Study of the Antihypertensive and Vasorelaxant Activities of Haloxylon scoparium in Rats

Aims: The work aimed to study the antihypertensive ability of Haloxylon scoparium. Background: Haloxylon scoparium Pomel is used to treat various diseases, including hypertension. Objective: This study aimed to evaluate the antihypertensive effect of Haloxylon scoparium (H. scoparium) in hypertensive rats, and to evaluate its probable vasorelaxant activity. Materials and Methods: The aqueous extract of Haloxylon scoparium (AEHS) was prepared and used to investigate its antihypertensive ability in L-NAME(Nω-L-arginine methyl ester)-induced hypertensive rats, and its vasorelaxant activity was studied on the isolated thoracic aorta of rats. The acute and subchronic effects of (AEHS) on blood pressure parameters were evaluated after oral administration of AEHS (60 and 100 mg/kg body weight) for 6 h for the acute experiment and for 7 days for the subchronic test. Results: The results indicated that AEHS decreased blood pressure parameters (systolic, mean, and diastolic blood pressure) after repeated oral administration in hypertensive rats without affecting normal rats. In addition, AEHS (375-1250 μg/mL) revealed a vasorelaxant effect in thoracic aortic rings precontracted with norepinephrine (NE) (10 μM) or KCl (80 mM). This effect was partially decreased in the presence of nifedipine by inhibition of the vascular calcium channel pathway in isolated rat thoracic aorta. Conclusion: The study demonstrates the beneficial effect of Haloxylon scoparium as an antihypertensive agent. Moreover, this plant exerts vasorelaxant activity via the blockade of Ca²⁺ channels.