Preventive effects of Resveratrol against azoxymethane-induced testis injury in rats.

To evaluate the protective effects of Resveratrol (RES) on azoxymethane (AOM)-induced testicular damage using histopathology and biochemical analyses, 28 male rats were randomly divided into four groups. Groups were control, RES, AOM and ARES. At the end of the 7 weeks, following routine tissue processing procedure, testis sections were stained with haematoxylin-eosin and Masson's trichrome. The blood samples were taken for biochemical analysis of testosterone, total oxidative stress, total antioxidant status and oxidative stress index. Degenerative changes in the seminiferous tubules such as atrophy, loss in the number of germ cells and arrested spermatogenic cell, and increase in the connective tissue of the tunica albuginea in the groups with AOM treatment were found. RES treatment (ARES) reduced the number of affected seminiferous tubules significantly (p < .05) compared to AOM alone. The testosterone levels in AOM group were significantly lower than in the control group (p < .05). The total oxidative stress levels were significantly higher in AOM group compared to control group (p < .05). The total antioxidant status levels in ARES group were significantly higher than in the AOM group (p < .05). This study results suggest that an antioxidant like Resveratrol may be useful for decreasing the harmful effects of azoxymethane.

Protective role of caffeic acid phenethyl ester (cape) on gentamicin-induced acute renal toxicity in rats.

The toxicity of gentamicin (GEN) in the kidney seems to relate to the generation of reactive oxygen species (ROS). Caffeic acid phenethyl ester (CAPE) has been demonstrated to have antioxidant, free radical scavenger and anti-inflammatory effects. It has been proposed that antioxidant maintain the concentration of reduced glutathione (GSH) may restore the cellular defense mechanisms and block lipid peroxidation thus protect against the toxicity of wide variety of nephrotoxic chemicals. We investigated the effects of CAPE on GEN-induced changes in renal malondialdehyde (MDA), a lipid peroxidation product, nitric oxide (NO) generation, superoxide dismutase (SOD), catalase (CAT) activities, GSH content, blood urea nitrogen (BUN) and serum creatinine (Cr) levels. Morphological changes in the kidney were also examined. A total of 32 rats were equally divided into four groups which were: (1) control, (2) injected with intraperitoneally (i.p.) GEN, (3) injected with i.p. GEN+CAPE and (4) injected with i.p. CAPE. GEN administration to control rats increased renal MDA and NO generation but decreased SOD and CAT activities, and GSH content. CAPE administration with GEN injections caused significantly decreased MDA, NO generation and increased SOD, CAT activities and GSH content when compared with GEN alone. Serum level of BUN and Cr significantly increased as a result of nephrotoxicity. CAPE also, significantly decreased serum BUN and Cr levels. Morphological changes in the kidney due to GEN, including tubular necrosis, were evaluated qualitatively. In addition, CAPE reduced the degree of kidney tissue damage induced by GEN. Both biochemical findings and histopathological evidence showed that administration of CAPE reduced the GEN-induced kidney damage. Our results indicated that CAPE acts in the kidney as a potent scavenger of free radicals to prevent the toxic effects of GEN both at the biochemical and histological level. Thus, CAPE could be effectively combined with GEN treatment.

Effects of pentoxifylline and vitamin E on the bilateral ovary after experimental ovarian ischemia.

Pentoxifylline (PTX) and vitamin E inhibit the release of superoxide and hydroxyl radicals, and PTX improves capillary flow and tissue oxygenation. This experimental study was designed to determine the effects of PTX and vitamin E in the ovary after unilateral ovarian ischemia reperfusion (I-R) in albino Wistar rats. A vascular clamp was placed on the left ovary for 4 hours in all groups except for the control group. Following this, in the ischemia (I) group bilateral ovariectomy was performed. Saline, PTX, vitamin E, and PTX plus vitamin E were infused 30 min before reperfusion in the reperfusion (R), pentoxifylline (P), vitamin E (E), and pentoxifylline plus vitamin E (PE) groups, respectively. After 4 hours of reperfusion, the ovaries were removed for biochemical and histologic examination. MDA levels of bilateral ovaries in the PE group were significantly lower than in the E group (p < 0.0033). NO levels of bilateral ovaries in the PE group were significantly lower than in the P and E groups (p < 0.0033). Massive hemorrhage was determined in the ipsilateral ovaries of the R group. Hemorrhage was minimal or moderate in the ipsilateral ovaries of other groups. The contralateral ovaries showed congestion in different degrees. The contralateral ovaries of the group PE and the bilateral ovaries of the control group showed no pathological changes. PTX and vitamin E given together seems to be more effective in reducing I-R injury in ovarian tissue compared to administration of PTX, or vitamin E alone. However, further studies are required to evaluate the effective dose and duration of PTX and vitamin E on bilateral ovaries.

Resveratrol reduces ischemia reperfusion injury after experimental testicular torsion.

The aim of the study was to evaluate the effects of resveratrol on testicular ischemia reperfusion injury. Forty Wistar albino rats were divided into 4 groups. Torsions (ischemia) were created by rotating the right testis 720 degrees in a clockwise direction for 4 hours in all groups except the control group. In the torsion group after 4 hours' ischemia bilateral orchiectomy was performed. In the detorsion group, saline was injected by an intraperitoneal route, 30 min before detorsion (reperfusion). In the resveratrol group, 30 mg/kg resveratrol was injected by an intraperitoneal route, 30 min before detorsion. In the detorsion and resveratrol groups, the bilateral testes were removed after 20 hours of detorsion. In all groups, the tissue levels of malondialdehyde (MDA) and glutathione (GSH) and histological changes were determined. In rats treated with resveratrol, MDA levels (138 +/- 25 nmol/mg protein) were significantly decreased compared with torsion (426 +/- 178 nmol/mg protein) and detorsion (370 +/- 76 nmol/mg protein) groups (p < 0.05). GSH levels (6.54 +/- 0.8 micromol/g wet tissue) were significantly increased compared with torsion (4.61 +/- 0.4 micromol/g wet tissue) and detorsion groups (5.24 +/- 0.9 micromol/g wet tissue) (p < 0.05). The mean testicular tissue injury score in the resveratrol group was significantly lower than in torsion and detorsion groups (p < 0.05). The present study demonstrates that intraperitoneal administration of resveratrol in rats may protect testis against injury associated with reperfusion.

Protective effect of chelerythrine on gentamicin-induced nephrotoxicity.

Despite their beneficial effects, aminoglycosides including gentamicin (GEN) have considerable nephrotoxic side-effects. The toxicity of GEN at the level of the kidney seems to relate to the generation of reactive oxygen species (ROS). ROS have been reported to be involved in the activation of protein kinase C (PKC). The unique structural aspects of PKC cause it to function as a sensor for oxidative stress. It seems likely that the increased NAD(P)H oxidase-derived superoxide (O2) production is at least in part mediated by PKC. We investigated the effects of chelerythrine, a commonly used PKC inhibitor, on GEN-induced changes of renal malondialdehyde (MDA), nitric oxide (NO) generation, catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities, glutathione (GSH) content, and serum creatinine (Cr), blood urea nitrogen (BUN) levels. Morphological changes in the kidney were also examined. GEN administration to control rats increased MDA and NO generation but decreased CAT, SOD and GSH-Px activities, and GSH content. Chelerythrine administration with GEN caused significantly decreased MDA, NO generation and increased CAT, SOD and GSH-Px activities, and GSH content when compared with GEN alone. Chelerythrine also significantly decreased serum Cr and BUN levels. Morphological changes in the kidney including tubular necrosis were evaluated qualitatively. Both biochemical findings and histopathological evidence showed that administration of chelerythrine reduced the GEN-induced kidney damage. We propose that chelerythrine acts in the kidney as a potent scavenger of free radicals to prevent the toxic effects of GEN via the inhibition of a PKC pathway.

The effect of sustained and local administration of epidermal growth factor on improving bilateral testicular tissue after torsion.

Epidermal growth factor (EGF) modulates Leydig cell proliferation, steroidogenesis, spermiogenesis, and Sertoli cell activity. It plays an important role in repairing ischemia-reperfusion injury in different tissues. The aim of this study was to evaluate the effects of sustained and local administration of EGF on improving bilateral testicular tissue after torsion. A total of 57 Wistar albino rats were used. For the EGF transport system, 1x2 cm gelatin films containing 2 microg EGF were used. Torsion was created by rotating the right testis 720 degrees in a clockwise direction for 4 h in all groups except the control group. Then, in the torsion group, bilateral orchiectomy was performed. After returning the torsioned ipsilateral testes to their normal state, the bilateral testes were wrapped by 1x2 cm unloaded gelatin films in the gelatin (G7 and G21) groups and, by 2 microg EGF loaded gelatin films in the EGF 7 and EGF 21 groups. The testes were removed on the seventh and 21st days, respectively, for biochemical and histological examination. Histologically, Johnsen's spermatogenesis criteria and mean seminiferous tubule diameter (MSTD) measurements were used. The EGF7 group did not show significant loss of Sertoli cells, while in the G7 group the number of these cells decreased. The ipsilateral ischemic testis of the EGF21 group showed Leydig cell hyperplasia, and the contralateral non-ischemic testes in this group were similar to the control group. In the G21 group, the bilateral testes showed Sertoli cell only syndrome in some sections, and most of the cells were undergoing apoptosis. The mean spermatogenesis scores and MSTD in the EGF7 and EGF21 groups were higher than in the G7 and G21 groups ( P<0.05). Malondialdehyde levels were significantly lower in the EGF groups than in the G groups ( P<0.05). Glutathione peroxidase (GSH-Px) levels in the G21 group were significantly higher than in the EGF21 group. Our study shows that local and sustained EGF release after testicular torsion improves bilateral testicular injury. EGF administration may be a new treatment choice for bilaterally injured testis after detorsion without removing the twisted testis.