I have just come across an article in the 25th June issue of New Scientist magazine citing clinical trials of a traditional Chinese herb called gou teng. Apparently this seems to work by targeting rogue cell producing the protein alpha-synclein, which has been implicated in the destruction of Dopamine producing brain cells. The "active ingredient" has been identified as an alkaloid called isorhy. Clinical trials with synthethised isorhy on rodents are now under way.
I had a consultation with a Chinese doctor late last year, and I spent a small fortune on some Chinese herbs (including the gou teng discussed at the beginning of this thread), which I took every day for two weeks. Sadly, they had absolutely no effect on any of my symptoms.
However, I've been having accupuncture since last August, and I find it really helpful for energy levels and mood.