careful with those red grapes

[Lani]

as I have mentioned before, one of the dangers of "self-treatment" by diet is
the lack of knowledge of what amounts of a compound in a food inhibit cancer cell growth and invasion and if a different amount might do the opposite. Here is an example:
Neoplasia. 2007 Feb;9(2):147-58.
Estrogen and resveratrol regulate Rac and cdc42 signaling to the actin cytoskeleton of metastatic breast cancer cells.

Azios NG,
Krishnamoorthy L,
Harris M,
Cubano LA,
Cammer M,
Dharmawardhane SF.
Department of Anatomy and Cell Biology, Universidad Central del Caribe, Bayamon, Puerto Rico.
Estrogen and structurally related molecules play critical roles in breast cancer. We reported that resveratrol (50 microM), an estrogen-like phytosterol from grapes, acts in an antiestrogenic manner in breast cancer cells to reduce cell migration and to induce a global and sustained extension of actin structures called filopodia. Herein, we report that resveratrol-induced filopodia formation is time-dependent and concentration-dependent. In contrast to resveratrol at 50 microM, resveratrol at 5 microM acts in a manner similar to estrogen by increasing lamellipodia, as well as cell migration and invasion. Because Rho GTPases regulate the extension of actin structures, we investigated a role for Rac and Cdc42 in estrogen and resveratrol signaling. Our results demonstrate that 50 microM resveratrol decreases Rac and Cdc42 activity, whereas estrogen and 5 microM resveratrol increase Rac activity in breast cancer cells. MDA-MB-231 cells expressing dominant-negative Cdc42 or dominant-negative Rac retain filopodia response to 50 microM resveratrol. Lamellipodia response to 5 microM resveratrol, estrogen, or epidermal growth factor is inhibited in cells expressing dominant-negative Rac, indicating that Rac regulates estrogen and resveratrol (5 microM) signaling to the actin cytoskeleton. These results indicate that signaling to the actin cytoskeleton by low and high concentrations of resveratrol may be differentially regulated by Rac and Cdc42.
PMID: 17356711 [PubMed - in process]

[heblaj01]

Risk from resveratrol in the skin of red grapes grown in large scale commercial vineyards is likeky to be very low if not nil.
This is because the level of resveratrol in these grapes is quite low.
Resveratrol is secreted in the skins as a reaction against fungus infestation.
Fungus is mostly found in cool climates & where antifungus sprays are not used.
In the US most grapes come from warm California big vineyards which are not shy of using protective sprays.
Ironically risk may be with small scale organically grown grapes (& even this is not a sure thing) in cool regions such as Washington or Oregon States or some places in Canada.
Concentrated resveratrol in pills is an other matter (to consider by those who are ER+)

[Lani]

From This Abstract That Low Dose Reservatrol Was More Dangerous Than Higher Dose Ie, Low Dose Increased Metastatic Potential Whereas Higher Dose Was Antiestrogenic

I Think The Point Is, As We Don't Know How Well It Is Absorbed Or Metabolized, Beware...

[Hopeful]

Lani, heblaj01 -

Any idea if this is limited to the grapes in their raw state? Would grapes that have been processed into jelly, raisins or wine still contain Reservatrol?

Thanks,

Hopeful

[heblaj01]

Hopeful,
Raisins are said to contain much less antioxidants (which probably include resveratrol) than fresh grapes probably as a result to exposition to the sun, air & possibly other processing steps. This is in spite of being mostly skin.
Regarding grape jelly I have not a clear answer as I don't know exactly how it manufactured. If the grape juice used to make the jelly does not contain any part of the grape skin, then there is no resveratrol.
In addition, juice extraction can be cold or hot pressed followed in many cases by pasteurisation with uncertain results for resveratrol content. And depending on which country, jellyfication is either with pectin (USA)or with gelatin or agar (U.K.).
Since I have not seen in the past any recommandation to consume grape jelly as a source of resveratrol, I assume it is not a good one.
Red wines do contain highly variable levels of resveratrol depending on grape type & wether or not they come from vineyards in warm or cool regions.
Once a bottle of red wine is opened & the remaining portion in the bottle is exposed to outside air there is some degradation taking place.
There are special corks which prevent this to occur.
Aside of resveratrol pills, there is no perfect source of this natural product: grapes are high in sugar, wines are high in alcohol, both of which are not considered advisable for cancer patients if consumed in the relatively large amounts necessary to reach therapeutic levels.
I have thought of a way to get rid of the alcohol in wines which may preserve the resveratrol. But I have no way to verify if it really works.
Here is how it is supposed to be done:
In a small diameter pan (not too wide neck) pour the wine & top it with a small amount of a good vegetable oil (say olive oil) to cover the wine with a very thin layer.
Heat slowly the wine on a stove until a thermometer indicates 85 to 90 degree Celcius. If this procedure works, the alcohol should evaporate through the oil which would prevent the remaining wine from getting in contact with air. Since the wine is not going to boil at the indicated temperatures, only a possible interaction, if any,between the oil & wine may be detrimental.

[Roz]

Sounds pretty good to me (I like a drop of wine) but how to separate the wine and the oil so it's drinkable? (probably not, I guess!!)

[heblaj01]

Roz,
The quantity of required oil is very small. But if you insist in having it discarded before drinking the wine there are at least two easy ways,
One way is to poor the wine in a container with a tap at the bottom. After waiting a little until the oil has settled on the top of the wine you take out the wine through the bottom tap leaving the oil inside.
An other way is to hold a paper tissue (kleenex type, preferably double ply) with both hands at two corners & quickly pull it through the surface of the wine: the oil will stick to the paper. If one time is not enough use more tissues.
By the way, this last method works well with removing excess fat from foods such as chicken soups.
This brings to my mind an other method for both soups & wines (although I have not tried it with wine) : refrigeration to let the top surface fat become solid which makes it easy to remove with a spoon.