ABSTRACT
Background: Toxic effects of anti-cancer and other drugs on the normal tissues could be reduced by the herbal plants and their fractions. This study investigated the protective effect of thymoquinone [TQ] as a fraction of Nigella sativa on methotrexate [MTX]- induced germ cell apoptosis in male mice
Materials and Methods: In this experimental study, thirty male Balb/c mice were divided randomly into 5 groups [n=6]. A single dose of MTX [20 mg/kg] and different concentrations of TQ were administrated for 4 consecutive days. Terminal deoxynucleotidyl transferase dUTP nick end labeling [TUNEL] assay was performed on paraffin embedded tissue sections to analysis the occurrence of apoptosis in the testis. Reverse transcription polymerase chain reaction [RT-PCR] of apoptosis-related genes was performed with RNA extracted from testes of the mice. Statistical analysis was done using one-way ANOVA
Results: In the MTX group, there was a significant increase in morphologic sign of germ cell degeneration of tubules [48 +/- 0.6%], apoptotic index [AI; 2.3 +/- 0.6%], as well as mRNA expression of p53 [P=0.008], caspase 8 [P=0.002], caspase 3 [P=0.005], caspase 9 [P=0.000], bax [P=0.004] and the ratio of bax/bcl-2 [P=0.000], whereas there was an decrease in the expression of bcl-2 [P=0.003], as compared to control group. In MTX+TQ groups, the data showed that different concentrations of TQ could improve the harmful effects caused by the MTX. The best protective effects were achieved in MTX+TQ [10 mg/kg]
Conclusion: TQ protects testicular germ cell against MTX-induced apoptosis by affecting related genes regulation