Came across the interesting blog of the nephrologist Dr. Veeraish Chauhan today while trying to find evidence supporting nettle seed extract for kidney regeneration. He also investigated nettle LEAF treatment and could find no evidence for it, though some of his readers swear it seemed to reduce their creatinine levels. In any case it's a very interesting source of information for anyone struggling with kidney disease as it comes directly from someone with medical training engaged in treating people day in day out:
http://www.kidneydoctorbradenton.org/2013/06/can-certain-herbal-medications-treat.html