Arsenic-induced autophagic alterations and mitochondrial impairments in HPG-S axis of mature male mice offspring (F1-generation): A persistent toxicity study

Arsenic-induced neurocardiac toxicity and protective role of Resveratrol: histopathological and molecular insights

Arsenic toxicity is a global health problem chiefly targeting soft tissues of the body like the brain and heart. The major mechanism underlying arsenic-induced neurotoxicity is oxidative stress. Particularly, the neurons and cardiac myocytes show limitless susceptibility to oxidative stress. Herein, we examined the impact of prolonged arsenic exposure and resveratrol post-treatment on the cardiac and neuronal [Ventromedial hypothalamic nucleus (VMH)] morphology. Adult mice were segregated into control and experimental groups; controls received distilled water, while experimental groups received oral gavage of arsenic trioxide (ATO) at low (2 mg/kg bw) or high (4 mg/kg bw) doses for 45 days. Cardiac effects were assessed at the low dose (2 mg/kg bw), whereas neurological effects were evaluated at both low and high doses. Mice were sacrificed on day 45 to obtain perfusion-fixed hearts and brains for histological and morphometric studies. Long-term ATO exposure resulted in a higher heart-to-body weight ratio than controls, suggesting ATO-induced hypertrophy. Microscopic observations revealed a regular arrangement of cardiac muscle fibres, branching patterns of cardiomyocytes, and fibroblasts across all the treatment groups. However, increased cardiac myocyte diameter in ventricles and substantial fibrosis in vessel walls were noticed in ATO-alone exposed hearts relative to controls. Selective vulnerability of hypothalamic neurons following ATO exposure was evident by significant alterations in morphometric parameters (reduced cell density and soma size) in the VMH nucleus of animals receiving ATO (2 and 4 mg/kg) alone. These dramatic histopathological alterations were found to be restored after ATO + Res co-treatment. We also examined the expression of ER-α in the preoptic area of the hypothalamus and indicated downregulation of ER-α due to prolonged ATO exposure. Our findings highlight Resveratrol as a potent neurocardiac protector against ATO toxicity via estrogen signaling modulation, supporting its therapeutic potential in arsenic poisoning.

Sex-Specific Mechanisms of Fluoride-Induced Gonadal Injury: A Multi-Omics Investigation into Reproductive Toxicity and Gut Microbiota Disruption

Fluoride, a common agricultural additive used to enhance plant resilience and pest control, poses toxicity risks when exposure surpasses safe thresholds, affecting ecosystems and human health. While its reproductive toxicity is recognized, the sex-specific and cross-generational effects remain underexplored. To address this gap, we employed an integrative approach combining transcriptomics (next-generation sequencing (NGS)), bioinformatic network analysis, gut microbiota sequencing, and in vivo functional assays. ICR mice (F0 generation), both male and female, were exposed to fluoride (100 mg/L in drinking water) for 35 days, continuing through gestation and offspring weaning. Our transcriptomic analysis revealed significant upregulation of autophagy (via the PI3K-AKT-mTOR pathway) and oxidative stress-induced mitochondrial dysfunction in gonadal tissue, with more pronounced effects observed in males. Further integrated analyses of transcriptomic and metabolomic data, supported by in vivo experiments, highlighted oxidative stress, mitochondrial dysfunction, and PI3K-AKT-mTOR pathway activation with stronger effects in males. The principal component analysis confirmed sex-specific transcriptome alterations, with males showing more substantial disruption. Additionally, 16S rRNA sequencing identified significant gut dysbiosis, particularly in males, with an increased Firmicutes/Bacteroidetes ratio and higher abundances of Oscillospirales and Anaerovoracaceae. Moreover, our study identified significant correlations between specific gut microbiota (e.g., Firmicutes, Proteobacteria) and autophagy, oxidative stress, and mitochondrial dysfunction pathways, with notable sex-dependent differences. These findings suggest that gut microbiota may play a critical role in modulating fluoride-induced reproductive toxicity, particularly through their effects on oxidative stress and cellular homeostasis. The breakdown of the gut barrier and elevated serum/gonadal lipopolysaccharide (LPS) levels in fluoride-treated mice further established a link between gut dysbiosis and fluoride-induced reproductive toxicity. These findings underscore the importance of considering sex differences in xenobiotic-induced reproductive and developmental toxicity.

Fluoride-Induced Autophagy and Apoptosis in the Mouse Ovary: Genomic Insights into IL-17 Signaling and Gut Microbiota Dysbiosis

Chronic fluoride (F) exposure is linked to gonadotoxicity in females, yet the underlying molecular mechanisms remain unclear. This study investigated fluoride-induced reprotoxicity using advanced genomic profiling. RNA-seq analysis identified significant activation of autophagy, apoptosis, and IL-17 signaling pathways in fluoride-exposed female mice. To explore these mechanisms, F0 pregnant mice were exposed to deionized water (control) or 100 mg/L sodium fluoride (NaF) during gestation and throughout the F1 generation (n = 16 females/group), covering puberty to weaning and maturity. NaF exposure caused significant reductions in body weight, organ coefficients, and pathological indices, with increased ovarian autophagic vacuoles, mitochondrial injuries, and elevated serum/ovary LPS levels in F1 females. qRT-PCR, fluorescent staining, biochemical assays, and Western blotting confirmed the activation of IL-17 signaling, apoptosis, and autophagy. Moreover, 16S rRNA sequencing revealed gut microbiota dysbiosis in NaF-exposed F1 females, potentially exacerbating ovary injury via serum LPS elevation. The gut dysbiosis could justify deteriorated serum LPS levels and its connection to F-induced ovary injury. These findings provide mechanistic insights into fluoride-induced reprotoxicity, emphasizing the interplay of IL-17 signaling, autophagy, and apoptosis in disrupting cellular homeostasis and suggesting potential therapeutic targets.

Environmental arsenic exposure and reproductive system toxicity in male and female and mitigatory strategies: a review

Environmental Arsenic (As) exposure is one of the main health challenges in different area of the world. As is a significant factor responsible to the reproductive system toxicity in both male and female. In this study, the most important effects mechanisms and biomarkers related to environmental exposure to As and the reproductive system toxicity, and infertility risk are reviewed in male and female. The results showed that the most important As-induced reproductive system toxicity in the male were alteration in the quantity and quality of semen, testicular toxicity, oxidative stress, testosterone reduction, and sperm apoptosis. For female were oxidative stress, spontaneous miscarriage, reproductive cycle disruption, decrease in the estradiol, progesterone, and testosterone levels and impair fecundity. The main mechanisms of reproductive system toxicity caused by As exposure in male were, genotoxic effects, reduction of glutathione, disruption of sex hormones, sperm flagellum formation impairment, inhibition of spermatogenesis, disruption of cell signaling pathways, and metabolites disruption. For female were abnormal signaling in gene expression, hormonal homeostasis, As-accumulation in placental tissue and creation of reactive oxygen, disruption in the neurotransmitters balance, and sex hormones disruption. The suitable biomarkers for As-induced reproductive toxicity in male were changes in testosterone, one-carbon and lipid metabolism, noncoding RNAs, and steroid hormone homeostasis, and for female was human chorionic gonadotropin (hCG) changes. Finaly, taking selenium, zinc, silymarin, vitamins (C and E) and phytonutrients can be effective in reducing the As-induced reproductive system toxicity and infertility risk.

Arsenic-Induced Thyroid Hormonal Alterations and Their Putative Influence on Ovarian Follicles in Balb/c Mice

Thyroid issues are common among women in their reproductive years, and women with thyroid dysfunction often encounter challenges with fertility. Arsenic is known for its toxic effects on the thyroid and ovaries, investigated independently. However, there is no known study directly or indirectly addressing the association between arsenic, thyroid function, and ovarian reserve. This study aims to investigate the effect of arsenic on thyroid function and its possible implications on ovarian follicular reserve. Female Balb/c mice were given sodium arsenite (0.2 ppm, 2 ppm, and 20 ppm) via drinking water for 30 days. Findings showed that arsenic decreased thyroid hormone levels (fT3 and fT4) while increasing TSH levels, which might have led to elevated levels of FSH and LH. Furthermore, arsenic treatment not only decreased thyroid follicle sizes but also altered the ovarian follicular count. The finding demonstrates that arsenic significantly reduced the expression of LAMP1, a lysosomal marker protein. This reduction leads to increased lysosomal permeability in the thyroid, resulting in a significant release of cathepsin B. These changes led to hypothyroidism, which might indirectly affect the ovaries. Also, the elevated levels of growth differentiation factor-8 in arsenic-treated ovaries indicate impaired folliculogenesis and ovulation. Furthermore, arsenic significantly increased the expressions of pAkt and pFoxo3a, implying that arsenic accelerated the activation of the primordial follicular pools. In conclusion, arsenic disrupts lysosomal stabilization, potentially leading to a decline in circulating fT3 and fT4 levels. This disturbance could, in turn, affect the estrous cycle and may alter the pattern of follicular development.

Toxic impacts of arsenic bioaccumulation on urinary arsenic metabolites and semen quality: A systematic and meta-analysis

This study aims to investigate the effect of arsenic exposure on urinary levels of arsenic metabolites, semen parameters, and testosterone concentrations. A systematic comprehensive literature search was conducted up till 31st January 2024 using Embase, MEDLINE/Pubmed, and Scopus. This study adopted the Population Exposure Comparator Outcome and Study Design (PECOS) framework. Four studies with a total of 380 control subjects and 347 exposed men were included. Arsenic exposure significantly increased urinary levels of total arsenic (Mean Difference (MD) - 53.35 [95 % Confidence Interval (CI): - 100.14, - 6.55] P= 0.03), and reduced primary arsenic methylation index (PMI) (MD 0.22 [95 % CI: 0.14, 0.31] P< 0.00001), semen volume (MD 0.30 [95 % CI: 0.05, 0.54] P= 0.02) and total testosterone (MD 0.48 [95 % CI: 0.23, 0.73] P= 0.0002). In addition, arsenic exposure marginally reduced sperm concentration (MD 25.04 [95 % CI: - 45.42, 95.50] P= 0.49) and total sperm motility (MD 22.89 [95 % CI: - 14.15, 59.94] P= 0.23). The present meta-analysis demonstrates that arsenic exposure lowers semen quality and testosterone levels. Since the general human population is exposed to arsenic occupationally or domestically, adequate strategic measures should be put in place to limit arsenic exposure in an attempt to preserve semen quality. In addition, studies investigating interventions that may inhibit the bioaccumulation of arsenic in men who are exposed are recommended.

Pesticide-Induced Alterations in Locomotor Activity, Anxiety, and Depression-like Behavior Are Mediated through Oxidative Stress-Related Autophagy: A Persistent Developmental Study in Mice

Chlorpyrifos (CPF), dichlorvos (DDV), and cypermethrin (CP), as commonly used pesticides, have been implicated in inducing neuropsychiatric disorders, such as anxiety, depression-like behaviors, and locomotor activity impairment. However, the exact molecular mechanisms of these adverse effects, particularly in both sexes and their next-generation effects, remain unclear. In this study, we conducted behavioral analysis, along with cellular assays (monodansylcadaverine staining) and molecular investigations (qRT-PCR and western blotting of mTOR, P62, and Beclin-1) to clear the potential role of autophagy in pesticide-induced behavioral alterations. For this purpose, 42 adult female and 21 male inbred ICR mice (F0) were distributed into seven groups. Maternal mice (F0) and 112 F1 offspring were exposed to 0.5 and 1 ppm of CPF, DDV, and CP through drinking water. F1 male and female animals were studied to assess the sex-specific effects of pesticides on brain tissue. Our findings revealed pronounced anxiogenic effects and impaired locomotor activity in mice. F1 males exposed to CPF (1 ppm) exhibited significantly elevated depression-like behaviors compared to other groups. Moreover, pesticide exposure reduced mTOR and P62 levels, while enhancing the Beclin-1 gene and protein expression. These changes in autophagy signaling pathways, coupled with oxidative and neurogenic damage in the cerebral cortex and hippocampus, potentially contribute to heightened locomotor activity, anxiety, and depression-like behaviors following pesticide exposure. This study underscores the substantial impact of pesticides on both physiological and behavioral aspects, emphasizing the necessity for comprehensive assessments and regulatory considerations for pesticide use. Additionally, the identification of sex-specific responses presents a crucial dimension for pharmaceutical sciences, highlighting the need for tailored therapeutic interventions and further research in this field.

Hepatotoxic of polystyrene microplastics in aged mice: Focus on the role of gastrointestinal transformation and AMPK/FoxO pathway

Microplastic (MP) toxicity has attracted widespread attention, whereas before triggering hepatotoxicity, ingested MPs first undergo transportation and digestion processes in the gastrointestinal tract, possibly interacting with the gastrointestinal contents (GIC). More alarming is the need for more understanding of how this process may impact the liver health of aged animals. This study selected old mice. Firstly, we incubated polystyrene microplastics (PS-MPs, 1 μm) with GIC extract. The results of SEM/EDS indicated a structural alteration in PS-MPs. Additionally, impurities resembling corona, rich in heteroatoms (O, N, and S), were observed. This resulted in an enhanced aggregating phenomenon of MPs. We conducted a 10-day experiment exposing aged mice to four concentrations of PS-MPs, ranging from 1 × 103 to 1 × 1012 particles/L. Subsequent measurements of tissue pathology and body and organ weights were conducted, revealing alterations in liver structure. In the liver, 12 crucial metabolites were found by LC-MS technology, including purines, lipids, and amino acids. The AMPK/FoxO pathway was enriched, activated, and validated in western blotting results. We also comprehensively examined the innate immune system, inflammatory factors, and oxidative stress indicators. The results indicated decreased C3 levels, stable C4 levels, inflammatory factors (IL-6 and IL-8), and antioxidant enzymes were increased to varying degrees. PS-MPs also caused DNA oxidative damage. These toxic effects exhibited a specific dose dependence. Overall, after the formation of the gastrointestinal corona, PS-MPs subsequently impact various cellular processes, such as cycle arrest (p21), leading to hepatic and health crises in the elderly. The presence of gastrointestinal coronas also underscores the MPs' morphology and characteristics, which should be distinguished after ingestion.

Inactivation of Mst/Nrf2/Keap1 signaling flexibly mitigates MAPK/NQO-HO1 activation in the reproductive axis of experimental fluorosis

Fluoride induced reprotoxicity through oxidative stress-mediated reproductive cell death. Hence, the current study evaluated the importance of the MST/Nrf2/MAPK/NQO-HO1 signaling pathway in fluorosis-induced reproductive toxicity. For this purpose, the reproductive toxicity of sodium fluoride (NaF) at physiological, biochemical, and intracellular levels was evaluated. In-vivo, NaF at 100 mg/L instigated physiological dysfunction, morphological, stereological, and structural injuries in the gut-gonadal axis of fluorosis mice through weakening the antioxidant signaling, Nrf2/HO-1/NQO1signaling pathway, causing the gut-gonadal barrier disintegrated via oxidative stress-induced inflammation, mitochondrial damage, apoptosis, and autophagy. Similar trends were also observed in-vitro in the isolated Leydig cells (LCs) challenging with 20 mg/L NaF. Henceforth, activating the cellular antioxidant signaling pathway, Nrf2/HO-1/NQO1, inactivating autophagy and apoptosis, or attenuating lipopolysaccharide (LPS) can be the theoretical basis and valuable therapeutic targets for coping with NaF-induced reproductive toxicity.

Pre/postnatal taurine supplementation improves neurodevelopment and brain function in mice offspring: A persistent developmental study from puberty to maturity

Taurine (TAU) is a sulfur-containing amino acid abundantly found in the human body. Endogenously, TAU is synthesized from cysteine in the liver. However, newborns rely entirely on TAU's dietary supply (milk). There is no investigation on the effect of long-term TAU administration on next-generation neurological development. The current study evaluated the effect of long-term TAU supplementation during the maternal gestational and litter weaning time on several neurological parameters in mice offspring. Moreover, the effects of TAU on mitochondrial function and oxidative stress biomarkers as plausible mechanisms of its action in the whole brain and hippocampus have been evaluated. TAU (0.5 % and 1 % w/v) was dissolved in the drinking water of pregnant mice (Day one of pregnancy), and amino acid supplementation was continued during the weaning time (post-natal day; PND = 21) until litters maturity (PND = 65). It was found that TAU significantly improved cognitive function, memory performance, reflexive motor activity, and emotional behaviors in F1-mice generation. TAU measurement in the brain and hippocampus revealed higher levels of this amino acid. TAU and ATP levels were also significantly higher in the mitochondria isolated from the whole brain and hippocampus. Based on these data, TAU could be suggested as a supplement during pregnancy or in pediatric formula. The effects of TAU on cellular mitochondrial function and energy metabolism might play a fundamental role in the positive effects of this amino acid observed in this investigation.

Ferulago angulata extract alleviates testicular toxicity in male mice exposed to diazinon and lead

In this study, we investigated the protective effects of Ferulago angulata extract (FAE) against the reproductive toxicants Diazinon (DZN) and Lead (Pb) in mice. These pollutants are known to induce oxidative stress (OS), while FAE acts as a natural antioxidant. Adult male NMRI mice were exposed to DZN, Pb, and DZN+Pb, with or without FAE treatment for six weeks. We evaluated OS markers, testicular histology, and expression of mRNA related to enzymatic antioxidants. Exposure to DZN and Pb led to increased levels of thiobarbituric acid reactive substance (TBARS) and nitric oxide (NO) in the testes, along with a decrease in the total antioxidant capacity (TAC). Furthermore, the mRNA expression of antioxidant enzymes such as superoxide dismutase 1 (SOD1) and glutathione peroxidase 4 (GPX4) was altered. However, when FAE was administered concurrently, it restored the biochemical parameters to normal levels, reduced the toxic effects of DZN and Pb, and provided protection against testicular histopathological injury. These findings suggest that FAE has the potential to serve as a protective agent against oxidative damage caused by contaminants in reproductive organs, specifically in the testes.

Low-dose ketamine improves animals' locomotor activity and decreases brain oxidative stress and inflammation in ammonia-induced neurotoxicity

Ammonium ion (NH4 + ) is the major suspected molecule responsible for neurological complications of hepatic encephalopathy (HE). No specific pharmacological action for NH4 + -induced brain injury exists so far. Excitotoxicity is a well-known phenomenon in the brain of hyperammonemic cases. The hyperactivation of the N-Methyl- d-aspartate (NMDA) receptors by agents such as glutamate, an NH4 + metabolite, could cause excitotoxicity. Excitotoxicity is connected with events such as oxidative stress and neuroinflammation. Hence, utilizing NMDA receptor antagonists could prevent neurological complications of NH4 + neurotoxicity. In the current study, C57BL6/J mice received acetaminophen (APAP; 800 mg/kg, i.p) to induce HE. Hyperammonemic animals were treated with ketamine (0.25, 0.5, and 1 mg/kg, s.c) as an NMDA receptor antagonist. Animals' brain and plasma levels of NH4 + were dramatically high, and animals' locomotor activities were disturbed. Moreover, several markers of oxidative stress were significantly increased in the brain. A significant increase in brain tissue levels of TNF-α, IL-6, and IL-1β was also detected in hyperammonemic animals. It was found that ketamine significantly normalized animals' locomotor activity, improved biomarkers of oxidative stress, and decreased proinflammatory cytokines. The effects of ketamine on oxidative stress biomarkers and inflammation seem to play a key role in its neuroprotective mechanisms in the current study.

Hepatic encephalopathy complications are diminished by piracetam via the interaction between mitochondrial function, oxidative stress, inflammatory response, and locomotor activity

Background

of the study: Hepatic encephalopathy (HE) is a complication in which brain ammonia (NH4+) levels reach critically high concentrations because of liver failure. HE could lead to a range of neurological complications from locomotor and behavioral disturbances to coma. Several tactics have been established for subsiding blood and brain NH4+. However, there is no precise intervention to mitigate the direct neurological complications of NH4+.

Purpose

It has been found that oxidative stress, mitochondrial damage, and neuro-inflammation play a fundamental role in NH4+ neurotoxicity. Piracetam is a drug used clinically in neurological complications such as stroke and head trauma. Piracetam could significantly diminish oxidative stress and improve brain mitochondrial function.

Research methods

In the current study, piracetam (100 and 500 mg/kg, oral) was used in a mice model of HE induced by thioacetamide (TA, 800 mg/kg, single dose, i.p).

Results

Significant disturbances in animals' locomotor activity, along with increased oxidative stress biomarkers, including reactive oxygen species formation, protein carbonylation, lipid peroxidation, depleted tissue glutathione, and decreased antioxidant capacity, were evident in the brain of TA-treated mice. Meanwhile, mitochondrial permeabilization, mitochondrial depolarization, suppression of dehydrogenases activity, and decreased ATP levels were found in the brain of the TA group. The level of pro-inflammatory cytokines was also significantly high in the brain of HE animals.

Conclusion

It was found that piracetam significantly enhanced mice's locomotor activity, blunted oxidative stress biomarkers, decreased inflammatory cytokines, and improved mitochondrial indices in hyperammonemic mice. These data suggest piracetam as a neuroprotective agent which could be repurposed for the management of HE.

Arsenic exposure induced anxiety-like behaviors in male mice via influencing the GABAergic Signaling in the prefrontal cortex

Arsenic contamination in drinking water causes a global public health problem. Emerging evidence suggests that arsenic may act as an environmental risk factor for anxiety disorders. However, the exact mechanism underlying the adverse effects has not been fully elucidated. This study aimed to evaluate the anxiety-like behaviors of mice exposed to arsenic trioxide (As2O3), to observe the neuropathological changes, and to explore the link between the GABAergic system and behavioral manifestations. For this purpose, male C57BL/6 mice were exposed to various doses of As2O3 (0, 0.15, 1.5, and 15 mg/L) through drinking water for 12 weeks. Anxiety-like behaviors were assessed using the open field test (OFT), light/dark choice test, and elevated zero maze (EZM). Neuronal injuries in the cerebral cortex and hippocampus were assessed by light microscopy with H&E and Nissl staining. Ultrastructural alteration in the cerebral cortex was assessed by transmission electron microscope (TEM). The expression levels of GABAergic system-related molecules (i.e., glutamate decarboxylase, GABA transporter, and GABAB receptor subunits) in the prefrontal cortex (PFC) were determined by qRT-PCR and western blotting. Arsenic exposure showed a striking anxiogenic effect on mice, especially in the group exposed to 15 mg/L As2O3. Light microscopy showed neuron necrosis and reduced cell counts. TEM revealed marked ultrastructural changes, including the vacuolated mitochondria, disrupted Nissl bodies, an indentation in the nucleus membrane, and delamination of myelin sheath in the cortex. In addition, As2O3 influenced the GABAergic system in the PFC by decreasing the expression of the glutamate decarboxylase 1 (GAD1) and the GABAB2 receptor subunit, but not the GABAB1 receptor subunit. To sum up, sub-chronic exposure to As2O3 is associated with increased anxiety-like behaviors, which may be mediated by altered GABAergic signaling in the PFC. These findings shed light on the mechanisms responsible for the neurotoxic effects of arsenic and therefore more cautions should be taken.

Ameliorative effects of different doses of selenium against fluoride-triggered apoptosis and oxidative stress-mediated renal injury in rats through the activation of Nrf2/HO-1/NQO1 signaling pathway

Excess fluoride (F) exposure can cause oxidative stress in the kidney. As an antioxidant, selenium (Se) can potentially protect the kidney from F-induced injury in rats. Hence, the histopathological, renal biochemical, oxidative stress, and apoptotic-related indices upon exposure to 100 mg/L sodium fluoride (NaF) and various doses of sodium selenite (Na₂SeO₃; 0.5, 1, and 2 mg/L) were assessed. Our results demonstrated that F-mediated renal structural damage and apoptosis elevated the content of serum creatinine (SCr), inhibited the activity of catalase (CAT) in serum, and increased the production of reactive oxygen species (ROS) in kidney and malondialdehyde (MDA) in serum. Interestingly, 1 mg/L dietary supplementation of Se tangibly mitigated these injuries. Furthermore, F could also change the gene and protein expression of the nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NAD(P)H quinone oxidoreductase1 (NQO1). Concomitantly, the different concentrations of Se notably alleviated their expression. Taken together, 1-2 mg/L Se ameliorated F-induced renal injury through oxidative stress and apoptosis-related routes. The recorded ameliorative effects might be related to the activation of the Nrf2/HO-1/NQO1 signaling pathway.

Crosstalk between autophagy and the Keap1-Nrf2-ARE pathway regulates realgar-induced neurotoxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Realgar, the main component of which is As₂S₂ or As₄S₄ (≥90%), is a traditional Chinese natural medicine that has been used to treat carbuncles, furuncles, snake and insect bites, abdominal pain caused by parasitic worms, and epilepsy in China for many years. Because realgar contains arsenic, chronic or excessive use of single-flavor realgar and realgar-containing Chinese patent medicine can lead to drug-induced arsenic poisoning, but the exact mechanism underlying its toxicity to the central nervous system is unclear.

AIM OF THE STUDY

The aim of this study was to clarify the mechanism of realgar-induced neurotoxicity and to investigate the effects of realgar on autophagy and the Keap1-Nrf2-ARE pathway.

MATERIALS AND METHODS

We used rats treated with the autophagy inhibitor 3-methyladenine (3-MA) or adeno-associated virus (AAV2/9-r-shRNA-Sqstm1, sh-p62) to investigate realgar-induced neurotoxicity and explore the specific relationship between autophagy and the Keap1-Nrf2-ARE pathway (the Nrf2 pathway) in the cerebral cortex. Molecular docking analysis was used to assess the interactions among the Nrf2, p62 and Keap1 proteins.

RESULTS

Our results showed that arsenic from realgar accumulated in the brain and blood to cause neuronal and synaptic damage, decrease exploratory behavior and spontaneous movement, and impair memory ability in rats. The mechanism may have involved realgar-mediated autophagy impairment and continuous activation of the Nrf2 pathway via the LC3-p62-Keap1-Nrf2 axis. However, because this activation of the Nrf2 pathway was not sufficient to counteract oxidative damage, apoptosis was aggravated in the cerebral cortex.

CONCLUSIONS

This study revealed that autophagy, the Nrf2 pathway, and apoptosis are involved in realgar-induced central nervous system toxicity and identified p62 as the hub of the LC3-p62-Keap1-Nrf2 axis in the regulation of autophagy, the Nrf2 pathway, and apoptosis.

HIF-1α-mediated autophagy and canonical Wnt/β-catenin signalling activation are involved in fluoride-induced osteosclerosis in rats

Fluoride (F) exposure can cause osteosclerosis, which is characterised by a high bone mass, but its mechanism is not fully illustrated. Here, we aimed to evaluate the effects of excessive F exposure on the bone lesion by treating female Sprague-Dawley rats with different concentrations of sodium fluoride (NaF) (0, 55, 110 and 221 mg/L) for 90 days and the corresponding concentrations of fluorine ion (0, 25, 50 and 100 mg/L, respectively). Histopathological results showed that excessive F exposure caused the enlargement of trabeculae and their integration into one large piece, growth plate thickening, articular cartilage impairment and bone collagen abnormality. Meanwhile, F promoted calcium deposition and bone mineralisation, and induced abnormal osteogenesis increased. The results of micro-computed tomography also confirmed that excessive F destroyed the bone microstructure and induced a high-bone-mass phenotype, consistent with the results of pathomorphology. Mechanistically, excessive amounts of F led to angiogenesis inhibition and HIF-1α signalling enhancement. Subsequently, F induced autophagy and canonical Wnt/β-catenin signalling pathway activation. Collectively, these results manifested that F enhanced the hypoxia inducible factor-1α signalling, which in turn triggered autophagy and canonical Wnt/β-catenin signalling activation, ultimately leading to osteosclerosis in the rats.

Glycine protects the male reproductive system against lead toxicity via alleviating oxidative stress, preventing sperm mitochondrial impairment, improving kinematics of sperm, and blunting the downregulation of enzymes involved in the steroidogenesis

Lead (Pb) is a highly toxic heavy metal widely dispersed in the environment because of human industrial activities. Many studies revealed that Pb could adversely affect several organs, including the male reproductive system. Pb-induced reproductive toxicity could lead to infertility. Thus, finding safe and clinically applicable protective agents against this complication is important. It has been found that oxidative stress plays a fundamental role in the pathogenesis of Pb-induced reprotoxicity. Glycine is the simplest amino acid with a wide range of pharmacological activities. It has been found that glycine could attenuate oxidative stress and mitochondrial impairment in various experimental models. The current study was designed to evaluate the role of glycine in Pb-induced reproductive toxicity in male mice. Male BALB/c mice received Pb (20 mg/kg/day; gavage; 35 consecutive days) and treated with glycine (250 and 500 mg/kg/day; gavage; 35 consecutive days). Then, reproductive system weight indices, biomarkers of oxidative stress in the testis and isolated sperm, sperm kinetic, sperm mitochondrial indices, and testis histopathological alterations were monitored. A significant change in testis, epididymis, and Vas deferens weight was evident in Pb-treated animals. Markers of oxidative stress were also significantly increased in the testis and isolated sperm of the Pb-treated group. A significant disruption in sperm kinetic was also evident when mice received Pb. Moreover, Pb exposure caused significant deterioration in sperm mitochondrial indices. Tubular injury, tubular desquamation, and decreased spermatogenic index were histopathological alterations detected in Pb-treated mice. It was found that glycine significantly blunted oxidative stress markers in testis and sperm, improved sperm mitochondrial parameters, causing considerable higher velocity-related indices (VSL, VCL, and VAP) and percentages of progressively motile sperm, and decreased testis histopathological changes in Pb-exposed animals. These data suggest glycine as a potential protective agent against Pb-induced reproductive toxicity. The effects of glycine on oxidative stress markers and mitochondrial function play a key role in its protective mechanism.

Contemporary Comprehensive Review on Arsenic-Induced Male Reproductive Toxicity and Mechanisms of Phytonutrient Intervention

Arsenic (As) is a poisonous metalloid that is toxic to both humans and animals. Drinking water contamination has been linked to the development of cancer (skin, lung, urinary bladder, and liver), as well as other disorders such as diabetes and cardiovascular, gastrointestinal, neurological, and developmental damage. According to epidemiological studies, As contributes to male infertility, sexual dysfunction, poor sperm quality, and developmental consequences such as low birth weight, spontaneous abortion, and small for gestational age (SGA). Arsenic exposure negatively affected male reproductive systems by lowering testicular and accessory organ weights, and sperm counts, increasing sperm abnormalities and causing apoptotic cell death in Leydig and Sertoli cells, which resulted in decreased testosterone synthesis. Furthermore, during male reproductive toxicity, several molecular signalling pathways, such as apoptosis, inflammation, and autophagy are involved. Phytonutrient intervention in arsenic-induced male reproductive toxicity in various species has received a lot of attention over the years. The current review provides an in-depth summary of the available literature on arsenic-induced male toxicity, as well as therapeutic approaches and future directions.

Arsenic exposure during porcine oocyte maturation negatively affects embryonic development by triggering oxidative stress-induced mitochondrial dysfunction and apoptosis

Arsenic (AS), an environmental contaminant, is a known human carcinogen that can cause cancer of the lung, liver, and skin. Furthermore, AS induces oxidative stress and mitochondrial impairments in mammalian cells. However, limited information is available on the effect of AS exposure on oocyte maturation of porcine, whose anatomy, physiology, and metabolism are similar to those of human. Therefore, we examined the effect of AS exposure on the in vitro maturation (IVM) of porcine oocytes and the possible underlying mechanisms. Cumulus-cell enclosed oocytes were cultured with or without AS for maturation, and then were used for analyses. This study indicated that AS under a concentration of 1 μM significantly increased the abnormal expansion of cumulus cells and the number of oocytes maintained in meiotic arrest. In addition, AS exposure significantly reduced subsequent development of embryos and increased the rate of apoptosis of blastocysts following parthenogenetic activation (PA) and in vitro fertilization (IVF). Moreover, AS exposure induced oxidative stress with increased reactive oxygen species (ROS), and decreased glutathione (GSH), leading to reduced mitochondrial membrane potential, mitochondrial quantity, DNA damage, excessive autophagy activity, and early apoptosis in porcine oocytes. Taken together, the results demonstrated that AS exposure exerts several negative effects, such as meiotic defects and embryo developmental arrest by causing mitochondrial dysfunction and apoptosis via inducing oxidative stress.

Ameliorative effect of bee products on in vitro maturation of sheep oocytes

The present study was undertaken to investigate the possible stimulating effects of Nigella sativa (N. sativa) honey, natural Saudi Sider honey, and honeybee pollen to the in vitro maturation (IVM) medium of sheep oocytes on their subsequent development. Hence, immature oocytes were exposed to various concentrations of natural Nigella sativa (N. sativa), and Saudi Sider honey (5, 10, and 20%), as well as honeybee pollen (1, 10, 50 μg/ml) during an in vitro maturation period (24 hours). After the exposure time, the maturation rate, glutathione (GSH) concentration, and candidate gene expression (GDF-9, MPF, CMOS, IGF-1, and BAX) were evaluated. Our results showed that the maturation rate was higher in the groups challenged with the lowest level of the bee products (5% and 1 μg/ml) when compared with that in the control group; where the mean number of oocytes in the metaphase II stage reached 0.360 for the honeybee pollen-treated group, 0.293 for the N. sativa-treated group, and 0.203 for the natural Saudi Sider honey-treated group. The glutathione level was significantly increased in the group exposed to N. sativa honey when compared with the other groups. Concerning the gene expression results, the Saudi Sider honey treatment showed the best results for all the genes except the CMOS gene, which was significantly higher than the GI and GII groups and lower than the GIV group and the BAX gene which did not show a significant difference when compared with the other groups. In conclusion, the addition of natural honey and honeybee pollen at a low concentration to an IVM medium improved the in vitro maturation rate, increased the glutathione level, and gene expression of the in vitro matured ovine oocytes.

The crucial role of oxidative stress in non-alcoholic fatty liver disease-induced male reproductive toxicity: the ameliorative effects of Iranian indigenous probiotics

Several studies have focused on the high potential effects of probiotics on the reproductive system. However, there is a paucity of information regarding the ameliorative intracellular roles of indigenous Iranian yogurt-extracted/cultured probiotics on animals' reproductive health suffering from obesity and/or fatty liver disease, such as non-alcoholic fatty liver disease (NAFLD). For this purpose, simultaneously with the consumption of D-fructose (200 g/1000 mL water, induction of NAFLD model), all pubertal animals were also gavaged every day for 63 consecutive days with extracted probiotics, including 1 × 109 CFU/mL of Lactobacillus acidophilus (LA), Bifidobacterium spp. (BIF), Bacillus coagulans (BC), Lactobacillus rhamnosus (LR), and a mixture form (LA + BIF + BC + LR). At the end of the ninth week, the indices of epididymal sperm, and oxidative stress, as well as histopathological changes, were assessed. The results show that NAFLD could induce robust oxidative stress, highlighted as considerable increments in ROS level, TBARS content, total oxidized protein levels, along with severe decrements in reduced glutathione reservoirs, total antioxidant capacity in the hepatic and testicular tissues, as well as testicular and hepatic histopathological alterations. Moreover, a significant decrease in the percentage of sperm progressive motility, sperm count, and membrane integrity along with an increment in the percentage of sperm abnormality was detected in NAFLD animals. The observed adverse effects were significantly reversed upon probiotics treatment, especially in the group challenged with a mixture of all probiotics. Taken together, these findings indicate that the indigenous yogurt-isolated/cultured probiotics had a high potential antioxidant activity and the ameliorative effect against reprotoxicity and blood biochemical alterations induced by the NAFLD model. Highlights: 1. Reproductive indices could be reversely affected by xenobiotics and diseases. 2. NAFLD and cholestasis considerably affect the reproductive system in both genders. 3. NAFLD induced hepatic and testicular oxidative stress (OS). 4. NAFLD induced histopathological alterations and spermatotoxicity through OS. 5. The adverse effects were significantly reversed upon exposure to probiotics.

Autophagy: a multifaceted player in the fate of sperm

BACKGROUND

Autophagy is an intracellular catabolic process of degrading and recycling proteins and organelles to modulate various physiological and pathological events, including cell differentiation and development. Emerging data indicate that autophagy is closely associated with male reproduction, especially the biosynthetic and catabolic processes of sperm. Throughout the fate of sperm, a series of highly specialized cellular events occur, involving pre-testicular, testicular and post-testicular events. Nonetheless, the most fundamental question of whether autophagy plays a protective or harmful role in male reproduction, especially in sperm, remains unclear.

OBJECTIVE AND RATIONALE

We summarize the functional roles of autophagy in the pre-testicular (hypothalamic–pituitary–testis (HPG) axis), testicular (spermatocytogenesis, spermatidogenesis, spermiogenesis, spermiation) and post-testicular (sperm maturation and fertilization) processes according to the timeline of sperm fate. Additionally, critical mechanisms of the action and clinical impacts of autophagy on sperm are identified, laying the foundation for the treatment of male infertility.

SEARCH METHODS

In this narrative review, the PubMed database was used to search peer-reviewed publications for summarizing the functional roles of autophagy in the fate of sperm using the following terms: ‘autophagy’, ‘sperm’, ‘hypothalamic–pituitary–testis axis’, ‘spermatogenesis’, ‘spermatocytogenesis’, ‘spermatidogenesis’, ‘spermiogenesis’, ‘spermiation’, ‘sperm maturation’, ‘fertilization’, ‘capacitation’ and ‘acrosome’ in combination with autophagy-related proteins. We also performed a bibliographic search for the clinical impact of the autophagy process using the keywords of autophagy inhibitors such as ‘bafilomycin A1’, ‘chloroquine’, ‘hydroxychloroquine’, ‘3-Methyl Adenine (3-MA)’, ‘lucanthone’, ‘wortmannin’ and autophagy activators such as ‘rapamycin’, ‘perifosine’, ‘metformin’ in combination with ‘disease’, ‘treatment’, ‘therapy’, ‘male infertility’ and equivalent terms. In addition, reference lists of primary and review articles were reviewed for additional relevant publications. All relevant publications until August 2021 were critically evaluated and discussed on the basis of relevance, quality and timelines.

OUTCOMES

(i) In pre-testicular processes, autophagy-related genes are involved in the regulation of the HPG axis; and (ii) in testicular processes, mTORC1, the main gate to autophagy, is crucial for spermatogonia stem cell (SCCs) proliferation, differentiation, meiotic progression, inactivation of sex chromosomes and spermiogenesis. During spermatidogenesis, autophagy maintains haploid round spermatid chromatoid body homeostasis for differentiation. During spermiogenesis, autophagy participates in acrosome biogenesis, flagella assembly, head shaping and the removal of cytoplasm from elongating spermatid. After spermatogenesis, through PDLIM1, autophagy orchestrates apical ectoplasmic specialization and basal ectoplasmic specialization to handle cytoskeleton assembly, governing spermatid movement and release during spermiation. In post-testicular processes, there is no direct evidence that autophagy participates in the process of capacitation. However, autophagy modulates the acrosome reaction, paternal mitochondria elimination and clearance of membranous organelles during fertilization.

WIDER IMPLICATIONS

Deciphering the roles of autophagy in the entire fate of sperm will provide valuable insights into therapies for diseases, especially male infertility.

Nickel chloride induces spermatogenesis disorder by testicular damage and hypothalamic-pituitary-testis axis disruption in mice

As a common environmental pollutant, nickel chloride (NiCl₂) poses serious threat to human and animals health. NiCl₂ has adverse effects on reproductive function in male, however, the underlying mechanisms are not fully illuminated. In this study, 64 male ICR mice were divided into four groups (8 mice per each period/ group), in which mice orally administrated with 0, 7.5, 15 or 30 mg/kg body weight for 14 or 28 consecutive days, respectively. The results showed that the sperm concentration (12.95%, 29.78% and 37.63% -) and sperm motility (19.79%, 34.88% and 43.10%) were dose-dependent significantly reduced, and the total sperm malformation rates (110.15%, 206.84% and 292.27%) were dose-dependent significantly elevated in the 7.5, 15 and 30 mg/kg NiCl₂ treatment groups (vs control at 28 days), respectively (P < 0.05). Meanwhile, NiCl₂ also decreased the relative weights of testis and epididymis and caused histopathological lesions of testis and epididymis. Furthermore, serum testosterone levels were significantly decreased after NiCl₂ treatment. And the findings showed that NiCl₂ down-regulated the expression of LH-R, StAR, P450scc, 3β-HSD, 17β-HSD, ABP and INHβB in the testis, however, the relative genes in the hypothalamus (Kiss-1, GPR54 and GnRH) and pituitary (GnRH-R, LHβ and FSHβ) did not exhibit noticeable change. In summary, NiCl₂ induced spermatogenesis disorder by testicular damage and hypothalamic-pituitary-testis axis disruption in mice, and only impaired the genes on the testis of HPT axis.

Ameliorative Effects of Caffeic Acid Against Arsenic-Induced Testicular Injury in Mice

Arsenic (As) is an environmental pollutant with destructive effects on different body organs, including the testis. This work was aimed to assess the ameliorative role of caffeic acid (CA) against As-provoked testicular damage in mice. Twenty-four adult male mice (31 ± 9 g) were randomly allocated to four equal groups. The first group served as control and was provided basal diet and tap water. Animals in the second group received water containing 200 ppm arsenite. The third group of mice received CA (60 mg/kg body weight; i.p.) during exposure to arsenite. Animals in the fourth group received CA. At the end of the experiment period (21 days), blood and testicular tissue sampling was done for biochemical and histopathological assessments. The results showed a significant decline of testicular ferric reducing antioxidant power (FRAP), superoxide dismutase, and glutathione peroxidase (GPx), as well as plasma concentrations of testosterone and dihydrotestosterone in As-treated mice compared to controls (p < 0.05). A significant increase in testicular malondialdehyde was also detected in group 2 relative to controls. Moreover, As exposure resulted in some morphological and histopathological alterations of the testis, including hyperemia, reduced tubular diameter and thickness of epithelial cell layers of seminiferous tubules, and Leydig cell necrosis. Simultaneous administration of CA plus As increased GPx, FRAP, testosterone, and dihydrotestosterone amounts and attenuated MDA levels as well as histopathological alterations to the levels that were not significantly different from those of the control group. These results indicate that caffeic acid can be suggested as an alleviative natural compound against As-induced damage in mice testes.

Mitochondrial dysfunction and oxidative stress are involved in the mechanism of tramadol-induced renal injury

Tramadol (TMDL) is an opioid analgesic widely administered for the management of moderate to severe pain. On the other hand, TMDL is commonly abused in many countries because of its availability and cheap cost. Renal injury is related to high dose or chronic administration of TMDL. No precise mechanism for TMDL-induced renal damage has been identified so far. The current study aimed to evaluate the potential role of oxidative stress and mitochondrial impairment in the pathogenesis of TMDL-induced renal injury. For this purpose, rats were treated with TMDL (40 and 80 ​mg/kg, i.p, 28 consecutive days). A significant increase in serum Cr and BUN was detected in TMDL groups. On the other hand, TMDL (80 ​mg/kg) caused a substantial increase in urine glucose, ALP, protein, and γ-GT levels. Moreover, urine Cr was significantly decreased in TMDL-treated rats (40 and 80 ​mg/kg). Renal histopathological alterations included inflammation, necrosis, and tubular degeneration in the kidney of TMDL-treated animals. Reactive oxygen species (ROS) formation, increased oxidized glutathione (GSSG), lipid peroxidation, and protein carbonylation was increased, whereas total antioxidant capacity and reduced glutathione levels were considerably decreased in TMDL groups. Significant mitochondrial impairment was also detected in the form of mitochondrial depolarization, adenosine-tri-phosphate (ATP) depletion, mitochondrial permeabilization, lipid peroxidation, and decreased mitochondrial dehydrogenase activity in the kidney of TMDL (80 ​mg/kg)-treated animals. These data suggest mitochondrial impairment and oxidative stress as mechanisms involved in the pathogenesis of TMDL-induced renal injury.

Metformin alleviates cholestasis-associated nephropathy through regulating oxidative stress and mitochondrial function

Background and aim

Cholestasis-associated renal injury or cholemic nephropathy (CN) is a serious clinical problem. Previous studies mentioned that oxidative stress and mitochondrial impairment play a role in CN. There is no specific pharmacological intervention for CN. Metformin is an anti-diabetic drug administered for decades. On the other hand, novel pharmacological properties have emerged for this drug. The effect of metformin on oxidative stress parameters has been well-recognized in different experimental models. It has also been found that metformin positively affected mitochondrial function. The current study aimed to evaluate the effects of metformin in an animal model of CN.

Methods

Rats underwent bile duct ligation (BDL) and were treated with metformin (250 and 500 mg/kg) for 14 consecutive days. Two weeks after the BDL operations, urine, serum, and kidney samples were collected and analyzed.

Results

Markers of oxidative stress, including reactive oxygen species (ROS) formation, lipid peroxidation, protein carbonylation, depleted antioxidant capacity, and decreased glutathione (GSH) levels were detected in BDL animals. Moreover, mitochondrial indices, including adenosine triphosphate (ATP) level, dehydrogenase activity, mitochondrial membrane potential, and mitochondrial permeability, were impaired in the kidney of cholestatic rats. Renal histopathological alterations in cholestatic animals included tubular degeneration and interstitial inflammation, cast formation, and fibrosis. It was found that metformin significantly alleviated oxidative stress and improved mitochondrial indices in the kidney of cholestatic rats. Tissue histopathological alterations were also mitigated in metformin-treated groups.

Conclusions

Metformin could be a candidate for managing CN. The nephroprotective role of metformin is primarily associated with its effects on oxidative stress parameters and mitochondrial function.

Expression of Autophagy-Related Factors LC3A and Beclin 1 and Apoptosis-Related Factors Bcl-2 and BAX in Osteoblasts Treated With Sodium Fluoride

OBJECTIVE

This study aims to analyze the expressions of autophagy-related factors light chain 3 alpha (LC3A) and Beclin 1 and apoptosis-related factors B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (BAX) in primary osteoblasts treated with sodium fluoride (NaF).

METHODS

Osteoblasts were extracted from Sprague-Dawley rats and treated with 0, 2.5, 5, and 10 mg/L NaF solutions, followed by 10 mmol/L 3-methyladenine (3-MA) for 24 h. The apoptotic rate was determined by flow cytometry, and the expressions of the autophagy- and apoptosis-related factors were measured by western blotting and real-time quantitative polymerase chain reaction.

RESULTS

The mRNA expressions of LC3A, Beclin 1, and BAX in the NaF-treated osteoblast group were higher than those in the control group, while the protein expressions of these factors in the NaF-treated group were significantly higher than those in the control group. However, the Bcl-2 protein expression in the NaF-treated osteoblasts was significantly decreased compared to that in the control cells. After the 3-MA treatment, the protein expressions of LC3A, Beclin 1, and Bcl-2 were significantly decreased compared with those of the NaF-treated group, whereas the expression of BAX increased. Moreover, the apoptosis rate was increased after the addition of the 3-MA inhibitor.

CONCLUSION

NaF stimulation promoted autophagy and apoptosis of the osteoblasts, suggesting the involvement of fluoride damage in these processes.

Drug-induced organ injury in coronavirus disease 2019 pharmacotherapy: Mechanisms and challenges in differential diagnosis and potential protective strategies

The world is currently facing an unprecedented pandemic caused by a newly recognized and highly pathogenic coronavirus disease 2019 (COVID-19; induced by SARS-CoV-2 virus), which is a severe and ongoing threat to global public health. Since COVID-19 was officially declared a pandemic by the World Health Organization in March 2020, several drug regimens have rapidly undergone clinical trials for the management of COVID-19. However, one of the major issues is drug-induced organ injury, which is a prominent clinical challenge. Unfortunately, most drugs used against COVID-19 are associated with adverse effects in different organs, such as the kidney, heart, and liver. These side effects are dangerous and, in some cases, they can be lethal. More importantly, organ injury is also a clinical manifestation of COVID-19 infection. These adverse reactions are increasingly recognized as outcomes of COVID-19 infection. Therefore, the differential diagnosis of drug-induced adverse effects from COVID-19-induced organ injury is a clinical complication. This review highlights the importance of drug-induced organ injury, its known mechanisms, and the potential therapeutic strategies in COVID-19 pharmacotherapy. We review the potential strategies for the differential diagnosis of drug-induced organ injury. This information can facilitate the development of therapeutic strategies, not only against COVID-19 but also for future outbreaks of other emerging infectious diseases.

The Role of Mitochondrial Impairment and Oxidative Stress in the Pathogenesis of Lithium-Induced Reproductive Toxicity in Male Mice

Lithium (Li+) is prescribed against a wide range of neurological disorders. Besides its excellent therapeutic properties, there are several adverse effects associated with Li+. The impact of Li+ on renal function and diabetes insipidus is the most common adverse effect of this drug. On the other hand, infertility and decreased libido is another complication associated with Li+. It has been found that sperm indices of functionality, as well as libido, is significantly reduced in Li+-treated men. These adverse effects might lead to drug incompliance and the cessation of drug therapy. Hence, the main aims of the current study were to illustrate the mechanisms of adverse effects of Li+ on the testis tissue, spermatogenesis process, and hormonal changes in two experimental models. In the in vitro experiments, Leydig cells (LCs) were isolated from healthy mice, cultured, and exposed to increasing concentrations of Li+ (0, 10, 50, and 100 ppm). In the in vivo section of the current study, mice were treated with Li+ (0, 10, 50, and 100 ppm, in drinking water) for five consecutive weeks. Testis and sperm samples were collected and assessed. A significant sign of cytotoxicity (LDH release and MTT assay), along with disrupted testosterone biosynthesis, impaired mitochondrial indices (ATP level and mitochondrial depolarization), and increased biomarkers of oxidative stress were detected in LCs exposed to Li+. On the other hand, a significant increase in serum and testis Li+ levels were detected in drug-treated mice. Moreover, ROS formation, LPO, protein carbonylation, and increased oxidized glutathione (GSSG) were detected in both testis tissue and sperm specimens of Li+-treated mice. Several sperm anomalies were also detected in Li+-treated animals. On the other hand, sperm mitochondrial indices (mitochondrial dehydrogenases activity and ATP levels) were significantly decreased in drug-treated groups where mitochondrial depolarization was increased dose-dependently. Altogether, these data mention oxidative stress and mitochondrial impairment as pivotal mechanisms involved in Li+-induced reproductive toxicity. Therefore, based on our previous publications in this area, therapeutic options, including compounds with high antioxidant properties that target these points might find a clinical value in ameliorating Li+-induced adverse effects on the male reproductive system.

Taurine mitigates bile duct obstruction-associated cholemic nephropathy: effect on oxidative stress and mitochondrial parameters

AIM OF THE STUDY

Cholestasis is a serious complication affecting other organs such as the liver and kidney. Oxidative stress and mitochondrial impairment are proposed as the primary mechanisms for cholestasis-induced organ injury. Taurine (TAU) is the most abundant free amino acid in the human body, which is not incorporated in the structure of proteins. Several pharmacological effects have been attributed to TAU. It has been reported that TAU effectively mitigated oxidative stress and modulated mitochondrial function. The current study aimed to evaluate the impact of TAU on oxidative stress biomarkers and mitochondrial parameters in the kidney of cholestatic animals.

MATERIAL AND METHODS

Bile duct ligated (BDL) rats were used as an antioxidant model of cholestasis. Animals were treated with TAU (500 and 1000 mg/kg, oral) for seven consecutive days. Animals were anesthetized (thiopental 80 mg/kg, i.p.), and kidney and blood specimens were collected.

RESULTS

Severe elevation in serum and urine biomarkers of renal injury was evident in the BDL group. Significant lipid peroxidation, reactive oxygen species (ROS) formation, and protein carbonylation were detected in the kidney of BDL animals. Furthermore, depleted glutathione reservoirs and a significant decrease in the antioxidant capacity of renal tissue were detected in cholestatic rats. Renal tubular atrophy and interstitial inflammation were evident in BDL animals. Cholestasis also caused significant mitochondrial dysfunction in the kidney. TAU significantly prevented cholestasis-induced renal injury by inhibiting oxidative stress and mitochondrial impairment.

CONCLUSIONS

These data indicate TAU as a potential therapeutic agent in the management of cholestasis-induced renal injury.

Spermatotoxic Effects of Single-Walled and Multi-Walled Carbon Nanotubes on Male Mice

Carbon-based nanomaterials possess a remarkably high potential for biomedical applications due to their physical properties; however, their detrimental effects on reproduction are also concerned. Several reports indicate the toxicity of carbon nanotubes (CNT); nevertheless, their impact on intracellular organelles in the male reproductive organs has not been fully elucidated. Herein, we report on the reprotoxicity of single-walled (SWCNT) and multi-walled carbon nanotubes (MWCN) on several intracellular events and histological criteria in pubertal male BALB/c mice orally treated with 0, 10, and 50 mg/kg/day doses for 5 weeks. Biomarkers of oxidative stress and mitochondrial functionality, histopathological alterations, and epididymal sperm characteristics were determined. Oral administration of CNTs at 10 and 50 mg/kg evoked a significant decrement in weight coefficient, sperm viability and motility, hypo-osmotic swelling (HOS) test, sperm count, mitochondrial dehydrogenase activity, ATP content, total antioxidant capacity, and GSH/GSSH ratio in the testis and epididymal spermatozoa. On the other hand, percent abnormal sperm, testicular and sperm TBARS contents, protein carbonylation, ROS formation, oxidized glutathione level, and sperm mitochondrial depolarization were considerably increased. Significant histopathological and stereological alterations in the testis occurred in the groups challenged with CNTs. The current findings indicated that oxidative stress and mitochondrial impairment might substantially impact CNTs-induced reproductive system injury and sperm toxicity. The results can also be used to establish environmental standards for CNT consumption by mammals, produce new chemicals for controlling the rodent populations, and develop therapeutic approaches against CNTs-associated reproductive anomalies in the males exposed daily to these nanoparticles.

The mechanisms of arsenic-induced ovotoxicity, ultrastructural alterations, and autophagic related paths: An enduring developmental study in folliculogenesis of mice

Arsenic (As) exerts a wide range of adverse effects on biological systems, including the reproductive organs in males and females. However, the mechanisms of As-induced reproductive toxicity are mostly obscure. Recently, we showed that autophagy is an essential route for As₂O₃-induced reprotoxicity through the hypothalamic-pituitary-gonadal-sperm (HPG-S) axis in pubertal and matured F1-male mice. However, the role of autophagy in As₂O₃- induced ovarian toxicity is mostly unknown. Hence, this study aimed to elucidate the role of oxidative stress, mitochondrial impairment, and autophagic processes in the ovary of As-exposed female mice. For this purpose, mature female mice were challenged with 0, low (0.2), medium (2), and high (20 ppm) As₂O₃ from 35-days before mating till weaning their pups, and the F1- females from weaning until maturity. Then, all the mice were sacrificed, and oxidative stress parameters, mitochondrial indices, electron microscopic evaluation of the ovaries, expression of autophagic-related genes and proteins, and autophagosome formation were assessed. It was shown that medium and high As₂O₃ doses were a potent inducer of oxidative stress, mitochondrial dysfunction, and autophagy in the ovary of F1-generation. A dose-dependent increment in the gene expression of PDK₁, PI3K, TSC2, AMPK, ULK1, ATG13, Beclin1, ATG12, ATG5, LC3, P62, ATG3, ATG7, and p62, as well as protein expression of Beclin1, and LC3- I, II, was evident in the ovaries of the As-treated animals. Moreover, a dose-dependent decrease in the expression of mTOR and Bcl-2 genes, and mTOR protein was detected with increasing doses of As, suggesting that As treatment-induced autophagy. Along with a dose-dependent increase in the number of MDC-labeled autophagic vacuoles, transmission electron microscopy also confirmed more autophagosomes and injured mitochondria in medium and high As₂O₃ doses groups. As₂O₃ also negatively affected the mean body weight, litter size, organ coefficient, and stereological indices in female mice. Finally, in physiological conditions, arsenic trioxide (As₂O₃) leads to an increased level of autophagy in the oocyte when many oocytes were being lost. These findings indicated that an imbalance in the oxidant-antioxidant system, mitochondrial impairment, and the autophagic process, through inhibition of mTOR, dependent and independent pathways, and Bcl-2, as well as activation of AMPK/PI3K/Beclin1/LC3 routes, could play a pivotal role in As-induced reproductive toxicity through ovarian dysfunction in females.

Taurine mitigates cirrhosis-associated heart injury through mitochondrial-dependent and antioxidative mechanisms

Cirrhosis-induced heart injury and cardiomyopathy is a serious consequence of this disease. It has been shown that bile duct ligated (BDL) animals could serve as an appropriate experimental model to investigate heart tissue injury in cirrhosis. The accumulation of cytotoxic chemicals (e.g., bile acids) could also adversely affect the heart tissue. Oxidative stress and mitochondrial impairment are the most prominent mechanisms of bile acid cytotoxicity. Taurine (Tau) is the most abundant non-protein amino acid in the human body. The cardioprotective effects of this amino acid have repeatedly been investigated. In the current study, it was examined whether mitochondrial dysfunction and oxidative stress are involved in the pathogenesis of cirrhosis-induced heart injury. Rats underwent BDL surgery. BDL animals received Tau (50, 100, and 500 mg/kg, i.p.) for 42 consecutive days. A significant increase in oxidative stress biomarkers was detected in the heart tissue of BDL animals. Moreover, it was found that heart tissue mitochondrial indices of functionality were deteriorated in the BDL group. Tau treatment significantly decreased oxidative stress and improved mitochondrial function in the heart tissue of cirrhotic animals. These data provide clues for the involvement of mitochondrial impairment and oxidative stress in the pathogenesis of heart injury in BDL rats. On the other hand, Tau supplementation could serve as an effective ancillary treatment against BDL-associated heart injury. Mitochondrial regulating and antioxidative properties of Tau might play a fundamental role in its mechanism of protective effects in the heart tissue of BDL animals.