• Korean journal of applied entomology
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• v.30 no.1
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• pp.18-28
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• 1991

The optimal pH of the extraction buffer was 7.5 considiering AChE stability and its buffer capacity when AChE was isolated and extracted from the housefly(Musca domesitca L.)and three other insect species with 0.01 M sodium phosphate buffer. Also, the optimal pH of the reaction buffer was 7.5 considering enzyme activity and its buffer capacity when AChE activity was measured with the substrate in 0.1 M sodium phosphate buffer. The Potter Elvehjem type homogenizer with Teflon pestle was used to homgenize the tissues. When preparing a AChE suspension by centrifuging the homogenate, 700 g supernatant of adult head for the housefly, 700 g supernatnat of 5th instar nymphal whole body for the brown planthopper, lipid-eliminated 10,000 g supernatant of 5th instar larval whole body for the diamondback moth, and 700 g supernatant of 4th instar larval head for the tobacco cutworm were considered satisfactory as enzyme sources in view of mass preparation, extraction efficiency and stability of enzyme activity during evaluation. When AChE suspensions of 4 insect species were stored at $-18^{\circ}C$, more than 90% of activity was maintained up to 3 weeks. Km values of AChEs of the housefly, the brown planthopper, and the diamondback moth were 0.042, 0.037 and 0.043 mM, respectively and AChE-specific substrate inhibition was observed at high concentration. Km value of the tobacco cutworm ChE was 1.15 mM and BuChE characteristics was observed, though further study is needed. The optimal substrate concentration for the AChE inhibition tests was 0.5 mM for the housfly, the brown planthopper, and the diamondback moth and 12 mM for the tobacco cutworm.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.1
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• pp.73-78
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• 2000

We investigated some biochemical properties of acetylcholinesterase (AChE) in the Bombyx mori larval head. 1% Triton X-100 (v/v) was suitable for extracting AChE from the silkworm larval head but 1 M NaCl was not suitable. PAGE analysis showed a single band of AChE that was detected by histochemical staining using acetylthiocholine as a substrate. AChE was also partially purified with Sepharose 6B and DEAE-cellulose column. Finally, the specific activity of partially purified enzyme solution was 7.6. The study on inhibitor specificity indicated that the enzyme under study was a true cholinesterase (ChE) or AChE. AChE activity was maximum at the substrate concentration of $5{\times}10^{-4}$ M and the excess substrate inhibited the AChE activity. The optimal pH and temperature were pH 7.0-9.0 and 30-35$^{\circ}C$.

• Journal of Nutrition and Health
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• v.28 no.8
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• pp.706-716
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• 1995

This study was undertaken to investigate the influence of age and dietary linolenic acid content and the linolenic acid/linoleic acid (LAN/LA) ratio on the brain lipid composition and membrane-bound enzyme, acetylcholinesterase(AchE) activities. AchE was selected as a test case for the relationship between cell lipid composition and cell membrane function. The male rats were fed diets with 0.2, 0.4, 0.6 of LNA/LA ratio within 8% LNA(H-LNA) or 4% LNA(L-LAN) of total fatty acid content for different feeding period(1, 4, 12 month). The fats used s source were sesame oil, perilla oil, soybean oil and beef tallow. The AchE activity of brain crude synaptosomal fraction was reduced with advancing age, showing 20-30% reduction in 12M compared with 1 M, and the P/C ratio was reduced in old rats. In 1 and 4 monthed rats, AchE activites was higher in H-LAN-0.2 and L-LNA-0.2 and 0.4 group. In accordance with rising of AchE activities was higher in H-LNA-0.2 and L-LNA-0.2 and 0.4 group. In accordance with rising of AchE activities, the PC/PE ratio increasedin those groups. Paricularly in L-LNA, the PC/PE ratio increased as the AchE activites for decline of membrane fluidity with increasing cholesterol and decreasing P/C ratio when rats were old. Also, AchE activity increaed with increasing PC/PE ratio which depended on the dietary LNA/LA ratio within each LNA content. Therefore, it is concluded that the lipid composition of cell membrane influenced the AchE activiteis, which was mediated by aging and the modification of dietary LNA/LA ratio.

• Bulletin of the Korean Chemical Society
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• v.27 no.3
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• pp.395-398
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• 2006

Nerve agents (sarin, tabun, soman and VX) are class of military important substances able to cause many severe intoxications during few minutes. Currently, the threat of misuse of these agents is daily discussed. Unfortunately, there is no single antidote able to treat intoxication caused by all of these agents. Owing to this fact, new generation of antidotes, especially acetylcholinesterase (AChE; EC 3.1.1.7) reactivators, is still developed. In this study, we have tested four newly developed AChE reactivators: 1-(4-hydroxyiminomethylpyridinium)- 5-(4-carbamoylpyridinium)-3-oxa-pentane dibromide (1), 1-(3-hydroxyiminomethylpyridinium)-5-(4-carbamoylpyridinium)-3-oxa-pentane dibromide (2), 1,5-bis(2-hydroxyiminomethylpyridinium)-3-oxa-pentane dichloride (3) and 1,5-bis(4-hydroxyiminomethylpyridinium)-3-oxa-pentane dibromide (4) for their potency to reactivate in vitro tabun and cyclosarin-inhibited AChE. Their reactivation efficacy was compared with currently the most promising oxime HI-6 (1-(2-hydroxyiminomethylpyridinium)-3-(4-carbamoylpyridinium)-2-oxa-propane dichloride). According to obtained results, two AChE reactivators 1 and 4 were able to reactivate tabun-inhibited AChE. On the contrary, there was no better AChE reactivator than HI-6 able to reactivate cyclosarin-inhibited AChE.

• 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.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.817-819
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• 2002

In the course of screening Korean natural products for acetylcholinesterase (AChE) inhibitory activity, it was found that a methanolic extract of the aerial parts of Corydalis incisa (Papaveraceae) showed significant inhibitory effects on AChE. Corynoline isolated from this plant inhibited AChE activity in a dose-dependent manner, and the $IC_{50}$ value of corynoline was $30.6{\;}{\mu}M$. The AChE inhibitory activity of corynoline was reversible and noncompetitive.

• Korean journal of applied entomology
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• v.31 no.2
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• pp.122-132
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• 1992

Experiments were conducted to establish an in vitro AChE inhibition test system to evaluate the potency of AChE inhibition of new chemical compounds. For a fixed time inhibition test, optimal inhibition (incubation) time to evaluate their AChE inhibition potency was 10 min. for AChE inhibitors such as DFP, DDVP, and paraoxon. The concentration of new chemical compounds with an ester group for evaluation of their inhibition potency was 10 $\mu$M under 10 min. preincubation conditions. However, the stepwise inhibition test with higher concentrations seemed to be needed for other chemical compounds. For a progressive inhibition test to calculate inhibition constants such as $K_d$, $K_3$ and $K_i$, extremely low $K_d(1.3\times10-^85.6\times10^{-7})$ and $K_3$(0. 21-0.27 $min^{-1}$) were observed under lagged preincubation time (0.8-13.3 min) and low in¬hibitor concentrations $(1\times10-^92\times10-^6M)$. However, this method seemed to be useful for comparison of AChE inhibition potency among inhibitors. Differences in inhibition potency among DFP, paraoxon, and KH501 were due to the differences in $K_d$, in other words, differences in affinities between inhibitors and AChEs. Therefore, AntiChE screening should consist of two steps. The first step is to evaluate the potency of AChE inhibition based on $I_50$ valuse obtained from fixed time inhibition tests. The second step is to study inhibition patterns and characteristics of chemical compounds selected in the first step.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.447-451
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• 2012

In order to investigate the efficacies for cognitive function of edible plants, we measured the inhibitory effects of acetylcholinesterase(AChE) activity, radical scavenging activities, and the contents of GABA and glutamate in the plant extracts. Among the plant extracts, Schizandra chinensis contained the highest GABA 14.8 mg/g and the extracts of Cnidium officinale and Polygonum multiflorum also had a relatively high GABA. On the other hand, plant extracts except, Acorus gramineus, showed similar glutamate contents. S. chinensis, Hovenia dulcis, Thuja orientalis, and Eleutherococcus senticosus exhibited high inhibition against AChE activities at about 18-33% at 1 mg/mL. In addition, strong radical scavenging activities were also detected in those extracts which showed high AChE inhibition. Taken together, H. dulcis, T. orientalis, E. senticosus, and S. chinensis could be effective resources for enhancing cognitive function. Further, it was suggested that the AChE inhibitory activities of plant extracts might be related to antioxidative activity.

• 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.