Other strategies that end up showing altered AMPK levels along the way have been shown to extend life and improve health in laboratory species. It is very complex, and researchers are very far from understanding how even very reliable and straightforward ways of slowing aging work. E.g. calorie restriction. Studied for a century, no comprehensive explanation of how it works yet.
This, along with tiny beneficial effects, is the reason we should largely ignore all of these efforts to throw drugs at metabolism in the hopes of lengthening healthspan. It is a grand waste of time, because even if wondrously successful the best you could hope for in the next few decades is something that is outperformed by actually exercising or practicing calorie restriction.
What a waste of billions of dollars that will be. Yet that's what is going to happen, judging by the willingness to fund this sort of work. It is like the research and development community has learned nothing from the outcome of fifteen years of sirtuin research.
If we want to see radical life extension in our lifetimes, it is going to come from SENS and the like, deliberate targeted efforts to repair specific aspects of biochemical damage that cause cell and tissue dysfunction. Not random drugs mined from the natural world, but elegantly engineered biotechnologies that do exactly what they are intended to do. You might look at allotopic expression of mitochondrial DNA for example, as developed by Gensight at the moment ( http://www.gensight-biologics.com/ ). The problem is identified, and a precise fix applied to cells via gene therapy to make exactly the problem and only the problem go away.
That is the future of medicine. Yet the regulations and inertia behind the old drug development pipeline is very resistant to change. We'd better hope that the disruption represented by Gensight and other similar efforts takes hold, because we're going to age and suffer just like our parents and on pretty much the same schedule if it doesn't.