Plant sterols and casein-derived tripeptides attenuate blood pressure increase in spontaneously hypertensive rats

Abstract In this study, we investigated the synergistic effects of plant sterols (PS) and casein-derived tripeptides on arterial tone and blood pressure in experimental hypertension. We hypothesized that PS and tripeptides could have positive, synergistic effects on the development of hypertension and endothelial dysfunction in young spontaneously hypertensive rats (SHR). Six-week-old male SHR were divided into 3 groups to receive milk products containing PS, or PS with tripeptides, or a control containing no active components for 8 weeks. Systolic blood pressure (SBP) was measured weekly, and vascular reactivity measurements with isolated mesenteric arteries were performed at the end of the study. Biochemical measurements for several parameters were performed by enzyme-linked immunosorbent assay using plasma samples. Levels of angiotensin-converting enzyme 1, cyclooxygenase-2, endothelial nitric oxide synthase, and P-selectin messenger RNA expressions were determined from aortic tissue by real-time polymerase chain reaction. The study showed that long-term treatment with PS + tripeptides attenuated the development of hypertension in SHR (SBP, 187 ± 5 mm Hg vs 169 ± 4 mm Hg in control group; P