Busulfan-mediated oxidative stress and genotoxicity decrease in sperm of Satureja Khuzestanica essential oil-administered mice. 
Here, we studied the protective effects of Satureja Khuzestanica essential oil (SKEO) as a potent anti-oxidant, against damage caused by chemotherapy with busulfan in testis and epididymal sperm of adult mice.  The NMRI adult mice were assigned: G1: control, G2: was treated with busulfan (4 days, 3.2 mg/kg), G3: was treated with busulfan (4 days, 3.2 mg/kg) and SKEO (28 days, 225 mg/kg) at the same time, and G4: was pre-treated with SKEO (7 days, 225 mg/kg) and subsequently co-treated with busulfan (4 days, 3.2 mg/kg) and SKEO (28 days, 225 mg/kg).  Apoptosis and Bcl-2 family gene expression were evaluated in sperm by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay and Real-Time PCR, respectively.  The level of oxidative stress was studied in sperm and testis by Superoxide Dismutase (SOD) and Glutathione Peroxidase (GPx) assays.  Lactate Dehydrogenase (LDH), and Thiobarbituric assays were used for analyzing cytotoxicity and lipid peroxidation in testis and sperm of mice, (TBA) respectively.  The results showed a significant decrease in the percentage of apoptotic sperm in G4 versus G2 and G3 (p < 0.05).  SKEO pre-treatment potentially increased Bcl-2 expression and decreased BAX expression in sperm of G4 compared with G2 and G3.  The activities of SOD and GPx were increased, also, LDH and TBA decreased significantly in testis and sperm of G4 compared with G2 and G3 (p < 0.05).  SKEO pre-treatment had a notable role in reducing oxidative stress, apoptosis, cytotoxicity, and genotoxicity in sperm of busulfan-treated mice.  In addition, cytotoxicity and oxidative stress were decreased significantly in testes of this group.  Thereby, SKEO may inhibit busulfan-mediated apoptosis in sperm via decreasing oxidative stress and regulating Bcl-2 family genes expression.  In conclusion, the beneficial properties of SKEO pre-treatment and co-treatment by its herbal potent anti-oxidants may reduce adverse effects of chemotherapy in the reproductive system in a rodent system.  SKEO: Satureja Khuzestanica essential oil; SOD: superoxide dismutase; GPx: glutathione peroxidase; LDH: lactate dehydrogenase; GC-MS: gas chromatography/mass spectrometry; TdT: terminal deoxynucleotidyl transferase; TUNEL: terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling; ROS: reactive oxygen species.