Metabonomic analysis of seminal plasma in necrozoospermia patients based on liquid chromatography-mass spectrometry

Background In the pathological study of necrozoospermia—a form of sperm mortality—the underlying metabolic mechanism remains unclear. Thus, the aim of this study was to characterize metabolic alterations in the seminal plasma of necrozoospermic patients and to provide insights into the etiology of the disease. Methods Seminal plasma samples were collected from patients diagnosed with necrozoospermia (n=28) as well as normozoospermia (n=37). The samples were analyzed using nontargeted metabolomics based on liquid chromatography-mass spectrometry (LC-MS). The raw data were subjected to multivariate analysis to identify metabolites correlated with necrozoospermia. Differential metabolites were subjected to pathway analysis using MetaboAnalyst. Results The results of the metabolomic analysis showed that there were 194 differential metabolites between the two groups; 129 metabolites were upregulated and 65 metabolites were downregulated. Among the differential metabolites, the top ten differential metabolites were choline, benzaldehyde, pyrazinamide, 5-aminoimidazole-4-carboxamide, and dihydrothymine. The following differential metabolite pathways were identified, and the top five metabolite pathways were arachidonic acid metabolism, steroid hormone biosynthesis, alanine aspartate and glutamate metabolism, bile secretion, and prostate cancer. Conclusions The elevation of choline and 2-hydroxyglutarate levels in seminal plasma was an important finding, and the results also indicate that abnormalities in arachidonic acid metabolism and glutamate metabolism were an underlying pathological mechanism of necrozoospermia.