Decrease in pyridoxal-5'-phosphate concentration and increase in pyridoxal concentration in rat plasma by 4'-O-methylpyridoxine administration.
Nutr Res
; 35(7): 637-42, 2015 Jul.
Article
in En
| MEDLINE
| ID: mdl-26092494
ABSTRACT
Food poisoning from Ginkgo biloba seeds can cause epilepsy because of a decrease in γ-aminobutyric acid (GABA) concentrations in the brain. We previously demonstrated that 4'-O-methylpyridoxine (MPN) is responsible for this observed toxicity of G biloba seeds; however, the mechanism for the decrease in GABA and plasma concentration profile of MPN has not been clarified. Our hypothesis is that MPN induces a decrease in vitamin B6 concentrations, resulting in a decrease in GABA concentration. This study aimed to characterize the plasma concentration profile of MPN and intrinsic vitamin B6 concentrations (pyridoxal [PL], PL-5'-phosphate [PLP], and 4-pyridoxic acid) using a rat model. Plasma concentrations of B6 vitamers after intravenous MPN administration (5 mg/kg) were determined using high-performance liquid chromatography with a fluorescence detector. The half-life of MPN (0.91 ± 0.05 hours) was shorter in rats than the previously reported value in humans. We found a significant decrease in the plasma concentration of PLP, an active form of vitamin B6, after MPN administration. We also observed an increase in plasma PL and 4-pyridoxic acid concentrations; the increase in PL concentration may be caused by either metabolism of MPN to PL or by MPN-mediated inhibition of PL kinase. The present study is the first in vivo study showing relatively rapid elimination of MPN in rats and a decrease in plasma PLP concentration caused by MPN.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pyridoxal Kinase
/
Pyridoxal Phosphate
/
Pyridoxine
/
Vitamin B 6 Deficiency
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Brain
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Ginkgo biloba
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Gamma-Aminobutyric Acid
Limits:
Animals
/
Humans
/
Male
Language:
En
Journal:
Nutr Res
Year:
2015
Document type:
Article
Affiliation country:
Japan