Effect of Selenium on Carbimazole Induced Alterations in Testicular Function in Albino Rats Abeer A. Shoman MD, Noha I. Hussien MD, Nessrine I. Ahmad MD* and Hanan T. Emam MD** Departments of Physiology, Histology* and Pharmacology** Faculty of Medicine, Benha University, Egypt. Abstract Carbimazole is an antithyroid drug used in treatment of hyperthyroidism. The use of Carbimazole was associated with various adverse effects in male reproductive system. Spermatogenesis is an extremely active process with high rate of cell division that leads to high rates of mitochondrial oxygen consumption by the germinal epithelium. However, oxygen tensions in this tissue are low so both spermatogenesis and Leydig cell steroidogenesis are vulnerable to oxidative stress. Testes and epididymes contain high concentrations of Selenium indicating its vital role during spermatogenesis to improve semen quality. This study was designed to evaluate the effect of Carbimazole on testicular activity in albino rats and the ameliorative role of selenium. The rats in this study were divided into 4 groups. Group (1) that were served as normal control, Group (2) were orally given Carbimazole Group (3) were orally given sodium selenite and Group (4) that were orally administered Carbimazole and sodium selenite for 8 weeks. Testicular reduced glutathione concentration (GSH), Testicular malondialdehyde (MDA) concentrations, Epididymal sperm count, Sperm motility, Sperm abnormalities, serum testosterone, LH, FSH levels and testicular histopathology were examined. From this study we can conclude that, treating animals with selenium causes improvement in normal testicular function of rats. Also we concluded that combination of selenium with Carbimazole showed improvement in testicular alterations induced by Carbimazole in rats. 1 Introduction Carbimazole is an antithyroid agent that decreases the uptake and concentration of inorganic iodine by thyroid; it also reduces the formation of diiodotyrosine and thyroxin (1) . Serum Carbimazole is a common oral treatment for hyperthyroidism. On the other hand, the use of Carbimazole was associated with various adverse effects (2) . Carbimazole produced mild necrosis of renal tubules in rats. Carbimazole was capable of inducing acute pancreatitis, pulmonary hemorrhage and necrotizing glomerulonephritis and cholestatic hepatitis in 33-year old female (3). Reactive oxygen species (ROS) are molecules that have at least one unpaired electron, rendering them highly unstable and highly reactive in the presence of lipids, amino acids and nucleic acids. At physiologic levels, ROS are essential for normal reproductive function, acting as metabolic intermediates in the metabolism of prostanoid, in the regulation of vascular tone, in gene regulation, and in facilitated sperm capacitation and acrosome reaction(4). However, at higher concentrations, they exert negative effects. The main source of ROS production in seminal plasma is leukocytes and immature spermatozoa. Spermatids and mature spermatozoa are deemed highly sensitive to ROS because their membranes are particularly rich in polyunsaturated lipids. By altering membrane integrity, ROS may impair sperm motility and morphology and can lead to sperm cell death (5). Spermatogenesis is an extremely active replicative process capable of generating approximately 1,000 sperm a second. The high rates of cell division inherent in this process lead to high rates of mitochondrial oxygen consumption by the germinal epithelium. However, the poor vascularization of the testes means that oxygen tensions in this tissue are 2 low and that competition for this vital element within the testes is extremely intense (6). The testes contain an elaborate array of antioxidant enzymes and free radical scavengers to ensure that the twin spermatogenic and steroidogenic functions of this organ are not impacted by oxidative stress. These antioxidant defense systems are of major importance because peroxidative damage is currently regarded as the single most important cause of impaired testicular function (7). Selenium (Se) is an essential element for normal testicular development, spermatogenesis, and spermatozoa motility and function. Se may protect against oxidative DNA damage in human sperm cells. However, the exact mechanism by which Se eliminates oxidative stress to improve male fertility and semen quality in humans is still controversial (8). There are at least 25 selenoproteins in the human body, and they help maintain sperm structure integrity (9). The best-characterized spermatozoal effects of Se deficiency are: important loss of motility, breakage at the midpiece level and increased incidence of sperm-shape abnormalities, mostly of the sperm head. This is evidenced by studies that reported a significant correlation between Se levels in seminal plasma and the percentage of morphologically normal sperm in a sample (10). Selenium is an essential element important in many biochemical and physiological processes including the biosynthesis of coenzyme Q (a component of mitochondrial electron transport systems), regulation of ion fluxes across membranes, maintenance of the integrity of keratins, stimulation of antibody synthesis, and activation of glutathione peroxidase (11). Selenium ameliorated the testicular damage and oxidative stress induced by Carbimazole in albino rats (12). 3 The present work aims to investigate the effect of selenium on histology of testis, serum testosterone level, LH, FSH, Testicular GSH, Testicular MDA and semen analysis alterations induced by Carbimazole in male albino rats. MATERIALS AND METHODS Animals Thirty two male adult albino rats of locally breaded strain weighing between 150+ 5 g at the beginning of the study were used. They have acclimatized for one week in groups (8/cage) in fully ventilated room at ordinary room temperature. Rats were allowed to water and balanced diet. At the beginning of the experiment they were divided into 4 groups each contained 8 rats: Group I: Control normal rats. They received no drugs Group II: Animals of this group were orally given Carbimazole (1.35 mg/Kg b.w) dissolved in water, daily for 8 weeks (13). Group III: animals of this group were orally given sodium selenite (10 μg/Kg b.w) dissolved in water, daily for 8 weeks (14). Group 4: animals of this group were orally administered Carbimazole (1.35mg/Kg b.w) and sodium selenite (10μg/Kg b.w) for 8 weeks. The treated animals were sacrificed by cervical decapitation after 8 weeks of treatment. Drugs: Selenium (sodium selenite): gray powder 5gm in bottle from (Sigma chemicals Co., U.S.A.). Carbimazole: 10 mg Tablet (Ambica Intl Trading). Hematoxylin and eosin: (E. Merk, Darmastadt.,) [U.S.A.]. 4 Formalin (neutral 10% formalin): El-Gomhoria Pharmaceutical Chemi.Ocal Co, ARE. Diagnostics Limited lot. No. 18933. The procedures used: Each animal of all groups was killed after the end of the experiments by decapitation and the following were done. Blood was collected in a test tube and left to clot then centrifuged for serum separation and serum was collected and stored at – 20oC for hormonal assays. Both testes of each animal were separated from the surrounding tissues. The testis tissue washed by ice water, apart was weighed and homogenized in 9 volumes saline 0.9% in homogenizer apparatus. The homogenate was collected and kept at −70 ◦C. GSH activity and MDA were measured (15). Semen collection One epididymis was separated rapidly, the tail of the epididymis was scraped longitudinally by scalpel and the semen was collected by stripping of the epididymis then 0.1 ml of saline was added and mixed with the semen for liquefaction (16). Sperm counting The semen obtained was diluted with saline at a ratio of 1: 20 and by the hemocytometer slide the sperm count could be calculated using a light microscope (17). Sperm motility The right epididymis along with part of the vas deferens was clamped with a hemostat at approximately the corpus cauda junction. The cauda was then gently dissected with a scalpel blade to allow sperm to emerge from the engorged cauda epididymis, which was 5 then dipped into a plastic Petri dish (35 mm) containing pre-warmed incubation medium (saline). Sperm released into the medium were incubated for approximately 3 min with intermittent gentle swirling to disperse them throughout the suspension. Following the 3-min incubation, an aliquot of the sperm suspension was taken using capillary tubes and loaded into the analyzer. A drop of the collected semen was taken using 100µl capillary tube and loaded into a slide then examined by high power for the number of forward motile sperm per 100 sperms (18). Stained slides : One drop of the collected diluted semen was taken into the middle of a clean slide, one drop of the eosin stain was added near to the semen drop then gently mixed and by the edge of another slide the stained semen was spread into the slide and examined by light microscope at lens 40 for the sperm abnormalities and acrosomal deformity (19). Hormonal assays : Serum LH, FSH and testosterone levels were measured. After functional studies were completed, one testis from each rat was removed and was put into a buffered 4% formalin fixation solution and processed with paraffin wax for histopathological examination. Sections 5um were stained with Mayer’shematoxylin and eosin (20). All groups were subjected to the following investigation: Serum testosterone ,LH, FSH levels Testicular GSH, Testicular MDA Epididymal sperm count Sperm motility Sperm abnormalities and acrosomal deformity Testicular histopathological examination 6 Statistical Analysis: All data were expressed as mean S.D; data were evaluated by the one way analysis of variance. Difference between groups were compared by Student's t-test with P 0.05 selected as the level of statistical significance. RESULTS Administration of Carbimazole (1.35 mg/Kg b.w) dissolved in water, daily for 8 weeks resulted in significant (P < 0.001) decrease of testosterone, LH &FSH from means of (1.8875±0.280), (2.788±0.203), (2.054±0.123) in control group to means of (1.075±0.205), (2.1625±0.220)&( 1.715±0.173). Testicular GSH was significantly reduced (P < 0.001) from mean of (10.158±1.355) in control group to mean of (5.929±1.23). Testicular MDA was significantly increased (P < 0.001) from mean of (4.36±1.193) in control group to mean of (10.88±1.267) (table 1). The results showed also that administration of Carbimazole resulted in significant (P < 0.001) decrease of sperm count, sperm motility from means of (15.866±0.276) & (59.1675±0.391) in control group to means of (11.45±0.127) & (34.474±0.248) .sperm abnormalities was significantly increased (P < 0.001) from mean of (14.695±0.410) in control to mean of (24.165±0.191) in group received Carbimazole (table 2). Histopathological examination of testicular tissues of rats received Carbimazole only showed degenerative changes of the majority of the seminiferous tubules. These changes were characterized by shrunken, disorganized seminiferous tubules with irregular, buckled basement membrane and incomplete spermatogenesis. Moreover, the seminiferous tubules were almost devoid of spematids and spermatozoa. Vacuolar 7 degeneration of spermatogonia and Sertoli cells was evident. Degenerated germinal epithelial cells were sloughed in the lumina of most seminiferous tubules. Regarding to the interstitium, there were congestion of the interstitial blood vessels and edema that was represented by faint eosinophilic material (Fig. 3) in comparison to the normal testicular tissues of the control group (Fig. 2). Administration of sodium selenite (10 μg/Kg b.w) dissolved in water, daily for 8 weeks resulted in significant (P < 0.05) increase of testosterone from mean of (1.8875±0.280) in control group to means of (2.2625±0.267) & significant (P < 0.001) increase of FSH from mean of (2.054±0.123) in control group to mean of (2.51±0.207).Testicular GSH was significantly increased (P < 0.002) from mean of (10.158±1.355) in control group to mean of (12.931±1.597). Testicular MDA was significantly reduced (P < 0.05) from mean of (4.36±1.193) in control group to mean of (3.231±0.86) (table 3). The results showed also that administration of sodium selenite resulted in significant (P < 0.001) increase of sperm count, sperm motility from means of (15.866±0.276) & (59.1675±0.391) in control group to means of (17.939±0.147) & (60.22±0.224) .Sperm abnormalities was significantly decreased (P < 0.001) from mean of (14.695±0.410) in control to mean of (11.529±0.333) in group received sodium selenite (table 4). Histopathological examination of testicular tissues of rats received sodium selenite alone showed normal testicular structure (Fig. 4). Administration of Carbimazole (1.35mg/Kg b.w) and sodium selenite (10μg/Kg b.w) for 8 weeks resulted in significant (P < 0.001) increase of testosterone, LH &FSH from means of (1.075±0.205), (2.1625±0.220) & (1.715±0.173) In group received Carbimazole alone to 8 means of (1.9625±0.262), (3.016±0.228) & (2.5262±0.188) in groups received Carbimazole and sodium selenite. Testicular GSH was significantly increased (P < 0.001) from mean of (5.929±1.23) in group received Carbimazole alone to mean of (8.218±0.853) in groups received Carbimazole and sodium selenite. Testicular MDA was significantly decreased (P < 0.001) from mean of (10.88±1.267) in group received Carbimazole alone to mean of (6.253±1.814) in group received Carbimazole and sodium selenite (table 5) & (Fig. 1-a). The results showed also that administration of Carbimazole and sodium selenite resulted in significant (P < 0.001) increase of sperm count, sperm motility from means of (11.45±0.127) & (34.474±0.248) In group received Carbimazole alone to means of (14.541±0.327)&( 51.614±0.430) in group received Carbimazole and sodium selenite. Sperm abnormalities was significantly decreased (P < 0.001) from mean of (24.165±0.191) in group received Carbimazole alone to mean of (11.919±0.293) in group received Carbimazole and sodium selenite (table 6) & (Fig. 1-b). Histopathological examination of testicular tissues of rats received Carbimazole and sodium selenite showed few seminiferous tubules contained sloughed germinal epithelium (arrows), marked improvement of spermatogenesis (Fig. 5). 9 Table (1): Effects of Carbimazole on serum levels of testosterone, LH &FSH; testicular GSH and testicular MDA in male rats. (Mean± SD) (n = 8). parameters Testosterone ng/ml LH U Iu/ml FSH U Iu/ml GSH (umol/g tissue) MDA (nmol /g tissue) Group 1.8875±0.280 Control 2.788±0.203 2.054±0.123 1.075±0.205*** 2.1625±0.220*** 1.715±0.173*** Carbimazole group *** Significant P < 0.001 compared with control normal rats. 10.158±1.355 4.36±1.193 5.929±1.23*** 10.88±1.267*** Table (2): Effect of Carbimazole on sperm count, sperm motility and sperm abnormalities in male albino rats parameters Group Control Sperm count (10)6 Sperm motility % Sperm abnormalities % 15.866±0.276 59.1675±0.391 14.695±0.410 11.45±0.127*** 34.474±0.248*** Carbimazole group *** Significant P < 0.001 compared with control normal rats. 24.165±0.191*** Table (3): Effects of selenium on serum levels of testosterone, LH & FSH, testicular GSH and testicular MDA in male rats. (Mean± SD) (n = 8). parameters Group Control Selenium group Testosterone ng/ml LH U Iu/ml FSH U Iu/ml GSH (umol/g tissue) MDA (nmol /g tissue) 1.8875±0.280 2.2625±0.267** 2.788±0.203 2.9875±0.173 2.054±0.123 2.51±0.207*** 10.158±1.355 12.931±1.597*** 4.36±1.193 3.231±0.86** ** Significant P < 0.01 compared with control normal rats. ***Significant P < 0.001 compared with control normal rats. Table (4): Effect of selenium on sperm count, sperm motility and sperm abnormalities in male albino rats parameters Group Control Sperm count (10)6 Sperm motility % Sperm abnormalities % 15.866±0.276 59.1675±0.391 14.695±0.410 17.939±0.147*** 60.22±0.224*** Selenium group *** Significant P < 0.001 compared with control normal rats. 10 11.529±0.333*** Table (5): Effects of combination of selenium and Carbimazole on serum levels of testosterone, LH &FSH, testicular GSH and testicular MDA in male rats. (Mean± SD) (n = 8). parameters Group Testosterone ng/ml LH U Iu/ml FSH U Iu/ml 1.075±0.205 2.1625±0.220 1.715±0.173 Carbimazole group 1.9625±0.262*** 3.016±0.228*** 2.5262±0.188*** Group received carbimazole and Selenium *** Significant P < 0.001 compared with Carbimazole treated rats. GSH (umol/g tissue) MDA (nmol /g tissue) 5.929±1.23 10.88±1.267 8.218±0.853*** 6.253±1.814*** Table (6): Effect of combination of Carbimazole and selenium on sperm count, sperm motility and sperm abnormalities in male albino rats Group parameters Sperm count (10)6 Sperm motility % Sperm abnormalities % Carbimazole group 11.45±0.127 34.474±0.248 24.165±0.191 Group received carbimazole and Selenium 14.541±0.327*** 51.614±0.430*** 11.919±0.293*** *** Significant P < 0.001 compared with Carbimazole treated rats. Fig (1-a) Fig (1-b) 12 60 # 10 50 # 8 40 6 4 # 30 # # # 20 2 # # 10 0 0 test LH FSH Carbimaz GSH MDA sperm cou. cab.&selin. sperm mot carbimaz. sperm ab. carb.&selen # Significant (P < 0.001) compared with Carbimazole treated rats. Fig. (1-a) & Fig. (1-b) Effects of combination of selenium and Carbimazole on serum levels of testosterone, LH &FSH, testicular GSH, testicular MDA, sperm count, sperm motility and sperm abnormalities in male albino rats 11 Fig. (2): Cut section of testicular tissues of control normal rats showing no remarkable pathologic changes (H&E100) Fig. (3): Cut section of testicular tissues of rats received Carbimazole (H&E100) 12 Fig. (4): Cut section of testicular tissues of rats received selenium (H&E100) Fig. (5): Cut section of testicular tissue of rats received both carbimazole and selenium (H&E100) Fig. (6): detached head Fig. (7): double head and bifid tail 13 Fig. (8): damaged acrosome . Fig. (9): coiled tail Discussion Carbimazole is a common oral treatment for hyperthyroidism but it was associated with various adverse effects on the male reproductive system. Hence, this study was conducted to evaluate the effect of Carbimazole on testicular function as sperm characteristics, serum testosterone, LH & FSH levels as well as the effect of Carbimazole on Testicular reduced glutathione (GSH) activity ,lipid peroxidation (LPO) content in the form of testicular MDA level and histopathology of the testes and to assess the ameliorative role of selenium. Our study revealed that Carbimazole caused significant decrease in testicular reduced glutathione (GSH) activity, serum testosterone; LH & FSH levels with significant increase in testicular MDA level in the testis. As well as it caused significant increase in sperm abnormalities with significant decrease in sperm motility and sperm count. Histopathological examination of testicular tissue of rats received Carbimazole showed degenerative changes of the majority of the seminiferous tubules. These changes were characterized by shrunken, disorganized seminiferous tubules with irregular, buckled basement 14 membrane and incomplete spermatogenesis. Moreover, the seminiferous tubules were almost devoid of spematids and spermatozoa. Degenerated germinal epithelial cells were sloughed in the lumina of most seminiferous tubules. Regarding to the interstitium, there were congestion of the interstitial blood vessels and edema that was represented by faint eosinophilic material. These results were in agreement with (13) as they revealed that treating rats with Carbimazole daily for 8 weeks caused distinct histological alterations in prostate gland compared with control group. Also (21) indicated that superoxide dismutase, catalase and glutathione peroxidase was reduced in erythrocytes of rats treated with Carbimazole compared with control animals. Carbimazole administration caused a significant decrease testicular weight and DNA content in rat pups (22). High lipid peroxidation with a concomitant decrease in the enzymatic antioxidant status, superoxide dismutase and catalase were recorded in testis of rats treated with Carbimazole (23) . Thus, it is suggested that Carbimazole induced oxidative stress which resulted in the alterations observed in the testes. Testosterone is required for the attachment of different generations of germ cells in seminiferous tubules. Therefore, low level of intratesticular testosterone may lead to detachment of germ cells from seminiferous epithelium and may initiate germ cell apoptosis and subsequent male infertility (24) . This finding was parallel to the reduction in epididymal sperm count. Sloughing of germ cells was observed in the lumen of some epididymal ducts indicating testicular dysfunction (25). Our study revealed that the effect of selenium on normal control rats was significant improvement in testicular function. These results were in agreement with (26) as they concluded that the administration of 15 antioxidants such as selenium or ascorbate to normal animals, not suffering from induced oxidative stress, also appears to improve testicular function, suggesting that oxidative stress is a consistent feature of testicular physiology. In light of such results, antioxidants have frequently been administered to infertile men in the hope of improving the quality of the semen profile. Increased generation of ROS in semen affects sperm function, especially fusion events associated with fertilization, and leads to infertility. ROS are known to be generated from spermatozoa and leucocytes and the resultant peroxidative damage causes impaired sperm function. Elevated ROS levels correlate negatively with sperm concentration and sperm motility Spermatozoa are particularly susceptible to ROS-induced damage because their plasma membranes contain large quantities of polyunsaturated fatty acids and their cytoplasm contains low concentrations of the scavenging enzymes (27). Concerning the effect of selenium on rats suffering from induced oxidative stress, the present study indicated that combination of selenium with Carbimazole improved the oxidative status as selenium caused significant increase in testicular reduced glutathione (GSH) activity and significant decrease in testicular MDA content. Also selenium caused significant increase in testosterone, LH, FSH levels and significant increase in sperm count, sperm motility and significant decrease in sperm abnormalities. These results were in agreement with (28) as they revealed that selenium ameliorated the reduction in the reproductive organs weights, sperm characteristics, Deltamethrin induced oxidative damage of testes 16 and the histopathological alterations of testes, epididymes and accessory sex glands. Also (29) found that after co-administration of vitamin E and Selenium, serum testosterone level significantly increased parallel to the reduction in LPO concentration. This could be attributed to a relationship between steroidogenesis and ROS. Our results are also in consistence with (30) who concluded that 0.1 mg/kg selenium (Na2 SeO3) inhibited oxidative stress, apoptosis and cell cycle changes induced by excess fluoride in kidney of rats. Selenium protected rat testes against cadmium-induced oxidative damage (31). Sodium selenite supplementation significantly protected against exercise-induced testicular gametogenic and spermatogonia disorders, prevented testicular oxidative stress and increased antioxidant status (32). The effectiveness of combined treatment with selenium and vitamin E in treatment of oligoasthenoteratozoospermia has been studied since Vitamin E is well known to work in synergy with selenium as an antiperoxidant. A prospective, uncontrolled study reported that this drug combination led to statistically significant increases in motility and mean seminal plasma glutathione peroxidase activity. Although no improvements in sperm concentration were documented, and no pregnancies were achieved, the better sperm motion characteristics may be explained by the amplified antioxidant enzyme activity (33) . These results were further confirmed by a more recent randomized controlled trial in which vitamin E and selenium improved sperm motility and lipid peroxidation markers (34). 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