Human sperm motility stimulating activity of a sulfono glycolipid isolatedfrom Sri Lankan marine red alga Gelidiella acerosa

Aim: To evaluate the sperm motility stimulating activity of a sulfono glyco lipid (S-ACT-1) isolated from Gelidiella acerosa, a Sri Lankan marine red a lgae. Methods: S-ACT-1, a white amorphous powder was separated from more polar fr actions of the hexane soluble of 1:1 CH2Cl2/MeOH extract and subjected to H -1, C-13 NMR and IR Spectroscopy after reverse phase HPLC for identificatio n. Effects of S-ACT-1 on human sperm motility was assessed in vitro at 10, 100 and 1000 mug/mL concentrations at 37 degreesC for 0, 5, 15, 30 and 60 m in. Results: S-ACT-1 was identified as a glycolipid sulfate. The lower dose inc reased the sperm motilily slightly, whilst the medium dose significantly in creased the motility (P < 0.05) from 5 min of incubation reaching a peak at 15 min and the stimulant effect was sustained throughout the experimental period. Furthermore, the medium dose rendered 80% of the immotile viable sp erm motile. In contrast, the highest dose impaired the sperm motility. The sperm stimulating activity of S-ACT-1 was dose-dependent and had a bell-sha ped dose response curve for all the 5 incubation periods. Conclusion: S-ACT-1 of Gelidiella acerosa is a Sulfono glycolipid. S-ACT-1 has a potent sperm motility stimulating activity in vitro and has the poten tial to be developed into a sperm stimulant.