RESUMO
ObjectiveTo observe the effect of Cuscutae Semen total flavonoids combined with Tripterygium wilfordii polyglycoside tablets （TWPT） on ovarian germline stem cells of female physiological mice through neurogenic locus notch homolog （Notch） signaling pathway. MethodSixty female Kunming mice （5 weeks old） were randomly divided into normal group， Tripterygium wilfordii polyglycoside tablets low-， high-dose groups （13.65 mg·kg-1·d-1 and 27.3 mg·kg-1·d-1， 1 and 2 times clinical equivalent dose）， Cuscutae Semen total flavonoids low- and high-dose groups （150 mg·kg-1·d-1 and 300 mg·kg-1·d-1）， and combination group （13.65 mg·kg-1·d-1 TWPT and 150 mg·kg-1·d-1 Cuscutae Semen total flavonoids）， with 10 in each group. After 3 weeks of continuous administration， the uterus/brain and ovarian/brain indexes were calculated， and the pathological changes of ovarian tissue were observed under light microscope. The content of estradiol in serum was determined by enzyme linked immunosorbent assay （ELISA）. Immunofluorescence assay was performed to observe the expressions of germline stem cell markers in ovarian epithelium， including mouse vasa homologue （Mvh）， octamer-binding transcription factor 4 （Oct4）， tyrosine-protein kinase receptor （c-kit）， Nanog， Notch signaling pathway molecules， neurogenic locus notch homolog protein 1 （Notch1）， hes family BHLH transcription factor 1（Hes1）， and jagged canonical Notch ligand 1 （JAG1）. ResultCompared with the normal group， low and high doses of TWPT had no significant effect on the uterus/brain and ovary/brain indexes and the uterus and ovary morphologies of mice， while only the number of atretic follicles was increased （P<0.01）. The expressions of ovarian germline stem cell markers and Notch signaling pathway molecules had a decreasing trend in TWPT low-dose group， while the expressions of Mvh， c-kit， and Nanog were down-regulated （P<0.05， P<0.01） and the expressions of Notch1 and Hes1 were also reduced （P<0.01） in TWPT high-dose group. However， the above indexes were increased in Cuscutae Semen total flavonoids low-dose group （P<0.05， P<0.01）. Compared with the low does of TWPT group， the combination group had a decrease in the increased number of atretic follicles （P<0.01）， an improvement in the down-regulated expressions of Mvh and Nanog （P<0.01）， and an increase in the expressions of Notch1 and Hes1 （P<0.05， P<0.01）. ConclusionOvarian germline stem cells are the source target of the reproductive toxicity of TWPT. Cuscutae Semen total flavonoids participate in the regulation of the germline stem cell pathways to alleviate the reproductive toxicity caused by TWPT， and its mechanism of action may be related to the Notch signaling pathway.