Recent advances in the clinical management of intoxication by five heavy metals: Mercury, lead, chromium, cadmium and arsenic

Metals have been used for many centuries, but their nutritional and toxic effects have been investigated since the last century. The common toxic heavy metals (THM) include mercury, lead, chromium cadmium, and arsenic. As human exposure to THM increasingly causes systemic and organ complications, it seems required to review the recent advances of treatment of the toxic metals. Despite the current knowledge of the hazards of heavy metals, there is still high incidents of their poisonings particularly in developing countries. In this review, after an introduction, we briefly describe the routes of exposure, clinical features and prognosis of each metal poisoning. Then, review the different treatments for each metal with particular attention to recent advances in the treatment of both acute and chronic poisonings. The main antidotes for all THM are still chelating agents, but new agents were developed over the past decades and have been used successfully for the THM poisonings. Dimercaptosuccinic acid (DMSA) known as succimer has been prescribed as a safe oral chelator in lead poisoning. Similarly, dimercapto-propanesulfonic acid (DMPS) has also revealed fewer side effects than the old chelating agents. The two are currently gaining increased acceptance among clinical toxicologists. However, there is no specific antidote for mercury poisoning. Dimercaprol is almost no longer used as an antidote of choice in the treatment of chronic THM poisoning. Comparison of clinical management of intoxication by the five heavy metals reveals similar treatment strategies. On the other hand, some of them require specific interventions to reduce the toxicity. Because of drawbacks in the application of commonly known chelating agents, treatment with bioactive compounds which have antioxidant and anti-inflammatory properties has been the subject of much interest in recent research. However, despite the promising results observed in experimental animals, clinical trials on their clinical therapeutic benefits have not been yet successful and need further studies to determine their efficacy and safety in humans. Development of less toxic chelating agents are still under investigations. Moreover, the development of orally administrable chelating agents for home health care would likely be of great interest for future research.

Cadmium as a male reproductive toxicant and natural and non-natural ways to tackle it: a review

Cadmium (Cd) is a naturally occurring environmental pollutant, a toxic substance that causes oxidative stress. According to epidemiological studies, the data suggested that environmental and occupational Cd exposure may be related to several diseases and severe testicular damage. However, studies are going on to explore the mechanism of Cd-induced male reproductive toxicity and its treatment strategies. Currently, researchers are focusing on naturally occurring bioactive compounds, plant extracts, and biochemical, which have better efficacy, less toxicity, and high bioavailability. This review focuses on the mechanistic effect of Cd on testicular toxicity and different categories of compounds having a beneficial impact on Cd-induced male reproductive toxicity. Some potent bioactive antioxidants are quercetin, caffeic acid phenethyl ester, cyanidin-3-O-glucoside, curcumin, and silymarin. In comparison, plant extracts are Costus afer leaf methanol extract, methanol root extract of Carpolobia lutea, red carrot methanolic extract, Panax ginseng extract, and biochemicals including melatonin, progesterone, glutamine, L-carnitine, and selenium. Advanced and more detailed studies are needed on these compounds to explore their mechanism in attenuating Cd-induced testicular toxicity and can be potential therapeutics in the future.

Environmental and occupational exposure to cadmium associated with male reproductive health risk: a systematic review and meta-analysis based on epidemiological evidence

There is an abundance of epidemiological evidence and animal experiments concerning the correlation between cadmium exposure and adverse male reproductive health outcomes. However, the evidence remains inconclusive. We conducted a literature search from PubMed, Embase, and Web of Science over the past 3 decades. Pooled r and 95% confidence intervals (CIs) were derived from Cd levels of the type of biological materials and different outcome indicators to address the large heterogeneity of existing literature. Cd was negatively correlated with semen parameters (r = - 0.122, 95% CI - 0.151 to - 0.092) and positively correlated with sera sex hormones (r = 0.104, 95% CI 0.060 to 0.147). Among them, Cd in three different biological materials (blood, semen, and urine) was negatively correlated with semen parameters, while among sex hormones, only blood and urine were statistically positively correlated. In subgroup analysis, blood Cd was negatively correlated with semen density, sperm motility, sperm morphology, and sperm count. Semen Cd was negatively correlated with semen concentration. As for serum sex hormones, blood Cd had no statistical significance with three hormones, while semen Cd was negatively correlated with testosterone. In summary, cadmium exposure might be associated with the risk of a decline in sperm quality and abnormal levels of sex hormones.

Pharmacological Activity of Flavonoid Quercetin and Its Therapeutic Potential in Testicular Injury

Quercetin is a natural flavonoid widely found in natural fruits and vegetables. Recent studies have shown that quercetin mediates multiple beneficial effects in a variety of organ damage and diseases, and is considered a healthcare supplement with health-promoting potential. Male infertility is a major health concern, and testicular damage from multiple causes is an important etiology. Previous studies have shown that quercetin has a protective effect on reproductive function. This may be related to the antioxidant, anti-inflammatory, and anti-apoptotic biological activities of quercetin. Therefore, this paper reviews the mechanisms by which quercetin exerts its pharmacological activity and its role in testicular damage induced by various etiologies. In addition, this paper compiles the application of quercetin in clinical trials, demonstrating its practical effects in regulating blood pressure and inhibiting cellular senescence in human patients. However, more in-depth experimental studies and clinical trials are needed to confirm the true value of quercetin for the prevention and protection against testicular injury.

The Role of Dietary Nutrients in Male Infertility: A Review

Male infertility is the main health issue with economic, psychological, and medical attributions. Moreover, it is characterized by an inability to produce a sufficient amount of sperm for the fertilization of an oocyte. Dietary nutrients (DN) have a great effect on male reproductive potential. Observations have indicated that adding DN may protect or treat male infertility. The scope of this criticism is to scrutinize the DN, such as omega-3 fatty acids, vitamins, minerals and other phytochemicals, in enhancing the semen attributes, sperm bioenergetics and sperm functionality in male infertility. It seems that diets rich in omega-3 fatty acids affect sperm quality and maintain the sperm membrane and mitochondria stability. An administration of phytochemicals caused an escalation in sperm mitochondrial function and a decrease in oxidative damage. Furthermore, sundry dietary natural phytochemicals differentially affect (negatively or positively) sperm motility, semen quality, and mitochondrial function, dependent on their levels. Vitamins and trace elements are also nutritional modulators in reducing oxidative stress, thereby enhancing sperm quality, which is accurately connected with sperm mitochondrial function. Also, we described the different types of DN as mitochondrial enhancer for sperm functionality and health. We believe that understanding the DN supports sperm mitochondria and epigenetic modulators that may be responsible for sperm quality and health, and will lead to more embattled and efficient therapeutics for male infertility.

Opioid replacement therapy with methadone or buprenorphine effects on male mice reproduction

RATIONALE

Opioid use disorders are commonly treated by long-acting agonist opioids including methadone and buprenorphine which could affect various aspects of male reproduction especially spermatogenesis.

OBJECTIVES

We aimed to determine whether detoxification with methadone or buprenorphine was associated with reproductive disorders in male mice.

METHODS

We orally induced morphine dependence in NMRI male mice, and then performed detoxification programs using either methadone or buprenorphine. Testis architecture and sperm parameters including sperm nuclear DNA integrity, mitochondrial activity, oxidative stress in seminal plasma, and routine sperm parameters were assessed to find the involved mechanisms.

RESULTS

The number of Leydig cells and the thickness of germinal epithelium reduced following morphine use and increased differently after detoxification with methadone or buprenorphine. Morphine dependence and detoxification with methadone and buprenorphine had different effects on sperm parameters. Morphine altered chromatin integrity, mitochondrial activity, and oxidative stress in sperm. Detoxification with methadone improved mitochondrial activity but worsened chromatin integrity, whereas detoxification with buprenorphine improved neither chromatin integrity nor mitochondrial activity. Seminal plasma oxidative stress was higher in the treated groups compared to control groups but was comparable among treatment groups. Our study revealed that long-term morphine use followed by detoxification with methadone or buprenorphine impairs testis structure and sperm parameters. Detoxification from morphine use with methadone and buprenorphine led to different preclinical outcomes in semen quality parameters, including chromatin integrity. Therefore, clinical detoxification protocols should be performed more cautiously, considering the desire of the individuals to reproduce.

Effects of Quercetin on the Intestinal Microflora of Freshwater Dark Sleeper Odontobutis potamophila

Flavonoids have antimicrobial and anti-oxidation properties. The effects of the flavonoid quercetin on the intestinal microflora of freshwater dark sleeper Odontobutis potamophila were tested for the first time. Odontobutis potamophila juveniles were treated with quercetin for 21 days at one of three concentrations (2.5, 5.0, or 10.0 mg/L) and compared with a control group that was not treated with quercetin. Quercetin improved the stability of the intestinal flora in O. potamophila and the probiotic bacteria Bacillus spp. and Lactobacillus spp. increased in species abundance after the low concentration quercetin treatments. Furthermore, the abundance of pathogenic bacteria Plesiomonas spp., Aeromonas spp., and Shewanella spp. decreased after the fish had been exposed to quercetin. Activity of hepatic antioxidant enzymes (superoxide dismutase, SOD), (glutathione S-transferase, GST), (glutathione peroxidase, GSH-Px), and (total antioxidant capacity, T-AOC) increased in the livers of O. potamophila treated with quercetin, thereby increasing their hepatic antioxidant capacity and their ability to scavenge free radicals.

An electron microscopic and biochemical study of the potential protective effect of ginger against Cadmium-induced testicular pathology in rats

Background: Cadmium (Cd) is a toxic heavy metal used in many industries. Since the second half of the 20th century, legislation on Cd use was put to limit the exponential rise in its environmental levels. This study aimed to investigate Cd's functional and ultrastructural changes on rats' reproductive systems and the role of Zingiber officinale (Ginger) in protecting against Cd-induced toxicity. Methods: Thirty adult male albino rats were randomly assigned into three equal groups (n = 10); control, Cd-exposed/untreated, and Cd-exposed/Gin-treated. Rat testes were weighed, and testicular tissue sections were examined under the electron microscope. Semen analysis, morphological examination of spermatozoa, and serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone were measured. In addition, testicular tissue homogenates were analyzed for malondialdehyde (MDA), nitric oxide (NO), and reduced glutathione (GSH) levels. Results: Cd-induced significant reduction in the mean testicular weight and GSH levels and plasma testosterone, LH and FSH levels with a concomitant increase in testicular MDA and NO levels. There was also a deterioration in semen analysis parameters and spermatozoa morphology, with testicular structural damage in the form of architecture distortion and necrosis of seminiferous tubules and testicular interstitial cells. Daily administration of ginger for 4 weeks protected against CD-induced toxicity, preserving tissue architecture, improved plasma levels of testosterone, LH and FSH and testicular levels of GSH, and reduced testicular levels of MDA, NO. Conclusion: Ginger has a protective effect on Cd-induced deterioration of testicular tissue's structural and functional integrity by improving testicular tissue antioxidant capacity and steroid production, which ameliorates sex hormone levels in the blood.

Pharmacological action of quercetin against testicular dysfunction: A mini review

The testis is an immune-privileged organ susceptible to oxidative stress and inflammation, two major factors implicated in male infertility. A reduction in the concentration and activities of testicular function biomarkers has been shown to correlate with impaired hypothalamic-pituitary-testicular axis and oxidative stress. However, the use of natural products to ameliorate these oxidative stress-induced changes may be essential to improving male reproductive function. Quercetin possesses several pharmacological activities that may help to combat cellular reproduction-related assaults, such as altered sperm function and reproductive hormone dysfunction, and dysregulated testicular apoptosis, oxidative stress, and inflammation. Studies have shown that quercetin ameliorates testicular toxicity, largely by inhibiting the generation of reactive oxygen species, with the aid of the two antioxidant pharmacophores present in its ring structure. The radical-scavenging property of quercetin may alter signal transduction of oxidative stress-induced apoptosis, prevent inflammation, and increase sperm quality in relation to the hormonal concentration. In this review, the therapeutic potential of quercetin in mediating male reproductive health is discussed.

Impacts of cadmium on male fertility: Lessons learnt so far

Cadmium (Cd) is one of the most dangerous heavy metals in the world. Globally, toxicities associated with cadmium and its attendant negative impact on humans and animals cannot be under-estimated. Cd is a heavy metal, and people are exposed to it through contaminated foods and smoking. Cd exerts its deleterious impacts on the testes (male reproductive system) by inducing oxidative stress, spermatogenic cells apoptosis, testicular inflammation, decreasing androgenic and sperm cell functions, disrupting ionic homeostasis, pathways and epigenetic gene regulation, damaging vascular endothelium and blood testes barrier. In association with other industrial by-products, Cd has been incriminated for the recent decline of male fertility rate seen in both man and animals. Understanding the processes involved in Cd-induced testicular toxicity is vital for the innovation of techniques that will help ameliorate infertility in males. In this review, we summed up recent studies on the processes of testicular toxicity and male infertility due to Cd exposure. Also, the usage of different compounds including phytochemicals, and plant extracts to manage Cd reprotoxicity will be reviewed.

Ultrastructural analysis of cadmium-induced toxicity and its alleviation by antioxidant quercetin in caprine testicular germ cells in vitro

Increasing evidence has demonstrated that cadmium (Cd), a common environmental toxicant, has been associated with testicular toxicity. Quercetin, an efficient flavonoid, has been shown to exert cytoprotective effect in numerous pathological processes. The current study has employed ultrastructural analysis to examine the Cd-induced toxicity in goat testicular tissue along with the ameliorative action of quercetin in a dose- and time-dependent manner in-vitro. Results of transmission electron microscopy (TEM) revealed that at lower selected concentrations (10 and 50 µM), Cd induced apoptosis-mediated cytotoxicity in testicular tissue as supported by presence of various morphological attributes of apoptosis in testicular germ cells such as condensed and marginated chromatin followed by breakdown of chromatin material, swollen mitochondria, and vacuolization. At 100 µM concentration, along with apoptosis, Cd-induced cytotoxicity in testicular tissue was associated with induction of necrosis also. However, the simultaneous supplementation of antioxidant quercetin has markedly abrogated the testicular cytotoxicity as shown by restoration of Cd-evoked aberrant ultrastructure of testicular germ cells in a dose- and time-dependent manner, providing a basis for future studies to involve quercetin in management of Cd-induced reproductive toxicity in males.

Nutraceuticals: A New Challenge against Cadmium-Induced Testicular Injury

Cadmium (Cd) is a widespread heavy metal and a ubiquitous environmental toxicant. For the general population, the principal causes of Cd exposure are cigarette smoking, air pollution and contaminated water and food consumption, whereas occupational exposure usually involves humans working in mines or manufacturing batteries and pigments that utilize Cd. The aim of the present review is to evaluate recent data regarding the mechanisms of Cd-induced testicular structural and functional damages and the state of the art of the therapeutic approaches. Additionally, as the current literature demonstrates convincing associations between diet, food components and men's sexual health, a coherent nutraceutical supplementation may be a new valid therapeutic strategy for both the prevention and alleviation of Cd-induced testicular injury. The toxic effects on testes induced by Cd include many specific mechanisms, such as oxidative stress, inflammation and apoptosis. As no specific therapy for the prevention or treatment of the morbidity and mortality associated with Cd exposure is available, the development of new therapeutic agents is requested. Dietary strategies and the use of nutraceuticals, particularly abundant in fresh fruits, beans, vegetables and grains, typical of the Mediterranean diet, are recommended against Cd-induced testicular injury.

Mediterranean Diet as a Shield against Male Infertility and Cancer Risk Induced by Environmental Pollutants: A Focus on Flavonoids

The role of environmental factors in influencing health status is well documented. Heavy metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls, dioxins, pesticides, ultrafine particles, produced by human activities put a strain on the body’s entire defense system. Therefore, together with public health measures, evidence-based individual resilience measures are necessary to mitigate cancer risk under environmental stress and to prevent reproductive dysfunction and non-communicable diseases; this is especially relevant for workers occupationally exposed to pollutants and/or populations residing in highly polluted areas. The Mediterranean diet is characterized by a high intake of fruits and vegetables rich in flavonoids, that can promote the elimination of pollutants in tissues and fluids and/or mitigate their effects through different mechanisms. In this review, we collected evidence from pre-clinical and clinical studies showing that the impairment of male fertility and gonadal development, as well as cancers of reproductive system, due to the exposure of organic and inorganic pollutants, may be counteracted by flavonoids.

Roles of Oxidative Stress in the Male Reproductive System: Potential of Antioxidant Supplementation for Infertility Treatment

The decline of fertility in modern society is a serious worldwide concern, and the reasons behind it are complex and difficult to unveil. The fact that a big percentage of infertility cases remain diagnosed as idiopathic, turn the strategies to treat such conditions very limited. Nevertheless, one must agree that keeping the oxidative balance of the reproductive tissues should be one of the first lines of treatment for infertile patients. As reported, 30-80% of male infertile individuals present high levels of prooxidant species in the seminal fluid. Thus, antioxidant therapies, which consist of dietary supplementation therapy with one or more antioxidant compound, remain the first step in the treatment of male infertility. Nevertheless, the efficacy of such therapies is variable between individuals. The most common prescribed antioxidants are carnitines and vitamins C and E, but recently phytochemical quercetin has emerged as a potential compound for the treatment of oxidative stress in the male reproductive system. Although there are several animals' evidence about the great potential of quercetin for the treatment of infertility, clinical trials on this subject remain scarce.

Astaxanthin Induces the Expression of CatSper1 Gene and Protects Sperms in Toxicity Induced by Cadmium in Mice

Cadmium (Cd) as a heavy metal damages testis and decreases fertility, however, antioxidants can improve sperm parameters and decrease male infertility. In this study we investigated the effect of astaxanthin (AST) on sperm parameters, expression levels of CatSper1 and CatSper2 genes in presence of Cd in mice. Thirty adults' mice were divided into 4 groups, sham group received olive oil and saline (olive oil is the solvent of AST and saline is the solvent of Cd), Cd group received 1 mg/kg Cdcl₂, a group received 10 mg/kg AST and 1 mg/kg Cdcl₂ and a group received 10 mg/kg AST. The treatments were done intraperitoneally for 14 days. After 14 days sperm parameters were analyzed. Malondialdehyde level, catalase enzyme activity, the alteration of CatSper1 and CatSper2 genes expression were measured in testis. Results showed that Sperm count, viability, CatSper1 gene expression and catalase activity significantly decreased by Cd compared to sham group. Cd significantly increased sperm DNA fragmentation (SDF), abnormal sperm morphology and malondialdehyd level compared to sham group. AST significantly increased sperm count, viability and CatSper1 gene expression and decreased SDF and abnormal sperm in comparison with Cd group. AST protected testis and decreased oxidative stress induced by Cd. Our findings indicated that AST could protect sperm DNA, enhanced CatSper1 gene expression and sperm quality in presence of Cd. No significant differences were found in CatSper2 expression among treatments. Therefore, AST as a strong antioxidant can help to protect the potential of fertility against Cd toxicity.

Quercetin mediated attenuation of cadmium-induced oxidative toxicity and apoptosis of spermatogenic cells in caprine testes in vitro

Cadmium (Cd), an environmental toxic heavy metal, has been reported to cause testicular toxicity, which contributes to the recent decline in male fertility worldwide. Quercetin (Qcn), a major dietary antioxidant, has been shown to have protective effects under various pathological conditions. However, whether Qcn provides protection against Cd-stimulated testicular toxicity remains obscured. The present study was therefore aimed at investigating the ameliorative effect of Qcn supplementation on Cd-induced toxicity in the goat testis in vitro in a dose-(10, 50, and 100 μM) and time-dependent (4 and 8 h) manner. Different cytotoxicity, genotoxicity, and biochemical analyses have been carried out using appropriate methods. Cytotoxicity in testicular cells induced by Cd treatment was apparently mitigated by Qcn treatment, evidenced by decreased apoptotic attributes or frequency in Qcn plus Cd-treated groups compared to the only Cd-treated groups. Qcn treatment provides substantial protection to the Cd-triggered aggression in oxidative (increased MDA levels) and total antioxidant capacity (reduced FRAP activity) in testicular tissue, indicating the anti-oxidative function of Qcn against Cd exposure. Moreover, Cd-induced decline in antioxidant status (CAT, SOD, and GST activity) was markedly restored by Qcn supplementation in testicular tissue. In conclusion, this study shows that Qcn treatment significantly attenuated the Cd-evoked testicular damage, suggesting its beneficial potential in preventing or at least in managing the gonadotoxicity in males induced by steadily increasing Cd contamination in the environment.

Quercetin Protects Human Thyroid Cells against Cadmium Toxicity

Various natural compounds have been successfully tested for preventing or counteracting the toxic effects of exposure to heavy metals. In this study, we analyzed the effects of cadmium chloride (CdCl₂) on immortalized, non-tumorigenic thyroid cells Nthy-ori-3-1. We investigated the molecular mechanism underlying its toxic action as well as the potential protective effect of quercetin against CdCl₂-induced damage. CdCl₂ suppressed cell growth in a dose- and time-dependent manner (IC50 value ~10 μM) associated with a decrease in levels of phospho-ERK. In addition, CdCl₂ elicited an increase in reactive oxygen species (ROS) production and lipid peroxidation. A significant increase in GRP78, an endoplasmic reticulum (ER) stress-related protein, was also observed. Supplementation of quercetin counteracted the growth-inhibiting action of CdCl₂ by recovering ERK protein phosphorylation levels, attenuating ROS overproduction, decreasing MDA content and reducing the expression of GRP78 in cells exposed to CdCl₂. Thus, in addition to revealing the molecular effects involved in cadmium-induced toxicity, the present study demonstrated, for the first time, a protective effect of quercetin against cadmium-induced damages to normal thyroid cells.

Antioxidant, Antigenotoxic, and Hepatic Ameliorative Effects of Quercetin/Zinc Complex on Cadmium-Induced Hepatotoxicity and Alterations in Hepatic Tissue Structure

Applications of medicinal uses of metals and their complexes have been gaining major clinical significance, especially during the COVID-19 pandemic. The ligation behavior of quercetin (Q), a flavonoid, and Zn metal, i.e., the Zn/Q complex, was fully characterized based on molar conductance, infrared (IR) spectra, elemental analysis, electronic spectra, thermogravimetric analysis, proton nuclear magnetic resonance (1H-NMR), and transmission electron microscopy (TEM) in our lab. Hepatotoxicity was induced by cadmium (CdCl2). A total of 40 male albino rats were randomly distributed into the following four groups: Control, hepatotoxic group (CdCl2), Zn/Q-treated group, and group treated with a combination of CdCl2 and Zn/Q. Serum hepatic enzymes (AST, ALT, and LDH), total protein, and enzymatic and nonenzymatic antioxidant levels were determined. Histology and TEM for hepatic tissues, in addition to the gene expression of SOD as an antioxidant enzyme in the hepatic tissues, were evaluated. The Q/Zn treatment demonstrated potent protective effects against CdCl2-induced sever oxidative stress and suppressed hepatic toxicity, genotoxicity, liver enzyme disturbances, and structural alterations. In conclusion, the Zn/Q complex produced a high potent antioxidant effect against the oxidative injury and genotoxicity induced by CdCl2 and could be considered to be a potent ameliorative hepatoprotective agent against CdCl2 hepatotoxicity, which could be beneficial during the COVID-19 pandemic.

A Flavonoid-Rich Extract from Bergamot Juice, Alone or in Association with Curcumin and Resveratrol, Shows Protective Effects in a Murine Model of Cadmium-Induced Testicular Injury

It is known that cadmium damages testis structure and functionality. We examined the effects of nutraceuticals such as a flavonoid-rich extract of bergamot juice (BJe), alone or in association with curcumin (Cur) and resveratrol (Re), on mice testicular dysfunction caused by cadmium chloride (CdCl₂). Controversial data on the protective effects of Cur and Re are available, while no evidence on the possible role of BJe exists. Adult male C57 BL/6J mice were administered with CdCl₂ and treated with Cur, Re, or BJe alone or in combination for 14 days. Then, testes were removed and processed for molecular, structural, and immunohistochemical analyses. CdCl₂ increased the mRNA of IL-1β, TNF-α, p53, and BAX while reduced that of Bcl-2 and induced tubular lesions and apoptosis of germinal cells. Cur, Re, and BJe at 40 mg/kg significantly improved all of these parameters and events, although BJe at 20 mg/kg showed a lower protective effect. The association of Cur, Re, and BJe at both doses of 50/20/20 and 100/20/40 mg/kg brought each parameter close to those of the control. Our results indicate that the nutraceuticals employed in this study and their associations exert a positive action against Cd-induced testicular injury, suggesting a possible protection of testis functionality in subjects exposed to environmental toxicants.

Ins and outs of cadmium-induced carcinogenesis: Mechanism and prevention

Cadmium (Cd) is a heavy metal and a highly toxic pollutant that is released into the environment as a byproduct of most modern factories and industries. Cd enters our body in significant quantities from contaminated water, cigarette smoke, or food product to many detrimental health hazards. Based on causal association all the Cd-related or derived compounds have been classified as carcinogens. In this study, we present an overview of the published literature to understand the molecular mechanisms for Cd-induced carcinogenesis and its prevention. In acute Cd poisoning production of reactive oxygen species is a key factor. However, chronic Cd exposure can transform cells to become more resistant to oxidative stress. Also, as an epigenetic mechanism Cd acts indirectly on DNA repair mechanisms via alteration of reactions upstream. Those transformed cells acquire resistance to apoptosis and deregulation of calcium homeostasis. Leading to uncontrolled carcinogenic cell proliferation and inherent DNA lesions. Flavonoids commonly found in plant foods have been shown to have a protective effect against Cd-induced carcinogenicity. A wide variety of tumorigenic mechanisms involved in chronic Cd exposure and the beneficial effects of flavonoids against Cd-induced carcinogenicity necessitate further investigations.

Quercetin ameliorates cytotoxic effects of zinc oxide nanoparticles on sertoli cells by enhancing autophagy and suppressing oxidative stress

Previous studies have demonstrated the toxic impacts of zinc oxide nanoparticles (ZO-NPs) on male reproductive cells. The effect of quercetin (QCT) on ZO-NPs-induced mouse Sertoli cell (TM4 cell line) toxicity and its underlying mechanisms were investigated in this study. The TM4 cells were exposed to ZO-NPs or QCT in different groups for 24 hr. The TM4 cells pre-treated with 3MA (3-Methyladenine, an autophagy inhibitor) to evaluate the autophagy role of QCT and ZO-NPs in the TM4 cells. ZO-NPs significantly reduced the viability percentage of the TM4 cells. The apoptosis percentage and Bax/Bcl-2 ratio of the ZO-NPs group were significantly increased, while the expression of autophagy-related genes was considerably downregulated. ZO-NPs also induced oxidative stress in the TM4 cells through increasing malondialdehyde contents and reactive oxygen species levels (ROS) and reducing antioxidant factors including superoxide dismutase, catalase, glutathione and glutathione peroxidase. In QCT + ZO-NPs group, these events were considerably reversed. 3MA could significantly decrease the cell viability of TM4 cells exposed to the QCT and ZO-NPs in comparison with the untreated 3MA groups. According to these results, the protective effects of QCT on ZO-NPs-exposed TM4 cells are related to inducing autophagy, prevention apoptosis and suppressing oxidative stress.

Comprehensive Review of Cadmium Toxicity Mechanisms in Male Reproduction and Therapeutic Strategies

Cadmium (Cd) has been widely studied as an environmental pollutant for many years. Numerous studies have reported that Cd exposure causes damage to the heart, liver, kidneys, and thyroid in vivo. The emerging evidence suggests that Cd exposure induces damage on male reproductive system, which is related to oxidative stress, inflammation, steroidogenesis disruption, and epigenetics. Current preclinical animal studies have confirmed a large number of proteins and intracellular signaling pathways involved in the pathological process of Cd-induced male reproductive damage and potential measures for prophylaxis and treatment, which primarily include antioxidants, anti-inflammatory agents, and essential ion supplement. However, explicit pathogenesis and effective treatments remain uncertain. This review collects data from the literatures, discusses the underlying mechanisms of Cd-induced toxicity on male reproductive function, and summarizes evidence that may provide guidance for the treatment and prevention of Cd-induced male reproductive toxicity.

Comparison of the deleterious effects of yaji and cadmium chloride on testicular physiomorphological and oxidative stress status: The gonadoprotective effects of an omega-3 fatty acid

Objective

This study investigated testicular oxidative stress status and physiomorphological function in Wistar rats fed with yaji and cadmium chloride (CdCl₂).

Methods

Sixty male albino Wistar rats (12 per group) were randomly assigned to five groups: group I (control), group II (300 mg/kg.bw of yaji), group III (500 mg/kg.bw of yaji), group IV (2.5 mg/kg.bw of CdCl₂), and group V (2.5 mg/kg.bw of yaji+4 mg/kg.bw omega-3). Each group was evenly subdivided into two subgroups and treatment was administered for 14 days and 42 days, respectively. Semen quality (sperm count, progressive motility, normal morphology, and gonadosomatic index), hormones (testosterone, follicle-stimulating hormone, and luteinizing hormone), testicular oxidative stress markers (superoxide dismutase, catalase, glutathione peroxidase, and malonaldehyde) and testicular histomorphological features were examined.

Results

Yaji caused significant (p< 0.05) dose- and duration-dependent reductions in semen quality, the gonadosomatic index, testosterone, follicle-stimulating hormone, and luteinizing hormone. Yaji also caused significant (p< 0.05) dose- and duration-dependent decreases in superoxide dismutase, catalase, and glutathione peroxidase activity, as well as increased testicular malonaldehyde levels. Yaji induced distortions in the testicular histological architecture. CdCl₂ damaged testicular function by significantly (p< 0.05) reducing semen quality, reproductive hormone levels, and oxidative stress markers in albino Wistar rats. CdCl₂ also altered the histology of the testis.

Conclusion

This study shows that yaji sauce has similar anti-fertility effects to those of CdCl₂, as it adversely interferes with male reproduction by impairing oxidative stress markers and the function and morphological features of the testis.

Current mechanistic perspectives on male reproductive toxicity induced by heavy metals

Environmental and occupational exposures to heavy metals have led to various deleterious damages to the biological system of which infertility is one of them. Infertility is a global public health concern, affecting 15% of all couples of reproductive age. Out of the 100% cases of reported infertility among couples, 40% of the cases are related to male factors; including decreased semen quality. This review focuses on the recent mechanistic perspectives of heavy metal-induced male reproductive toxicity. The associated toxic metal-mediated mechanisms of male reproductive toxicity include ion mimicry, disruption of cell signaling pathways, oxidative stress, altered gene expression, epigenetic regulation of gene expression, apoptosis, disruption of testis/blood barrier, inflammation and endocrine disruption. The current literature suggests that non-coding RNAs (ncRNAs) mediate paternal intergenerational epigenetic inheritance and thus has a direct functional importance, as well as possess novel biomarker potential, for male reproductive toxicity. To identify the specific ncRNAs with the most profound impacts on heavy metal-induced male reproductive toxicity should be thrust of further research.

Effects of Myo-inositol Alone and in Combination with Seleno-Lmethionine on Cadmium-Induced Testicular Damage in Mice

BACKGROUND

Cadmium (Cd) impairs gametogenesis and damages the blood-testis barrier.

OBJECTIVE

As the primary mechanism of Cd-induced damage is oxidative stress, the effects of two natural antioxidants, myo-inositol (MI) and seleno-L-methionine (Se), were evaluated in mice testes.

METHODS

Eighty-four male C57 BL/6J mice were divided into twelve groups: 0.9% NaCl (vehicle; 1 ml/kg/day i.p.); Se (0.2 mg/kg/day per os); Se (0.4 mg/kg/day per os); MI (360 mg/kg/day per os); MI plus Se (0.2 mg/kg/day); MI plus Se (0.4 mg/kg/day); CdCl2 (2 mg/kg/day i.p.) plus vehicle; CdCl2 plus MI; CdCl2 plus Se (0.2 mg/kg/day); CdCl2 plus Se (0.4 mg/kg/day); CdCl2 plus MI plus Se (0.2 mg/kg/day); and CdCl2 plus MI plus Se (0.4 mg/kg/day). After 14 days, testes were processed for biochemical, structural and immunohistochemical analyses.

RESULTS

CdCl2 increased iNOS and TNF-α expression and Malondialdehyde (MDA) levels, lowered glutathione (GSH) and testosterone, induced testicular lesions, and almost eliminated claudin-11 immunoreactivity. Se administration at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression, maintained GSH, MDA and testosterone levels, structural changes and low claudin-11 immunoreactivity. MI alone or associated with Se at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression and MDA levels, increased GSH and testosterone levels, ameliorated structural organization and increased claudin-11 patches number.

CONCLUSION

We demonstrated a protective effect of MI, a minor role of Se and an evident positive role of the association between MI and Se on Cd-induced damages of the testis. MI alone or associated with Se might protect testes in subjects exposed to toxicants, at least to those with behavior similar to Cd.

Protective effect of quercetin on rat testes against cadmium toxicity by alleviating oxidative stress and autophagy

Cadmium (Cd), a highly toxic heavy metal, adversely affects human and animal health. Quercetin (Que) is a kind of flavonoid that can protect many tissues from the toxic effect of heavy metals. Although many studies have explored the adverse effects of cadmium on rats and other animals, the mechanism of Cd-induced testicular autophagy and the antagonistic effect of Que on cadmium remain unclear. In this study, Sprague-Dawley rats were treated with Cd, Que or Cd, and Que supplements to explore the mechanisms of Que-alleviated testis injury caused by Cd exposure. The rat body weight and relative testicular weight were measured. Morphological changes in testes and indices of oxidative stress were also examined. The expression levels of autophagy-related genes were detected as well. Results showed that Cd decreased the rat body weight and relative testicular weight and induced pathological changes in testes. Conversely, Que alleviated these changes. We also found that Cd increased the malondialdehyde content and decreased the contents of total superoxide dismutase, glutathione peroxidase, catalase, and glutathione. Moreover, the protein expression levels of P62 and LC3-II increased under Cd exposure conditions. Conversely, Que obviously alleviated these toxic activities induced by Cd. Overall, this study showed that Cd accumulated in rat testes, leading to oxidative stress and autophagy. Que can reduce cadmium toxicity by reducing oxidative stress and inhibiting autophagy. The specific mechanism of Que antagonizing Cd toxicity can provide new insights into countering cadmium toxicity.

Cyanidin-3-O-glucoside restores spermatogenic dysfunction in cadmium-exposed pubertal mice via histone ubiquitination and mitigating oxidative damage

Cadmium (Cd) is an environmental contaminant found in soil, water, and food, and can cause oxidative stress and male reproductive damage. During puberty, the male reproductive system is very vulnerable to interference, however, the dysregulation of Cd on spermatogenesis in this period is ambiguous. The anthocyanin cyanidin-3-O-glucoside (C3G) is phytochemical rich in plants and fruits and has been shown to have remarkable anti-oxidant activity, making it an ideal nutrient for nutritional intervention. By modeling Cd-induced damage in male pubertal mice and feeding with C3G, we demonstrated that the C3G could rescue the amount and activity of sperm predominantly. Furthermore, C3G showed partial resistance to Cd-induced histone modification during spermiogenesis and prevented oxidative damage of the DNA in the sperm nucleus. Additionally, C3G mitigated the oxidative stress of testis to achieve the level coinciding with the control group. Meanwhile, Cd-induced mitochondrial apoptosis of sperm cells was reduced significantly via the MAPK signaling pathway in the presence of C3G. Collectively, our findings can offer a potential intervention for combating Cd-induced reproductive damage during puberty by taking anthocyanin as a dietary supplement.

The Role of Natural Antioxidants Against Reactive Oxygen Species Produced by Cadmium Toxicity: A Review

Cadmium (Cd) is a significant ecotoxic heavy metal that adversely affects all biological processes of humans, animals and plants. Exposure to acute and chronic Cd damages many organs in humans and animals (e.g. lung, liver, brain, kidney, and testes). In humans, the Cd concentration at birth is zero, but because the biological half-life is long (about 30 years in humans), the concentration increases with age. The industrial developments of the last century have significantly increased the use of this metal. Especially in developing countries, this consumption is higher. Oxidative stress is the imbalance between antioxidants and oxidants. Cd increases reactive oxygen species (ROS) production and causes oxidative stress. Excess cellular levels of ROS cause damage to proteins, nucleic acids, lipids, membranes and organelles. This damage has been associated with various diseases. These include cancer, hypertension, ischemia/perfusion, cardiovascular diseases, chronic obstructive pulmonary disease, diabetes, insulin resistance, acute respiratory distress syndrome, idiopathic pulmonary fibrosis, asthma, skin diseases, chronic kidney disease, eye diseases, neurodegenerative diseases (amyotrophic lateral sclerosis, Parkinson's disease, Alzheimer's disease, and Huntington disease). Natural antioxidants are popular drugs that are used by the majority of people and have few side effects. Natural antioxidants play an important role in reducing free radicals caused by Cd toxicity. Our goal in this review is to establish the relationship between Cd and oxidative stress and to discuss the role of natural antioxidants in reducing Cd toxicity.

Cadmium-Induced Testicular Toxicity in Mice: Subacute and Subchronic Route-Dependent Effects

This study aimed to compare Cd exposure by intraperitoneal (i.p.) and oral routes, evaluating the testicular subacute and subchronic effects. Adult male mice were separated into three groups subdivided according to the experimental period (7 and 42 days after Cd exposure: subacute and subchronic effects, respectively): one group received water and two groups received CdCl₂ (1.2 mg/kg i.p. and 24 mg/kg oral). The testicular concentration of essential minerals and Cd, activity of antioxidant enzymes and markers of oxidative stress, histology, and testicular histomorphometry were evaluated. The subacute effect of oral Cd showed reduced Fe concentration, while Ca and Cu increased in this route. The subchronic effect promoted decreasing in Mg in i.p. and oral routes, whereas Zn decreased only in the oral, and the Fe concentration did not change. SOD activity decreased in the oral subacute evaluation and in both pathways, i.p. and oral routes, in the subchronic evaluation, while GST activity increased, and MDA concentration decreased. Labeling of apoptotic cells was increased in the subacute and subchronic evaluation. Seminiferous epithelium degeneration, death of germ cells, and Leydig cell damages occurred in i.p. and oral routes. However, these damages were more intense in the oral route, mainly evaluating the subchronic effects. The results confirm that the severity of Cd-induced testicular injury depends on the pathway, as well as the duration of exposure.

Restoring strategy of ethanolic extract of Moringa oleifera leaves against Tilmicosin-induced cardiac injury in rats: Targeting cell apoptosis-mediated pathways

Tilmicosin (Til), an effective macrolide antibiotic, is widely used against respiratory diseases in livestock; however, its treatment is associated with cardiac tissue impairments. In this study, the ethanolic extract of Moringa oleifera (MO) leaves was investigated at two doses (400 and 800 mg/kg body weight [bw], orally) to determine its role in counteracting the effects of Til treatment (75 mg/kg bw) on the cardiac tissue in rats, exploring the oxidative stress-mediated damage and apoptosis. A high dose of MO ethanolic extract elicits considerable changes in the body weight, reduces the mortality rate, neutralizes the impaired cardiac injury markers, improves antioxidant endpoints (total antioxidant capacity, superoxide dismutase, catalase activity, and reduced glutathione level). Also it attenuates the oxidative stress indices (total reactive oxygen species, 8-hydroxy-2-deoxyguanosine, lipid peroxides [malondialdehyde], and protein carbonyl levels) that are associated with Til injection. The co-administration of MO ethanolic extract with Til considerably modulates the expression of apoptosis pathway-encoding genes (Bcl-2, caspase-3, Bax, p53, apoptosis-inducing factor, and Apaf-1), particularly in the high-dose group. Our results support that the concurrent administration of MO ethanolic extract with Til at a dose of 800 mg/kg bw increases the protective activity of the antioxidant system and delays or slows the pathological development of cardiotoxicity mediated by Til injection.

The ameliorative effect of monotropein, astragalin, and spiraeoside on oxidative stress, endoplasmic reticulum stress, and mitochondrial signaling pathway in varicocelized rats

Background

Monotropein, astragalin, and spiraeoside (MAS) are active compounds extracted from medicinal herbs; monotropein from Morinda officinalis How (Rubiaceae), astragalin (kaempferol 3-O-glucoside) from Cuscuta chinensis Lamark (Convolvulaceae) and spiraeoside from the outer scales of Allium cepa L. (Liliceae) in a ratio of 6.69:0.41:3.61. Monotropein, astragalin, and spiraeoside are well-known antioxidants, anti-inflammatory, and antinociceptive agents. The current investigation aims to study the molecular mechanism of varicocele-induced male infertility and the underlying pharmacological mechanisms of MAS.

Methods

Four groups were included: control (CTR), MAS 200 group (MAS 200 mg/kg), varicocele group (VC), and VC + MAS 200 group (MAS 200 mg/kg). Sprague-Dawley (SD) rats were treated with 200 mg/kg MAS or vehicle once daily for 28 days. The possible signaling mechanism and effects of MAS were measured via histological staining, immunohistochemistry, western blot, and biochemical assays.

Results

Parameters such as sperm motility and count, Johnsen’s scores, spermatogenic cell density, serum testosterone, testicular superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and expression of the steroidogenic acute regulatory protein (StAR) improved significantly in the VC + MAS 200 group compared with the VC group. MAS treatment of varicocele-induced group significantly decreased the levels of serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH), as well as testicular interleukin-6 (IL6), tumor necrosis factor-α (TNF-α), ROS/RNS, and malondialdehyde (MDA). It also decreased the apoptotic index and reduced the expression of endoplasmic reticulum (ER) protein levels (Grp78, p-IRE1α, and p-JNK) and apoptotic markers such as cleaved caspase-3 and Bax/Bcl2 ratio.

Conclusion

This study suggests that the crosstalk between oxidative stress, ER stress, and mitochondrial pathway mediates varicocele-induced testicular germ cell apoptosis. MAS promotes spermatogenesis in varicocele-induced SD rat, probably by decreasing cytokines (IL-6, TNF-α) levels, regulating abnormal sex hormones, and decreasing oxidative stress, ER stress, and apoptosis.

Effects of benzene, quercetin, and their combination on porcine ovarian cell proliferation, apoptosis, and hormone release

We hypothesized that the environmental contaminant benzene and the plant antioxidant quercetin may affect ovarian cell functions and that quercetin could offer protection against the adverse effects of benzene. This study aimed to examine the action of benzene, quercetin, and their combination on porcine ovarian granulosa cell functions. We elucidated the effects of benzene (20  µ g mL - 1 ), quercetin (at the doses 0, 1, 10, 100  µ g mL - 1 ), and their combination on ovarian granulosa cell functions (proliferation, apoptosis, and hormone release) in vitro using immunocytochemistry and enzyme immunoassay respectively. Benzene alone stimulated proliferation, apoptosis, and oxytocin release and inhibited progesterone and prostaglandin F release. Quercetin alone inhibited proliferation, apoptosis, and stimulated oxytocin release but did not affect progesterone and prostaglandin F release. When used in combination with benzene, quercetin promoted the inhibitory effect of benzene on progesterone release. Overall, these data suggest that benzene and quercetin have direct stimulatory and inhibitory effects, respectively, on basic ovarian functions. Moreover, no protective action of quercetin against the effects of benzene was found. Rather, it was found to enhance the effect of benzene on progesterone release. Therefore, quercetin cannot be considered for preventing or mitigating the effects of benzene on reproductive processes.

Protective effects of quercetin supplementation against short-term toxicity of cadmium-induced hematological impairment, hypothyroidism, and testicular disturbances in albino rats

The aim of this study was to evaluate the probable protective effect of quercetin (QUE) against cadmium (Cd)-induced sub-chronic toxicity in rats. Adult male rats were given either Cd (as cadmium chloride; 5 mg/kg) alone or in combination with QUE (50 mg/kg) daily for 4 weeks by oral gavage. At the end of the experimental period, Cd accumulation, and selected hematological, thyroid, and reproductive markers were assessed. Results revealed that Cd treatment significantly increased Cd concentrations in blood, thyroid gland, and testicular tissue of rats. Cd also caused a decline in hemoglobin content, hematocrit value, and total erythrocyte and leucocyte counts. Further, significant suppressions in the blood levels of hormones related to thyroid gland function, and male reproductive hormones (i.e., testosterone, luteinizing hormone and follicle-stimulating hormone), were observed in Cd-treated rats compared to the control. In parallel, low sperm count and sperm motility, increased sperm abnormalities, and marked pathology occurred in testis. Combination with QUE recorded amelioration of the deleterious effects of Cd, involving regulation of hematological toxicity and thyroid hormonal levels and subsequently modulation of testicular function. In conclusion, it appears that dietary QUE can rescue from Cd-induced hematological dysfunctions and testicular damage by reversing the hypothyroid state.

Protective effect of tea against lead and cadmium-induced oxidative stress-a review

Exposure to Cd and Pb reduces the activity of antioxidant enzymes, which points to a decrease in the antioxidant potential of the body as a result of supplying factors which enhance cellular oxidation processes. Man is exposed to the effects of toxic metals because they are present in the environment, including in food. Since no effective ways to reduce the concentrations of Cd an Pb in food exist, studies are undertaken to develop methods of reducing their toxic effect on the body through chelating these metals using nutrients (which reduces their absorption by tissues) or increasing the oxidative capacity of the body (which decreases the possibility of inducing oxidative damage to internal organs). Studies performed on laboratory animals have shown that the use of tea infusions fulfil both functions.

The In Vitro Anti-Proliferative Interaction of Flavonoid Quercetin and Toxic Metal Cadmium in the 1321N1 Human Astrocytoma Cell Line

Cadmium (Cd) is a toxic heavy metal occurring in the environment as an industrial pollutant. The systematic accumulation of Cd in the human body may lead to major health problems. Quercetin (QE) is a natural flavonoid widely distributed in plants and is a part of human diet. Many studies have demonstrated the multiple benefits of QE to humans in protecting cells of our bodies. The aim of this study was to investigate the effect of QE and Cd on the proliferation of astrocytoma 1321N1 cells. Results indicated that the simultaneous exposure of the cells to 200 µM QE and 16 μM Cd significantly reduced cell viability to 6.9 ± 1.6% with respect to vehicle-treated cells. Other experiments of QE pre-treatment followed by the exposure to Cd alone or with QE indicated significant but decreased ability of QE or Cd to reduce proliferation of the cells compared to their co-incubation. Our study suggested a synergetic anti-proliferative interaction of Cd and QE in malignantly transformed cells. This adds new information regarding the biological effects of QE.

Dose- dependent ameliorative effects of quercetin and l-Carnitine against atrazine- induced reproductive toxicity in adult male Albino rats

This study aimed to determine the protective effects of co-administration of Quercetin (QT) or l-Carnitine (LC) against the oxidative stress induced by Atrazine (ATZ) in the reproductive system of intact male Albino rats. 36 rats were divided equally into 6 groups. Rats in the control negative "CNT" group received 1.5 ml distilled water for 21 days. All rats in the other groups received ATZ (120 mg/kg bw) through gavage. Groups 3 and 4 were co-administered with either low or high dose of QT (10 "ATZLQT" and 50 "ATZHQT" mg/kg bw, respectively). Groups 5 and 6 were co-administered with either low or high dose of LC (200 "ATZLLC" and 400 "ATZHLC" mg/kg bw, respectively). At the end of the experiment, animals were sacrificed and all samples were collected. ATZ significantly increased serum level of malondialdehyde (MDA) and decreased total antioxidant capacity (TAC). Also, ATZ increased significantly the sperm cell abnormalities and reduced both testicular IgA and serum testosterone levels. Testicular DNA laddering % and CYP17A1 mRNA expression were significantly reduced in ATZ group. Interestingly, co-administration with low dose QT or different doses of LC succeeded to counteract the negative toxic effects of ATZ on serum oxidative stress indicators, serum testosterone levels, testicular IgA level and improved testicular CYP17A1 mRNA expression. In conclusion, QT in low dose and LC in both low and high doses exerted a significant protective action against the reproductive toxicity of ATZ, while higher dose of QT failed induce immune-stimulant effect against ATZ in adult male Albino rats.

Ameliorative Effect of Arctium lappa Against Cadmium Genotoxicity and Histopathology in Kidney of Wistar Rat

BACKGROUND AND OBJECTIVE

Cadmium (Cd) is a non-essential metal whose dispersion in the environment has increased recently, Cd may enhance cell oxidative stress that leads to DNA damage and apoptotic cell death. The study aimed to evaluate the antioxidative capability of Burdock root 'Arctium lappa' on cadmium-induced oxidative stress and histopathology of the kidney of Wistar rats.

METHODOLOGY

Cadmium was applied in a form of cadmium chloride to three groups (15 mg Cd kg-1) for five weeks with two groups pre-treated with 'Arctium lappa' administration, 100 and 200 mg kg-1 b.wt. Data were analyzed using one way analysis of variance (ANOVA) followed by Least Significant Difference (LSD) test to determine the difference among means using the JMP version 12.

RESULTS

Results revealed that cadmium induced a significant disorganization (p<0.05) of renal structure with collapsed tubular lamina and 76 μm tail length of the cells was observed, while histological sections of kidney pre-treated with 100 mg Arctium lappa kg-1 b.wt., showed a slightly less hypercellularity of glomerulus and reduction in the cell tail (59 μm). Furthermore, histological sections of kidney of rats pre-treated with 200 mg Arctium lappa kg-1 b.wt., showed high improvement of renal tubules and glomerulus with a prominent urinary space beside tail length of cells was recorded as 39 μm which was lower in comparison to other groups.

CONCLUSION

Moreover, cadmium induced cellular destruction of the kidney was resumed with the pre-treatment of the secondary metabolites as an antioxidant compounds that produced from plant extracts. Arctium lappa leaf extract was efficient at both applied doses while 200 mg Arctium lappa kg-1 b.wt., had the most ameliorative effect.

Paclitaxel and quercetin nanoparticles co-loaded in microspheres to prolong retention time for pulmonary drug delivery

High drug resistance, poor water solubility, short half-life, and low local drug concentration are obstacles for successful delivery of chemotherapeutic drugs for lung cancer. A new method involving the use of nanoparticles (NPs) for pulmonary delivery is proposed. However, use of NPs is limited by the particle size range for pulmonary drug delivery considering that NPs cannot be deposited directly into the lungs. NPs polymerized into microspheres (polymeric microspheres, PMs) will result in suitable particle sizes and retain the advantages of nanodrugs after redispersion when applied in pulmonary delivery. We report the development of novel NPs in the form of PMs loaded with paclitaxel (PTX) and quercetin (QUE) double drugs based on the synthesis of oleic acid-conjugated chitosan (OA-CTS) for pulmonary delivery. This approach is aimed toward prolonging PTX retention time in the presence of QUE and bypassing P-glycoprotein drug efflux pumps. NPs loaded with PTX or QUE were prepared with 11% substitution degree using OA-CTS as the carrier by ionic cross-linking method, which NPs loaded with PTX or QUE were used in the preparation of PMs by spray-drying. The diameters of the PMs ranged from 1 to 5 μm which had uniform size range. Scanning electron microscopy showed that PMs were polymers formed by a large number of NPs and readily redispersed (after redispersion, size of NPs ranged between 250 and 350 nm) in water within 1 h. PMs displayed slow-release characteristics at pH 4.5 and 7.4. The in vivo pharmacokinetic and biodistribution studies suggested that PMs exhibit prolonged circulation time and a markedly high accumulation in the lung. The obtained results indicate that PMs can serve as a promising pulmonary delivery system for combined pharmacotherapy using hydrophobic anticancer drugs.

The environment and male reproduction: The effect of cadmium exposure on reproductive function and its implication in fertility

Cadmium is an environmental pollutant known as endocrine disruptor. Testis is particularly susceptible to cadmium, and testis injury occurs at high but even low levels of exposure. Cadmium reproductive toxicity is mediated by multiple mechanisms, including structural damage to testis vasculature and blood-testis barrier, inflammation, cytotoxicity on Sertoli and Leydig cells, oxidative stress mainly by means of mimicry and interference with essential ions, apoptosis, interference with selected signaling pathways and epigenetic regulation of genes involved in the regulation of reproductive function, and disturbance of the hypothalamus-pituitary-gonadal axis. The current review outlines epidemiological observational findings from environmental and occupational exposure in humans, and reports experimental studies in humans and animals. Lastly, a focus on the pathogenetic mechanisms of cadmium toxicity and on the specific mechanisms of cadmium sensitivity and resistance, particularly assessed in animal models, is included. Despite convincing experimental findings in animals and supporting evidences in humans identifying cadmium as reproductive toxicant, observational findings are controversial, suffering from heterogeneity of study design and pattern of exposure, and from co-exposure to multiple pollutants.

Cadmium chloride-induced testicular toxicity in male wistar rats; prophylactic effect of quercetin, and assessment of testicular recovery following cadmium chloride withdrawal

This study assessed the effect of quercetin (QE) on cadmium chloride (CdCl₂) - induced testicular toxicity, as well as the effect of withdrawal of CdCl₂ treatment on same. Thirty male Wistar rats aged 10 weeks old and weighing 270-300g were assigned into 5 groups and used for this study. Rats in groups 1-4 were administered vehicle, CdCl₂ (5mg/kg bwt), CdCl₂+QE (5mg/kg bwt and 20mg/kg bwt, respectively) or QE (20mg/kg bwt) orally for 4 weeks. Group 5 rats received CdCl₂, with 4 weeks recovery period. Results showed that cadmium accumulated in serum, testis and epididymis, decreased body weight, testicular and epididymal weights, sperm count, motility and viability. Cadmium decreased serum concentrations of reproductive hormones, but increased testicular glucose, lactate and lactate dehydrogenase activity. Cadmium decreased testicular enzymatic (superoxide dismutase, catalase and glutathione peroxidase) and non-enzymatic (glutathione, vitamins C and E) antioxidants, and increased malondialdehyde and hydrogen peroxide. Cadmium down-regulated Bcl-2 protein, up-regulated Bax protein, increased Bax/Bcl-2 ratio and cleaved caspase-3 activity. Histopathology of the testis showed decreased Johnsen's score and Leydig cell count. These negative effects were attenuated by QE administration, while withdrawal of CdCl₂ did not appreciably reverse toxicity. We conclude that QE better protected the testis from CdCl₂ toxicity than withdrawal of CdCl₂ administration.

Effects of cadmium exposure on Iberian ribbed newt (Pleurodeles waltl) testes

To characterize the histomorphologic effects of cadmium on adult newt testes, male Iberian ribbed newts (6 months post-hatching) were intraperitoneally exposed to a single dose of 50 mg/kg of cadmium, with histologic analysis of the testes at 24, 48, 72, and 96 h. Beginning 24 h after cadmium exposure, apoptosis of spermatogonia and spermatocytes was observed, and congestion was observed in the interstitial vessels of the testes. Throughout the experimental period, the rates of pyknotic cells and TUNEL and cleaved caspase-3 positivity were significantly higher in the spermatogonia and spermatocytes of cadmium-treated newts compared with control newts. There were no significant differences between cadmium-treated and control newts in phospho-histone H3 positivity in the spermatogonia and spermatocytes. These results suggest that spermatogonia and spermatocytes in adult Iberian ribbed newts are highly sensitive to cadmium. This is the first report of the histomorphologic characteristics of cadmium-induced testicular dysfunction in newts.

Protective effect of Lycium barbarum polysaccharides against cadmium-induced testicular toxicity in male mice

The present study was performed to determine whether Lycium barbarum polysaccharides (LBPs) would protect mice against cadmium (Cd)-induced testicular toxicity. Seventy-two male mice were randomly divided into six groups with twelve mice per group. Four groups were administered orally with cadmium chloride (5.0 mg per kg body weight) for 35 days and treated in combination with LBPs (0, 10.0, 33.3 or 100 mg kg^-1) from one week before exposure to Cd until the end of the experiment. The other two groups were administered orally with vehicle or LBP (100 mg kg^-1) only. Pretreatment with LBP ameliorated the Cd-induced reduction in the body weights, sperm motility as well as the level of testosterone in serum. Moreover, Cd-induced increase in the abnormal sperms was reduced and effects of Cd on the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were reversed. Histopathological examination further confirmed that the LBPs effectively attenuated Cd-induced degeneration of seminiferous tubules. Thus, LBPs attenuated Cd-induced testicular injury by improving the activity of antioxidant enzymatic activity and lowering the oxidative stress, so it could be a potential auxiliary therapeutic agent for Cd-induced testicular toxicity.

Effects of cadmium exposure on medaka (Oryzias latipes) testes

Adult male medaka (Oryzias latipes) were exposed to 10 ppm of cadmium for 96 h, and the testes were examined histopathologically. Numerous apoptotic cells were found in the spermatogonia and spermatocytes at 72 and 96 h after initiation of cadmium exposure, and the pyknotic index, TUNEL-positive rate, and cleaved caspase-3-positive rate in the spermatogonia and spermatocytes of the cadmium-treated group were higher compared with the control group. No significant difference between the control and cadmium-treated groups was found in the phospho-histone H3-positive rate in the spermatogonia and spermatocytes. No edematous, hemorrhagic, or necrotic changes were observed within the testes in the cadmium-treated group. These results suggest that spermatogonia and spermatocytes in medaka testes are highly sensitive to cadmium. Exposure to 10 ppm of cadmium induced histopathologic changes in the testes that were similar to those described in rodents exposed to low doses of cadmium.

Quercetin exerts preventive, ameliorative and prophylactic effects on cadmium chloride - induced oxidative stress in the uterus and ovaries of female Wistar rats

This study examined the possible protective effect of quercetin(QE) on cadmium chloride (CdCl₂) - induced reproductive toxicity in female rats. Cadmium (Cd) accumulated in the uterus and ovaries of rats, decreased antioxidants [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione (GSH)], and raised the concentrations of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) in the uterus and ovaries of rats. Serum concentrations of estradiol, progesterone, follicle stimulating hormone and luteinizing hormone decreased significantly after CdCl₂ administration. Caspase-3 activity significantly increased in the ovaries, with an increase in Bax and a decrease in Bcl-2 protein expressions after CdCl₂ treatment. Histopathology of the ovaries revealed significant decrease in follicle number, while the uterus showed cyst-like endometrial glands. All three models of QE treatment [pre-treatment (QE + CdCl₂), post-treatment (CdCl₂+QE), simultaneous treatment (CdCl₂/QE)] decreased Cd accumulation, MDA, H₂O₂, and increased SOD, CAT and GPx activities in the uterus and ovaries, decreased apoptosis of follicular cells, and increased serum reproductive hormones. However, the QE pre-treated model offered better protection against CdCl₂ relative to the other two models. These results suggest that, QE exerts multi-mechanistic protective effects against cadmium toxicity attributable to its antioxidant and anti-apoptotic actions.

Beneficial effects of quercetin on titanium dioxide nanoparticles induced spermatogenesis defects in mice

Many recent studies have demonstrated that most nanoparticles (NPs) have an adverse or toxic action on male germ cells. In present study, protective effect of quercetin (Que) on titanium dioxide nanoparticle (NTiO₂)-induced spermatogenesis defects in mice was investigated. Thirty-two Naval Medical Research Institute (NMRI) mice were randomly divided into four groups. Que group received 75 mg/kg of Que for 42 days. NTiO₂ group received 300 mg/kg NTiO₂ for 35 days. NTiO₂ + Que group initially received 75 mg/kg Que for 7 days and was followed by concomitant administration of 300 mg/kg NTiO₂ for 35 days. Control group received only normal saline for 42 days. Sperm parameters, testosterone concentration, histological criteria, and apoptotic index were assessed. Product of lipid peroxidation (MDA), superoxide dismutase (SOD), and catalase (CAT) activities were also evaluated for oxidative stress in testicular tissue. Administration of NTiO₂ significantly induced histological changes in testicular tissue; increased apoptotic index; and decreased testicular weight, testosterone concentration, and sperm quality (p < 0.01). In the testis, NTiO₂ increased oxidative stress through an increase in lipid peroxidation and a decrease in SOD and CAT activities (p < 0.05). Que pretreatment could significantly attenuate testicular weight; apoptotic index; and histological criteria including vacuolization, detachment, and sloughing of germ cells in seminiferous tubules. Serum and tissue testosterone levels were significantly increased in Que-pretreated mice (p < 0.01). Sperm parameters including sperm number, motility, and percentage of abnormality were also effectively improved by Que pretreatment (p < 0.01). Pretreatment of Que significantly ameliorated oxidative stress and increased the activities of SOD and CAT in testicular tissue. These results indicate that sperm production can be increased by Que pretreatment in NTiO₂-intoxicated mice. The improved sperm quality and reverse testis histology by Que pretreatment may be a consequence of elevation testosterone concentration, reduction in germ cell apoptosis, and suppression of oxidative stress in testicular tissue.

Walnut Polyphenol Extract Attenuates Immunotoxicity Induced by 4-Pentylphenol and 3-methyl-4-nitrophenol in Murine Splenic Lymphocyte

4-pentylphenol (PP) and 3-methyl-4-nitrophenol (PNMC), two important components of vehicle emissions, have been shown to confer toxicity in splenocytes. Certain natural products, such as those derived from walnuts, exhibit a range of antioxidative, antitumor, and anti-inflammatory properties. Here, we investigated the effects of walnut polyphenol extract (WPE) on immunotoxicity induced by PP and PNMC in murine splenic lymphocytes. Treatment with WPE was shown to significantly enhance proliferation of splenocytes exposed to PP or PNMC, characterized by increases in the percentages of splenic T lymphocytes (CD3+ T cells) and T cell subsets (CD4+ and CD8+ T cells), as well as the production of T cell-related cytokines and granzymes (interleukin-2, interleukin-4, and granzyme-B) in cells exposed to PP or PNMC. These effects were associated with a decrease in oxidative stress, as evidenced by changes in OH, SOD, GSH-Px, and MDA levels. The total phenolic content of WPE was 34,800 ± 200 mg gallic acid equivalents/100 g, consisting of at least 16 unique phenols, including ellagitannins, quercetin, valoneic acid dilactone, and gallic acid. Taken together, these results suggest that walnut polyphenols significantly attenuated PP and PNMC-mediated immunotoxicity and improved immune function by inhibiting oxidative stress.

Efficacy of Crocus sativus L. on reduction of cadmium-induced toxicity on spermatogenesis in adult rats

Cadmium is a toxic heavy metal element, which probably cause infertility by impairment in spermatogenesis. The present work aimed (i) to study the toxic effect of cadmium on spermatogenesis in rat, as well as (ii) the protective effect of Crocus sativus L. on cadmium-intoxicated rats. Cadmium chloride was administered intraperitoneally during 16 days at intervals of 48 h between subsequent treatments. Crocus sativus L. was pre-treated in both of control and cadmium-injected rats. Animals were sacrificed on day 17 after the first treatment. The left cauda epididymis was removed and immediately immersed into Hank's balanced salt solution for the evaluation of sperm count and viability, and left testis was fixed in 10% formalin for histological evaluation. Following contamination with cadmium, a decrease was observed in the number and viability of cauda epididymis sperm, which were increased by Crocus sativus L. pre-treatment (P < 0.05). In addition, cadmium decreased both cell proliferation and Johnsen Scores in the seminiferous tubules, which were reversed by Crocus sativus pre-treatment (P < 0.05). Furthermore, cadmium-induced decrease in the amount of free serum testosterone as well as an increase in lipid peroxidation activity in the testicular tissue was reversed by Crocus sativus L. (P < 0.05). These findings may support the concept that Crocus sativus L. can improve the cadmium toxicity on spermatogenesis.