• Biomolecules & Therapeutics
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• v.13 no.1
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• pp.26-31
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• 2005

The present study examined effects of a water-soluble fraction from mulberry leaves (ML water fraction) on the circulatory and autonomic nervous systems, which were compared with those of acetylcholine (ACh) used as a reference drug in order to elucidate its mechanism of action. Intravenous administration of ACh or a ML water fraction produced temporary depressor and tachycardiac responses in a dose-dependent manner in unrestrained, conscious Sprague-Dawley rats. The systemic hemodynamic effects of ACh and a ML water fraction were almost completely blocked by pretreatment with atropine, a muscarinic antagonist. The depressor responses to ACh and a ML water fraction were slightly enhanced and prolonged by pretreatment with neostigmine, an anticholinesterase, whereas the tachycardiac responses were remarkably blocked by pretreatment with pentolinium, a ganglionic blocking agent. In vitro experiments using the ileum isolated from rats showed that ACh and a ML water fraction increased ileal contractility in a dose-dependent manner. The increases in ileal contractility were also completely abolished in the presence of atropine. Finally, the specific binding of [$^3H$]quinuclidinyl benzilate, a muscarinic antagonist, to rat cortical synaptic membranes was inhibited by a ML water fraction in a concentration-dependent manner with an IC$_{50}$ value of 9.5 mg/ml. The results suggest that the effects of a ML water fraction are mediated through direct stimulation of muscarinic cholinergic receptors by unknown cholinomimetic substance(s) contained in that fraction.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.326-332
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• 1999

Background: In korea the agricultural community widely uses organophosphorous, and organophosphorous poisonings are increasing every year. We compared change in activity of acetylcholinesterase and pseudocholinesterase by organophosphorous and by the interaction of ethanol and organophosphorous. We also compared the effect of reversible anticholinesterase drugs, physostigmine and neostigmine The object of this study is to investigate the effects of several anticholinesterase drugs and on how ethanol influences the activity of cholinesterase. Materials and Methods: Fifteen male university students were randomly selected, and blood samples were taken from the antecubital vein. The acetylcholinesterase in the RBC and the pseudocholinesterase in the serum were extracted and separated. The enzyme activity change was measured by the electrometric method. After adding acetylcholine, the pH change was measured with a pH meter. Results and Conclusion: Our results indicated that reversible anticholinesterase drugs decreased the cholinesterase activity more efficiently than organophosphorous. The acetyl cholinesterase and pseudocholinosterase activity were decreased by ethanol. When ethanol was added, oxime a cholinesterase activator, increased acetylcholinesterase activity but does not increased pseudocholinesterase activity.