Immunohistochemical and stereological investigation of the protective effects of curcumin on the cypermethrin treated rat testes

Cypermethrin is a pesticide of type II synthetic pyrethroid group and has been found to be of widespread use as it is thought to be less toxic in mammals such as other synthetic pyrethroids. However, the studies on the toxic effects of cypermethrin on many systems, including the male reproductive system, are increasing recently. Curcumin is an antioxidant obtained from turmeric (Curcuma longa) plant, which has a protective effect against many physical and chemical harmful substances. This study was carried out to investigate the negative effects of cypermethrin on rat testicles and the possible protective properties of curcumin on these negative effects. Three-month-old male rats were divided into 6 groups of 8 animals in each group, and 30 days of gastric gavage of chemicals were applied. The first group was the "control" group, the second group was "cypermethrin", the third group was "curcumin", the fourth group was "15 days cypermethrin + 15 days curcumin", the fifth group was "15 days curcumin + 15 days cypermethrin", and the sixth group was "cypermethrin + curcumin" group. After 30 days of application, the right testicles of euthanized rats were taken for stereological examination and left testicles were taken for measurement, histological and immunohistochemical examinations. The volume was calculated by the Cavalieri method from the right testicles, which were cut at 2 mm equal intervals for stereological examination. Left testicles were embedded in paraffin blocks followed by reduction and histological tissue procedures. 5 µm thick sections were taken from the blocks and stained with Hematoxylin-Eosin method for histological examination and measurement. Other sections were stained immunohistochemically. As a result of the investigations, no statistically significant difference was found between the control group and the experimental groups in terms of live weight, testicle weight, seminiferous tubule diameter. In the group of Cypermethrin histological disorders were detected in the testis structure but in "cypermethrin + curcumin" and "15 days cypermethrin + 15 days curcumin" groups these disorders were not found. Histological findings were similar to the cypermethrin group in the "15 days curcumin + 15 days cypermethrin" group. Leydig cell number and seminiferous tubule epithelial height were significantly decreased in the "cypermethrin" group. However, in the group of "cypermethrin + curcumin" and "15 days cypermethrin + 15 days curcumin" these values were similar to the control group. These values were similar to the cypermethrin group in the "15 days cypermethrin + 15 days curcumin" group. In the immunohistochemical examination, the intensity of AR immunostaining in Leydig, Sertoli and peritubular myoid cells in cypermethrin group were decreased compared to the control group, cypermethrin and curcumin group were given together and the first 15 days of cypermethrin followed by cypermethrin in 15 days curcumin group was similar to the control group. The first 15 days of curcumin followed by cypermethrin for 15 days in the group of AR immunostaining density cypermethrin showed similarity with the group. As a result, the negative effects of cypermethrin in rat testes and the protective effects of curcumin against cypermethrin were determined.