Antihypertensive and antioxidant effects of a hydroalcoholic extract obtained from aerial parts of Otostegia persica (Burm.) Boiss

Abstract

Otostegia persica (Burm.) Boiss. is used for the treatment of various diseases in traditional medicine. The aim of this study was to assess the effects of hydroalcoholic extract of the aerial parts of O. persica in dexamethasone (Dex) induced hypertension in male Wistar rats. For induction of hypertension, Dex at 30 μg/kg/day was administered subcutaneously for 14 days. In a prevention study, animals received O. persica extract orally at various doses of 100, 200 and 400 mg/kg 4 days before Dex administration and during the test period lasted for 18 days. In a reversal study, rats received O. persica extract from day 8 to 14. Systolic blood pressure (SBP) was measured using tail-cuff method. The weight of thymus gland was measured as a marker of glucocorticoid activity. The hydrogen peroxide (H2O2) concentration and ferric reducing antioxidant power (FRAP) were determined in plasma samples. Dex injection significantly increased SBP and plasma H2O2 levels while decreased the body and thymus weights and FRAP values. Oral administration of O. persica extract prevented and dose-dependently reversed a rise in SBP. Pre-treatment with O. persica extract also reduced the plasma H2O2 concentration, increased the plasma FRAP levels and prevented the body weight loss upon Dex administration. These results suggest antihypertensive and antioxidant effects of O. persica extract in Dex-induced hypertension. However, further investigations are needed to elucidate the detailed mechanism(s) of antihypertensive effect of this traditional herbal medicine.

Keywords: Antioxidant activity; Hypertension; Otostegia persica.

Fig. 1

Effects of O. persica extract (100-400 mg/kg) and captopril (40 mg/kg) on systolic blood pressure in Dexinduced hypertension in prevention groups. Values are means ± SEM for six rats. ^##; P<0.01 and ^###; P<0.001 versus saline control group, **; P<0.01 and ***; P < 0.001 versus Dex control group.

Fig. 2

Effects of O. persica extract (100-400 mg/kg) and captopril (40 mg/kg) on systolic blood pressure in Dexinduced hypertension in reversal groups. Values are means ± SEM for six rats. ^#; P<0.05, ^##; P<0.01 and ^###; P<0.001 versus saline control group, **; P<0.01 and ***; P<0.001 versus Dex control group.

Fig. 3

Effects of O. persica extract (400 mg/kg) and captopril (40 mg/kg) on body weight in Dex-induced hypertension in prevention (Prev) and reversal (Rev) groups. Values are means ± SEM for six rats. ^#; P<0.05, ^##;P<0.01 and ^###; P<0.001 versus saline control group, *; P<0.05 and **; P<0.01 versus Dex control group.

Fig. 4

Effects of administration of O. persica (400 mg/kg) and captopril (40 mg/kg) on thymus weight in Dex-induced hypertension in prevention (Prev) and reversal (Rev) groups. Values are weights for six rats.

Fig. 5

Effects of O. persica extract (100-400 mg/kg) and captopril (40 mg/kg) on plasma H₂O₂ concentrations on Dexinduced hypertension in prevention (Prev) and reversal (Rev) groups. Values are means ± SEM for six rats. ^#; P<0.05, ^##; P<0.01 and ^###; P<0.001 versus saline control group, **; P<0.01 and ***; P<0.001 versus Dex control group.

Fig. 6

Effects of O. persica extract (100-400 mg/kg) and captopril (40 mg/kg) on plasma FRAP values on Dex-induced hypertension in prevention (Prev) and reversal (Rev) groups. Values are means ± SEM for six rats. ^##; P<0.01 and ^###; P<0.001 versus saline control group, **; P<0.01 versus Dex control group.