The examination of effect of ellagic acid on testicular tissues of rats exposed to radiation

Irradiation of biological materials is known to cause rapid increase in concentration of reactive oxygen species (ROS). Oxidative stress has been shown to play role in pathogenesis of radiation-associated male infertility. One strategy to eliminate oxidative stress is to enhance the sweeping capacity of the seminal plasma. Ellagic acid, found in many plants including pomegranate, strawberry, blackberry, raspberry and grape, is a polyphenolic antioxidant famously known for its ability to protect tissues against oxidative damage. The present study aims to investigate the effect of ellagic acid on testis tissue in rats exposed to radiation. The study was conducted on 30 Spraque-Dawley rats that were 8 weeks old and had an average weight of 180-200 gr. The rats were randomly assigned to 5 groups as Group I (control), Group II (radiation), Group III (radiation + ellagic acid), Group IV (ellagic acid), and Group V (corn oil). In Group II and III, all rats were exposed to a single dose 8 Gy radiation on the first day of the study, in hospital setting by experienced personnel. In Group III and IV, all rats received ellagic acid in the dose of 12 mg/kg, dissolved in corn oil, administered via oral gavage every other day for 7 weeks period starting from the second day of the study. At the end of the experiment, rats in all groups were decapitated under xylasine-ketamine anesthesia. Testis specimens were stained with hematoxylin-eosin and PAS dyes. Additionally, TUNEL method was applied. Biochemical analyses were performed on testis tissues. Histological examinations of the sections in the group exposed to radiation showed significant degree of degeneration in the germinal epithelium of the seminiferous tubuli, vascular congestion, atrophic tubuli, interstitial edema and immature cell shedding into the lumen of some tubuli. In the group that received ellagic acid following radiation, there was profound improvement in the germinal epithelium degeneration, vascular congestion and interstitial edema. In comparison to the control group, radiation groups showed significant increase in TUNEL-positive cells. The number of TUNEL-positive cells was similar in radiation + ellagic acid group and the control group. Malondialdehyde levels and catalase activity were significantly increased in the radiation group compared to the control group, while radiation + ellagic acid application resulted in decreased malondialdehyde level and catalase activity. Superoxide dismutase (SOD) activity and glutathione level were significantly reduced in the radiation group compared to the control group. Compared to the radiation group, radiation + ellagic acid group showed increased SOD activity and further reduced glutathione level. In conclusion, radiation exposure causes damage in the testis tissue. Due to its antioxidant properties, ellagic acid administration following radiation exposure resulted in profound improvements in the adverse effects caused by radiation.