ABSTRACT
<p><b>OBJECTIVE</b>To study the effects of Qingli Shengjing Pills (QSP) on the apoptosis of germ cells and expressions of Fas and FasL in male mice infected with Escherichia coli (E. coli), and to clarify the molecular mechanism of QSP in the treatment of male infertility induced by E. coli infection.</p><p><b>METHODS</b>Fifty male mice were injected with E. coli via the bladder to make infection models, and at 15 dpi equally randomized into five groups: an untreated, a high-dose QSP (22.5 g/ml), a medium-dose QSP (13.5 g/ml), a low-dose QSP (4.50 g/ml) and a Furadantin treatment group, which were coded as MN, MTa, MTb, MTc and MTd, respectively. Another 10 mice were injected with saline and included in the control group coded as CT. After 10 days of oral medication, the apoptosis of germ cells in the testis of the mice was detected by flow cytometry, the expressions of Fas and FasL determined by immunohistochemistry and the histopathological changes observed simultaneously.</p><p><b>RESULTS</b>After the treatment, the apoptosis of germ cells was observed in all the infected groups, and the apoptosis level in MN (57.44%) was significantly higher than that in CT (28.54%), MTb (28.59%) or MTa (30.11%) (P < 0.01) but had no significant difference from that in MTc (46.54%) or MTd (43.41%) (P > 0.05). The expressions of Fas and FasL proteins were significantly higher in MN than in CT, MTa, MTb, MTc and MTd (P < 0.01). Histopathological changes of the testis tissue were observed in MN, but not in other groups.</p><p><b>CONCLUSION</b>E. coli infection could increase the apoptosis rate of germ cells and the expressions of Fas and FasL proteins. Qingli Shengjing Pills, capable of enhancing reproductivity by reducing the expressions of Fas and FasL and apoptosis of germ cells, can be used as one of the effective drugs for infertility induced by E. coli infection.</p>