Berberine Ameliorates the Germ Cells Cycle Arrest During Spermatogenesis Following Experimental Varicocele Induction; Evidences for Cyclin D1, CDK-4 and P21 Proteins Involvement

Background: The present study was done to analyze the protective effect of berberine (BBR), an antioxidant chemical, on experimental varicocele (VCL)-induced pathogenesis on germ cells cycle machinery during early mitosis.Methods and Materials: For this purpose, 30 mature male Wistar rats (180-20 gr) were divided into control-sham (undergone simple laparotomy), VCL-sole induced, 50 mg kg−1 and 100 mg kg−1 BBR-treated VCL groups. Following 60 days, the histological characteristics, including tubular differentiation (TDI), repopulation (RI) and spermiogenesis (SPI) were investigated. Moreover, the cyclin D1+, cyclin-dependent kinase-4 (cdk4+) and p21+ cells number per mm2 of tissue were assessed by using Immunohistochemical staining. Finally, the DNA fragmentation was analyzed using DNA ladder test.Results: The BBR significantly (p<0.05) enhanced the percentages of tubules with positive TDI, RI and SPI versus VCL-sole group. Moreover, the mean distributions of cyclin D1+ and cdk+ were decreased in VCL-sole animals. However, the animals in BBR-treated groups (especially in 100 mg kg-1) exhibited enhanced cyclin D1+ and cdk+ cells per mm2. Finally, the BBR-treated groups exhibited diminished p21+ cells per mm2 and represented a remarkable DNA recovery versus VCL-sole groups. No histopathological changes were revealed in the control-sham animals.Conclusion: The BBR is potentially able to promote germ cells cycle through protecting cellular DNA content, down-regulating p21 expression and ameliorating the cyclin-D1 and cdk4 expressions. However, more studies are needed to completely confirm the protective effect of BBR against VCL-suppressed cell cycle machinery.

Keywords:

Varicocele , Berberine , Germ Cells , Cell Cycle Machinery , DNA Fragmentation