i think your title is very misleading btw, the experiment involved monkeys, not humans, they used a mucana extract THAT ONLY A LAB COULD PRODUCE EASILY and in reading the paper it appeared sinemet produced better UPDRS(?) scores,

"Effects of MPWE and LD. MPEP was
dissolved in sterile water and thoroughly mixed for 30–
45 mins. The mixture was then centrifuged at 14,000–15,000
RPM for 15–20 mins, and the supernatant was extracted
and filtered. The MPWE solution was then stored in sterile
containers at 4◦C. Prior to administration, the MPWE
solution was briefly agitated and dispensed orally. The dosage
concentration of MPWE was based on 4-5% of natural
occurring LD in MPEP such that the MPWE solution had
approximately 24mg LD per mL.
]


I also have to wonder about the following in possibly causing dyskinesias by possibly producing a very quick increase in l-dopa:
"When
compliance was an issue with oral LD+CD, animals received
systemic injections of LD at the equivalent optimal doses
of oral LD (LD methyl ester with benserazide (BZ))."


"3.1. MPEP and LD Effects on Parkinsonism and Basal Ganglia
Electrophysiology. mUPDRS scores on placebo were 15.6 ±
2.6 and decreased to 8.0 ± 1.6 with MPEP alone, 7.7 ± 1.5
with MPEP+CD, and 4.5 ± 1.1 with LD+CD, optimal doses
(Figure 1). These doses caused no observable adverse effects.
????????