I will read those and get back to you. I will tell you that if peak GH values are used vs. AUC, it's not helpful. GH is a long-term substance. It has to be elevated above baseline for extended periods of time to be useful. A 100% increase based on a peak reading, which returns to baseline shortly after, isn't helpful to a BBer.
The analogy in performance auto parts is that between a supercharger and a nitrous kit for a endurance race. If you're in a long distance race, the supercharger will provide a significant, long-term HP increase. The nitrous kit will only provide short bursts which, in the long-term, isn't what the driver needs.
I will not comment further until I read the two articles.
Most LD/Mucuna Pruriens L., comparative studies measure onset, peak serum concentrations, latency to peak concentrations, as well as AUC (measuring area under peak concentration) as key components in LD and naturopathic LD-related modalities; as the vast majority of Mucuna-related research is centered around treating PD, the AUCs, and not peak-concentrations, are key points of analysis!
Mucuna pruriens in Parkinson's disease: a double blind clinical and pharmacological study. Katzenschlager R, et al.
National Hospital for Neurology and Neurosurgery, London, UK.
BACKGROUND: The seed powder of the leguminous plant, Mucuna pruriens has long been used in traditional Ayurvedic Indian medicine for diseases including parkinsonism. We have assessed the clinical effects and levodopa (L-dopa) pharmacokinetics following two different doses of mucuna preparation and compared them with standard L-dopa/carbidopa (LD/CD). METHODS: Eight Parkinson's disease patients with a short duration L-dopa response and on period dyskinesias completed a randomised, controlled, double blind crossover trial. Patients were challenged with single doses of 200/50 mg LD/CD, and 15 and 30 g of mucuna preparation in randomised order at weekly intervals. L-dopa pharmacokinetics were determined, and Unified Parkinson's Disease Rating Scale and tapping speed were obtained at baseline and repeatedly during the 4 h following drug ingestion. Dyskinesias were assessed using modified AIMS and Goetz scales. RESULTS: Compared with standard LD/CD, the 30 g mucuna preparation led to a considerably faster onset of effect (34.6 v 68.5 min; p = 0.021), reflected in shorter latencies to peak L-dopa plasma concentrations. Mean on time was 21.9% (37 min) longer with 30 g mucuna than with LD/CD (p = 0.021); peak L-dopa plasma concentrations were 110% higher and the area under the plasma concentration v time curve (area under curve) was 165.3% larger (p = 0.012).[/B] No significant differences in dyskinesias or tolerability occurred. CONCLUSIONS: The rapid onset of action and longer on time without concomitant increase in dyskinesias on mucuna seed powder formulation suggest that this natural source of L-dopa might possess advantages over conventional L-dopa preparations in the long term management of PD. Assessment of long term efficacy and tolerability in a randomised, controlled study is warranted.
Further, trials with HP200 (crude preparation of Mucuna Pruriens L., standardized to 4% L-DOPA) suggest that MP's pharmacokinetic profile in healthy, normal patients is similar to that of synthetic LD - suggesting that the results found in the Tucci and Greenspan studies [using 500mg synthetic LD] are directly translatable to preparations of Mucuna Pruriens L., In respects to USP Labs' PowerFULL, the MP is standardized to 50% L-DOPA for production, and per three caps contains approximately 500-550mg natural L-DOPA with postulated PDIs and/or independent LD enhancing adjuvants.
Bioavailability of L-DOPA from HP-200 - a Formulation of Seed Powder of Mucuna pruriens (Bak): a Pharmacokinetic and Pharmacodynamic Study. S. S. Mahajani et al.
ABSTRACT
...The results indicate that on oral administration, L-DOPA was absorbed from HP-200 with plasma peak levels (Cmax=1.56±0.163 g/mL) achieved at Tmax=83±16.09 min. The plasma half life was 102±2 min and the auc was determined as 6.508±0.421 g/h/mL. The pharmacokinetic profile of HP-200 exhibited characteristics similar to formulations of synthetic L-DOPA, except for the lack of a sharp peak. HP-200, a new herbal formulation, appears to be suitable for the treatment of Parkinson's disease.
It must be noted, also, that the Greenspan and Tucci studies above were using pure, synthetic LD without concomitant PDI (peripheral decarboxylase inhibitors) and/or COMT administration; trials comparing Mucuna Pruriens L., as well Sinemet (LD preparation with carbidopa) relate a demonstrated efficacy of 2-3x that of the standard LD used in the above studies. Essentially relating that 100mg of LD w/ concomitant PDI administration is equivalent to 500mg intravenously injected LD. Needless to say, the LD concentration in USP Labs' PowerFULL is sufficient enough to warrant a direct comparison with the studies found above.
The ones found below all utilized healthy, normal patients, and all elicited GH responses:
Boyd, A. et al (1970) “Stimulation of human-growth-hormone secretion by L-dopa” New Engl J Med 283: 1425-29.
Boden, G. et al (1971) “The influence of levodopa (L-dopa) on release of anterior pituitary hormones in man” Clin Res 19:716.
Ajlouni, K. et al (1975) “Effect of glucose on the growth hormone response to L-dopa in normal and diabetic subjects” Diabetes 24:633-36.
Finally, trials with MP on PD patients have reflected an GHRH
and GH increase post-MP administration ; suggesting the Hypothalamic-Pituitary-Axis is being positively affected by the neuroregenerative capacities of MP, producing greater AUC GH readings due to positive feedback.
