Ischemia-reperfusion injury of rabbit ovary and protective effect of trapidil: an experimental study

Ramifications of Heat Stress on Rabbit Production and Role of Nutraceuticals in Alleviating Its Negative Impacts: An Updated Review

Heat stress has become a widespread concern worldwide, which is a major environmental stress that causes substantial economic loss in the rabbit industry. Compared to other agricultural animals, rabbits are more sensitive to heat stress as they have fewer sweat glands and a thicker coat of fur, increasing the heat dissipation complexity. Thus, heat stress hurts rabbits' productivity, meat quality, reproductive performance, antioxidative properties, immune responsiveness, intestinal histomorphology, and microbiome. Nutraceuticals include vitamins, minerals, antioxidants, organic acids, fatty acids, probiotics, prebiotics, synbiotics, enzymes, and medicinal plants due to the possible impacts on maintaining common biological situations, strengthening immune response, and preventing illness, which ultimately led to an increase in productivity. Nutraceuticals have recently attracted a lot of attention to alleviate the adverse impacts of heat stress in rabbit farms. The objective of the current review is to provide acquaintance with the recent findings about the impact of heat stress on rabbit productivity and the advantages of dietary supplementation of nutraceuticals in mitigating it.

Tocilizumab is effective in preventing ovarian injury induced by ischemia- reperfusion in rats

Ovarian torsion can be defined as the bending of the ovaries on the supporting ligament, disrupting both venous and arterial blood circulation. Insufficient blood flow causes ovarian tissue hypoxia and leads to ischemia. This study aimed to investigate whether tocilizumab has a protective effect on ischemia-reperfusion injury due to ovarian torsion in rats. Eighteen female Wistar albino rats were divided into three equal groups (Sham (SG), ischemia-reperfusion (OIR), and ischemia-reperfusion+tocilizumab (OIRT)). Degeneration, necrosis, vascular dilatation/congestion, interstitial edema, hemorrhage, and polymorphonuclear lymphocyte (PMNL) infiltration scores were significantly different between the groups (p=0.001 for all parameters). Moreover, the OIRT group had a significant improvement in these criteria compared to the OIR group (p<0.05). Additionally, there was a considerable difference between OIRT and OIR groups in the number of primordial, developing, and atretic follicles groups (p<0.05), while there was no difference in the number of corpus luteum (p=0.052). Stress markers or cytokines, such as MDA, tGSH, NF-κB, TNF-α, IL-1β, and IL-6, were significantly different between groups (p<0.05). Furthermore, a significant improvement was found in the measured variables when the OIRT group was compared with the OIR group (p<0.05). Tocilizumab may be an alternative option for treating ischemia-reperfusion injury due to ovarian torsion.

Construction of a competing endogenous RNA network to identify drug targets against polycystic ovary syndrome

STUDY QUESTION

Would the construction of a competing endogenous RNA (ceRNA) network help identify new drug targets for the development of potential therapies for polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

Both Food and Drug Administartion (FDA)-approved and candidate drugs could be identified by combining bioinformatics approaches with clinical sample analysis based on our established ceRNA network.

WHAT IS KNOWN ALREADY

Thus far, no effective drugs are available for treating PCOS. ceRNAs play crucial roles in multiple diseases, and some of them are in current use as prognostic biomarkers as well as for chemo-response and drug prediction.

STUDY DESIGN, SIZE, DURATION

For the bioinformatics part, five microarrays of human granulosa cells were considered eligible after applying strict screening criteria and were used to construct the ceRNA network for target identification. For population-based validation, samples from 24 women with and without PCOS were collected from January 2021 to July 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The public data included 27 unaffected women and 25 women with PCOS, according to the Rotterdam criteria proposed in 2003. The limma and RobustRankAggreg R packages were used to identify differentially expressed messenger RNAs and noncoding RNAs. Gene Ontology, Reactome and Kyoto Encyclopedia of Genes and Gemomes (KEGG) enrichment analyses were performed. A ceRNA network was constructed by integrating the differentially expressed genes and target genes. The population-based validation included human luteinized granulosa cell samples from 12 unaffected women and 12 women with PCOS. Quantitative real-time polymerase chain reaction was conducted to detect the levels of mRNAs and microRNAs (miRNAs). Connectivity map and computational model algorithms were implemented to predict therapeutic drugs from the ceRNA network. Additionally, we compared the predicted drugs with known clinical medications in DrugBank.

MAIN RESULTS AND THE ROLE OF CHANCE

A set of 10 mRNAs, 11 miRNAs and 53 long non-coding RNAs (lncRNAs) were differentially expressed. Functional enrichment analysis revealed the highest relevance to immune system-related biological processes and signalling pathways, such as cytokine secretion and leucocyte chemotaxis. A ceRNA consisting of two lncRNAs, two miRNAs and five mRNAs was constructed. Through network construction via bioinformatic analysis, we identified some already approved drugs (such as metformin) that could target some molecules in the network as potential drug candidates for PCOS.

LARGE SCALE DATA

Public sequencing data were obtained from GSE34526, GSE84376, GSE102293, GSE106724 and GSE114419, which have been deposited in the Gene Expression Omnibus database.

LIMITATIONS, REASONS FOR CAUTION

Experiments, such as immunoprecipitation, luciferase reporter assays and animal model studies, are needed to validate the potential targets in the ceRNA network before the identified drug candidates can be tested using cellular and animal model systems.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings provide new bioinformatic insight into the possible pathogenesis of PCOS from ceRNA network analysis, which has not been previously studied in the human reproductive field. Our study also reveals some potential drug candidates for the future development of possible therapies against PCOS.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the National Key Research and Development Program of China (2021YFC2700400) and the National Natural Science Foundation of China (82001498). The authors have no conflicts of interest to disclose.

Negative effects of heat stress on ovarian tissue in female rabbit

Numerous studies have highlighted the role of miRNA in the deformation and necrosis of cells of ovarian tissue caused by heat stress (HS), which ultimately affects ovarian function. Although the role of small RNAs has been investigated in alterations in ovarian tissue functioning in response to HS, the expression profile of ovarian miRNA has been explored to a lesser extent. In this study, female rabbits were subject to HS treatment by using electrical heater. The current work demonstrated that HS could significantly change physiological performance of female rabbits including body weight, rectal temperature and relative ovary weight, and significantly reduce serum IL-2, IL-8, CAT, and GSH-Px concentrations by enzyme-linked immunosorbent assay (ELISA) technique. As a result, an increase in apoptosis in ovarian cells, as well as unhealthy follicles, were observed by Hematoxylin-eosin (HE) and TUNEL staining. Additionally, small RNA-seq revealed changes in the miRNA expression profile of rabbit ovaries under HS. Five hundred fourteen miRNAs were obtained including known miRNAs 442 and novel miRNAs 72. Among these miRNAs, 23 miRNAs were significantly expressed under HS. Eleven differentially expressed miRNAs (DE miRNAs) and 9 their predicted targets were confirmed by qPCR, which were expected miRNA-mRNA negative regulation pattern. Among the DE miRNAs and targets, miR-141-39 may target COQ6, miR-449a-5p and miR-34c-5p may control RFC5 and RTN2 together, miR-449a-5p may target ACADVL, miR-34c-5p potentially targets Bcl-2 and miR-196b-5p potentially regulates CASK and HOXB6. Thus, the current work suggested the negative effects of HS on the ovarian tissue of female rabbits, and in conclusion these changes could be caused by decreased serum IL-2, IL-8, CAT and GSH-Px levels, increased ovarian apoptosis, and changed the expression of miRNAs.

Evaluation of the protective effects of gossypin for ischemia/reperfusion injury in ovary tissue

AIM

Ovarian ischemia-reperfusion (I/R) injury is a serious gynecological condition that affects women of reproductive age and reduces ovarian reserve. Management of I/R injury with detorsion causes reperfusion damage, in which oxidative stress plays a central role. This study aimed to investigate whether the gossypin (GOS) with antioxidant properties, a flavonoid, has beneficial effects on the biochemical, molecular, and histopathological aspects of ovarian I/R injury.

METHODS

Thirty-three female Balb/c mice were randomly divided into five groups as follows: Healthy (Sham-operated control group), I/R (IR group), I/R + GOS 5 (I/R with GOS 5 mg/kg), I/R + GOS 10 (I/R with GOS 10 mg/kg), and I/R + GOS 20 (I/R with GOS 20 mg/kg). This was followed by 3 h of ischemia and subsequent reperfusion for 3 h after detorsion was exposed. GOS was injected 2 h before reperfusion.

RESULTS

IL-1β, IL-6, TNF-α, NF-κB, and CASP-3 mRNA expressions, SOD (superoxide dismutase) activity, GSH (glutathione), and MDA (malondialdehyde) levels, and histopathological changes were evaluated in ovarian tissue. Histological examination indicated that treatment of ovarian I/R injury with GOS led to the improvement of ovarian tissue, which was accompanied by an increase in SOD activity and GSH level and a decrease in MDA level, NF-κB, TNF-α, IL-1β, and IL-6 expressions. GOS was also corrected by reducing the elevated expression of CASP-3 as apoptosis-change marker.

CONCLUSION

These findings indicate that the treatment of GOS may be useful as a conservative approach to reverse I/R injury via amelioration of oxidative stress parameters and histopathological scores, attenuation of inflammation, and the suppression of apoptosis.

Oxidative and histopathological effects of the application of electrosurgical devices to the penile tissue of rats

INTRODUCTION

This study was performed to evaluate the oxidative and histopathological changes that occur following the application of electrosurgical devices (monopolar or bipolar cautery) to penile tissue.

MATERIAL AND METHODS

Eighteen Wistar albino male rats were randomly distributed into three groups. In the control group (CG, n = 6), all penile tissues were sampled without any additional process following the administration of anesthesia. In the monopolar cautery group (MPG, n = 6), a 15-W cauterization process lasting 5 s was performed on an approximately 2 mm² area of the ventral side of the penile shaft, 0.5 cm proximal to the edge of the glans in the midline. Bipolar cautery was practiced in the third group (BPG, n = 6) using the same techniques outlined in the previous statement. Penile tissues consisted of the cautery application area, the edge of the glans, and dorsal side of the penis and were sampled after 90 min; then, histopathological evaluation and biochemical examination involving malondialdehyde (MDA), nitric oxide (NO), and superoxide dismutase (SOD) measurements were performed.

RESULTS AND DISCUSSION

Histopathologically, the MPG and BPG demonstrated increased inflammation, fibrosis, and epithelial loss in the urethra in the areas to which cautery was applied as compared to the CG (P < 0.05). The vascular structures of the corpus cavernosa were significantly decreased in the cautery application area of both the MPG and the BPG as compared to the CG (P < 0.05). In the Masson's trichrome stained samples, significant collagen deposition was observed in the cautery application area both in the MPG and the BPG as compared to the CG (P < 0.05). However, S-100 staining was decreased in these groups as compared to the CG (P < 0.05). S-100 staining was also decreased in the MPG as compared to the BPG on the edge of the glans (P < 0.05). Biochemically, MDA values were significantly increased in the MPG as compared to the CG and the BPG (P < 0.05).

CONCLUSION

Monopolar and bipolar cautery both did cause oxidative changes and triggered inflammatory, vascular, and peripheral nerve alterations in the cautery application area while bipolar cautery did not cause any distant effects.

An investigation of the effects of metformin on ovarian ischemia-reperfusion injury in rats

Damage to the ovaries or tissue torsion can significantly reduce the ovarian reserve and thus cause severe gynecological and hormonal deficiencies. The discovery of new agents is always needed in the treatment of this condition. Metformin (MET) has been shown to be beneficial in attenuating ovarian ischemia-reperfusion injury. Fifty-six female Sprague Dawley rats were divided into seven groups. Group 1 represented the control group (C), Group 2, the ischemia group (I), and Group 3, the ischemia/reperfusion group (I/R). Group 4, the ischemia (I)+250 group, and Group 5, the ischemia (I)+500 group, received 250 mg/kg and 500 mg/kg MET, respectively. Group 6, the ischemia/reperfusion (I/R)+250 group, and Group 7, the ischemia/reperfusion (I/R)+500 group, received 250 mg/kg and 500 mg/kg MET, respectively. Tissue malondialdehyde (MDA), glutathione (GSH), and tumor necrosis factor-alpha (TNF-α) levels in ovarian tissue increased following I/R, while estradiol (E₂) levels decreased. Moreover, infiltration and diffuse edematous areas were observed in addition to diffuse vascular congestion and hemorrhage findings. Caspase-3 and nuclear factor kappa B (NF-κβ) expression levels also increased. MDA and TNF-α concentrations decreased in the MET treatment groups, while GSH and E₂ levels increased. The findings showed that I/R causes ovarian damage through the induction of oxidative stress, inflammation, and apoptosis. However, MET application was effective in preventing damage in ovarian tissue by reducing levels of reactive oxygen species, proinflammatory cytokines, caspase-3 and NF-κβ.

Protective effects of tempol in an experimental ovarian ischemia-reperfusion injury model in female Wistar albino rats

The aim of this study was to investigate the antioxidant effects of tempol on ovarian ischemia-reperfusion (I/R) injury in rats. Forty female Wistar albino rats were randomly divided into 5 groups: Group I, sham; Group II, ischemia (I); Group III, I/R; Group IV, I/R + tempol 30 mg/kg i.p; Group V, I/R + tempol 50 mg/kg i.p. Oxidative stress index (OSI) was significantly higher in the ischemia group and the I/R group than in the sham group. Catalase levels were significantly lower in the I/R group than in the I/R + tempol 30 mg/kg i.p. and the I/R + tempol 50 mg/kg i.p. groups. Glutathione peroxidase levels were lower in the I/R group than in the I/R + tempol 30 mg/kg i.p. and the I/R + tempol 50 mg/kg i.p. groups. MDA levels were significantly lower in the I/R + tempol 30 mg/kg i.p. group and the I/R + tempol 50 mg/kg i.p. group than in the I/R group. The levels of the histopathological parameters were significantly decreased in the I/R + tempol 50 mg/kg i.p. group compared with the I/R group. Tempol can be used for reducing ovarian I/R injury.

The effect of antioxidant supplementation on bacterial translocation after intestinal ischemia and reperfusion

The intestine is highly sensitive to ischemia/reperfusion (I/R) injury. Intestinal I/R may cause local tissue injury and disruption of the intestinal mucosal barrier, allowing the passage of viable bacteria and endotoxins from the gastrointestinal lumen to distant organs. This phenomenon, known as bacterial translocation (BT), may lead to systemic disorders with high morbidity and mortality. Oxidative stress mediators such as reactive oxygen species, polymorphonuclear neutrophils and nitric oxide are believed to contribute to the intestinal I/R injury. Many antioxidants have shown protective effects against I/R injury of various organs. The present article provides an overview of studies investigating the effect of antioxidant supplementation on BT after intestinal I/R.

Aliskiren - a promising strategy for ovarian ischemia/reperfusion injury protection in rats via RAAS

The aim of this study was to evaluate the effects of aliskiren, direct renin inhibitor, as an antioxidant and tissue protective agent and evaluate the molecular, biochemical, and histopathological changes in experimental ischemia and ischemia/reperfusion injury in rat ovaries. Forty-eight female rats were randomly divided into eight groups: in Group 1, only sham operation was performed. Group 2 received 100 mg/kg aliskiren and sham operated. In Group 3, 3 h-period of bilateral ovarian ischemia was applied. Group 4 received a 3-h period of ischemia followed by 3 h of reperfusion. Groups 5 and 6 received 50 and 100 mg/kg, respectively, of aliskiren and bilateral ovarian ischemia was applied (after a 3-h period of ischemia, both ovaries were surgically removed). To Groups 7 and 8, 50 and 100 mg/kg of aliskiren were administered, respectively, and the induction of ischemia was performed. At the end of a 3-h period of ischemia, bilateral vascular clips were removed, and 3 h of reperfusion continued. After the experiments, IL-1β, IL-6, TNF-α, and iNOS mRNA expressions and SOD, GSH, MDA, renin, and angiotensin-II levels were determined and histopathological changes were examined in rat ovaries. Aliskiren treatment normalized excessive changes in cytokine and oxidative stress markers in both ischemia and ischemia/reperfusion injury. Histopathologically, treatment with aliskiren ameliorated the development of ischemia and/or ischemia/reperfusion tissue injury. This study concluded that aliskiren treatment is effective in reversing ischemia and/or ischemia/reperfusion induced ovary damage via the improvement of oxidative stress, reduction of inflammation, and suppression of the renin-angiotensin aldosterone system.

Effects of carvedilol on an ischemia/reperfusion model: Biochemical, histopathological and immunohistochemical evaluation

AIM

The aim of this study was to investigate the effects of carvedilol (CVD) on experimentally induced ovarian ischemia/reperfusion (I/R) injury in rats.

METHODS

An ovarian I/R model was applied to rats, classified into three groups: 1 (n = 7), sham operated (control); 2 (n = 7), 3 h ischemia + 3 h reperfusion (I/R); 3 (n = 7), 3 h ischemia + CVD + 3 h reperfusion (I/R + CVD). Malondialdehyde (MDA) levels and glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities in ovarian tissues and serum were measured. Tissue damage was examined histopathologically; Bax and caspase-3 expression was determined immunhistochemically. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to show apoptotic cell death.

RESULTS

MDA levels in ovarian tissues were significantly increased in the I/R group compared with the control. CVD administration significantly decreased tissue MDA levels in the I/R + CVD in comparison with the I/R group. GSH-Px activities in serum were higher in the I/R + CVD than in the I/R group. SOD activities in tissue and serum were significantly decreased in the I/R compared with the control group. Histological examination showed a significant improvement in ovarian morphology in the I/R + CVD compared with the I/R group. Bax and caspase-3 protein was more strongly expressed in the I/R group compared with the control and I/R + CVD groups. Apoptotic index detected by TUNEL assay was significantly increased in the I/R and decreased in the I/R + CVD group.

CONCLUSION

Our results suggest that CVD reduces the deleterious effects of oxidative damage on ovaries in a rat I/R model.

Protective effects of honokiol on ischemia/reperfusion injury of rat ovary: an experimental study

Aim

The purpose of this study was to investigate the protective effect of honokiol on experimental ischemia/reperfusion injury of rat ovary.

Materials and methods

A total of 40 female Wistar albino rats were used in this study. The rats were divided into five groups as follows: sham (Group I), torsion (Group II), torsion + detorsion (Group III), torsion + detorsion + saline (Group IV), and torsion + detorsion + honokiol (Group V). Bilateral adnexa in all the rats except for those in the sham group were exposed to torsion for 3 hours. The rats in Group IV were administered saline, whereas the rats in Group V were administered honokiol by intraperitoneal route 30 minutes before detorsion. Tissue and plasma concentrations of malondialdehyde and nitric oxide were determined. Ovarian tissue was histologically evaluated. Data analyses were performed by means of Kruskal–Wallis test and Mann–Whitney U-test (Bonferroni correction) in SPSS 15.0 (Statistical Package for Social Sciences; SPSS Inc., Chicago, IL, USA).

Results

The torsion and detorsion groups had higher scores in vascular congestion, hemorrhage, and inflammatory cell infiltration compared with the sham group (P<0.005). In addition, total histopathological scores were significantly higher in the torsion and detorsion groups compared with the sham group (P<0.005). A significant reduction was observed in hemorrhage, inflammatory cell infiltration, and cellular degeneration scores, of all histopathological scores, in the honokiol group (P<0.005). Ovarian tissue concentrations of malondialdehyde were significantly higher in the torsion and detorsion groups compared with the sham and honokiol groups (P<0.005). Ovarian tissue concentrations of nitric oxide, on the other hand, were significantly higher in the torsion group compared with the sham, saline, and honokiol groups (P<0.005).

Conclusion

Honokiol has a beneficial effect on ovarian torsion-related ischemia/reperfusion injury.

The Protective Effects of Alpha-Lipoic Acid and Coenzyme Q10 Combination on Ovarian Ischemia-Reperfusion Injury: An Experimental Study

Objective. This study aims to evaluate whether alpha-lipoic acid and/or coenzyme Q10 can protect the prepubertal ovarian tissue from ischemia-reperfusion injury in an experimental rat model of ovarian torsion. Materials and Methods. Forty-two female preadolescent Wistar-Albino rats were divided into 6 equal groups randomly. The sham group had laparotomy without torsion; the other groups had torsion/detorsion procedure. After undergoing torsion, group 2 received saline, group 3 received olive oil, group 4 received alpha-lipoic acid, group 5 received coenzyme Q10, and group 6 received both alpha-lipoic acid and coenzyme Q10 orally. The oxidant-antioxidant statuses of these groups were compared using biochemical measurement of oxidized/reduced glutathione, glutathione peroxidase and malondialdehyde, pathological evaluation of damage and apoptosis within the ovarian tissue, and immunohistochemical assessment of nitric oxide synthase. Results. The left ovaries of the alpha-lipoic acid + coenzyme Q10 group had significantly lower apoptosis scores and significantly higher nitric oxide synthase content than the left ovaries of the control groups. The alpha-lipoic acid + coenzyme Q10 group had significantly higher glutathione peroxidase levels and serum malondialdehyde concentrations than the sham group. Conclusions. The combination of alpha-lipoic acid and coenzyme Q10 has beneficial effects on oxidative stress induced by ischemia-reperfusion injury related to ovarian torsion.

Protective effects of ellagic acid and ozone on rat ovaries with an ischemia/reperfusion injury

AIM

This study investigated the effects of the antioxidant agents, ozone (O) and ellagic acid (EA), on ischemia/reperfusion (I/R) injuries developed from an ovarian torsion-detorsion model.

MATERIALS AND METHODS

Arteries in the left ovaries of rats were clamped for two hours to achieve torsion, and then the clamps were removed for a two-hour detorsion period. Thirty-five female Sprague-Dawley rats were randomly divided into five groups: control: administered only with anesthesia, rats were not subjected to torsion-detorsion; I/R: subjected to torsion and subsequent detorsion, without administering any treatment agent; and I/R + EA, I/R + O and I/R + O + EA: subjected to torsion and detorsion processes and administered with EA, O or EA + O at the 75th minute of torsion. The rats were then sacrificed under general anesthesia and the ovarian tissues were excised. The tissues were homogenized and levels of glutathione reductase, catalase, superoxide dismutase and malondialdehyde (MDA) were analyzed. Tissue damage was evaluated in terms of histopathological parameters, such as hemorrhage, congestion, edema and inflammation.

RESULTS

Antioxidant enzyme activity and MDA levels in the ovary tissue increased in the I/R group and decreased in the O, EA and O + EA groups (P < 0.05). Histopathological examination revealed that tissue damage in the O, EA and O + EA groups decreased in comparison with the I/R group (P < 0.05).

CONCLUSIONS

These biochemical and histopathological findings suggest that EA and O are effective against ovarian I/R injury.

Development of mouse preantral follicle after in vitro culture in a medium containing melatonin

Objective

Improvements in cancer treatment have allowed more young women to survive. However, many cancer patients suffer from ovarian failure. Cryopreservation is one of the solutions for fertility restoration in these patients. The cryopreservation of isolated follicles is a more attractive approach in the long term. Many endocrine and paracrine factors can stimulate the granulosa cells of preantral follicles to proliferate. Melatonin acts as direct free radical scavenger and indirect antioxidant. In this study, we investigated the direct effects of melatonin on follicle development and oocyte maturation by exposing in vitro cultured mouse vitrified-warmed ovarian follicles to melatonin.

Materials and Methods

In an experimental study, preantral follicles with diameter of 150-180 µm were isolated from prepubertal mouse ovaries. Follicles were vitrified and thawed using cryolock method. They were then cultured individually for 7 days in droplets supplemented with 0, 10 and 100 pM melatonin, while ovulation was induced using epidermal growth factor (EGF) and human chorionic gonadotropin (hCG). The survival rate of follicles and nuclear maturation of ovulated oocytes were determined.

Results

At the end of culture, significant increases in follicle survival (p<0.001) and in diameter (p<0.05) were noticed in 10 pM melatonin group compared to control group. In the 100 pM group, survival rate was not affected by melatonin. It was revealed that after induction of ovulation, total number of metaphase II oocytes in treatment groups were not influenced by melatonin (p>0.05).

Conclusion

Culture of mouse vitrified-warmed preantral follicles in a medium supplemented with 10 pM melatonin increased the number of surviving follicles.

Influence of ezetimibe on selected parameters of oxidative stress in rat liver subjected to ischemia/reperfusion

INTRODUCTION

Ischemia/reperfusion (I/R) is considered to be one of the main causes of liver damage after transplantation. The authors evaluated the effect of ezetimibe on selected oxidative stress parameters in ischemic/reperfused (I/R) rat liver.

MATERIAL AND METHODS

Rats were administered ezetimibe (5 mg/kg) (groups E and E-I/R) or saline solution (groups C and C-I/R) intragastrically for 21 days. Livers of animals in groups C-I/R and E-I/R were subjected to 60 min of partial ischemia (left lateral and median lobes) followed by 4 h of reperfusion. Alanine and asparagine aminotransferase (ALT, AST) activity was determined in blood before I/R and during reperfusion (at 15 and 240 min). After the reperfusion period, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GPx) were determined in liver homogenates using colorimetric methods.

RESULTS

Ezetimibe caused a significant increase in GSH level in groups subjected to I/R (E-I/R (99.91 ±9.01) vs. C-I/R (90.51 ±8.87), p < 0.05). Additionally, under I/R the decrease of GPx activity in the drug-treated group was lower compared to the non-treated group (E-I/R (3.88 ±1.11) vs. E (5.31 ±1.83), p = 0.076). Neither ezetimibe nor I/R affected SOD or MDA levels. I/R produced a significant increase in aminotransferase levels (ALT240-0: C-I/R (42.23 ±43.56) vs. C (9.75 ±11.09), and E-I/R (39.85 ±26.53) vs. E (4.38 ±1.36), p < 0.05 in both cases; AST 240-0: E-I/R (53.87 ±17.23) vs. E (24.10 ±9.66), p < 0.05) but no effect of ezetimibe on those enzymes was found.

CONCLUSIONS

Ezetimibe demonstrates antioxidant properties in rat livers subjected to I/R. However, neither a hepatoprotective nor a hepatotoxic effect of ezetimibe was demonstrated, regardless of I/R.

Effect of detorsion alone and in combination with enoxaparin therapy on ovarian reserve and serum antimüllerian hormone levels in a rat ovarian torsion model

OBJECTIVE

To investigate the effect of enoxaparin on ovarian reserve and serum antimüllerian hormone (AMH) levels in a rat ovarian torsion model.

DESIGN

Experimental study.

SETTING

Experimental surgery laboratory in a training and research hospital.

ANIMAL(S)

Fourteen female Wistar Hannover rats.

INTERVENTION(S)

1) Control group received no special treatment other than abdominal exposure; 2) detorsion-only group received bilateral adnexal torsion (3-hour ischemia), and then after 3-hour torsion period, detorsion (reperfusion) was performed; and 3) detorsion-enoxaparin group received 0.5 mg/kg enoxaparin subcutaneously 2 hours before the same surgery as the detorsion-only group and a second 0.5 mg/kg dose of enoxaparin 24 hours after the first surgeries. Apart from the surgeries, preoperative and postoperative 1-mL blood samples were drawn from the right jugular vein of each rat.

MAIN OUTCOME MEASURE(S)

Preoperative and postoperative serum AMH levels, histopathologic damage scores, and follicle counts in the ovarian tissue of the rats.

RESULT(S)

Vascular congestion and hemorrhage scores were higher in the detorsion-enoxaparin group than in the detorsion-only and control groups. The number of small antral follicles was smaller in the detorsion-only group than in the control group. The difference in the pre- and postoperative AMH levels was higher in the detorsion-only group than in the control and detorsion-enoxaparin groups.

CONCLUSION(S)

The combination of enoxaparin therapy with conventional ovarian detorsion is more effective in protecting the ovarian reserve than detorsion alone.

Protective effect of intraperitoneal ozone application in experimental ovarian ischemia/reperfusion injury

AIM

The current accepted management of ovarian torsion is ovary-sparing surgery. Ozone therapy is used to reduce ischemia/reperfusion (I/R) injury in several situations. An experimental study was designed to evaluate effect of ozone application in ovarian I/R injury.

MATERIALS AND METHODS

Three groups (n = 6) and 18 rats were included in the study. After anesthesia, right ovaries were fixed and removed at the end of 2 hours in sham group (SG). In torsion group (TG), right ovaries underwent 720° torsion in a counterclockwise direction. Ovaries were removed after 2 hours torsion and 2 hours reperfusion. In ozone group (OG), torsion was created by the same technique, and 95% oxygen plus 5% ozone gas mixture was given intraperitoneally (25 μg/mL, 0.5 mg/kg) 10 minutes before reperfusion. After 2 hours reperfusion, ovaries were removed. Histopathologic examination of ovarian and periovarian sections was performed for the presence of congestion (C), hemorrhage, interstitial edema (IE), and polymorphonuclear neutrophilic infiltrations. Tissue samples were analyzed for malondialdehyde, nitric oxide (NO), and total sulphidryl (t-SH) values. Results were compared between 3 groups.

RESULTS

At histopathologic examination, the TG have elevation in terms of ovarian C, polymorphonuclear neutrophilic infiltration, and periovarian IE when compared with SG (P < ,05). In OG, ovarian C and periovarian IE were reduced according to TG, whereas the increase was observed only in ovarian C compared with SG (P < .05). At biochemical evaluation of oxidative stress markers in SG and TG, there was no difference between them (P < .05). Malondialdehyde levels were significantly lower in OG than TG, whereas NO and t-SH values were higher (P < .05). Malondialdehyde levels were decreased in OG compared with SG (P < .05). However, no difference was observed in NO and t-SH levels (P > .05).

CONCLUSION

Intraperitoneal application of ozone creates a positive impact on histologic and biochemical markers on I/R injury owing to ovarian torsion. The ozone application can be developed to support efforts to protect ovary in ovarian torsion.

Caffeic acid phenethyl ester prevents ovary ischemia/reperfusion injury in rabbits

Protective effect of caffeic acid phenethyl ester (CAPE) on ovary ischemia/reperfusion (IR) injury was investigated in this study. Twenty four New Zealand rabbits were divided into 4 groups as follows: group S served as sham. Group C was intraperitoneally injected with CAPE (8.5mg/kg). In groups E+IR and C+IR, 1% ethanol and CAPE was given intraperitoneally before torsion, respectively. Then, the ovaries were subjected to IR in both groups. Ovary reduced glutathione (GSH) level and glutathione peroxidase (GSH-Px) activity in group E+IR were significantly reduced compared to that of group S. GSH level and GSH-Px activity was significantly increased in group C+I/R. Thiobarbituric acid reactive substances (TBARS) and catalase (CAT) activity in group E+I/R was significantly higher than in group S. CAT activity was decreased to normal levels by CAPE treatment in group C+I/R, while TBARS in group C+IR was significantly reduced compared to that of E+IR. According to histopathological examination, severe congestion, hemorrhage, edema and leukocyte infiltration were observed in E+I/R group. CAPE prominently reduced degenerative effects of IR injury thus it alleviates free radical damage. In conclusion, CAPE which is able to prevent IR-induced injury in the ovaries may be of therapeutic value before the surgical correction.