Fig. 1

a Methylation reaction pathway of homocysteine, to form essential amino acid methionine and another choline metabolite betaine, dependent pathway as methyl donor for methylation of homocysteine for methionine formation and b demonstrated that methionine as a universal donor of S-adenosyl methionine (SAM) which contribute to convert phosphatidylethanolamine into phosphatidylcholine to generates choline