In Vitro Study of Toxicity of Triptolide to the Testicles of SD Rats

To investigate the effect,in vitro,of triptolide on the proliferation and expression of the protein,pan-cadherin,in cultured primary sertoli and/or spermatogenic cells isolated from SD rat testis.METHODS: Sertoli and spermatogenic cells from rats were isolated and cultured singly or mixture of two.The effect of triptolide at different concentrations(0,0.1,1,10,1.0×102,1.0×103,1.0×104,1.0×105 μg/L) on cell proliferation were studied by the MTT assay.Four doses which were below the level of least toxic dose to sertoli cells cultured singly,were selected and expression of the pan-cadherin protein in the cultured cells was examined useing immunocytochemistry.RESULTS: The cell proliferation was inhibited at the dose level of ≥10 μg/L in mixed cell culture(most were spermatogenic cells),and ≥1.0×103 μg/L in pure sertoli cell culture,and that these inhibitions depended on doses.The two IC 50 concentrations to cultured cells were 1.22 mg/L and 28.15 mg/L,respectively.Increased expression of pan-cadherin was observed at lower TL concentrations(0.1 and 1 μg/L)in mixed culture compared with vehicle control.CONCLUSION: It is suggested that triptolide may inhibit proliferation of spermatogenic cells at lower concentrations,and that of sertoli cells at higher concentrations.The reason of testicular toxicity of triptolide is probably the increased expression of pan-cadherin protein.