[Yam polysaccharide improves sperm viability and protects sperm DNA integrity in vitro]

To clarify the roles of yam polysaccharide (YPS) in improving sperm viability and protecting sperm DNA integrity in vitro and provide a new approach to the treatment of oligoasthenozoospermia.

We collected samples by masturbation from 36 normal fertile males aged 27－39 years. Each sample was divided into six groups: blank control or treated with normal saline, vitamin C solution, and YPS solution at low (0.25 mg/ml), medium (1.0 mg/ml) or high concentration (5.0 mg/ml). Using eosin-Y staining, sperm hypotonic swelling (HOS) and sperm chromatin diffusion (SCD) test, we observed the effects of different concentrations of YPS on sperm viability, membrane integrity and nuclear DNA.

After 24 and 48 hours of treatment, sperm viability was markedly reduced in the vitamin C (［28.5 ± 3.1］ and ［6.5 ± 1.2］%), low-YPS (［31.3 ± 3.5］ and ［6.5 ± 2.2］%), medium-YPS (［37.1 ± 3.5］ and ［9.5 ± 2.8］%) and high-YPS groups (［38.3 ± 3.3］ and ［9.0 ± 3.2］%) as compared with the blank control (［17.3 ± 2.1］ and ［3.2 ± 1.3］%) (P <0.01) and normal saline groups (［13.4 ± 4.1］ and ［3.1 ± 2.0］%) (P <0.01), and it was significantly higher in the medium- and high-YPS than in the vitamin C group (P <0.05 and P <0.01). The rate of sperm DNA fragmentation was remarkably decreased at 48 hours in the vitamin C (［30.5 ± 3.1］%), low-YPS (［29.4 ± 2.6］%), medium-YPS (［28.5 ± 2.3］%) and high-YPS groups (［27.9 ± 1.9］%) in comparison with the blank control (［41.7 ± 2.2］%) (P <0.01) and normal saline groups (［42.1 ± 3.3］%), markedly lower in the medium- and high-YPS than in the blank control, normal saline and vitamin C groups (P <0.05 or P <0.01), but with no statistically significant difference between the low-YPS and vitamin C groups (P >0.05).

Yam polysaccharide can improve sperm viability and protect sperm DNA integrity in vitro.