The effect of hydro-alcoholic extract of Glycyrrhiza glabra on the cardiovascular system of male rats with normal blood pressure and its interaction with cholinergic and adrenergic systems

Glycyrrhiza glabra (Licorice) has been traditionally used as a medicinal plant in Iran for treatment of diseases such as gastric ulcer and arthrosclerosis. In this study, in order to determine some of its mechanisms, effects of hydroalcoholic extract of Glycyrrhiza glabra was examined on the blood pressure in rats. Adult male rats were anesthetized via injection of pentobarbital sodium, then the femoral vein and the femoral artery were canulated for injections and blood pressure recordings, respectively. Blood pressure and heart rate were recorded by pressure transducer linked to A-D instrument power lab. Tested groups were as follows: The first group, received Glycyrrhiza glabra extract (90mg/kg) and equivalent volume of the Licorice solvent (ethanol %70). The second group received Glycyrrhiza glabra extract and acetylcholine (0.01 mg/kg). The third group received Glycyrrhiza glabra extract and epinephrine (0.04 mg/kg). The data showed a significant decrease of blood pressure (mean blood pressure, systolic and diastolic pressure) in the presence of licorice extract, licorice and epinephrine, licorice and acetylcholine compared to the control condition. It can be concluded that Glycyrrhiza glabra has a hypotensive effect on blood pressure via modulation of adrenergic system and synergistic effect with cholinergic system.