This is not it. Fasting was done for pharmacokinetics study, not for chronic toxicity study. That two studies were separate is evident from the description, e.g. rats were acclimated for 7 days for pharmacokinetics study and 14 days for chronic toxicity study.
That is also a plausible reading of the paper. It doesn't look like they go into any great detail as to the protocol for administration in the longer term study.
I'm skeptical of significant antioxidant effects in vivo from a naturally occurring compound given that antioxidants in general haven't done much for longevity without being heavily designed substances (like SkQ1, for example). Simply flooding the body with antioxidants is usually slightly worse for longevity or a null effect - they don't get to the mitochondria where they might do some good.
More information from the authors would be good. All things considered, I'm sure we'll be hearing more on this in the years ahead; people will try to replicate it, the researchers will be grilled on their work, etc.