Magnolol Reduces Infarct Size and Suppresses Ventricular Arrhythmia in Rats Subjected to Coronary Ligation

Abstract

1. Magnolol is an active component of Magnolia officinalis. It is 1000-times more potent than alpha-tocopherol in inhibiting lipid peroxidation in rat heart mitochondria. In the present study, the in vivo antiarrhythmic and anti-ischaemic effects of magnolol in coronary ligated rats were investigated. 2. Male Sprague-Dawley rats were anaesthetized with urethane. Magnolol, at dosages of 10(-7), 10(-8) and 10(-9) g/kg, was administered intravenously 15 min before ligation of the coronary artery. 3. The incidence and duration of ventricular tachycardia and ventricular fibrillation during 30 min coronary ligation were significantly reduced by magnolol. Ventricular arrhythmias during 10 min reperfusion after the relief of coronary ligation were also reduced. 4. In rats subjected to 4 h coronary ligation, 10(-7) and 10(-8) g/kg magnolol significantly reduced infarct size. 5. We conclude that magnolol may protect the myocardium against ischaemic injury and suppress ventricular arrhythmia during ischaemia and reperfusion.

Antiarrhythmic Effect of Magnolol and Honokiol during Acute Phase of Coronary Occlusion in Anesthetized Rats: Influence of <i>L</i>-NAME and Aspirin

“…Both were demonstrated to be 10,000 times more potent than vitamin E in inhibiting lipid peroxidation in rat mitochondria [4]. The antioxidant effect could be the main mechanism in suppressing ventricular arrhythmia resulted from reperfusion injury [7,8] and to a lesser extent in ischemic injury. Magnolol and honokiol were reported to possess vasorelaxant effect [6].…”

“…Traditional Chinese medicinals, magnolol and honokiol purified Tsai/Huang/Huang/Hung/Hong from Magnolia officinalis, were reported to have oxygen-derived free radicals scavenging activity [4,5] and vasodilator effect [6]. Previously, we described a marked myocardial protective effect of magnolol and honokiol against arrhythmia and in reducing the infarct size in rats subjected to coronary occlusion [7,8]. The antioxidant effect can be attributed to scavenging the free radicals, which are formed during reperfusion injury.…”

“…10 -3 % (v/v) which had been shown to have no effect on ischemia-induced ventricular arrhythmia at such a concentration. 0.3 ml magnolol or honokiol solution were administered at 10 -7 g/ kg, a dose with the maximal cardiac protective effect from the result of a previous study [7,8], by intravenous injection at 15 min before the coronary occlusion was used as control. Magnolol and honokiol pretreated with L-NAME 1 mg/kg (Sigma) or D-NAME 1 mg/kg (Sigma) or aspirin 100 mg/kg (Sigma) at 5 min before injection was used for a study group.…”

Effect of Magnolol onin VitroMitochondrial Lipid Peroxidation and Isolated Cold-Preserved Warm-Reperfused Rat Livers

“…We recently found that magnolol isolated from Magnolia officinalis was 1000 times more potent than ␣-tocopherol in inhibiting lipid peroxidation induced by FeSO 4 in rat heart mitochondria [12]. Magnolol also suppressed ventricular arrhythmia and reduced infarct zone in coronary ligated rats [13]. Previously, transplantation injury has been hypothesized as a consequence of reperfusion injury rather than ischemic injury.…”

Magnolol Encapsulated by Liposome in Inhibiting Smooth Muscle Cell Proliferation

“…17,18 It could inhibit the cell growth at lower concentrations, 19 whereas it induces cell apoptosis at higher concentrations. 20,21 Therefore, magnolol was expected to be a pharmacological approach for restenosis by inhibiting VSMC proliferation. 22,23 Small unilamellar vesicles (SUVs) are vesicles with the membrane composed of phospholipid bilayers.…”