Featured Research

from universities, journals, and other organizations

Study Shows How Substance In Grapes May Squeeze Out Diabetes

Date:
October 20, 2009
Source:
UT Southwestern Medical Center
Summary:
A naturally produced molecule called resveratrol, found in the skin of red grapes, has been shown to lower insulin levels in mice when injected directly into the brain, even when the animals ate a high-fat diet.

From left: Drs. Giorgio Ramadori, Laurent Gautron and Roberto Coppari are researchers at UT Southwestern Medical Center.
Credit: UT Southwestern Medical Center

A naturally produced molecule called resveratrol, found in the skin of red grapes, has been shown to lower insulin levels in mice when injected directly into the brain, even when the animals ate a high-fat diet.

Related Articles


The findings from a new UT Southwestern Medical Center study suggest that when acting directly on certain proteins in the brain, resveratrol may offer some protection against diabetes. Prior research has shown that the compound exerts anti-diabetic actions when given orally to animals with type 2 diabetes (non-insulin dependent diabetes mellitus), but it has been unclear which tissues in the body mediated these effects.

"Our study shows that the brain plays an important role in mediating resveratrol's anti-diabetic actions, and it does so independent of changes in food intake and body weight," said Dr. Roberto Coppari, assistant professor of internal medicine at UT Southwestern and senior author of the study appearing online and in the December issue of Endocrinology.

"These animals were overrun with fat and many of their organs were inflamed. But when we delivered resveratrol in the brain, it alleviated inflammation in the brain," added Dr. Coppari.

Dr. Coppari emphasized that his study does not support the conclusion that consuming products made from red grapes, such as red wine, could alleviate diabetes.

"The main reason is that resveratrol does not cross the blood brain barrier efficiently," he said. "In order for the brain to accumulate the same dose of resveratrol delivered in our study, the amounts of red wine needed daily would surely cause deleterious effects, especially in the liver. Rather, our study suggests that resveratrol's analogs that selectively target the brain may help in the fight against diet-induced diabetes."

For the study, the researchers investigated what happens when resveratrol acts only in the brain. Specifically, they wanted to know whether resveratrol injected in the brain activated a group of proteins called sirtuins, which are found throughout the body and thought to underlie many of the beneficial effects of calorie restriction. Previous animal research has shown that when these proteins are activated by resveratrol, diabetes is improved. In addition, drugs activating sirtuins currently are being tested as anti-diabetic medications in human trials, Dr. Coppari said.

In one group of animals, researchers injected resveratrol directly into the brain; another group received a saline-based placebo. All the surgically treated animals consumed a high-fat diet before and after the surgery.

Dr. Coppari said the insulin levels of the animals treated with the placebo solution rose increasingly higher post-surgery. "That's a normal outcome because insulin sensitivity decreases the longer you keep an animal on a high-fat diet."

Insulin levels in the mice given resveratrol, however, actually started to drop and were halfway to normal by the end of the five-week study period, even though the animals remained on a high-fat diet.

In addition, the researchers found that resveratrol did indeed activate sirtuin proteins in the brain.

Dr. Coppari said the findings support his team's theory that the brain plays a vital role in mediating the beneficial effects of resveratrol and that manipulation of brain sirtuins also may have other beneficial outcomes. "By knowing that the central nervous system is involved, pharmaceutical companies can begin to focus on developing drugs that selectively target sirtuins in the brain," he said.

The next step, Dr. Coppari said, is to determine precisely which neurons in the brain are mediating the effects of the resveratrol.

Other UT Southwestern researchers involved in the study include Drs. Giorgio Ramadori, Laurent Gautron and Teppei Fujikawa, postdoctoral researchers in internal medicine; Dr. Claudia Vianna, instructor of internal medicine; and Dr. Joel Elmquist, professor of internal medicine and director of the Center for Hypothalamic Research at UT Southwestern.

The study was supported by the American Heart Association, National Institutes of Health and the American Diabetes Association.


Story Source:

The above story is based on materials provided by UT Southwestern Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Giorgio Ramadori, Laurent Gautron, Teppei Fujikawa, Claudia R. Vianna, Joel K. Elmquist, and Roberto Coppari. Central Administration of Resveratrol Improves Diet-Induced Diabetes. Endocrinology, 2009; DOI: 10.1210/en.2009-0528

Cite This Page:

UT Southwestern Medical Center. "Study Shows How Substance In Grapes May Squeeze Out Diabetes." ScienceDaily. ScienceDaily, 20 October 2009. <www.sciencedaily.com/releases/2009/10/091015084549.htm>.
UT Southwestern Medical Center. (2009, October 20). Study Shows How Substance In Grapes May Squeeze Out Diabetes. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2009/10/091015084549.htm
UT Southwestern Medical Center. "Study Shows How Substance In Grapes May Squeeze Out Diabetes." ScienceDaily. www.sciencedaily.com/releases/2009/10/091015084549.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Doctor in NYC Quarantined With Ebola

Doctor in NYC Quarantined With Ebola

AP (Oct. 24, 2014) An emergency room doctor who recently returned to the city after treating Ebola patients in West Africa has tested positive for the virus. He's quarantined in a hospital. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins