@feruze-- Red wine supplements are still better than grape supplements because it has higher concentrations of antioxidants. So I think you should use red wine extract.
Extra antioxidants is always good, as long as it comes from a pure source and toxic substances haven't been added to the supplements. But I think it's wrong to expect any miracles.
I hear about scientific studies done on extracts all the time too. Most of the time, the amount of extracts used in those studies are huge. Way more than we can consume under normal circumstances and definitely more than what the supplements on the market currently offer. So it would be illogical to expect the same results as what was seen in mice trials.