Wassef et al. [194], who performed studies in transgenic Drosophila melanogaster flies overexpressing α-synuclein and methionine sulfoxide reductase (MSRA), observed that dietary supplementation with S-methyl-L-cysteine was able to prevent or alleviate the symptoms of PD since it participates in the antioxidant mechanism of MSRA, inducing an increase in enzyme activity. This evidence concerns the gene MSRA and Parkinson disease.