[In vitro inhibition of celastrol on spermatozoa fertilization ability of guinea pig].

The effects of celastrol (Cel), isolated from Tripterygium wilfordii, on guinea pig sperm forward motility (FM), capacitation (Cap), the acrosome reaction (AR) and sperm penetration assay (SPA) were assessed in vitro. Cel (5 micrograms.ml-1) was found to inhibit these spermatozoal functions, and the inhibitions were proportional to the concentrations of Cel used. The potency of inhibition of Cel on the fertilizing ability in guinea pig spermatozoa in vitro seems to follow the order: Cap > FM > SPA > AR. The inhibitory effect appeared to be reversible after washing away Cel if the duration of exposure of spermatozoa to Cel was shorter than 3 h. In a comparative study, the inhibitory effects of Cel on guinea pig sperm FM and AR were significantly stronger than those of gossypol acetic acid.