Potential hypotensive effects of Umezu polyphenols: a 14-week community-based, double-masked and placebo-controlled trial.

OBJECTIVE: To evaluate blood pressure (BP)-lowering effects of Umezu polyphenols, polyphenols contained in Japanese plums, in a community-based sample by double-masked and placebo-controlled design. METHODS: Seventy-two Japanese community-dwellers who were interested in prevention or control of their BP (preferably high-normal BP or grade I hypertension) but without antihypertensive medication were randomized into Umezu polyphenols or placebo groups. Each subject took 800 mg/day of Umezu polyphenols or placebo for 12 weeks, followed by a 2-week washout period. Their home and office BP were monitored for 14 weeks in a double-masked manner. We analyzed 56 subjects who met the inclusion criteria. RESULTS: Home BP increased gradually in both the groups during the intervention period, while diastolic office BP insignificantly decreased in the intervention group. During the washout period, home systolic BP in the morning elevated only in the intervention group. CONCLUSIONS: The study failed to collect consistent evidence of a clear persistent hypotensive effect of Umezu polyphenols.

Antimicrobial Activity of the Phenolic Compounds of Prunus mume against Enterobacteria.

Mume fruit, the Japanese apricot (Prunus mume SIEB. et ZUCC.), is popular in Japan and is mostly consumed in the pickled form called umeboshi. This fruit is known to have anti-microbial properties, but the principal constituents responsible for the antimicrobial properties have not yet been elucidated. We investigated the antimicrobial activities of the phenolic compounds in P. mume against enterobacteria. In this study, growth inhibitory activities were measured as an index of the antibacterial activities. The phenolic compounds were prepared from a byproduct of umeboshi called umesu or umezu (often translated as "mume vinegar"). Umesu or umezu phenolics (UP) contain approximately 20% phenolic compounds with p-coumaric acid as a standard and do not contain citric acid. We observed the inhibitory effects of UP against the growth of some enterobacteria, at a relatively high concentration (1250-5000 µg/mL). Alkali hydrolysates of UP (AHUP) exhibited similar antibacterial activities, but at much lower concentrations of 37.5-300 µg/mL. Since AHUP comprises hydroxycinnamic acids such as caffeic acid, p-coumaric acid, and ferulic acid, the antibacterial activities of each of these acids were examined. Our study shows that the phenolic compounds in P. mume other than citric acid contribute to its antimicrobial activity against enterobacteria in the digestive tract.

Safety and adherence of Umezu polyphenols in the Japanese plum (Prunus mume) in a 12-week double-blind randomized placebo-controlled pilot trial to evaluate antihypertensive effects.

OBJECTIVES: Medications or lifestyle changes to prevent or improve hypertension often press considerable efforts on patients suffering from mild hypertension. Capsules including Umezu polyphenols (UP), polyphenols in Japanese plums, may help them to control their blood pressure (BP). The aim of this study is to evaluate the effectiveness of UP on BP and its safety. METHODS: A total of 15 healthy workers without antihypertensive medication who had some concerns about their BP, preferably normal-high BP or hypertension level 1, were randomized in a double-blind manner into UP ingesting and placebo groups. Each subject was instructed to take four capsules daily for 12 weeks (daily UP dose, 800 mg for the UP ingesting group; and 0 mg for the placebo group). These subjects were followed for 12 weeks, and their BP both at home and at the examination site, as well as self-perceived quality-of-life outcomes and possible side effects, was monitored during that period. Group × time interactions on BP changes were examined. RESULTS: All of the 15 subjects completed the 12-week intervention trial. The BP changes did not significantly differ between the UP ingesting and placebo groups, neither at the examination site nor at home. But during the study period, no adverse effects were observed. CONCLUSIONS: No remarkable effect of UP on BP was observed. However, a higher dose of UP was confirmed safe and high in adherence in this 12-week randomized controlled trial. Its effect on BP and other outcomes shall be confirmed in a larger sample.