Red wine instead of hormone injections
Researchers at Northwestern University Medical School have identified a chemical in red wine thought to reduce the risk of heart disease as a form of estrogen. This substance, resveratrol, is found in high concentrations in grape skins and also in red wine. As is often reported, when consumed in moderation, red wine reduces the risk of cardiovascular disease. According to some researchers, this is due to resveratrol, which is very abundant in the skin of grapes. Resveratrol protects grapes and some other plants from fungal infections. As previously shown, resveratrol has various he alth-promoting properties: It acts as an antioxidant and anticoagulant, is anti-inflammatory and even anti-cancer.
Resveratrol's molecular structure is similar to that of diethylstilbestrol, a synthetic estrogen. Therefore, Barry D. Gehm, Dr. medical J. Larry Jameson and colleagues from Northwestern University, whether the pharmacological properties of resveratrol are similar to those of estradiol, the main natural estrogen in humans.
As reported in the December 9 issue of the Proceedings of the National Academy of Sciences, the group's laboratory studies established that resveratrol is an estrogen, more specifically: a phytoestrogen, a plant compound. Resveratrol activates both artificially introduced "reporter genes" and naturally occurring estrogen-driven genes in human cell cultures, at concentrations where it also exerts its other biological effects. Researchers also discovered that resveratrol can replace estradiol, which promotes the proliferation of certain breast cancer cells that require estrogen to grow.
"Estrogen" is not a specific compound but a category of substances defined by their biological effects. Estrogens were originally named for their ability to induce estrus ('going into heat') in animals and act in cells by binding to a protein, the estrogen receptor, which causes certain genes to be expressed, or 'turned on'. In addition to the body's sex hormones, a number of other - natural and artificial - estrogens are known.
When studying gene effects, many laboratories use artificial reporter genes. The reporter gene used in these studies is the gene for the enzyme luciferase, which causes the glow in fireflies. It's attached to a piece of DNA that the estrogen receptor "recognizes." After the researchers introduced this reporter gene into the cells, luciferase production increased in the estrogen-treated cells. Measurements based on the emitted light were easily possible.
In some cells, resveratrol produced a greater effect of the reporter gene than estradiol. According to Gehm, this was a surprise since it had always been assumed that estradiol would activate the estrogen receptor the most. The scientists found that the most effective dose of resveratrol produces two to four times more light than the most effective dose of estradiol. However, estradiol works at much lower doses.
"The estrogenic properties of resveratrol may play a role in the cardiovascular benefits of red wine and the so-called 'French paradox,'" Gehm said.
Estrogen is known to protect against heart disease, and the same is believed to be true of red wine. Their specific effects are similar, for example both increase blood levels of “good cholesterol” (HDL). This effect of the red wine could be caused by the resveratrol. However, Gehm cautioned that it is not yet known whether the body absorbs enough resveratrol from wine to make this explanation plausible.
Nevertheless, the observation that resveratrol has a greater effect than estradiol on some estrogen-gated genes may ultimately lead to new, selectively applicable estrogenic drugs. Currently available selective estrogens are used in the treatment of breast cancer (tamoxifen) and postmenopausal osteoporosis (raloxifene).
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