主催: The Japanese Pharmacological Society, The Japanese Society of Clinical Pharmacology
会議名: WCP2018 (18th World Congress of Basic and Clinical Pharmacology)
開催地: Kyoto
開催日: 2018/07/01 - 2018/07/06
BACKGROUND: Bauhinia championii (Benth.) Benth. (BC) also knownas chu-hua-mu, is one of the commonly used medicinal herbs in Taiwan. The stemof this plant has been used in treatment of different pains and rheumatoidarthritis. With known nociceptive action, it may have potential to alternate thecharacteristics of different ion channels. Therefore, this study aims toinvestigate the effect of boiling water extracts of BC on cardiac arrhythmia andmyocytes lose in an isolated mice heart model.
MATERIALS AND METHODS: Isolated hearts from 8-12 weeks male C57BL/6JNarl micewere performed with ischemia (30 min)/reperfusion (60 min) (I/R) by LAD ligationon Langendorff-perfused apparatus. Lead II electrocardiogram (ECG) was alsocontinuously monitored. BC (10 mg/L) was pretreated 15 min before reperfusion.After reperfusion, hearts were removed for infarct size analysis by2,3,5-triphenyltetrazolium chloride (TTC) assay. To further determine theunderlying mechanism, ventricular myocytes of mice were enzymatically isolatedand then action potential, sodium current (INa),L-type calcium current (ICa), and transient outwardpotassium current (Ito) were recorded using thewhole-cell patch clamp technique.
RESULTS: BC not only decreased the frequency and duration of different types ofventricular arrhythmias, but also reduced infarct size induced by I/R.I/R-induced oxidation of Ca2+-calmodulin-dependent protein kinase(CaMKII) triggers myocardial necroptosis (myoglobin release), but when BC waspresence, they are all decrease. By patch clamp technique in current-clamp mode,we found maximum rise slope of action potential was reduced by BC treatment. Onthe other hand, the current density of INa, but notICa and Ito wassignificantly decreased by BC in voltage-clamp mode.
CONCULSION: The present study indicates that BC may prevent I/R-inducedventricular arrhythmias by inhibiting sodium channel. Since most of the clinicalantiarrhythmic remedies have their own serious side effects, to develop a noveltherapeutic agent for lethal arrhythmia is still needed. BC, in this concern,will be a new candidate for the treatment of myocardial infarction andventricular arrhythmia.
