selecionados para identificar novos antioxidantes. A maioria dos compostos avaliados apresentou de significativa a boa propriedade antioxidante (valor de IC50 399,07140.0 ± 50 µM). Eftuaram-se estudos de Teoria do Funcional de Densidade (DFT) com os compostos e os seus correspondentes radicais livres. As diferenças de energia entre os compostos protótipos e os radicais livres correspondentes proporcionaram boa justificativa para a tendência encontrada nos seus valores de IC50. O ancoramento in silico dos compostos com a acetilcolinesterase (AChE) e com a butirilcolinesterase (BChE), que contribuem para a DA, foi, também, realizado para prever o seu potencial anti-DA.

Inhibition of acetylcholinesterase by two genistein derivatives: kinetic analysis, molecular docking and molecular dynamics simulation

In this study two genistein derivatives (G1 and G2) are reported as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), and differences in the inhibition of AChE are described. Although they differ in structure by a single methyl group, the inhibitory effect of G1 (IC50=264 nmol/L) on AChE was 80 times stronger than that of G2 (IC50=21,210 nmol/L). Enzyme-kinetic analysis, molecular docking and molecular dynamics (MD) simulations were conducted to better understand the molecular basis for this difference. The results obtained by kinetic analysis demonstrated that G1 can interact with both the catalytic active site and peripheral anionic site of AChE. The predicted binding free energies of two complexes calculated by the molecular mechanics/generalized born surface area (MM/GBSA) method were consistent with the experimental data. The analysis of the individual energy terms suggested that a difference between the net electrostatic contributions (ΔE ele+ΔG GB) was responsible for the binding affinities of these two inhibitors. Additionally, analysis of the molecular mechanics and MM/GBSA free energy decomposition revealed that the difference between G1 and G2 originated from interactions with Tyr124, Glu292, Val294 and Phe338 of AChE. In conclusion, the results reveal significant differences at the molecular level in the mechanism of inhibition of AChE by these structurally related compounds.

Influence of Toxoplasma gondii Acute Infection on Cholinesterase Activities of Wistar Rats

Several studies have shown the mechanisms and importance of immune responses against Toxoplasma gondii infection and the notable role of cholinesterases in inflammatory reactions. However, the association between those factors has not yet been investigated. Therefore, the aim of this study was to evaluate the acetylcholinesterase (AChE) activity in blood and lymphocytes and the activity of butyrylcholinesterase (BChE) in serum of rats experimentally infected with T. gondii during the acute phase of infection. For that, an in vivo study was performed with evaluations of AChE and BChE activities on days 5 and 10 post-infection (PI). The activity of AChE in blood was increased on day 5 PI, while in lymphocytes its activity was enhanced on days 5 and 10 PI (P<0.05). No significant difference was observed between groups regarding to the activity of BChE in serum. A positive (P<0.01) correlation was observed between AChE activity and number of lymphocytes. The role of AChE as an inflammatory marker is well known in different pathologies; thus, our results lead to the hypothesis that AChE has an important role in modulation of early immune responses against T. gondii infection.

Evaluation of the Antioxidant and Anti-Cholineesterase activities of the Stem, Barks and Leaves of the Plant Vernonia Cinerea (Family: Asteraceae).

The aim of this study was to evaluate the anti-oxidant and anti-choline esterase activity of the stem, barks and leaves of the plant V. cinerea. The stems, barks and the leaves of the plant V.Cineria was sun dried and extracted using methanol. The anti-oxidant activity of the crude methanolic extract was measured by the DPPH free radical scavenging activity. The crude methanolic extract showed significant anti-oxidant activity by the DPPH free radical scavenging method. Evaluation of ChEs enzyme activity of the crude methanolic extract was done by Ellman method. The methanolic extract of V. cinerea leaves exerted significant AChE and BChE inhibitory effects.

The roles of catecholamine in cardiac injury after severe acute dichlorvos poisoning / 中华急诊医学杂志

ObjectiveTo study the role of catecholamine in genesis of myocardium injury after organophosphorus poisoning (OP) in order to elucidate the underlying mechanisms of OP-induced cardiotoxicity.Methods Of 92 patients with severe acute dichlorvos poisoning,41 were consecutively enrolled for study and followed up for three months. The levels of serum creatine kinase isoenzyme myocardium (CK-MB),cardiac troponin Ⅰ (cTnI),acetylcholinesterase (AChE),acetylcholine (Ach),epinephrine and norepinephrine were assayed on the 1st,3rd and 5th days after admission and on the day of discharge.Electrocardiography was recorded every day after admission.ResultsOf them,37 (90.2％ )patients survived and four ( 9.8％ ) patients died during treatment.Sinus tachycardia was found in 37 (90.2％ ) patients and ST-T changes in 33 (80.4％ ) patients.CK-MB and cTnI levels peaked 3 days after admission,and then decreased to normal levels.Serum Ach,epinephrine and norepinephrine peaked on the 1st day after admission and then decreased.ConclusionsSevere acute dichlorvos poisoning is associated with myocardial dysfunction likely caused by increase in catecholamine levels.

Contractile property of skeletal muscle after dicrotophos exposure in rats

Background: Dicrotophos is an organophosphate pesticide whose residue has been detected in most vegetables even in organic samples. Though this pesticide is classified as a highly hazardous Ib organophosphate, it is not banned in many countries including Thailand. Improper use of this chemical exposes the people to it through consumption of contaminated food and water. Some people develop signs of cholinergic syndrome following exposure and some suffer for days from paralysis of respiratory and limb muscles. However, there is no direct evidence indicating muscle weakness through decreased contractile property. All studies in humans thus far were clinically investigated and reported using information from subjective verbal histories. Objective: To investigate the contractile characteristics of skeletal muscles after dicrotophos exposure. Methods: A preliminary study was performed to determine the effective dose of dicrotophos that causes at least 30 % reduction in red blood cell cholinesterase activity. The rats were injected with dicrotophos daily at LD6.25, LD12.5 and LD25 doses for 5 weeks. It was found that the LD12.5 dose caused the effect, starting at the 4th week of injection. Therefore, this dose was injected into the rats before examining the isometric twitch characteristics of gastrocnemius muscle and cholinesterase activity in red blood cells and muscle homogenates. Results: Significant decreases in peak tension and time to peak tension were observed in rats exposed to this dose of dicrotophos. These decreases agreed with cholinesterase activity in RBC and muscle homogenates. Conclusion: Dicrotophos exposure in rats caused decreased contractile activity providing direct evidence implying the muscle weakness often found in humans.

Effects of Pine Needle Butanol Fraction on Acetylcholine (ACh) and Its Related Enzymes in Brain of Rats

This study was designed to investigate the effects of buthanol (BuOH) fraction of pine (Pinus densiflora Sieb et Zucc) needle on cholesterol and lipofuscin (LF) accumulations, acetylcholine (ACh) and its related enzyme activities such as choline acetyltransferase (CAhT) and acetylcholinesterase (AChE), and monoamone oxidase-B (MAO-B) activity, which destroyed the catecholamine-related neurotransmitters in brain membranes of Sprague-Dawley (SD) rats. Male SD rats were fed basic diets (control group) or experimental diets (BuOH-25, BuOH-50 and BuOH-100) for 45 days. Cholesterol accumulations in mitochondria and microsomes were significantly inhibited (about 14 - 17% and 23 - 34%, respectvely) in BuOH-50 and BuOH-100 groups, whereas LF levels were significantly inhibited (about 10 - 14%) in BuOH-50 and BuOH-100 groups compared with control group. ACh levels and ChAT activities were significantly increased (about 11 - 17% and 11 - 23%, respectively) in membranes of BuOH-50 and BuOH-100 groups compared with control group. AChE activities were significantly increased (about 14 - 17%) in membranes of BuOH-50 and BuOH-100 groups. There was no significant difference in MAO-B activities between control and experimental diet groups. The results suggest that butanol fraction of pine needle may play an effective role in an antiaging effect and improving a learning and memory impairments.

IMMUNOHISTOCHEMICAL LOCALIZATION OF GUANINE NUCLEOTIDE BINDING REGULATORY PROTEIN IN BRAIN AND SPINAL CORD OF RAT / 解剖学报

The subunit ?_0 of guanine nucleotide- binding protein, in the areas of rat brain and spinal cord was localized by immunohistochemical methods. It was found that in the rat brain, specific ?_0-like immunoreactivity(?_0-Li) displayed regional heterogeneity, a high density of ?_0-Li revealed in neuropil, and somatic membranes as well as the neuronal processes.Most intense ?_0-Li can be seen in substantia nigra(pars reticulata), interpcduncular nucleus, habenulo-interpeduncular tract, strata oriens and radiatum of the hippocampus, and substantia gelatinosa of the spinal cord. There are also areas of moderate staining ie: the molecular layer of cerebral and cerebellar cortex, habenula, caudate-putamen complexes, the midline nuclei of thalamus and hypothalamus, periaqueductal grey, grey layers of superior colliculus, the olivo-cerebellar tract and the spinal tract of the trigeminal nerve as well. By contrast, the immunoreactvity of ?_0 in septal nuclei, globus pallidus, red nucleus, and the regions adjacent canalis centralis of the spinal cord showed much weaker. In addition, on the membranes and the processes of the neuronal cell bodies in the periaqueductal grey, substantia nigra, reticular formation, medial geniculate body and the nucleus of the trapezoid body were ?_0-Li positive.The results of AChE staining revealed that the AChE-positivc nerve terminals was coinsident with the presence of ?_0-Li in the following regions. For instance: the molecular layer of cerebral cortex, hippocampus, spinal tract of the trigminal nerve, and substantia gelatinosa of the spinal cord, where both the ?_0-Li and the AChE activity were positive. It is suggested that ?_0 subunit of Go-protein in brain might play roles in membrane signal transduction, and might have some relationship with cholinergic nerve.

INNERVATION IN THE RAT THYMUS——AN INVESTIGATION BY SILVER STAIN AND ACETYLCHOLINESTERASE HISTOCHEMICAL METHOD / 解剖学报

The innervation in the thymus was observed by silver stain and acetylcho linesterase (AChE) histochemical method. It was shown by silver stain that nerve fibers constituted a complex network in the thymic medulla. In the cortex and medulla there were AChE-containing nerve fibers. which terminated near or encircled the thymocytes. AChE-containing nerve fibers contacted with mast cells. Some mast cells had AChE-containing substance. This study suggests that the cortex and medulla of thymus are innervated by parasympathetic cholinergic nerve fibers, which may regulate the thymocytes and mast cells.

AGING CHANGES IN ACETYLCHOLINESTERASE POSITIVE NEURONS OF THE GLOBUS PALLIDUS OF THE RAT——A MORPHOMETRIC STUDY / 解剖学报

Aging changes in acetylcholinesterase positive (AChE-P) neurons of the globus pallidus were investigated histochemically and morphometrically in young (3 months old) and old (24 months old) Spragur-Dawley male rats. The number of the positive neurons in the old group is decreased by 11.8％ in comparison with the young group. The total process length of the AChE-P neurons in the young rat is approximately 1.4 times as that in the old rat. The length of about 8.6％ of the positive neurons in the old group, however, exceeds the average length of AChE-P cellls in the young group (232.1 ?m). In the old rat, the gray value of AChE-P neurons of the globus pallidus is notably higher than that in the young rat, but the value of nearly 6.8％ of the positive cells in 24-month-old rat is inferior to the average value in 3-month-old rat (117.8). The transverse dimensions of AChE-P cell bodies in the old group are increased by 9.2％ as compared to those in the young group. Morphological observations show that most of AChE-P neurons in the old rat globus pallidus represent a typical degenerative alterations, while a substantial number of the positive neurons in the old animal are characterized by enlarged bodies, strong histochemical reaction as well as dense processes and their branches. The above findings indicate that, in the old rat, a decline of AChE histochemical reactivity and the morphological degeneraton of AChE-P neurons with the advanced age do not occur synchronously in all the AChE-P neurons of the globus pallidus. Therefore, it is suggested that there probably exist a compensative mechanism in senescence of the globus pallidus.

AGE-RELATED CHANGES OF SUBSTANTIA NIGRA OF THE RAT BRAIN:Ⅱ.QUANTITATIVE ANALYTICAL STUDY ON ACETYLCHOLINESTERASE ACTIVITY BY USING IMAGE ANALYSIS SYSTEM / 解剖学报

By means of pharmacohistochemical regimen method and image analysis system,the age-related changes of acetylcholinesterase activity of the substantia nigra neu-rons and the number and size(section area)of the AChE positive neurons in ratswere investigated quantitatively.The results showed that the number of AChE pos-itive neurons in the substantia nigra of the old rats decreased markedly,the rateand quantity of AChE synthesis in the perikaryon remarkable declined.The size(section area)of the AChE positive neurons also reduced with aging.These changeswith aging have never been studied in human or usual experimental animals,so thatsome new parameters were provided for the research field in experimental geronto-logy.In human and animal,the degeneration of the neurons in substantia nigra cau-sed by aging would disturb the balance between dopaminergic and acetylcholinergicsystem and hence interfere with the normal coordination of movement.