Introduction & Objective: Cardiovascular diseases are main causes of mortality and morbidity in the current world. Hypertension is one of the most important risk factors for the cardiovascular diseases. Herbal medicine is much regarded because of their natural source and less side effects. This study was done to evaluate the effects of hydro- alcoholic extract of Luctuca-Sativa (LS) on blood pressure in rats.

Materials & Methods: Hypertension was induced in the rats by Desoxycorticosterone (DOCA)-Salt then the hypertension induction was confirmed by tail-cuff method before treatment. The effects of one week treatment by LS hydro-alcoholic extract (100 mg/kg/day) on blood pressure Heart Rate (HR) and Plasma Renin Activity (PRA) were investigated and compared with the control groups. Under anesthesia (urethane 1gr/kg) Mean Arterial blood Pressure (MAP) and HR were measured directly from Femoral Artery. In order to investigate the extract effects on MAP and HR, also possible mechanisms of these effects, intravenous injection of different concentrations of extract with and without pretreatment with histamine H1 receptor antagonist (Chlorpheniramine 10 mg/kg ) were performed. PRA was measured by radioimmuonoassay method. Urine volume was also measured during the treatment

Results: The results of this study show that DOCA-Salt induced hypertension and decreased PRA in the rats. LS hydro- alcoholic extract treatment causes significant decrease of MAP in hypertension- treated group in comparison with non-treated group and also the level of PRA and urine volume increased by extract treatment. Our Findings showed that LS extract has no significant effect on HR.

Conclusion: The results of this study indicated hat LS hydro- alcoholic extract due to interaction with kidney and diuretic effects decreased MAP and normalized PRA in the DOCA- Salt hypertensive.