Seyed Sadegh Sadat
1, Shabnam Mohammadi
2,1* 
, Ghasem Sazegar
1, Alireza Fazel
1, Alireza Ebrahimzadeh
1, Majid Ghayour Mobarhan
3, Farimah Beheshti
4, Seyedeh Saleheh Attari
1, Shima Tavallaei
31 Department of Anatomy and Cell Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
2 Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
3 Biochemistry of Nutritional Research Center, Mashhad University of Medical Science, Mashhad, Iran.
4 Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Abstract
Background: Certain plants stimulate spermatogenesis and increase fertility; in contrast, some plants arrest the spermatogenesis cycle. Ceratonia siliqua is an herb plant with a strong antioxidant property. The aim of this study was to evaluate the effects of carob fruit extract on spermatogenesis, testicular apoptosis, and oxidative stress in adult male mice. Methods: Forty adult male mice were randomly divided into five groups: control, sham, and carob 1–3. The sham group was injected with normal saline and the carob 1–3 groups were injected with 200, 400, and 800 mg/kg of the carob fruit extract intraperitoneally for 14 days, respectively. At the end of the injection period, spermatogenesis, testicular apoptosis, and oxidative stress were examined. Results: The sperm parameters increased in the mice that received 200 mg/kg of carob compared to the sham group (p <0.05). There was a significant increase in the weight index of the epididymis in the carob 3 group in comparison to the sham group (p = 0.01). The number of positive tunnel cells was not statistically significant between different groups (p>0.05). The level of malondialdehyde decreased in the carob 1 and carob 3 groups, but this reduction was not statistically significant (p > 0.05). In addition, the statistical analysis showed a significant difference in the mean superoxide dismutase levels in the carob 2 and carob 3 groups in comparison to the sham group (p ≤ 0.001). The statistical analysis showed a significant increase in the mean level of the catalase enzyme in the carob 1 group in comparison to the sham (p = 0.02), and carob 2 groups (p = 0.008). Conclusion: The administration of 200 mg of the carob fruit extract for 14 days increased the testicular index as well as sperm parameters and decreased the level of oxidative stress in the testicular tissue of adult mice.