Which 2008-14 high-dose methylene blue rodent study showed no bad effects, and even life extension in females?

[marcuswhybrow]

In Nitric Oxide ray says

Two studies, one by the NIH, 6 years ago and one more recent, gave greater doses up to what would be the equivalent of about 4 or 5 or 6 grams a day for a person of the crystalline material, many times higher than the curative, anti-depressive dose. And they did it for the whole lifespan of rats and mice and saw no life-shortening effects in either rats or mice. But in female mice, in both studies, they saw an extension of the maximum lifespan with the highest dose.

The interview is from 2014, so "6 years ago" gives a range of 2008-2014.