4.4. Hypertensive Animal Model

To induce HT, 12 8-week-old male Wistar rats, weighing 250 g, were treated with N-nitro-L-arginine methyl ester (L-NAME; 40 mg/kg/day) [45,46]. Four rats receiving distilled water comprised the control group (without HT). After 6 weeks of treatment, BP of rats was determined using a non-invasive blood pressure device (NIBP); pulse signals were digitized using the LabChart 7 software (ADInstruments, Dunedin, New Zealand). Rats were considered hypertensive if a systolic blood pressure (SBP) ˃ 300 mmHg was recorded. Groups consisting of four animals each were formed, and antihypertensive treatments were initiated. These treatments consisted of daily administration (during 4 weeks) of: group (A), captopril (50 mg/kg) [39]; group (B), EESH (200 mg/kg) and group (C), without antihypertensive treatment (considered as the group with HT). In all groups, daily administration of L-NAME (40 mg/kg) continued until the end of the study. The last group (group D: rats with normal BP) served as the control, without HT. The SBP was measured after 4 weeks of antihypertensive treatment. Rats were euthanized by the guillotine decapitation method, following the guidelines of the Guide to the Care and Use of Experimental Animals of the Canadian Council on Animal Care (CCAC 1998).