Dr. Ron’s Research Review – March 11, 2020

©

This week’s research review focuses on methyl group-donating vitamins for Parkinson's disease.

Methyl Group-Donating Vitamins

Levodopa (LD)/dopa decarboxylase inhibitor application increases 3-O-methyldopa (3-OMD) concentrations in association with methyl group transfers, which demand for the conversion of methionine to homocysteine. This accompanying reaction is partially reversible by methyl group-donating vitamins.
A study investigated of the effect of methyl group-donating vitamins on 3-O-methyldopa synthesis in Levodopa-treated patients with Parkinson disease.
The study determined Levodopa, 3-O-methyldopa, and homocysteine plasma concentrations in relation to daily Levodopa dosage administered orally or as duodenal infusion with and without vitamins.
Cohort 1 consisted of 15 Parkinson's disease patients treated with oral Levodopa with dopa decarboxylase inhibitor. In cohort 2, seventeen Parkinson's disease patients received a daily duodenal Levodopa/Carbidopa gel infusion therapy. In cohort 3, eight patients received chronic monthly intramuscular injection of vitamins B6 (200 mg pyridoxine) and B12 (cyanocobalamin 1000 Kg) plus daily oral folic acid intake 5 mg within 1 year of duodenal Levodopa/Carbidopa gel infusion therapy.
Orally Levodopa-treated patients with Parkinson disease had a lower Levodopa dose compared with the ones on a Levodopa infusion, but Levodopa, 3-O-methyldopa, and homocysteine bioavailability was not different. The same 3-O-methyldopa and homocysteine accumulation despite the applied higher Levodopa dosage during the infusion indicates a limited methylation capacity. Higher 3-O-methyldopa concentrations occurred during chronic vitamin supplementation, whereas the other parameters did not vary from the ones before vitamin intake.  Vitamin supplementation elevated methylation of Levodopa to 3-O-methyldopa.
To a certain extent, plasma levels of homocysteine may reflect methyl group donation resources, whereas 3-O-methyldopa concentrations may mirror methylation capacity. (Müller et al., 2013)

 

Dr. Ron

 


Articles

 

Methyl group-donating vitamins elevate 3-O-methyldopa in patients with Parkinson disease.
            (Müller et al., 2013) Download
BACKGROUND:  Levodopa (LD)/dopa decarboxylase inhibitor application increases 3-O-methyldopa (3-OMD) concentrations in association with methyl group transfers, which demand for the conversion of methionine to homocysteine. This accompanying reaction is partially reversible by methyl group-donating vitamins. OBJECTIVE:  The objective of this study was to investigate of the effect of methyl group-donating vitamins on 3-OMD synthesis in LD-treated patients with Parkinson disease. METHODS:  We determined LD, 3-OMD, and homocysteine plasma concentrations in relation to daily LD dosage administered orally or as duodenal infusion with and without vitamins. RESULTS:  Orally LD-treated patients with Parkinson disease had a lower LD dose compared with the ones on an LD infusion, but LD, 3-OMD, and homocysteine bioavailability was not different. The same 3-OMD and homocysteine accumulation despite the applied higher LD dosage during the infusion indicates a limited methylation capacity. Higher 3-OMD concentrations occurred during chronic vitamin supplementation, whereas the other parameters did not vary from the ones before vitamin intake. CONCLUSIONS:  Vitamin supplementation elevated methylation of LD to 3-OMD. We suggest that, to a certain extent, plasma levels of homocysteine may reflect methyl group donation resources, whereas 3-OMD concentrations may mirror methylation capacity.

 

References

Müller, T, et al. (2013), ‘Methyl group-donating vitamins elevate 3-O-methyldopa in patients with Parkinson disease.’, Clin Neuropharmacol, 36 (2), 52-54. PubMed: 23503547