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4′-O-methylpyridoxine (MPN) and its 5′-glucoside (MPNG) in Ginkgo biloba seeds cause poisoning. Sample preparation for high-performance liquid chromatography was optimized to determine the amounts of MPN and MPNG at various extraction temperatures and pH levels. The effects of heating treatment on MPN and MPNG were investigated. MPNG was the main MPN analog in raw G. biloba seeds under the optimal temperature (0 °C) and pH (2.5). Boiling decreased the contents of MPN (81.76%), MPNG (9.15%), and total MPN (TMPN, 30.14%). The contents of MPN and TMPN considerably decreased (80.41% and 20.11%, respectively), whereas that of MPNG increased (4.42%) after microwave treatment. Results demonstrate that boiling can reduce the toxicity of G. biloba seeds for consumption. [ABSTRACT FROM AUTHOR]

Ginkgo biloba seeds are wildly used in the food and medicine industry. It has been found that 4′-O-methylpyridoxine (MPN) is responsible for the poisoning caused by G. biloba seeds. The objective of this study was to explore and optimize the extraction method of MPN from G. biloba seeds, and investigate its toxic effect on human gastric epithelial cells (GES-1) and the potential related mechanisms. The results showed that the extraction amount of MPN was 1.933 μg/mg, when extracted at 40 °C for 100 min, with the solid–liquid ratio at 1:10. MPN inhibited the proliferation of GES-1 cells, for which the inhibition rate was 38.27% when the concentration of MPN was 100 μM, and the IC50 value was 127.80 μM; meanwhile, the cell cycle was arrested in G2 phase. High concentration of MPN (100 μM) had significant effects on the nucleus of GES-1 cells, and the proportion of apoptotic cells reached 43.80%. Furthermore, the Western blotting analysis showed that MPN could reduce mitochondrial membrane potential by increasing the expression levels of apoptotic proteins Caspase 8 and Bax in GES-1 cells. In conclusion, MPN may induce apoptosis in GES-1 cells, which leads to toxicity in the human body. [ABSTRACT FROM AUTHOR]

4′- O -methylpyridoxine (MPN), a recognized antivitamin B 6 compound, is a potentially poisonous substance found in Ginkgo biloba seeds and leaves. In this work, the body weights, histopathological changes, plasma vitamin B 6 (VB 6), biochemical parameters, oxidative stress responses, and amino acids of rats were investigated after intragastric administration of MPN for 15 days. Results showed that intragastric administration of 50 mg/kg BW MPN caused pathological changes in the brain and heart tissues of rats. Administration of 10 mg/kg and 30 mg/kg BW MPN can significantly increase VB 6 analogs in the plasma of rats, such as pyridoxal-5′-phosphate, pyridoxal. Results of biochemical parameters indicated that MPN can damage brains and hearts by changing the enzyme activity of these organs. These results suggest that consumption of Ginkgo biloba seeds for the long term, even in a small quantity, may lead to poisoning. [Display omitted] • Overconsumption of Ginkgo biloba seeds leads to poisoning. • 4′- O -methylpyridoxine, in Ginkgo biloba L., is responsible for the poisoning. • Administration of 4′- O -methylpyridoxine caused pathological changes in rats. • 4′- O -methylpyridoxine can significantly increase Vitamin B 6 analogs in rats. [ABSTRACT FROM AUTHOR]

Highlights • The composition and contents of 4ʹ- O -methylpyridoxine analogues were significantly influenced by growth regions of Ginkgo biloba seeds. • 4ʹ- O -methylpyridoxine and its glycoside may play important roles in the growth of Ginkgo biloba seeds. • Pyridoxamine-5ʹ-phosphate had greater differences in nine regions compared to other 4ʹ- O -methylpyridoxine analogues. • Ginkgo biloba seeds as vitamin B 6 supplements have potential application in food and drug industries. Abstract Ginkgo biloba seeds are widely used in the food and medicine industry. This study aimed to compare the contents of anti-vitamin B 6 (VB 6), including 4′- O -methylpyridoxine (MPN) and MPN-5′-glucoside (MPNG), and VB 6 compounds in Ginkgo biloba seeds in terms of growth regions in China. Results showed that growth regions have a significant effect on the composition and content of MPN analogues. The total MPN and VB 6 contents in G. biloba seeds varied from 187.17 μg/g to 224.04 μg/g and 400.44 μg/g to 586.82 μg/g, respectively. Principal component analysis revealed that MPN and MPNG are important contributors in determining the difference of nine regions in China. Moreover, pyridoxal phosphate, an active form of VB 6 , had dispersed distribution in nine regions of China. These results suggest that the environmental condition may lead to the difference and similarities of MPN analogues in different regions of China. [ABSTRACT FROM AUTHOR]