Antihypertensive Effect of Boysenberry Seed Polyphenols on Spontaneously Hypertensive Rats and Identification of Orally Absorbable Proanthocyanidins with Vasorelaxant Activity

Effects of Acute and Chronic Boysenberry Intake on Blood Pressure and Endothelial Function in Spontaneous Hypertensive Rats

“…Key Words boysenberry juice, blood pressure, endothelial function, eNOS cyanidins are absorbable and bioavailable in humans. In fact, we also confirmed that a boysenberry proanthocyanidin extract exerted an in vitro vasodilative effect on the rat aortic endothelium, as well as an in vivo acute antihypertensive effect on systolic blood pressure (SBP) in spontaneous hypertensive rats (SHR) (6). Berry vinegars, produced from the juice, are also consumed worldwide.…”

“…We have previously shown that boysenberry proanthocyanidins are not acutely associated with plasma ACE activity in SHR (6), but the BJ used in this study contained a multitude of other uncharacterized phytochemical constituents in addition to the proanthocyanidins. Therefore, we compared the effects of boysenberry intake on plasma renin-angiotensin system activities among the five acute and three chronic treatment groups (Fig.…”

“…Plasma angiotensin-converting enzyme (pACE) activity was determined by the modified method of Furuuchi et al (6), using the synthetic substrate Hip-His-Leu (Sigma-Aldrich Corp., St. Louis, MO). Each plasma sample (10 mL) prepared by centrifuging the blood sample was immediately incubated for 30 min at 37˚C with Hip-His-Leu (40 mL, 5 mmol/L) in borate buffer (200 mmol/L, pH 8.3) containing NaCl (400 mmol/L).…”

“…The beverages and products of many kinds of berries, such as blueberry, blackcurrant, cranberry, chokeberry, and strawberry, contain distinctive proanthocyanidin constituents (2). We recently reported on the structural identification (5) and antihypertensive effect of polyphenols from boysenberry fruit (6). Boysenberry, a hybrid Rubus berry likely derived from a cross between Rubus loganobaccus and Rubus baileyanus Britt.…”

Boysenberry Polyphenols Suppressed Elevation of Plasma Triglyceride Levels in Rats

“…1. Recent studies have indicated that orally administered boysenberry juice (BBJ) shows positive biological effects such as reduction of oxidative stress (9,10), prevention of liver injury (11) and anti-hypertension (12).…”