Background: Male infertility annoys many couples. Traditional Chinese medicine (TCM) has been used for a long time in the treatment of male infertility. Although assisted reproductive technology is an effective therapy, TCM still plays an important role in the treatment of male infertility. TCM therapy is based on the diagnosis of TCM syndrome. But the essence of TCM syndrome is not well studied by modern science, especially in male infertility. We aim to investigate the metabolic changes of infertility males with Kidney-Yang deficiency syndrome (KYDS), the major TCM syndrome in male infertility, via metabolomics technique.
Methods: Seminal plasma samples were collected from 18 infertility males with KYDS and 18 fertility males. Liquid chromatography and mass spectrometry (LC-MS) were used for characterizing metabolomics profiles. Multivariate statistics of principal component analysis (PCA), partial least squares—discriminate analysis (PLS-DA) and pathway analysis were used for pattern recognition and metabolites identification.
Results: PCA shows difference in metabolism between the two groups and PLS-DA distinguish them well. 41 discriminating metabolites (18 in positive mode and 23 in negative mode) were identified. Seven metabolites were found to be linked to potential metabolic pathways (phenylalanine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, glyoxylate and dicarboxylate metabolism, tyrosine metabolism and sphingolipid metabolism).
Conclusions: Metabolic changes in tricarboxylic acid cycle, biosynthesis and metabolism of aromatic amino acids and sphingolipid metabolism may play an important role in the genesis of Kidney-Yang deficiency male infertility. This study gives a better understanding in KYDS and may provide a new approach to the essence of TCM syndromes in male infertility. Seminal plasma metabolomics analysis may be a possible way in diagnosing TCM syndrome in infertility males, especially for those asymptomatic patients with no TCM syndrome to differentiate.
