THE INOTROPIC AND CHRONOTROPIC EFFECTS OF AQUEOUS ETHANOLIC EXTRACT FROM TEUCRIUM POLIUM L. ON GUINEA PIG ISOLATED HEART

BACKGROUND AND OBJECTIVE: Teucrium polium L. (TP) is widely used in traditional medicine. There are some reports on antidiabetic, antihyperlipidemic and antibacterial effects of TP. The aim of this study was to investigate the inotropic and chronotropic effects of aqueousethanolic extract from TP on guinea pig isolated heart. METHODS: In this experimental study, 24 Dunkin Hartley guinea pigs weighted 350-450 g were used. The animals randomly divided into three groups (8 in each group): group 1 which the heart perfused by Krebs solution, group 2 which the heart perfused by Krebs calcium free solution and group 3 which the heart perfused by Krebs+diltiazem solution. The heart isolated after the aorta cannulated and connected to Langendorff setup. Three concentration of aqueousethanolic extarct from TP were infused to the heart for 1 minute. The heart rate and contractility recorded by computer. FINDINGS: The TP extract increased significantly the heart rate (HR) and contractility in all three groups. This effect was not concentration dependent. Comparing mean percent changes of HR and contractility between three groups showed a significant difference between groups 1 and 3 and also between groups 2 and 3, but the difference between groups 1 and 2 was not significant. CONCLUSION: The aqueous ethanolic extract from TP has a positive chronotropic and inotropic effects on guinea pig isolated heart. The extract has an agonistic effect on L-type calcium channels