Featured Research

from universities, journals, and other organizations

Molecules Discovered That Extend Life In Yeast, Human Cells; Group Of Compounds Found In Red Wine, Vegetables Simulate Benefit Of Low-calorie Diet

Date:
August 25, 2003
Source:
Harvard Medical School
Summary:
Mice, rats, worms, flies, and yeast all live longer on a low-calorie diet, which also seems to protect mammals against cancer and other aging-related diseases. Now, in yeast cells, researchers at Harvard Medical School and BIOMOL Research Laboratories have for the first time found a way to duplicate the benefits of restricted calories in yeast with a group of compounds found in red wine and vegetables.

BOSTON, MA – Mice, rats, worms, flies, and yeast all live longer on a low-calorie diet, which also seems to protect mammals against cancer and other aging-related diseases. Now, in yeast cells, researchers at Harvard Medical School and BIOMOL Research Laboratories have for the first time found a way to duplicate the benefits of restricted calories in yeast with a group of compounds found in red wine and vegetables. One compound extended yeast life span by up to 80 percent. The molecules are also active in human cells cultured in the laboratory.

The findings are reported in the August 24 Nature advanced online edition. The research suggests a promising route to find and develop drugs to lengthen life and prevent or treat aging-related diseases.

The molecules belong to a familiar group of compounds known as polyphenols, such as the resveratrol found in red wine and the flavones found in olive oil. For these particular polyphenols, the beneficial effects seem to be independent of their famed antioxidant properties. Instead, the molecules activate sirtuins, a family of enzymes known to extend the life span of yeast and tiny lab round worms. In screening tests, the researchers found 17 molecules that stimulated SIRT1, one of seven human sirtuins, and the yeast sirtuin SIR2.

"We think sirtuins buy cells time to repair damage," said molecular biologist David Sinclair, assistant professor of pathology at Harvard Medical School and co-author of the new study. "There is a growing realization from the aging field that blocking cell death -- as long as it doesn't lead to cancer -- extends life span."

"The sirtuin stimulation provided by certain, but not all, polyphenols may be a far more important biological effect than their antioxidant action," said co-author Konrad Howitz, director of molecular biology at BIOMOL, a biochemical reagents company in Pennsylvania.

Calorie restriction (in mammals, reducing intake to 60 or 70 percent of the normal daily calories) may be one of many mild stresses that trigger beneficial effects, a phenomenon called hormesis. To explain their new findings, the researchers propose that plant polyphenols, which increase in response to stressful conditions, cue organisms to prepare for impending harsh conditions by switching to a more beneficial survival program. They call their hypothesis "xenohormesis."

The most potent molecule in the study, resveratrol, helped yeast cells live as much as 60 to 80 percent longer, as measured by the number of generations. Other studies have linked resveratrol to health benefits in mitigating age-related diseases, including neurodegeneration, cancer and clogged arteries. In this study, researchers were surprised to find that yeast cells treated with small doses of resveratrol lived for an average of 38 generations, compared to 19 for the untreated yeast. The polyphenol worked through a known sirtuin molecular pathway to help yeast and human cells survive environmental stresses.

In experiments with human cells, resveratrol activated a similar pathway requiring SIRT1. This enabled 30 percent of the treated human cells to survive gamma radiation compared to 10 percent of untreated cells. Little is known about the human sirtuin SIRT1, except that it turns off the tumor suppressor gene p53. This raises the concern that any promotion of this pathway might promote cancer even as it switches on a longevity program. But Sinclair said that calorie-restricted animals in experiments by others have lower, not higher rates of cancer.

In the paper, the researchers report that preliminary experiments in flies and worms are encouraging. Mouse studies are in the works. They are exploring synthetic variations on the molecules, which they call sirtuin activating compounds or "STACs," to improve the sirtuin activity. They are also searching for endogenous activators that may naturally exist in human cells.

In the May 8 Nature, Sinclair's research group reported the first known genetic link between environmental stresses and longer life in yeast. Triggered by low salt, heat, or calorie restriction (to as low as 25 percent of normal), a yeast "longevity gene" stimulated Sir2 activity. Sinclair and his colleagues are testing equivalent genes in humans to see if they similarly speed up human sirtuin activity.

The work was supported by the National Institute on Aging and the Harvard-Armenise Foundation. Researchers were further supported by fellowships and training grants from the Ellison Medical Research Foundation, the American Federation for Aging Research, the National Eye Institute, and the National Science Foundation. A provisional patent has been filed for refined versions of the natural molecules.


Story Source:

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


Cite This Page:

Harvard Medical School. "Molecules Discovered That Extend Life In Yeast, Human Cells; Group Of Compounds Found In Red Wine, Vegetables Simulate Benefit Of Low-calorie Diet." ScienceDaily. ScienceDaily, 25 August 2003. <www.sciencedaily.com/releases/2003/08/030825072453.htm>.
Harvard Medical School. (2003, August 25). Molecules Discovered That Extend Life In Yeast, Human Cells; Group Of Compounds Found In Red Wine, Vegetables Simulate Benefit Of Low-calorie Diet. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2003/08/030825072453.htm
Harvard Medical School. "Molecules Discovered That Extend Life In Yeast, Human Cells; Group Of Compounds Found In Red Wine, Vegetables Simulate Benefit Of Low-calorie Diet." ScienceDaily. www.sciencedaily.com/releases/2003/08/030825072453.htm (accessed July 31, 2014).

Share This




More Health & Medicine News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Republicans Vote to Sue Obama Over Healthcare Law

House Republicans Vote to Sue Obama Over Healthcare Law

Reuters - US Online Video (July 31, 2014) The Republican-led House of Representatives votes to sue President Obama, accusing him of overstepping his executive authority in making changes to the Affordable Care Act. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Despite Health Questions, E-Cigs Are Beneficial: Study

Despite Health Questions, E-Cigs Are Beneficial: Study

Newsy (July 31, 2014) Citing 81 previous studies, new research out of London suggests the benefits of smoking e-cigarettes instead of regular ones outweighs the risks. Video provided by Newsy
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
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:
from the past week

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