The effect of calcium blocker activity on vasorelaxant of Teucriumpolium extract on rat isolated aorta

Background: Teucrium polium (TP) is a herbaceous plant of the Lamiaceae family which has many
pharmacological properties such as anti-diabetic, anti-inflammatory, anti-nociceptive effects. There are some reports indicating the cardiovascular effects of TP such ashypotensive responses and also positive inotropic and cronotropic effects. The aim of this study was to investigate the activity of calcium channels on vaso relaxant extract of TP on isolated rat aorta.
Methods: In this experimental study, 28 male Wistar rats randomlywere divided into 4 groups (n= 7). In groups 1 and 2, the effect of the extract (1, 2, 4 and 8 mg/ml) on contracted aorta by PE (10-6 M) in intact and denuded endothelium were investigated. In groups 3 and 4, the effect of the extract on contracted aorta by PE in the presence of Diltiazem (Dil), (10-5 M) and Heparin, (50 mg/ml) were investigated respectively.Statistical analysis was carried out by SPSS software version 13 and the results were analyzed by student's t-test and ANOVA.
Results: The extract significantly relaxed the contracted aorta by PE in both intact and denuded endothelium in concentration-dependent manner (P<0.001 ،P=0.002). All the extract concentrations (except 1, 2 mg/ml)
significantly relaxed PE induced contraction in the presence of Dil (P<0.001). The extract concentrations (except 1, 2 mg/ml) significantly relaxed PE induced contraction in the presence of Heparin (P<0.001).
Conclusion: The extract of TP has the relaxation effect on vascular smooth muscle. It seems, the relaxation was mediated by inhibition of voltage-and receptor-dependent Ca+2channels and may partly by inhibition the release of calcium from intracellular stores in vascular smooth muscle cells.