Cardiovascular effects of five native plants from southern of Khorasan State

Background: Traditionally, medicinal plants have been used to treat many diseases. To
investigate the effects of different plants extract on cardiovascular system, five native southern
Khorasan plants were used. Different concentration from the decoction of ziziphora, achillea
millefolium (A.M) and aqueous extract of valeriana officinalis (V.O), viola and peganum harmala
(P.H) were made.
Methods and Materials: Animals, Male Sprague Dawley rats (200-250 g, n=25) were
anaesthetized with sodium thiopental (30 mg/kg, i.p.), then systemic arterial blood pressure
(systolic, diastolic and mean) was measured.
Results: Mean arterial blood pressure was 140 ± 5 mmHg. Intravenous administration of
extract reduced the arterial blood pressure (eg. administration of 0.03 mg/kg of aqueous extract of
valeriana officinialis changed the blood pressure from 140 ± 5 to 77 ± 10 mmHg, P<0.0001). There
was a non-significant bradycardia with the administration of this extract. These results show that
extract of ziziphora, V.O and A.M have hypotensive effects in the control rats and the most potent is
V.O.
Conclusions: By attention to non significant effect of these extract on heart rate, it is suggested
that their hypotensive effect is induced by depletion in peripheral vascular resistance. For
investigate of possible mechanism on vascular resistance, the isolated thorasic aorta rings in male
rat were used. Therefore in another sets of experiments, after measuring blood pressure, chest was
expanded and thoracic aorta was removed and cut into rings (3-4 mm). Aqueous extract of V.O, in
isolated aortic rings which was contracted by phenyl ephrin relaxed. Incubation of tissue with LNAME
(10-5 molar) for 20 minutes significantly increased the response to different concentration of
extract. Thus the vasodilatory mechanism of V.O is nondependent endothelium manner but it
accomplish by vascular smooth muscle relaxation. In future, the effects of these extracts will be
studied in the hypertensive rats, so that in case obtaining the same results and safety proof, these
extracts on other systems, we can recommend take of these plant accompaniment by other
treatment.