Quote 1 from article 1:
NURR1 activates genes associated with the survival of the dopamine neurons, such as the receptor c-RET. cRET is the receptor for the neurotrophic factor GDNF (or Glial cell-derived neurotrophic factor) which has had a long history associated with Parkinson’s disease
Quote 2 from article 1:
NURR1 is very important for activating the transcription of a lot of genes that are required for making and maintaining a dopamine neuron.
The researchers of above study 2 tested the cancer drug bexarotene (also known as Targretin) on rats finding that is the dopamine neurons were restored in rats.
The researchers in another study 3 successfully screened a large FDA-approved drug library to identify NURR1-activating compounds. They identified three:
- amodiaquine (anti-malaria drug)
- chloroquine (anti-malaria drug)
- glafenine (a pain-relieving drug)
All those drugs bexarotene, amodiaquine, chloroquine and glafenine have all been FDA-approved for use on human. So, why are they not directly tested on human with Parkinson's disease?