• Food Science and Biotechnology
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• v.16 no.2
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• pp.265-269
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• 2007

There is significant interest in finding new sources of acetylcholinesterase (AChE) inhibitors for use in treating Alzheimer's disease, since only a few AChE inhibitors are available for clinical use, such as galanthamine, physostigmine, and tacrine. The ethanol extract of Chrysanthemum indicum Linne flowers was analyzed and found to markedly decrease AChE activity. Acaciin and $acacetin-7-O-{\beta}-D-galactopyranoside$ were identified as the active compounds responsible for the AChE inhibition by using an activity-guided fractionation strategy. The relationship between structure and activity for five flavonoids (acaciin, $acacetin-7-O-{\beta}-D-galactopyranoside$, luteolin, and two other commercially available flavonoids, i.e., apigenin and acacetin) was also investigated, revealing that the presence of methoxy groups at C-4' in the B ring and a sugar at O-7 in ring A appear to be essential for the inhibition of AChE.

• Applied Microscopy
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• v.27 no.2
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• pp.131-144
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• 1997

The present study was carried out to investigate the processes of the ultrastructural differentiation and the acetylcholinesterase (AChE) activities of the developing rat retina. The results are as follows. The retina of fetal rat on the 13th day of gestation showed the early stage of differentiation. Briefly, there appeared dividing chromosomes, the plentiful free ribosomes, and the high ratio of nucleus to cytoplasm. The reaction products by AChE were localized at the membrane of endoplasmic reticulum and on the outer membrane of nucleus. Ultrastructures and AChE activities in the retina of the fetal rats on the 18th day of gestation were similar to those of the prior stages, except the appearence of rough endoplasmic reticulum and Golgi apparatus. According to the ultrastructural observations, the rat retina was still in immature state at birth, but the pigment epithelial cells were fully differentiated, e. g. the increase of melanin granules, the development of mitochondria and Golgi apparatus. The AChE activity was weekly detected. The differentiated retinal layers and the outer segment of photoreceptor cells were observed on the 7th postnatal day. And the pigment epithelium appeared to be fully differentiated. On the 14th postnatal day, rat retina were completely differentiated. In other words, the rat retina was characterized by the prominent outer segments, phagocytosed residues in the pigment epithelium, and the localization of reaction products by AChE in the synapses. In conclusion, the differentiation of rat retina is charaterized by the changes of cell shape, the increase of retinal layers, and the alterations of AChE activities. It seems that rat retina is to be functional from 2 weeks of birth onward, coinciding with the eye opening of the juvenile rats.

• Food Engineering Progress
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• v.15 no.4
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• pp.289-296
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• 2011

Twenty four fractions by solvent extraction and/or acid precipitation from fruit body and culture broth of Inonotus obliquus were prepared, and their inhibitory effect against acetylcholinesterase (AChE) was investigated. Among these fractions, acid (1 M HCl) precipitates from cell-free culture broth and fruit body exhibited the highest inhibitory effect on AChE in vitro. Acid precipitates inhibited AChE activity in a concentration-dependant manner and $IC_{50}$ values of both acid precipitates were 0.53 mg/mL. The inhibition pattern was general non-competitive inhibition. The energetic parameters were also determined by dual substrate/temperature design. Both acid precipitates increased the values of Ea, ${\Delta}H,/;{\Delta}G$ and ${\Delta}H^{\ast}$ decreasing the value of ${\Delta}S$ for AChE. The results implied that the acid precipitates from I. obliquus increased the thermodynamic barrier, leading to the breakdown of ES complex and the formation of products as inhibitory mechanism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.3
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• pp.427-432
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• 2005

This study was performed to investigate the effect of natural plant extracts on acetylcholinesterase (AChE) activity and the free radical scavenging activity. The methanolic extracts of plants were tested for AChE inhibitory activity using Ellman's colorimetric method in 96-welled microplates and antioxidant activity as the scavenging effect of 1, 1-diphenyl-2-picryl hydrazyl radical (DPPH). The results showed that AChE activities were inhibited (about 20-30%) in whole plant extract of Daucus carota var. sativa, Hypericum erectum and Fragaria yezoensis. AChE activities were inhibited (about 32-34%) in stems extract of Gingko biloba and leaves extract of Rhododendrondron yedoensa var. poukhanense. Fruit extract of Zanthoxylum schinifolium inhibited (about 18%) AChE activity. And the DPPH scavenging effects as antioxidant activity were similar to L-ascorbic acid in whole plant extract of Fragaria yezoensis and fruits extract of Comus officinalis.

• Korean Journal of Environmental Agriculture
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• v.6 no.2
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• pp.77-83
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• 1987

Present study was carried out to elucidate the effect of phorate (0,0-dietyl S-ethylthiomethyl phosphorodithioate), an organophosphorus insecticide on the acetylcholinesterase(AChE) and cholinesterase(ChE) activity in the chicken brain and plasma. The inhibitory effect of phorate and its metabolites on AChE and ChE activity was also increased in the order of phorate (p=S,S)$(p=S,SO_2)<phoratoxon$ (p=O,S)$(P=O,SO_2)$. Acute oral $LD_{50}$ of phorate was 1.02mg/kg. After oral administration of phorate, the activity of plasma ChE was inhibited more rapidly then that of brain AChE, whereas recovery of plasma ChE activity was more rapid than that of brain AChE activity.

• Korean Journal of Plant Resources
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• v.30 no.1
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• pp.17-21
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• 2017

Since the acetylcholinesterase (AChE) inhibitor is used to treat Alzheimer's disease, the present study aimed to analyze the component with anti-AChE activity from the essential oil of Artemisia iwayomogi (Compositae). The four major components of the essential oil were identified to be camphor (29.8%), borneol (28.0%), eucalyptol (5.81%) and coumarin (5.49%) from a gas chromatography-mass spectrometry (GC-MS). The essential oil and its three components, camphor, borneol, and coumarin, were subjected to anti-AChE assay. The $IC_{50}$ values of the essential oil and coumarin were shown to be $0.298mg/m{\ell}$ and $0.236mg/m{\ell}$, though those of other two components, camphor and borneol, were more than $0.250mg/m{\ell}$. These results suggest that coumarin is an active substance of this essential oil with anti-AChE activity.

• Korean Journal of Pharmacognosy
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• v.33 no.3 s.130
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• pp.211-218
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• 2002

The methanol extracts of 340 kinds of Korean medicinal herbs were examined in vitro for the inhibitory effect on the acetylcholinesterase (AChE, E.C. 3.1.1.7) from electric eel using acetylthiocholine as a substrate. Among tested, the extracts of Coptidis Rhizoma, Phellodendri Cortex, Evodiae Fructus, Myrrha, Arecae Semen and Piperis nigri Fructus were found to exhibit a significant inhibition upon the acetylcholinesterase in a dose dependent manner, respectively.

• Environmental Analysis Health and Toxicology
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• v.17 no.3
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• pp.265-272
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• 2002

This study was carried out with the detection for multiresidue of the organophosphorus pesticides such as malathion, parathion. diazinon, and carbamate pesticide such as carbaryl, by enzyme-inhibition method. The acetylcholinesterase (AChE) and cholinesterase (ChE) activities in chicken brain determined by the Ellman's method were 166.6 and 5.8 $\mu$mol/min/g protein, and in chicken plasma were 23.1 and 8.3 $\mu$mol/min/g protein, respectively. The optimum pH of AChE and ChE was 8.2 and 7.8, respectively. The Km of AChE and ChE was 0.034 and 0.045 mM, respectively. I$\_$50/ for AChE and ChE by some organophosphorus was 55.82 and 99.42 mg/L of malathion, 31.16 and 29.13 mg/L of parathion, and 17.89 and 19.62 mg/L of diazinon, respectively. I$\_$50/ for AChE and ChE by carbaryl of carbamate was 0.10 and 0.05 mg/L, respectively. The 0.07 mg/L of drinking water advisory level for carbaryl could be detected with I$\_$50/ of AChE and ChE. Enzyme-Inhibition (EI) method with AChE and ChE was used the multiresidue method to detect the 1 mg/L of the carbamate pesticides.

• BMB Reports
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• v.43 no.8
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• pp.573-578
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• 2010

Several organophosphorus (OP) insecticides can selectively kill the silkworm maggot, Exorista sorbillans (Es) (Diptera: Tachinidae), while not obviously affecting the host (Bombyx mori) larvae, but the mechanism is not yet clear. In this study, the cDNA encoding an acetylcholinesterase (AChE) from the field Es was isolated. One point mutation (Gly353Ala) was identified. The Es-353G AChE and Es-353A AChE were expressed in baculovirus-insect cell system, respectively. The inhibition results showed that for eserine and Chlorpyrifos, Es-353A AChE was significantly less sensitive than Es-353G AChE. Meanwhile, comparison of the I50 values of eserine, dichlorvos, Chlorpyrifos and omethoate of recombinant Es AChEs with its host (Bombyx mori) AChEs indicated that, both Es AChEs are more sensitive than B. mori AChEs. The results give an insight of the mechanism that some OP insecticides can selectively kills Es while without distinct effect on its host, B. mori.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.174-178
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• 1995

The purpose of this study was to investigate a role of cytochrome $P_{450}$, for the toxicity of the phosalone in in vitro and in vivo bioactivation systems. The bimolecular inhibition rate constants$(k_i)$ of the phosalone to acetylcholinesterase(AChE) and butyrylcholinesterase(BuChE) were approximately $10^2M^{-1}{\cdot}min^{-1}$, respectively, which meant a poor inhibitor. The potency of the phosalone as an inhibitor of AChE and BuChE was increased about 300 and 40 fold, respectively, when the inhibitor and the ChE were incubated with microsomes fortified with NADPH compared with microsome alone. Piperonyl butoxide(PB) addition to these coupled systems greatly reduced the inhibition of both target enzymes by blocking a bioactivation process. The $I_{50}$ value of the Phosalone alone for rat brain AChE was 170 mg/kg. When PB was pretreated, that value was altered to 42.5 mg/kg. PB pretreatment synergized the inhibition of brain AChE with four times. Rat blood erythrocyte AChE and plasma BuChE were similarly inhibited in vivo by the phosalone and PB pretreatment didn't affect significantly the pattern of the inhibition. The in vivo studies showed different results in the role of cytochrome $P_{450}$ from those of the in vitro studies.