THIOBENCARB DECREASES TESTICULAR GERM CELL PROLIFERATION, INHIBITS SPERMATOGENESIS AND INCREASES APOPTOSIS: HISTOLOGICAL AND IMMUNOHISTOCHEMICAL ASSESSMENTS

Rania A. Ahmed*

ABSTRACT

Background: Herbicides were found to induce harmful health effects as oxidative stress, reproductive disorders and histopathological alterations in vital organs. Thiobencarb is heavily used in rice cultivation in Egypt. There weren't enough studies on the effect of thiobencarb on human or animal health especially on the reproductive functions. Purpose: Investigation of thiobencarb induced histopathological effects and alterations in the indices of spermatogenesis, germ cell proliferation and apoptosis via histological and immunohistochemical studies in albino rats. Methods : Twenty-five healthy adult male rats were divided into two groups : Group I : This group contained 10 rats , and was kept as control group ; Group II : This group included 15 rats and was administrated with thiobencarb at dose level (44.78 mg/kg/orally / 3 days a week (equivalent to 1/20 of LD50 , for 6 weeks ) . At the end of sixth week, testes were processed for histological examination, immunohistochemical detection of Caspase-3 and PCNA, and histochemical demonstration of total proteins. Concerning biochemical investigations, testosterone was investigated in serum, while Malondialdhyde (MDA) and total antioxidant capacity (TAC) were estimated in testicular tissue. Results: Thiobencarb induced histopathological alterations as pyknosis, vaculations, and congestion of blood vessels, tubular degeneration and hemorrhage. It also significantly decreased the Johnson score of spermatogenesis, significantly increased the apoptotic index (AI), and decreased the germ cell proliferation index (PI). Moreover, thiobencarb significantly decrease the epithelial height and total protein content. Thiobencarb decreased serum testosterone and testicular TAC, and significantly increased testicular MDA.

Keywords: Apoptosis, Caspase-3, Herbicides, Oxidative stress, Spermatogenesis, Thiobencarb, PCNA.