Preliminary research on abating rat testicle toxicity due to triptolide after oral polymer nanoparticle delivery

This study was undertaken to investigate the effect of triptolide (TP) on male rats after oral polymer nanoparticle delivery (TP-loaded poly(D,L-lactic acid) nanoparticles, TP-PLA-NPs). Free TP and TP-PLA-NPs were administered orally at doses of 0.2 and 0.6 mg/kg for 15 days and rats were sacrified at end of the dosage period. All rat testes were weighed, fructose content and activity of acid phosphatase (ACP) were assayed, and testis tissues were observed histopathologically. Testis weight, testis index, ACP activity, and fructose content of the treated animals were lower than those of the control group. Moreover, ACP activity and fructose content were markedly decreased for free TP of 0.6 mg/kg in comparison to the same dose of TP-PLA-NPs. Obvious pathological changes were not observed for a dose of 0.2 mg/kg free TP and TPPLA-NPs at the end of 15 days. At a dose of 0.6 mg/kg, however, free TP caused more serious damage to the testes than TP-PLA-NPs. These results revealed that TP-PLA-NPs might decrease the testis toxicity of TP because TP was slowly released from polymer nanoparticles. Further research on this mechanism of abated toxicity is in progress.