Investigation of protective effects of silymarin on methotrexate-induced injury in rat testis

The protective effects of silymarine (SLM) on the methotrexate(MTX)-induced testicular toxicity in rats was investigated by using enzyme activity, histopathological, and levels of hormone, protein and gene expression. Forty-six-male rats were divided into six-groups as following; groupI(control,n=7); groupII(MTX-on-day1,n=8); groupIII(MTX-on-first-day+7days SLM,n=8); groupIV(7days SLM, n=7); groupV(MTX-on-day-7,n=8), and groupVI(7days SLM+MTX-on-day7,n=8). SLM (100mg/kg) or MTX (20mg/kg) was administered intraperitoneally. On-day-8, rats were sacrificed. Plasma AST, ALT and testosterone levels were measured. Levels of MDA, CAT, SOD, TAS/TOS/OSI was measured. Real-time-PCR was used to evaluate genes in apoptosis(BCL2, BAX, CAD), anti-oxidant enzymes (Zn-SOD, Mg-SOD, CAT, GPx1), and steroidogenesis (ABP,StAR). The protein level of pro-caspase-3 was also evaluated. Data were analyzed using one-way-ANOVA and post-hoc Tukey test was applied. p<0.05 were accepted as statistically significant. Seven-day effect of MTX caused a decrease in body and testicular weights in groupII and III. Although testosterone levels decreased in groupII and III, AST and ALT increased in groupII. While antioxidant parameters decreased, oxidation parameters increased in group II. SLM (groupIII) had improving effects on those parameters. StAR-expression was down-regulated in groupII, and III. CAD and BAX expressions increased in groupsII and III. BCL2 and GPx1 increased in those groups where MTX and SLM were used together (III,VI). While Pro-Caspase-3 increased in groupIII, MTX decreased Pro-Caspase-3 in groupII. Compared to seven-day effect of MTX, one-day effect of MTX did not cause serious damage on rat testis. However, seven-day effect of MTX caused serious toxicity on rat testis. Moreover, SLM had protective effects on MTX-induced testicular toxicity in rats.