Dr. Jiancheng He and co-workers from Shanghai University of Traditional Chinese Medicine in China established a model of Parkinson's disease dyskinesia in rats, and treated these animals with Compound Formula Rehmannia.
They found that Compound Formula Rehmannia alleviates levodopa-induced dyskinesia in Parkinson's disease by modulating neurotransmitter signaling in the corpus striatum. The relevant article has been published in the Neural Regeneration Research
(Vol. 9, No. 4, 2014).