Effect of hydro–alcoholic extract of Olea europaea on apoptosis–related genes and oxidative stress in a rat model of torsion/detorsion–induced ovarian damage

Abstract

Objective: To evaluate the impact of Olea (O.) europaea extract on markers of oxidative stress and apoptosis of ovarian tissues in a rat model of torsion/detorsion-induced ovarian damage. Methods: A total of 28 Wistar female rats were randomly assigned into 4 groups, with 7 rats in each group. The sham group received a 2.5 cm longitudinal incision in the midline part of the abdomen which was then sutured with 5-0 nylon thread; the torsion/detorsion group underwent torsion induction for 3 h followed by reperfusion for 10 days; the torsion/detorsion+O. europaea group received 300 mg/kg hydro-alcoholic extract of O. europaea 30 min before detorsion, followed by reperfusion for 10 days; and the O. europaea group only received 300 mg/kg hydro-alcoholic extract of O. europaea for 10 days. After the treatment period, blood samples were taken; the levels of estrogen, glutathione peroxidase, superoxide dismutase, and malondialdehyde were assayed. The histological changes, as well as the rate of apoptosis in ovarian tissues, were also carried out by histomorphometric analysis at day 10 post-procedure. Results: Histological comparisons demonstrated a significant detrimental change in the torsion/ detorsion group as compared with other groups. The number of pre-antral and antral follicles and corpus luteum was significantly decreased in the torsion/detorsion group compared with the sham group, while treatment with O. europaea could enhance their numbers (P<0.05). The index of apoptosis and the number of atretic body in the ovarian tissue were significantly higher in the torsion/detorsion group compared with the sham group (P<0.05). The concentrations of glutathione peroxidase, estrogen, and superoxide dismutase as well as the mRNA expression of Bcl-2 were considerably diminished in the torsion/detorsion group while they were elevated in the torsion/detorsion+O. europaea group (P<0.05) compared with the torsion/detorsion group. The serum malondialdehyde level and the mRNA expression of Bax were markedly increased during ischemia, while treatment with O. europaea significantly diminished the increased concentrations of malondialdehyde and Bax level in the torsion/detorsion+O. europaea group (P<0.05). Conclusions: O. europaea extract can reduce the degree of tissue damage induced by oxidative stress and apoptosis in the ovary following ovarian ischemia/reperfusion.

Keywords

• ischemia/reperfusion
• oxidative stress
• olea europaea
• ovarian torsion
• apoptotic gene expression