This looks like a drug that shows promise in real neuroprotection, improving symptoms and maybe even restoring neurons. At least in rats.
Or is it just another research paper that never comes to reality, at least for people who are well into PD.



http://www.epda.eu.com/en/research-p...8-15-neurosci/

http://www.sciencedirect.com/science...6452213003539#

In conclusion, long-term administration of SMI resulted in a significant dopaminergic neuroprotection, including TH-positive neurons, dopamine receptors, and DAT expression in aged rats. More importantly, it also improved motor function. Given the role of GDNF as a critical trophic factor for protecting dopamine neurons, and the results showed in previous study in vitro, it implies that SMI may attenuate dopamine neuron degeneration and motor decline through elevating GDNF levels in aged rats. It suggests that SMI may become effective therapeutic strategies aiming at halting the progressive process of extrapyramidal disability in the elderly.
The purpose of this paper is to study the effect of smilagenin (SMI) (PYM50028), a sapogenin compound originally identified from Chinese medicinal herb, on dopamine neurons and locomotor ability in aged rats. Experiments were carried out on young and aged Sprague–Dawley rats, which were daily administered with either SMI (18 mg/kg/day) or vehicle (0.5% sodium carboxymethycellulose [CMCNa]). Open-field and rotarod performance tests revealed that behavioral ability was impaired in aged rats and was improved by oral administration of smilagenin. Immunohistochemical data showed that tyrosine hydroxylase (TH)-positive neuron numbers in the substantia nigra pars compacta (unbiased stereological counting) were altered with aging and were increased by smilagenin treatment. Likewise, the dopamine receptor density and the striatal dopamine transporter (DAT) density (125I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane [125I-FP-CIT] autoradiography) were significantly lowered in aged rats as compared to young rats, and treatment with smilagenin significantly elevated the dopamine receptor and DAT density in aged rats. Furthermore, smilagenin enhances glial cell-derived neurotrophic factor (GDNF) release both in the striatum and midbrain. These results indicate a possible role of smilagenin in the treatment of age-related extrapyramidal disorders.

Wasn't smilagenin the active ingredient in the late lamented Cogane that performed on par with placebo?

can be found in Zhi Mu, the Chinese herb from the plant Anemarrhena asphodeloides. Used as an antipyretic, anti-inflammatory, anti-diabetic, and antidepressant in TCM. It may assist learning, and may have anti-liver cancer properties.