Twenty eight patients who satisfied the entry criteria and had completed an initial 2 weeks treatment with placebo were titrated fortnightly with doses of Nicardipine ranging from 30 mg to 90 mg daily in two or three divided doses. Nicardipine treatment significantly reduced blood pressures both in the supine and standing positions (p < 0.0004) when compared with placebo treatment. Heart rates however did not change significantly. Forty six percent (13/28) of patients on 20 mg twice daily, 25% (7/28) on 10 mg three times daily, 18% (5/28) of patients on 20 mg three times daily and 11% (3/28) on 30 mg three times daily achieved supine diastolic blood pressures < 90 mm Hg. Nicardipine treatment at 16 weeks and at 24 weeks did not significantly alter the lipid profile when compared to the end of placebo treatment period. No other biochemical abnormalities were reported during the study period. Except for 2 cases of mild pedal oedema and 2 cases of transient headaches, no serious side-effects were encountered.
Nicardipine has been shown to have an anti-atherogenic effect in rabbits given a 2% cholesterol diet. Current evidence suggests that lipid peroxidation plays an important role in atherogenesis. This study examines the effect of nicardipine on lipid peroxidation in rabbits given a 2% cholesterol diet, 8 of these rabbits given nicardipine 0.5 mg/kg twice daily intramuscularly for ten weeks while the remaining untreated 6 were controls. After ten weeks, serum malondialdehyde in the control group was significantly higher compared to their baseline levels (P < 0.05). However, there was no increase in serum malondialdehyde in the nicardipine group after 10 weeks. The area of Sudan IV positive intimal lesions (atherosclerotic plaques) were significantly decreased (P < 0.01) in the treated group compared to the control group. The aortic tissue content of cholesterol and diene conjugates were also decreased in the nicardipine group (P < 0.01). These findings suggest a possible link between nicardipine and lipid peroxidation in mediating its antiatherogenic effects.
This study was conducted to determine whether the blood pressure-lowering effect of Nigella sativa might be mediated by its effects on nitric oxide, angiotensin-converting enzyme, heme oxygenase and oxidative stress markers.