Ginkgo Biloba Ameliorates Subfertility Induced by Testicular Ischemia/Reperfusion Injury in Adult Wistar Rats: A Possible New Mitochondrial Mechanism

Pathophysiology and management of testicular ischemia/reperfusion injury: Lessons from animal models

Testicular torsion is a urological emergency that involves the twisting of the spermatic cord along its course. Compelling pieces of evidence have implicated oxidative stress-sensitive signaling in pathogenesis of testicular I/R injury. Although, surgical detorsion is the mainstay management; blockade of the pathways involved in the pathogenesis may improve the surgical outcome. Experimental studies using various testicular I/R models have been reported in a bid to explore the mechanisms associated with testicular I/R and evaluate the benefits of potential therapeutic measures; however, most are limited by their shortcomings. Thus, this review was intended to describe the details of the available testicular I/R models as well as their merits and drawbacks, the pathophysiological basis and consequences of testicular I/R, and the pharmacological agents that have being proposed to confer testicular benefits against testicular I/R. This provides an understanding of the pathophysiological events and available models used in studying testicular I/R. In addition, this research provides evidence-based molecules with therapeutic potentials as well as their mechanisms of action in testicular I/R.

Effect of platelet rich plasma versus melatonin on testicular injury induced by Busulfan in adult albino rats: a histological and immunohistochemical study

This study was done to estimate the testicular histological alterations induced by Busulfan (BUS) and compare the possible protective effects of melatonin (MT) and platelet rich plasma (PRP) in a rat model. Sixty-four male rats were dispersed into: control group, BUS group, melatonin group, and PRP group. Blood samples were processed for biochemical analysis. Tissue specimens were managed for light and electron microscopic studies. Immunohistochemical expression of vimentin and proliferating cell nuclear antigen (PCNA) was performed. Busulfan induced severe testicular damage in all studied methodologies. It showed a statistically significant decrease in serum testosterone and elevation of MDA when compared to the control group. Abnormal testicular cytostructures suggesting defective spermatogenesis were observed: distorted seminiferous tubules, deformed spermatogenic cells, low germinal epithelium height, few mature spermatozoa, and also deformed barrier. Vimentin and PCNA expressions were reduced. Ultrastructurally, Sertoli cells and the blood testis barrier were deformed, spermatogenic cells were affected, and mature spermatozoa were few and showed abnormal structure. Both melatonin and PRP induced improvement in all the previous parameters and restoration of spermatogenesis as confirmed by improvement of Johnsen's score from 2.6 ± .74 to 7.6 ± .92. In conclusion, melatonin and PRP have equal potential to ameliorate the testicular toxicity of BUS. Melatonin can provide a better noninvasive way to combat BUS induced testicular injury.

Phytochemicals: Alternative for Infertility Treatment and Associated Conditions

Infertility and obstetric complications have become global health issues in the past few years. Infertility is defined as the inability of a couple to conceive even after twelve months or more of regular and unprotected intercourse. According to WHO data published in the year 2020, 186 million people have infertility globally. Factors leading to infertility are variable in both males and females. But some common factors include smoking, alcohol consumption, obesity, and stress. Various synthetic drugs and treatment options are available that are effective in treating infertility, but their prolonged usage produces various unwanted adverse effects like hot flashes, mood swings, headaches, and weight gain. In extreme cases, these may also lead to the development of anxiety and depression. Herbal remedies have gained a lot of popularity over the years, and people's inclination toward them has increased all over the world. The prime reason is that these show significant therapeutic efficacy and have fewer side effects. The therapeutic efficacy of plants can be attributed to the presence of diverse phytochemical classes of constituents like alkaloids, flavonoids, and volatile oils. These secondary metabolites, or phytomolecules, can be used to develop herbal formulations. The review highlights the applications and mechanisms of action of various phytochemicals for treating infertility. Also, it focuses on the various future prospects associated with it.

Functional mechanism of EGR3 in cerebral ischemia/reperfusion injury in rats by modulating transcription of pri-miR-146a/146b to miR-146 and suppressing SORT1 expression

OBJECTIVE

EGR3 is implicated in angiogenesis in rats with cerebral ischemia/reperfusion injury (CIRI). This research aimed to explore the effect and in vivo and ex vivo mechanisms of EGR3 in CIRI.

METHODS

CIRI rat models were established via middle cerebral artery occlusion. Cell models were established via oxygen-glucose deprivation/reoxygenation (OGD/R). Brain injury was assessed by neurological scoring, HE, and TTC staining. Inflammatory factors and oxidative stress markers were measured using corresponding kits. Mitochondrial membrane potential and mitochondrial respiration were examined by flow cytometry and respirometry. EGR3-miR-146 network was predicted on TransmiR v2.0 database. Target genes of miR-146 were screened on Starbase, Targetscan, and miRDB databases. miR-146 expression was determined by RT-qPCR. Levels of EGR3 and SORT1 were determined by Western blot. Binding relationships among EGR3, miR-146, and SORT1 were validated by dual-luciferase assay. EGR3, miR-146, and SORT1 levels were altered by injection or cell transfection to observe their functions.

RESULTS

EGR3 was poorly-expressed in CIRI rats and OGD/R-induced neurons. EGR3 overexpression reduced inflammatory factor levels and attenuated oxidative stress and mitochondrial injury in CIRI rats and OGD/R-induced neurons. EGR3 bound to miR-146b promoter region. EGR3 promoted pri-miR-146a/146b processing and stimulated miR-146 transcription. miR-146 overexpression ameliorated oxidative stress and mitochondrial injury and miR-146 downregulation abolished the effect of EGR3 overexpression in vitro. miR-146 targeted SORT1. SORT1 overexpression invalidated the protective function of miR-146 overexpression on oxidative stress and mitochondrial injury in vitro.

CONCLUSION

EGR3 protected against CIRI by mitigating oxidative stress and mitochondrial injury via the miR-146/SORT1 axis.

Baicalein Alleviates Testicular Ischemia-Reperfusion Injury in a Rat Model of Testicular Torsion-Detorsion

Testicular torsion/detorsion-induced ischemia/reperfusion injury is partly due to the overgeneration of reactive oxygen species. Baicalein, a main bioactive constituent derived from the dried root of Scutellaria baicalensis Georgi, possesses powerful antioxidative and anti-inflammatory properties. Therefore, we designed the research to explore the possible protective effect of baicalein against testicular ischemia-reperfusion injury. Sprague-Dawley rats were randomized into 4 groups, including control, testicular ischemia-reperfusion, testicular ischemia-reperfusion+vehicle injection, and testicular ischemia-reperfusion+baicalein therapy groups. The control group received surgical exposure of the left testis without torsion-detorsion. In the testicular ischemia-reperfusion group, the left testis underwent 720° counterclockwise torsion for two hours and then was allowed detorsion. Rats in the testicular ischemia-reperfusion+vehicle injection group received intraperitoneal injection of the vehicle at detorsion. In the baicalein-treated group, the intraperitoneal administration of baicalein dissolved in the vehicle was performed at detorsion. At four hours or three months following testicular detorsion, testicular tissues were removed to detect the levels of tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) which can recruit neutrophils into the testis, myeloperoxidase activity (an index of neutrophil infiltration in the testis), protein expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in neutrophils which can catalyze reactive oxygen species production, malondialdehyde concentration (a common marker of reactive oxygen species), and spermatogenesis. Both testicular ischemia-reperfusion and testicular ischemia-reperfusion+vehicle injection significantly increased the TNF-α and IL-1β levels, myeloperoxidase activity, NADPH oxidase protein expression, and malondialdehyde concentration, while decreased spermatogenesis in ipsilateral testes. In contrast, baicalein administration remarkably reduced TNF-α and IL-1β levels, myeloperoxidase activity, NADPH oxidase protein expression, and malondialdehyde concentration and also elevated spermatogenesis in ipsilateral testes. The results of our experiment demonstrate that baicalein alleviates testicular ischemia-reperfusion injury by inhibiting TNF-α and IL-1β secretion, neutrophil infiltration in the testis, and NADPH oxidase protein expression in neutrophils to reduce reactive oxygen species production.

Effect of sunitinib on testicular oxidative and proinflammatory damage induced by ischemia-reperfusion in rats

INTRODUCTION

This study aimed to biochemically and histopathologically investigate the effect of sunitinib on oxidative testicular damage induced by ischemia/reperfusion in rats.

MATERIAL-METHOD

Experimental animals were divided into three groups of six rats each: testicular torsion-detorsion (TTD), sunitinib+testicular torsion-detorsion (STD), and sham control (SC). Sunitinib (25mg/kg) was administered orally to the STD group by gavage. Normal saline (0.9% NaCl) was administered orally to the TTD and control groups as the solvent. One hour after administration of sunitinib and 0.9% NaCl, all animal groups were done torsion-detorsion. Then, all the rats were killed by high-dose anesthesia, and their testicles were removed. Biochemical and histopathological examinations were performed on the removed testicular tissues.

RESULTS

Malondialdehyde; it was observed that the results in the STD group were close to those of the SC group and statistically significant lower compared to the TTD group (p=0.001). The glutathione values were statistically significantly higher in the STD group compared to the TTD group (p<0.001). Nuclear factor kappa B values, revealing a statistically significant difference between the TTD and STD groups (p<0.001). The TNF-α levels were measured and indicating that the results of the STD group were statistically significantly lower than those of the TTD group (p<0.001). Histopathologically, animal tissues given sunitinib were observed to resemble normal tissues.

CONCLUSION

Sunitinib was shown to prevent histopathological changes in testicular tissue against ischemia/reperfusion damage.

Adipose Mesenchymal Stromal Cell-Derived Exosomes Prevent Testicular Torsion Injury via Activating PI3K/AKT and MAPK/ERK1/2 Pathways

Adipose mesenchymal stromal cell-derived exosomes (ADSC-Exos) have shown great potential in the treatment of oxidative stress induced by ischemia-reperfusion injury. However, alleviation of testicular torsion injury by ADSC-Exos has not been reported. Therefore, we investigated the protective effect of ADSC-Exos against testicular torsion-detorsion injury. ADSC-Exos were isolated by ultracentrifugation and injected into torsion-detorsion-affected testes of rats. H&E staining and sperm quality were used to evaluate the therapeutic effects of ADSC-Exos, and tissue oxidative stress was measured by determining MDA and SOD levels. In addition, TUNEL staining and immunohistological analysis (Ki67, Cleaved Caspase-3, IL-6, IL-10, CCR7, and CD163) were used to clarify the effects of ADSC-Exos on spermatogenic cell proliferation, apoptosis, and the inflammatory microenvironment in vivo. Possible signaling pathways were predicted using sequencing technology and bioinformatics analysis. The predicted signaling pathways were validated in vitro by assessing the proliferation (EdU assay), migration (transwell assay and scratch test), and apoptosis (flow cytometry, TUNEL staining, and western blotting) of spermatogenic cells. The results showed that ADSC-Exos alleviated testicular torsion-detorsion injury by attenuating oxidative stress and the inflammatory response. In addition, ADSC-Exos promoted the proliferation and migration of spermatogenic cells and inhibited their apoptosis by activating the PI3K/AKT and MAPK/ERK1/2 signaling pathways.

The NLRP3 inflammasome: molecular activation and regulation in spermatogenesis and male infertility; a systematic review

Background

Infertility related to varicocele, infections, metabolic dysfunctions, oxidative stress and environmental toxicants is also associated with inflammatory processes that ultimately lead to the activation of the inflammasome pathway (IP). IP is classically activated by DAMPs, MAMPs or LAMPs, which stand for Damage-, Microbe- or Lifestyle-Associated Molecular Patterns, respectively. The most important player in IP activation is the NLRP3 (NOD[Nuclear oligomerization domain]-, LRR[Leucine rich repeat]- and pyrin domain-containing protein 3) which functions as an intracellular sensor of D/M/L-AMPs resulting in activation of caspase-1, promotion of apoptosis, pyroptosis and generation of inflammatory cytokines. This review addresses the question of whether IP activation might be associated with male infertility situations.

Results & conclusions

We conducted a systematic review of articles published in the Google Scholar, and PubMed databases through October 2021. It turns out that inflammasome activation and its consequences including cytokine storms, apoptosis and pyroptosis could be associated with the reduced sperm count as well as the structural and functional sperm defects recorded in several situations associated with male infertility suggesting that anti-inflammatory therapeutic strategies could be possibly considered to restore male fertility in future research.

Remote limb ischaemic conditioning produces cardioprotection in rats with testicular ischaemia-reperfusion injury

NEW FINDINGS

What is the central question of this study? Can remote limb ischaemic conditioning produce cardioprotection in rats with testicular ischaemia-reperfusion injury? What is the main finding and its importance? Testicular ischaemia-reperfusion (TI/R)-injured rats were predisposed to myocardial reperfusion-induced atrioventricular block. Remote limb ischaemia preconditioning and postconditioning protected TI/R hearts against ischaemia-provoked ventricular arrhythmia and ultimately reduced the incidence of sudden cardiac death, with a possible role of c-Jun N-terminal kinase inhibition and connexin 43 activation.

ABSTRACT

Remote ischaemic conditioning can protect hearts against arrhythmia. Testicular ischaemia-reperfusion (TI/R) injury is associated with electrocardiographic abnormalities. We investigated the effect of remote limb ischaemia preconditioning (RIPre) and postconditioning (RIPost) on arrhythmogenesis in TI/R rats, and determined the potential role of c-Jun N-terminal kinase (JNK)/connexin 43 (Cx43) signalling. Rats were randomized to sham-operated, control, TI/R, RIPre and RIPost groups. TI/R rats were more predisposed to myocardial reperfusion-induced atrioventricular block (AVB). RIPre and RIPost reduced the incidence of sudden cardiac death (SCD) or AVB, and duration of ventricular tachyarrhythmias during myocardial reperfusion. RIPre and RIPost decreased myocardial I/R-induced phosphorylation level of JNK, while preserving myocardial Cx43 expression in TI/R rats. Taken together, TI/R rats were predisposed to myocardial reperfusion-induced AVB. RIPre and RIPost protected TI/R hearts against ischaemia-provoked ventricular arrhythmia and ultimately reduced the incidence of SCD by suppressing JNK activation and restoring Cx43 expression.

Cross-link between mitochondrial-dependent apoptosis and cell cycle checkpoint proteins after experimental torsion and detorsion in rats

The current study assessed the cross-link between mitochondria-related apoptosis and cell cycle machinery systems during ischemia and reperfusion in a rat model of testicular torsion and detorsion. The Wistar male rats were divided into control, 1 h, 2 h, 4 h and 8 h testicular torsion-induced, and 1 h, 2 h, 4 h and 8 h testicular detorsion-induced groups. The Johnson's score was analyzed. The mRNA and protein contents of Bcl-2, Bax, Caspase-3, Cyclin D1, Cdk4, P21 and P53 were investigated by sqRT-PCR and immunohistochemical staining, respectively. The apoptosis index was analyzed by TUNEL staining. The mRNA levels of bax, p53, p21 and cyclin D1 were increased, and the mRNA levels of bcl-2 and cdk4 were decreased in torsion and reperfusion-induced groups, time-dependently. The caspase-3 mRNA was increased in torsion-induced and diminished in detorsion-induced groups. A time-dependent reduction in Bcl-2⁺, Caspase-3⁺, Cyclin D1⁺, Cdk4⁺ and P53⁺ and increment in P21⁺ cells distribution per mm² of tissue were revealed after torsion and detorsion. The apoptosis index was increased after torsion and decreased after detorsion. In conclusion, torsion-induced severe DNA damage stimulates the cyclin D1, p53 and p21 mRNA expression while more than 8 h is needed to reveal them as protein content in testicular tissue. About detorsion, decreased Cyclin D1 and Cdk4 proteins and the P53-induced transcriptional effect on p21 expression, stimulates the p21 bind to cdk4 and consequent failure in Cyclin D1/Cdk4 complex formation. This situation in association with apoptotic genes results in spermatogenesis failure.

Role of Antioxidant Natural Products in Management of Infertility: A Review of Their Medicinal Potential

Infertility, a couple's inability to conceive after one year of unprotected regular intercourse, is an important issue in the world. The use of natural products in the treatment of infertility has been considered as a possible alternative to conventional therapies. The present study aimed to investigate the effects and the mechanisms of various natural products on infertility. We collected articles regarding infertility and natural products using the research databases PubMed and Google Scholar. Several natural products possess antioxidant properties and androgenic activities on productive factors and hormones. Antioxidants are the first defense barrier against free radicals produced by oxidative stress (OS). They remove reactive oxygen stress (ROS), reducing insulin resistance, total cholesterol, fat accumulation, and cancer growth. Moreover, various natural products increase endometrial receptivity and fertility ability showing androgenic activities on productive factors and hormones. For example, Angelica keiskei powder and Astragalus mongholicus extract showed anti-infertility efficacies in males and females, respectively. On the other hand, adverse effects and acute toxicity of natural products were also reported. Tripterygium glycoside decreased fertility ability both in males and females. Results indicate that management of infertility with natural products could be beneficial with further clinical trials to evaluate the safety and effect.

Paeonol protects against testicular ischaemia-reperfusion injury in rats through inhibition of oxidative stress and inflammation

Ischaemia-reperfusion (IR) is the most common form of testicular injury that results in oxidative damage and inflammation ending by subinfertility. Paeonol, a natural phenolic compound, exhibits antioxidant and anti-inflammatory effects. Thus, the present study investigated the role of paeonol in rat testicular IR injury. Thirty adult Wistar rats were randomly divided into five groups; sham, sham treated with paeonol, IR injury, and IR pre-treated with paeonol at low and high doses. Serum testosterone and testicular levels of malondialdehyde and reduced glutathione (GSH) besides superoxide dismutase (SOD) activity were determined. Gene quantifications for tumour necrosis factor-α (TNF-α), hypoxia-inducible factor-1α (HIF-1α) and heat shock protein 70 (HSP70) were also assessed. Histopathological pictures and the immunohistochemical expression of testicular nuclear factor erythroid 2-related factor 2 (Nrf2), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were shown. Pre-treatment with paeonol prevented the drop in serum testosterone, alongside with improvement of testicular malondialdehyde and GSH levels plus SOD activity. Paeonol regained the normal spermatogenesis with prevention of IR-induced increase in TNF-α, HIF-1α and HSP70 gene expression besides IL-1β and IL-6 immunostaining and reduction in Nrf2 protein expression. Paeonol exerted a dose-dependent beneficial effect on testicular IR injury. This effect was achieved by its antioxidant and anti-inflammatory effects.

Plants in the management of male infertility

This review attempts to collate existing data and provide the perspectives for future studies on the effects of plants on the male gonads. For many of these medicinal plants such as Lepidium meyenii, Rupus coreanus, Tribulus terrestres, Panax ginseng, Petasites japonicas, Apium graveolens, Eurycoma longifólia, Pedalium murex, Corchorus depressus, Mucuna pruriens, Astragalus membranaceus, Nigella sativa, Crataegus monogyna, Fagara tessmannii, Phaleria macrocarpa, Anacyclus pyrethrum, Cynomorium songaricum and Morinda officinalis, the mechanism of actions of their active principles and crude extracts has been shown in both laboratory animals, in vitro, and human studies, and includes their antioxidant, anti-inflammatory, spermatogenesis-inducing, aphrodisiac, smooth muscle relaxing and androgenic properties. Several active chemical leads including glucosinolates, anthocyanins, protodioscin, ginsenosides, sesquiterpenes, phyto-oestrogens, quassinoids, diosgenin, thymoquinone, proanthocyanidins and bajijiasu isolated from these plants are known to have target effects on the testis, but efforts have been limited in their application at the clinical level. There still appear to be many more extracts of medicinal plants that have not been characterised to determine the phytochemicals unique to them that have target effects on the gonads. Further, collaborative efforts at isolating pro-drug candidates from medicinal plants for studies at the molecular, cellular and clinical level towards elucidating their mechanisms of action on the testes are therefore warranted in the light of the current male fertility crisis.

The protective effect of low-energy shock wave on testicular ischemia-reperfusion injury is mediated by the PI3K/AKT/NRF2 pathway

AIMS

Testicular ischemia-reperfusion (IR) injury is the primary pathophysiological consequence of testicular torsion. Low-energy shock wave (LESW) is an effective treatment for certain diseases. The present study investigated whether LESW could improve on testicular IR injury in rats and examined the involved mechanism.

MAIN METHODS

Testicular reperfusion was induced in rats after 1-h ischemia. The first LESW treatment was performed 30 min prior to testicular reperfusion, and then every other day for another 3 applications. LY294002 was applied to investigate the involved mechanism. Testicular morphological changes and malonaldehyde (MDA) level were respectively assessed by hematoxylin-eosin staining. Western blot and thiobarbituric acid method. Western blot, real-time quantitative PCR and immunohistochemistry were performed to assess the apoptosis, the activation of phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B (PI3K/AKT) pathway the nuclear factor erythroid 2-related factor 2 (NRF2) and vascular endothelial growth factor A (VEGF-A) level in the testis of rats.

KEY FINDINGS

LESW improved testicular IR injury in rats. Moreover, LESW upregulated the phosphorylation levels of AKT and glycogen synthase kinase 3β (GSK-3β). Also, it upregulated the levels of nuclear NRF2, heme oxygenase 1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO-1) in these rats. Nevertheless, LY294002 blocked these protective effects. LESW also upregulated VEGF-A level in rats with testicular IR injury.

SIGNIFICANCE

This study demonstrated that LESW could ameliorate testicular IR injury in rats, which might be attributed to the activation of PI3K/AKT/NRF2 pathway. These findings suggested the potential of LESW in the treatment of testicular torsion.

The role of mesenchymal stem cells in chemotherapy-induced gonadotoxicity

Background

The therapeutic potential of bone marrow-derived mesenchymal stem cells (BM-MSCs) against cisplatin-induced nephrotoxicity has been reported, however, its efficacy in gonadotoxicity still has not been addressed. Herein, we investigated the effect of BM-MSCs in cisplatin-induced testicular toxicity and its underlying mechanism of action.

Methods

Thirty male Sprague–Dawley rats were divided into a control group: injected with phosphate-buffered saline (PBS) intraperitoneal (ip), a cisplatin group: injected with a single dose of 7 mg/kg cisplatin ip to induce gonadotoxicity and a BM-MSCs group: received cisplatin ip followed by BM-MSCs injection 1 day after cisplatin. In testicular tissues, malondialdehyde (MDA), superoxide dismutase (SOD), and reduced glutathione (GSH) levels were assessed. Additionally, gene expressions of inducible nitric oxide synthase (iNOS), caspase-3, and p38 mitogen-activated protein kinase (MAPK) were measured. The testicular tumor necrosis factor alpha (TNF-α) protein contents and Bcl-2 associated X protein (BAX) expression were determined. Histopathology of testicular tissues was examined.

Results

Cisplatin injection showed a significant decrease in GSH and SOD testicular levels besides a significant increase of MDA and TNF-α testicular levels and upregulation of testicular gene expressions of iNOS, caspase-3, and p38-MAPK in comparison to the control group. Moreover, a marked increase in BAX protein expression was observed in the cisplatin group when compared with the control one. Histopathological examination exhibited significant seminiferous tubules atrophy in cisplatin-treated rats.

Conclusions

The BM-MSCs injection significantly repaired the testicular injury and improved both biochemical and histopathological changes. The MSCs mitigated the gonadotoxicity induced by cisplatin through antioxidative, anti-inflammatory, and antiapoptotic mechanisms.