Role of Vitamin C in 1C metabolism
Vitamin C enhances folate cycle
A study (R1) observed significant changes in the metabolites of folate cycle and related metabolites after pre-treatment of the cell with ascorbic acid:
- Increased level of THF
- 10-fold Increase of 5-MTHF
- Decreased level of 10-Formyl-THF
- Increased level of methionine
- Increase in Thymidine
Quote:
Compared to untreated cells, treatment of C2C12 cells with AA at 100 µM resulted in enhanced concentrations of folic acid (2.5-fold) and 5-methyl-tetrahydrofolate (5-methyl-THF, 10-fold increase) whereas the relative concentrations of 10-formyl-tetrahydrofolate decreased by >90% upon AA pretreatment, indicative of increased utilization for the biosynthesis of active THF metabolites.
The impact of AA on the folate-mediated one-carbon cycle further manifested itself as an increase in the levels of methionine, whose formation from homocysteine is 5-methyl-THF dependent, and an increase in thymidine, whose formation from deoxyuridine monophosphate (dUMP) is dependent on 5,10-methylene-THF. (R1)
These changes are likely due to increased availability of NADPH as suggested by the authors (see Conclusions section below).
If that assumption is true, then other measures that increase NADPH availability should lead to the similar observations.
Conclusions
Our experiments <…> suggest that AA activates the folate-mediated one-carbon cycle thereby promoting the 5,10-methylene-THF-dependent formation of thymidine and facilitating the 5-methyl-THF-dependent conversion of Hcy into methionine. From a mechanistic perspective, AA appears to spare NAD(P)H and so increase availability of reducing equivalents for the reductive steps from 10-formyl-THF to 5-methyl-THF via 5,10-methylene-THF.
Graphical abstract
What is C21C12 myoblasts
C2C12 is an immortalized mouse myoblast cell line. The C2C12 cell line is a subclone of myoblasts that were originally obtained by Yaffe and Saxel at the Weizmann Institute of Science in Israel in 1977.
Developed for in vitro studies of myoblasts isolated from the complex interactions of in vivo conditions, C2C12 cells are useful in biomedical research.
These cells are capable of rapid proliferation under high serum conditions and differentiation into myotubes under low serum conditions.
Source: R3, Wikipedia