Juice from Japanese fruit may help reduce blood pressure

About half of the population in Western countries suffer from hypertension – high blood pressure – and have to take one or several drugs that do not always eliminate the condition, which is a major cause of cardiovascular disease and stroke. 

Now, researchers at Temple University in Philadelphia have found that a processed, infused juice concentrate from the Japanese plum (Prunus mume) – a fruit that is widely consumed in Asia and is promoted as a health food in that country – has anti-hypertensive effects in lab mice.

The new findings are described under the title “Infused juice concentrate of Japanese plum Prunus mume attenuates inflammatory vascular remodeling in a mouse model of hypertension induced by angiotensin II” in the journal Hypertension Research.

“It is recognized that drugs alone are not enough to reduce the risk of cardiovascular disease in hypertension patients,” explained cardiology Prof. Satoru Eguchi.

“To help solve this problem, we became interested in a supplement that could potentially decrease cardiovascular disease risk and began investigating the effects of bainiku-ekisu, an infused juice concentrate of the Japanese plum.”

A natural remedy

The raw fruit of the plum, traditionally referred to as Ume in Japan, contains toxins, so it is usually processed into juices or wine that are safe for consumption. The infused juice concentrate has been consumed in Japan as a health supplement for at least 300 years. 

In experiments in smooth muscle cells of blood vessels, bainiku-ekisu was found to reduce growth-promoting signals induced by angiotensin II – a circulatory hormone that plays a central role in the development of hypertension.

Hypertension and stress

The team used a mouse model in which animals received infusions of angiotensin II to induce hypertension; they were given either plain water, in the control group, or water containing bainiku-ekisu.

Those given the juice didn’t develop hypertension, and tissue analysis indicated that the juice concentrate protected the vasculature from the effects of angiotensin II. 

They next explored possible mechanisms by which juice prevented hypertension in mice. They looked specifically at molecular pathways involved in glycolysis, the process by which cells break down glucose and which is a central feature of hypertension-induced hypertrophy.

“In hypertension, cells shift from aerobic metabolism to glycolysis because there is less oxygen available in the cellular environment,” Dr. Eguchi explained.

“This switch results in high levels of oxidative stress, which leads to more inflammation, more vascular stiffness, and, eventually, the development of more severe cardiovascular disease.” 

Soon, the team will work to identify the specific compounds in bainiku-ekisu that are responsible for its protective effects. “There may be two or three compounds working together, which could explain why the infused juice concentrate of Ume is so popular as a health supplement,”. Eguchi concluded.

“Multiple compounds working together would produce additive or synergistic effects that might be lost in a pharmaceutical preparation.”