The effect of purple-black barberry (Berberis integerrima) on blood pressure in subjects with cardiovascular risk factors: a randomized controlled trial

Abstract

Ethnopharmacological relevanceBerberis integerrima commonly known as “barberry” belongs to the Berberidaceae family and has been used as a medicinal plant in Iranian traditional medicine. Aim of the studyOur aim in this study was to investigate the effects of barberry consumption on blood pressure (BP). Materials and methodsEighty-four medicated hypertensive patients were selected and randomly allocated to barberry and placebo groups. The barberry group received 10 g/day dried purple-black barberry powder, once daily, for 2-months. Systolic, diastolic, and mean arterial BP was assessed through 24-h ambulatory BP monitoring before and after 2-month treatment. The estimation of sodium and potassium intake was done through measurement of sodium and potassium in 24-h urinary samples. Plasma and urinary nitrite, and nitrate (NOx) levels, as well as plasma angiotensin-converting enzyme (ACE) activity, were also determined. ResultsSeventy-eight participants with an average age of 54.12 ± 10.32 years and BMI of 27.93 ± 2.22 kg/m2 completed the study. There was no significant difference in body weight, physical activity, and the 24-h urinary sodium and potassium excretion between the two groups before and after the study. After adjusting for baseline values and changes in sodium intake, systolic, and mean arterial BP decreased significantly in the barberry group compared to the placebo group (p = 0.015 and p = 0.008, respectively). Plasma NOx levels and ACE activity were not different between the two groups, but urinary NOx was increased significantly in the barberry group compared to the placebo group (p = 0.008). ConclusionsIn patients treated with antihypertensive drugs, daily consumption of purple-black barberry can be effective in improving systolic BP control.