Vitamin E improves testicular damage in streptozocin‐induced diabetic rats,via increasing vascular endothelial growth factor and poly(ADP‐ribose) polymerase‐1

The precise mechanism by which diabetes impairs spermatogenesis and testicular function is not exactly known. Vascular endothelial growth factor (VEGF) and poly(ADP‐ribose) polymerase‐1 (PARP‐1) are important for germ cell homeostasis and repair of DNA respectively. The aim of this study was to investigate the correlation between diabetes‐induced testicular damage and testicular VEGF and PARP‐1 expression and the possible protective role of vitamin E supplementation. A total of 45 male Wistar albino rats were randomly divided into three groups: Group I (nondiabetic rats), Group II (streptozocin‐induced diabetic rats) and Group III (streptozocin‐induced diabetic rats treated orally with 0.4 mg/kg vitamin E). Five weeks later, testicular tissue was used for assessment of MDA concentration by colorimetry, histopathological examination and immunostaining for PARP‐1 and VEGFIn diabetic rats, testicular weight, seminiferous tubule diameter and germinal epithelial thickness were decreased, basement membrane was thickened and Johnsen score decreased. Reduced VEGF and PARP‐1 immunostaining were associated with decreased Johnsen score in diabetic rats. Vitamin E administration was protective against oxidative stress‐associated damage evidenced by lower MDA levels, improved testicular weight, spermatogenesis and higher immunostaining for VEGF and PARP‐1. Testicular VEGF and PARP‐1 might therefore be helpful biomarkers for diabetic testicular damage. Administration of vitamin E may have a protective role against diabetes‐induced testicular damage.     

Antioxidant enzymes activity,lipid peroxidation,oxidative damage in the testis and epididymis,and steroidogenesis in rats after co‐exposure to atrazine and ethanol

Concomitant alcohol use and exposure to xenobiotics can adversely affect gonadal functions. This study investigated the oxidative status of the testis and epididymis and steroidogenesis of rats co‐exposed to ethanol (EtoH, 5 mg kg^?1 b.wt.) and atrazine (ATZ, 50, 100, 300 mg kg^?1 b.wt.) for 3 weeks. The activities of catalase, superoxide dismutase, glutathione peroxidase, as well as the concentrations of glutathione and malondialdehyde, as indicators of oxidative stress were measured in the homogenates of the testis and epididymis. Testosterone and cholesterol concentrations as well as 17β‐hydroxysteroid dehydrogenase (17β‐HSD) activity were assayed in the plasma and testis respectively. After the administration of EtoH alone, or in combination with different doses of ATZ, oxidative damage as evident by malondialdehyde level was not observed in both the testis and epididymis. The combine exposure group showed dose‐dependent decrease in plasma testosterone and testis cholesterol level and increase in testis 17β‐HSD activity compared to the EtoH group. Furthermore, the testes and epididymis of the EtoH‐exposed rats treated with high dose of ATZ had severe histopathological damage. Therefore, ATZ‐exposed alcohol‐treated rats have histological damage of the testis and epididymis and lower testosterone level than EtoH‐treated rats.     

Effects of cinnamon (Cinnamomum zeylanicum) bark oil on testicular antioxidant values,apoptotic germ cell and sperm quality

Cinnamon and its contents have multifactorial properties such as antioxidant, anti‐inflammatory and antidiabetic. Male infertility is one of the major health problems in life. The aim of this study was to investigate the effects of long‐term cinnamon bark oil (CBO) ingestion on testicular antioxidant values, apoptotic germ cell and sperm quality of adult rats. Twelve male healthy Wistar rats were divided into two groups, each group containing six rats. While olive oil was given to control group, 100 mg kg^?1 CBO was administered to the other group by gavage daily for 10 weeks. Body and reproductive organ weights, sperm characteristics, testicular lipid peroxidation and antioxidant enzyme activities, and testicular apoptosis via terminal deoxynucleotidyl transferase–mediated dUTP nick end labelling (TUNEL) method were examined. A significant decrease in malondialdehyde level and marked increases in reduced glutathione level, glutathione peroxidase and catalase activities were observed in rats treated with CBO compared with the control group. CBO consumption provided a significant increase in weights of testes and epididymides, epididymal sperm concentration, sperm motility and diameter of seminiferous tubules when compared with the control group. However, CBO consumption tended to decrease the abnormal sperm rate and apoptotic germ cell count, but it did not reach statistical significance. It is concluded that CBO has improvement effect on testicular oxidant–antioxidant balance and sperm quality, and its consumption may be useful for asthenozoospermic men.     

Effect of 3-amino benzamide, a poly(adenosine diphosphate-ribose) polymerase inhibitor, in experimental caustic esophageal burn

Introduction

The enzyme poly(adenosine diphosphate-ribose) polymerase affects the repair of DNA in damaged cells. However, its activation in damaged cells can lead to adenosine triphosphate depletion and death. This study was designed to investigate the efficacy of 3-amino benzamide (3-AB), a poly(adenosine diphosphate-ribose) polymerase inhibitor, on the prevention of esophageal damage and stricture-formation development after esophageal caustic injuries in rat.

Materials and Methods

Forty-five rats were allocated into 3 groups: sham-operated, untreated, and treated groups. Caustic esophageal burn was created by instilling 15% NaOH to the distal esophagus. The rats were left untreated or treated with 3-AB 10 mg/kg per day intraperitoneally. All rats were killed on the 28th day. Efficacy of the treatment was assessed by measuring the stenosis index and histopathologic damage score and biochemically by determining tissue hydroxyproline content, superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), and protein carbonyl content (PCC) in esophageal homogenates.

Results

Treatment with 3-AB decreased the stenosis index and histopathologic damage score seen in caustic esophageal burn rats. Hydroxyproline level was significantly higher in the untreated group as compared with the group treated with 3-AB. Caustic esophageal burn increased MDA and PCC levels and also decreased SOD and GPx enzyme activities. On the contrary, 3-AB treatment decreased the elevated MDA and PCC levels and also increased the reduced SOD and GPx enzyme activities.

Conclusion

3-Amino benzamide has a preventive effect in the development of fibrosis by decreasing tissue damage and increasing the antioxidant enzyme activity in an experimental model of corrosive esophagitis in rats.     

Medroxyprogesterone acetate,enoxaparin and pentoxyfylline cause alterations in lipid peroxidation,paraoxonase (PON1) activities and homocysteine levels in the acute oxidative stress in an experimental model of spinal cord injury

Summary.  Background: Effects of medroxyprogesterone acetate, enoxaparin and pentoxyfylline on lipid peroxidation, antioxidant defence system, paraoxonase activities, and homocysteine levels in an experimental model of spinal cord injury were investigated.  Method: Sixty-three male albino Wistar rats were anaesthetized by 400 mg/kg chloral hydrate and divided into 5 groups. G1 (n 7) = control group provided the baseline levels. G2–G5 underwent T3–6 total laminectomies and spinal cord injuries by clip compression at T4–5 levels. Medications were applied to G3–G5 right after the injury. Hence, G2 constituted laminectomy + injury (lam+I); G3 = lam + I + medroxyprogesterone acetate (MPA), G4 = lam + I + enoxaparin (E), and G5 = lam+I+pentoxyfylline (P) groups. Animals were decapitated either at the 1st or 4th hour after injury. Tissue and blood malonyldialdehyde (MDA) and plasma homocysteine and erythrocyte superoxide dismutase (SOD) levels, and erythrocyte glutathione peroxidase (GSH-Px) and plasma paraoxonase (PON1) activities were assayed. SPSS 9.0 program was used for statistical analysis and graphics. Intergroup comparisons were made by Bonferroni corrected Mann Whitney U test (P<0.025), and intragroups comparisons by Wilcoxon Rank test (P<0.03).  Findings: In intergroup comparison, G1–G2, G1–G3, G1–G5, G2–G3, G2–G4, and G4–5 groups differed from each other for all parameters (P<0.025, MWU) except for G4–G5 4th hour MDA levels. G1–G4 was similar for all 1st hour parameters (P>0.025, MWU), but different for 4th hour (P<0.025, MWU) except for GSH-Px and SOD levels. For G2–G5, all parameters for 1st and 4th hour were similar except for 4th PON1, Hcy and SOD levels. For G3–G4, all 1st hour parameters were different from each other (P<0.025, MWU); whereas all 4th hour parameters were similar except for SOD level. For G3–G5, all parameters at 1st and 4th hour were similar except for 4th hour GSH-Px, PON1, and Hcy. In intragroup comparison, all parameters differed from each other at all times (P<0.03, WRT) except for 1st hour G4 MDA, Hcy and SOD levels compared to basal levels.  Interpretation: In injury groups, plasma Hcy levels decreased and PON1 activities increased as erythrocyte SOD level and GSH-Px activities decreased in parallel to increases of tissue and blood MDA levels. These changes were relatively suppressed by MPA, enoxaparin and pentoxyfylline administrations at varying degrees. Enoxaparin was the most powerful agent, particularly at 1st hour. MPA was also effective, particularly at 4th hour. Pentoxyfylline despite having slight effect at 4th hour, was not effective according to both control and injury groups. Enoxaparin and MPA can be used in the treatment of spinal cord injuries. PON1 and Hcy are helpful in monitoring the antioxidant defence system as well as SOD and GSH-Px, both in injury and medically treated groups. Published online October 10, 2002 Acknowledgments  The experiments comply with the current laws of the country on the protection of animals. We wish to thank “Erciyes University Medical Faculty, Hakan Cetinsaya Experimental and Clinical Research Centre, Kayseri, Turkey” for providing us the animals for this study. Correspondence: Dr. Cahide Topsakal, Firat Universitesi Tip Fakultesi, Norosirurji Departmani, Elazig/Turkey.     

Benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC)‐mediated generation of reactive oxygen species causes cell cycle arrest and induces apoptosis via activation of caspase‐3, mitochondria dysfunction and nitric oxide (NO) in human osteogenic sarcoma U‐2 OS cells

Benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC), a member of the isothiocyanate family, have been shown to exhibit antineoplastic ability against many human cancer cells. In this study, we found that exposure of human osteogenic sarcoma U‐2 OS cells to BITC and PEITC led to induce morphological changes and to decrease the percentage of viable cells in a time‐ and dose‐dependent manner. BITC and PEITC induced cell cycle arrest at G2/M phase at 48 h treatment and inhibited the levels of cell cycle regulatory proteins such as cyclin A and B1 in U‐2 OS cells but promoted the level of Chk1 and p53 that led to G2/M arrest. BITC and PEITC induced a marked increase in apoptosis (DNA fragmentation) and poly(ADP‐ribose)polymerase (PARP) cleavage, which was associated with mitochondrial dysfunction and the activation of caspase‐9 and ‐3. BITC and PEITC also promoted the ROS production in U‐2 OS cells and the N‐acetylcysteine (NAC, an antoxidant agent) was pretreated and then treated with both compounds which led to decrease the levels of ROS and increase the cell viability. Interestingly, BITC and PEITC promoted the levels of NO production and increased the iNOS enzyme. Confocal laser microscope also demonstrated that BITC and PEITC promoted the release of cytochrome c and AIF, suggesting that both compounds induced apoptosis through ROS, caspase‐3 and mitochondrial, and NO signaling pathways. Taken together, these molecular alterations and signaling pathways offer an insight into BITC and PEITC‐caused growth inhibition, G2/M arrest, and apoptotic death of U‐2 OS cells. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1199–1209, 2011