Previous studies by others have demonstrated that pterostilbene also has antidiabetic properties. The current study is the first to identify it as a cancer-preventive agent, the researchers report. Their study is tentatively scheduled to appear in the June 19 issue of the Journal of Agricultural and Food Chemistry, a peer-reviewed publication of the American Chemical Society, the world’s largest scientific society. It was published on the Web version of the journal on May 10. “The study adds to the growing health benefits of grapes,” said Agnes M. Rimando, Ph.D., lead investigator for the study and a research chemist with the USDA’s Natural Products Utilization Research Unit in Oxford, Miss.

The research, limited to laboratory studies of cells, could lead to more healthful varieties of grapes and the design of better drugs to fight cancer and diabetes, two of the major medical problems in this country, says Rimando. However, she cautions that studies will be needed in both animals and humans to evaluate the potential health benefits of pterostilbene, whose biological activities are not well-understood.

Prompted by the structural similarity of pterostilbene to resveratrol, Rimando decided to test the compound to determine if it had similar anticancer and antioxidant activities. In lab tests using mouse mammary cells, pterostilbene prevented a type of cell damage that is normally induced by cancer-causing agents, she says. Earlier studies by the researcher showed that the compound is toxic to a human breast cancer cell line. The conclusion: It appears that pterostilbene is equal in potency to resveratrol as a cancer-preventive agent, as both have shown similar anticancer activity in lab tests, says Rimando. Their similar effect is likely due to the high antioxidant activity of these compounds, she says.

Antioxidants destroy free-radicals, highly reactive molecules whose excess has been linked to cancer. Pterostilbene has another benefit not found in resveratrol. Animal studies by others have shown that the compound can lower blood glucose and may be a potent antidiabetic agent. At least one study showed that it could lower plasma glucose levels in rats with high blood sugar by 42 percent, comparable to at least one known antidiabetic agent (metformin), according to the researcher.

By The Time It Gets Dark The delicately poetic second feature by Thai director Anocha Suwichakornpong weaves together mult. 0.5 0.5.org/itogovoe-attestaciya-reshebnik-otveti-na-zadaniya-i-lyashenko-170.html.

“My study is saying that there’s another compound in grapes with equal cancer-fighting power as resveratrol, but which has antidiabetic properties as well,” said Rimando. “The compound has always been in grapes, but no one has paid much attention to it.” Both pterostilbene and resveratrol belong to a group of chemicals called phytoalexins, which are produced by plants in response to fungal infection, ultraviolet light, and various chemical and physical stressors. While both exhibit strong antifungal activity, pterostilbene appears to be 60 to 100 times more potent as a fungicide, a property that may one day be exploited by farmers in search of a more disease-resistant grape, says Rimando. In plants that contain these chemicals, their content usually differs dramatically.

Copyright (c) doubletwo.net, 2007. All rights reserved.