• BMB Reports
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• v.37 no.3
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• pp.330-338
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• 2004

Different types of cardiotoxin (I-V and n) were isolated and purified from the venom of the Taiwan cobra (Naja naja atra). The effects of these cardiotoxins were studied on membrane-bound acetylcholinesterase, which was isolated from a sheep's brain cortex. The results showed that cardiotoxins I-III, V, and n activated the enzyme by modification of substrate inhibition, but cardiotoxin IV's reaction was different. The inhibition and activation of acetylcholinesterase were linked to the functions of the hydrophobicity index, presence of a cationic cluster, and the accessible arginine residue. Our results indicate that Cardiotoxins have neither a cationic cluster nor an arginine residue in their surface area of loop I; therefore, in contrast to fasciculin, cardiotoxins are attached by loop II to the peripheral site of the enzyme. As a result, fasciculin seems to stabilize nonfunctional conformation, but cardiotoxins seem to stabilize the functional conformation of the enzyme. Based on our experimental and theoretical findings, similar secondary and tertiary structures of cardiotoxins and fasciculin seem to have an opposite function once they interact with acetylcholinesterase.

• Journal of The Korean Society of Clinical Toxicology
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• v.10 no.1
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• pp.1-7
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• 2012

Purpose: Herbal preparations have long been used for medical purposes by traditional cultures, and their use is increasing in modern societies. However, many herbal agents produce specific cardiovascular toxicities in humans. We performed this study in order to investigate the clinical characteristics of the cardiac toxicities associated with herbal remedies. Methods: We conducted a retrospective study of 45 patients (mean age $57{\pm}10$ years) who presented with cardiotoxicity between January 2007 and May 2011 due to ingestion of herbal remedy substances. Patients were identified as suffering cardiotoxicity if they presented with chest pain, EKG abnormality, and elevation of cardiac enzyme. Results: Of the 45 total cases, 17 included hemodynamic instability (37.8%), 7 with increasing cardiac enzyme (15.6%), 2 with cardiac arrest (4.4%) and one case of mortality (2.2%). The cardiotoxic herb group that demonstrated the worst clinical course was Ranunculaceae. Conclusions: In our study results, 57.6% of the herbal intoxication patients demonstrated the effects of cardiotoxicity. Thus, we recommend careful monitoring of herbal intoxication patients.