OBJECTIVETo evaluate total antioxidant capacity (TAC) of seminal plasma in fertile and infertile men and understand the relation between seminal plasma TAC and male fertility.

METHODSTwo hundred and twenty-five infertile men were divided into 10 cases of obstructive azoospermic men, 42 cases of non-obstructive azoospermic men,20 cases of oligozoospermic men, 78 cases of asthenozoospermic men, 57 cases of oligoasthenozoospermic men, and 18 cases of normozoospermic men, then 28 fertile men were taken as the control. The seminal parameter analysis was performed by computer-assisted semen analysis (CASA) system. Seminal plasma TAC was measured using spectroscopic analysis.

RESULTSSeminal plasma TAC were (1.71 +/- 1.33) U in obstructive azoospermic men, (12.73 +/- 9.44) U in non-obstructive azoospermic men, (10.85 +/- 6.64) U in oligozoospermic men, (13.88 +/- 8.24) U in asthenozoospermic men, (11.20 +/- 7.02) U in oligoasthenozoospermic men, (18.07 +/- 8.73) U in normozoospermic men, and (19.82 +/- 6.33) U in fertile men. There was no significant difference in TAC between normozoospermic men and fertile men (P > 0.05). Compared with fertile men, seminal plasma TAC in other infertile groups was significantly lower (P < 0.01). There were significantly made positive correlation between seminal plasma TAC and sperm density (r = 0.182, P < 0.05), as well as sperm with grade a (r = 0.150, P < 0.05).

CONCLUSIONSeminal plasma TAC is closely related to male fertility, and the decreased level of TAC in seminal plasma may be one of the causes of male infertility.