Effects of ferulic acid on fertile and asthenozoospermic infertile human sperm motility, viability, lipid peroxidation, and cyclic nucleotides.

The capacity of human sperm fertilization principally depends on sperm motility and membrane integrity. Reactive oxygen species, such as superoxide anion and hydrogen peroxide, are known to impair sperm motility and membrane integrity by inducing membrane lipid peroxidation (LPO). Ferulic acid (FA), an effective constituent in various medicinal herbs, has recently been shown to scavenge oxygen free radicals and increase the intracellular cAMP and cGMP. The aim of this study is to investigate the effects of FA on human sperm motility, viability, lipid peroxidation, and cyclic nucleotides in fertile and asthenozoospermic infertile individuals in vitro. The sperm samples were obtained from 10 fertile volunteers and 10 asthenozoospermic infertile patients. Washed spermatozoa were incubated at 37 degrees C in Ham's F-10 medium with 0, 0.1, 0.2, 0.4, 0.8, or 1.6 mM of FA. Samples were analyzed for viability, determined by eosin-Y dye exclusion method at 0, 1, 2, 3, 5, and 6 h of incubation; motility, determined by the trans-membrane migration method within 2 h of incubation; LPO, determined by thiobarbituric acid (TBA) method at 3 h of incubation and the intracellular cAMP and cGMP, determined, respectively, by 3H-cAMP and 125I-cGMP radioimmunoassay at 3 h of incubation. The results showed: in both fertile and infertile spermatozoa, the viability, trans-membrane migration ratio (TMMR) and the levels of intracellular cAMP and cGMP in FA-treated spermatozoa were significantly higher than those of spermatozoa in control groups, while TBA-reactive substances contents in treated spermatozoa were significantly lower than those in control spermatozoa. The effects of FA on these processes were concentration dependent. These data suggested that FA is beneficial to sperm viability and motility in both fertile and infertile individuals, and that reduction of lipid peroxidative damage to sperm membranes and increase of intracellular cAMP and cGMP may be involved in these benefits. It is possible that FA may be used for cure of asthenozoospermic infertility.