Deciphering the molecular mechanism during doxorubicin-mediated oxidative stress, apoptosis through Nrf2 and PGC-1α in a rat testicular milieu

Carbenoxolone upregulates TRAIL\TRAILR2 expression and enhances the anti-neoplastic effect of doxorubicin in experimentally induced hepatocellular carcinoma in rats

AIMS

This study investigates the in vivo anticancer activity of carbenoxolone (CBX) and its role in fighting hepatocellular carcinoma (HCC) progression and alleviating resistance against doxorubicin (DOX). Moreover, the molecular mechanism of action of CBX is explored.

METHODS

HCC was induced in Sprague Dawley rats via biweekly administration of thioacetamide (TAA) (200 mg/kg) intraperitoneally (i.p.) for 16 weeks after administering a single dose of diethylnitrosamine (DEN) (200 mg/kg, i.p.). A prophylactic model was established by treating rats with i.p. CBX (20 mg/kg/day) for 4 weeks starting on week 13 post-TAA injection. A therapeutic model was established by treating rats with CBX, DOX, or their combination for 7 weeks following 16 weeks of TAA administration. Serum Alpha-fetoprotein (AFP) and biochemical markers of hepatic functions were assessed. Histopathological examinations of hepatic tissues were performed. Immunohistochemical and qRT-PCR analyses were applied to assess the differential expressions of TRAIL/TRAILR2, Bcl-2, TGF-β1, and caspases 3, 8, and 9.

RESULTS

CBX markedly improved hepatic functions, reduced serum AFP levels, and alleviated TAA-induced hepatic histopathological alterations. CBX triggered apoptosis as evident by upregulating apoptotic markers: TRAIL/TRAILR2, caspases 3, 8, and 9, and downregulating the antiapoptotic protein Bcl-2. CBX downregulated TGF-β1. Interestingly, CBX/DOX combination mitigated hepatic damage and induced apoptosis in a way that surpassed DOX-only treatment.

CONCLUSION

The current study proposes that CBX is a promising anti-tumor compound, which can work effectively under prophylactic and therapeutic modes. Interestingly, CBX enhanced the anti-tumor effect of DOX. CBX exerted these effects via, in part, stimulating TRAIL-induced apoptosis along with attenuating fibrosis.

Characterization of a new model of chemotherapy-induced heart failure with reduced ejection fraction and nephrotic syndrome in Ren-2 transgenic rats

All anthracyclines, including doxorubicin (DOXO), the most common and still indispensable drug, exhibit cardiotoxicity with inherent risk of irreversible cardiomyopathy leading to heart failure with reduced ejection fraction (HFrEF). Current pharmacological strategies are clearly less effective for this type of HFrEF, hence an urgent need for new therapeutic approaches. The prerequisite for success is thorough understanding of pathophysiology of this HFrEF form, which requires an appropriate animal model of the disease. The aim of this study was to comprehensively characterise a novel model of HF with cardiorenal syndrome, i.e. DOXO-induced HFrEF with nephrotic syndrome, in which DOXO was administered to Ren-2 transgenic rats (TGR) via five intravenous injections in a cumulative dose of 10 mg/kg of body weight (BW). Our analysis included survival, echocardiography, as well as histological examination of the heart and kidneys, blood pressure, but also a broad spectrum of biomarkers to evaluate cardiac remodelling, fibrosis, apoptosis, oxidative stress and more. We have shown that the new model adequately mimics the cardiac remodelling described as "eccentric chamber atrophy" and myocardial damage typical for DOXO-related cardiotoxicity, without major damage of the peritoneum, lungs and liver. This pattern corresponds well to a clinical situation of cancer patients receiving anthracyclines, where HF develops with some delay after the anticancer therapy. Therefore, this study may serve as a comprehensive reference for all types of research on DOXO-related cardiotoxicity, proving especially useful in the search for new therapeutic strategies.

Protective effect of Chlorella vulgaris on testicular damage, sperm parameters, androgen production, apoptosis and oxidative stress index in male rats following doxorubicin administration

Doxorubicin (DOX) is a chemotherapy agent associated with adverse effects on male reproductive health. Chlorella vulgaris (ChV) is a potent natural antioxidant with promising applications in maintaining health and preventing oxidative stress-related diseases. The present study aimed to investigate the protective effect of ChV on DOX-induced testicular toxicity. Twenty-five Wistar rats (230 ± 20 g) were randomly assigned to five groups (n = 5), including the control group, sham group (received normal saline by oral gavage daily and intraperitoneally (IP) once a week), DOX group (3 mg/kg; once a week; IP), ChV group (300 mg/kg/day; by oral gavage), and DOX (3 mg/kg; once a week; IP) + ChV (300 mg/kg/day; by oral gavage) group. After 8 weeks of treatment, the rats were euthanized and serum testosterone level, testes histomorphometry, gonadosomatic index (GSI), apoptotic gene expression, oxidative stress index, and sperm parameters were assessed. The results showed that DOX led to a significant decrease in histological indexes, testosterone level, GSI, sperm parameters, and Bcl-2 gene expression and increased expression of P-53 and Bax genes, and oxidative stress markers (P<0.05). The administration of ChV in the DOX+ChV group significantly improved testosterone levels, sperm parameters, testicular tissue apoptosis, antioxidant enzymes, and structural integrity of the testes (P<0.05). The findings suggest that the co-administration of ChV can be a promising therapeutic agent to reduce the adverse effects of DOX on male reproductive performance.

Donepezil and quercetin alleviate valproate-induced testicular oxidative stress, inflammation and apoptosis: Imperative roles of AMPK/SIRT1/ PGC-1α and p38-MAPK/NF-κB/ IL-1β signaling cascades

The mounting evidence of valproate-induced testicular damage in clinical settings is alarming, especially for men taking valproate (VPA) for long-term or at high doses. Both donepezil (DON) and quercetin (QUE) have promising antioxidant, anti-inflammatory, and anti-apoptotic effects. Therefore, this study aimed to determine whether DON, QUE, and their combination could mitigate VPA-induced testicular toxicity and unravel the mechanisms underlying their protective effect. In this study, male albino rats were randomly categorized into six equal groups: control, VPA (500 mg/kg, I.P., for 14 days), DON (3 and 5 mg/kg), QUE (50 mg/kg), and DON 3 + QUE combination groups. The DON and QUE treatments were administered orally for 7 consecutive days before VPA administration and then concomitantly with VPA for 14 days. VPA administration disrupted testicular function by altering testicular architecture, ultrastructure, reducing sperm count, viability, and serum testosterone levels. Additionally, VPA triggered oxidative damage, inflammatory, and apoptotic processes and suppressed the AMPK/SIRT1/PGC-1α signaling cascade. Pretreatment with DON, QUE, and their combination significantly alleviated histological and ultrastructure damage caused by VPA and increased the serum testosterone level, sperm count, and viability. They also suppressed the oxidative stress by reducing testicular MDA content and elevating SOD activity. In addition, they reduced the inflammatory response by suppressing IL-1β level, NF-κB, and the p38-MAPK expression as well as inhibiting apoptosis by diminishing caspase-3 and increasing Bcl-2 expression. These novel protective effects were mediated by upregulating AMPK/SIRT1/PGC-1α signaling cascade. In conclusion, these findings suggest that DON, QUE, and their combination possess potent protective effects against VPA-induced testicular toxicity.

Bioactive Compounds Protect Mammalian Reproductive Cells from Xenobiotics and Heat Stress-Induced Oxidative Distress via Nrf2 Signaling Activation: A Narrative Review

Oxidative stress occurs when there is an imbalance between the production of reactive oxygen species (ROS) and the body's antioxidant defenses. It poses a significant threat to the physiological function of reproductive cells. Factors such as xenobiotics and heat can worsen this stress, leading to cellular damage and apoptosis, ultimately decreasing reproductive efficiency. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway plays a crucial role in defending against oxidative stress and protecting reproductive cells via enhancing antioxidant responses. Dysregulation of Nrf2 signaling has been associated with infertility and suboptimal reproductive performance in mammals. Recent advancements in therapeutic interventions have underscored the critical role of Nrf2 in mitigating oxidative damage and restoring the functional integrity of reproductive cells. In this narrative review, we delineate the harmful effects of heat and xenobiotic-induced oxidative stress on reproductive cells and explain how Nrf2 signaling provides protection against these challenges. Recent studies have shown that activating the Nrf2 signaling pathway using various bioactive compounds can ameliorate heat stress and xenobiotic-induced oxidative distress and apoptosis in mammalian reproductive cells. By comprehensively analyzing the existing literature, we propose Nrf2 as a key therapeutic target for mitigating oxidative damage and apoptosis in reproductive cells caused by exposure to xenobiotic exposure and heat stress. Additionally, based on the synthesis of these findings, we discuss the potential of therapies focused on the Nrf2 signaling pathway to improve mammalian reproductive efficiency.

The mechanistic interplay between Nrf-2, NF-κB/MAPK, caspase-dependent apoptosis, and autophagy in the hepatoprotective effects of Sophorolipids produced by microbial conversion of banana peels using Saccharomyces cerevisiae against doxorubicin-induced hepatotoxicity in rats

BACKGROUND

Doxorubicin (DOX) is a well-known chemotherapeutic agent which causes serious adverse effects due to multiple organ damage, including cardiotoxicity, nephrotoxicity, neurotoxicity, and hepatotoxicity. The mechanism of DOX-induced organ toxicity might be attributed to oxidative stress (OS) and, consequently, activation of inflammatory signaling pathways, apoptosis, and blockage of autophagy. Sophorolipids (SLs) as a glycolipid type of biosurfactants, are natural products that have unique properties and a wide range of applications attributed to their antioxidant and anti-inflammatory properties.

AIMS

Production of low-cost SLs from Saccharomyces cerevisiae grown on banana peels and investigating their possible protective effects against DOX-induced hepatotoxicity.

MAIN METHODS

The yeast was locally isolated and molecularly identified, then the yielded SLs were characterized by FTIR, 1H NMR and LC-MS/MS spectra. Posteriorly, thirty-two male Wistar rats were randomly divided into four groups; control (oral saline), SLs (200 mg/kg, p.o), DOX (10 mg/kg; i.p.), and SL + DOX (200 mg/kg p.o.,10 mg/kg; i.p., respectively). Liver function tests (LFTs), oxidative stress, inflammatory, apoptosis as well as autophagy markers were investigated.

KEY FINDINGS

SLs were produced with a yield of 49.04% and treatment with SLs improved LFTs, enhanced Nrf2 and suppressed NF-κB, IL-6, IL-1β, p38, caspase 3 and Bax/Bcl2 ratio in addition to promotion of autophagy when compared to DOX group.

SIGNIFICANCE

Our results revealed a novel promising protective effect of SLs against DOX-induced hepatotoxicity in rats.

N-Acetylcysteine May Regulate Altered Meteorin-Like Levels in Testicular Tissue due to Aluminum Exposure

Aluminum (AL) is a heavy metal known to have toxic effects on the reproductive system. It is known that N-acetylcysteine (NAC), which has an antioxidant effect, is a useful chelator for heavy metals. This study aimed to determine whether NAC may reduce AL-induced oxidative stress, inflammation, and germ cell apoptosis in testicular tissues and its effects on meteorin-like (METRNL) levels, which are known to play a role in energy metabolism. In this experimental study, 28 Sprague-Dawley male rats were randomly divided into 4 groups (n = 7): control, AL (30 mg/kg/day AL), AL + NAC (30 mg/kg/day AL + 150 mg/kg/day NAC), and NAC (150 mg/kg/day NAC). All AL and NAC applications were performed intraperitoneally for 14 days. At the end of the experiment, the effects of AL and/or NAC applications on testicular tissue were examined histomorphometrically, histopathologically, immunohistochemically, and biochemically. It was determined that AL exposure caused histomorphometric and histopathological changes, oxidative stress, apoptosis of germ cells, and inflammation in testicular tissues. In addition, AL caused an increase in METRNL levels. It was determined that NAC treatment significantly reduced the negative effects of AL. NAC therapy may be a protective strategy in reproductive toxicity due to AL exposure.

Modulatory effect of liraglutide on doxorubicin-induced testicular toxicity and behavioral abnormalities in rats: role of testicular-brain axis

Doxorubicin (DOX) is a powerful chemotherapeutic agent used in many types of malignancies. However, its use results in testicular damage. DOX-induced testicular damage results in low level of serum testosterone which may affect cognitive function. The current study investigated the protective effect of liraglutide (50, 100 μg/kg/day) in testicular toxicity and the consequent cognitive impairment induced by DOX. DOX treatment reduced sperm count (62%) and sperm motility (53%) and increased sperm abnormalities (786%), as compared to control group. DOX also reduced serum testosterone level (85%) and the gene expression of testicular 3β-HSD (68%) and 17β-HSD (82%). Moreover, it increased testicular oxidative stress (MDA and GSH) by 103% and 59%, respectively, apoptotic (caspase-3 and P53) by 996% and 480%, respectively. In addition, DOX resulted in increasing autophagic markers including PAKT, mTOR, and LC3 by 48%, 56%, and 640%, respectively. Additionally, rats' behavior in Y-maze (60%) and passive avoidance task (85%) was disrupted. The histopathological results of testis and brain supported the biochemical findings. Treatment with liraglutide (100 μg/kg/day) significantly abrogated DOX-induced testicular damage by restoring testicular architecture, increasing sperm count (136%) and sperm motility (106%), and decreasing sperm abnormalities (84%) as compared to DOX group. Furthermore, liraglutide increased serum testosterone (500%) and steroidogenesis enzymes 3β-HSD (105%) and 17β-HSD (181%) along with suppressing oxidative stress (MDA and GSH) by 23% and 85%, respectively; apoptotic (caspase-3 and P53) by 59% and55%, respectively; and autophagic markers including PAKT, mTOR, and LC3 by 48%, 97%, and 60%, respectively. Moreover, it enhanced the memory functions in passive avoidance and Y-maze tests (132%). In conclusion, liraglutide is a putative agent for protection against DOX-induced testicular toxicity and cognitive impairment through its antioxidant, antiapoptotic, and antiautophagic effects.

Chemotherapy-Mediated Neuronal Aberration

Chemotherapy is a life-sustaining therapeutic option for cancer patients. Despite the advancement of several modern therapies, such as immunotherapy, gene therapy, etc., chemotherapy remains the first-line therapy for most cancer patients. Along with its anti-cancerous effect, chemotherapy exhibits several detrimental consequences that restrict its efficacy and long-term utilization. Moreover, it effectively hampers the quality of life of cancer patients. Cancer patients receiving chemotherapeutic drugs suffer from neurological dysfunction, referred to as chemobrain, that includes cognitive and memory dysfunction and deficits in learning, reasoning, and concentration ability. Chemotherapy exhibits neurotoxicity by damaging the DNA in neurons by interfering with the DNA repair system and antioxidant machinery. In addition, chemotherapy also provokes inflammation by inducing the release of various pro-inflammatory cytokines, including NF-kB, IL-1β, IL-6, and TNF-α. The chemotherapy-mediated inflammation contributes to chemobrain in cancer patients. These inflammatory cytokines modulate several growth signaling pathways and reactive oxygen species homeostasis leading to systemic inflammation in the body. This review is an effort to summarize the available information which discusses the role of chemotherapy-induced inflammation in chemobrain and how it impacts different aspects of therapeutic outcome and the overall quality of life of the patient. Further, this article also discusses the potential of herbal-based remedies to overcome chemotherapy-mediated neuronal toxicity as well as to improve the quality of life of cancer patients.

Attenuation of doxorubicin-induced hypothalamic-pituitary-testicular axis dysfunction by diphenyl diselenide involves suppression of hormonal deficits, oxido-inflammatory stress and caspase 3 activity in rats

BACKGROUND

Doxorubicin (DOX) is one of the popular anti-cancer drugs in the world and several literatures have implicated it in various toxicities especially cardiotoxicity and reproductive toxicity. Diphenyl diselenide (DPDS) is well acknowledged for its compelling pharmacological effects in numerous disease models and chemically-mediated toxicity. This study was carried out to investigate the effect of DPDS on DOX-induced changes in the reproductive indices of male Wistar rats.

METHODS

Rats were intraperitoneally injected with 7.5 mg/kg body weight of DOX alone once followed by treatment with DPDS at 5 and 10 mg/kg for seven successive days. Excised hypothalamus, testes and epididymis were processed for biochemical and histological analyses.

RESULTS

DPDS treatment significantly (p < 0.05) abated DOX-induced oxidative damage by decreasing the levels of oxidative stress indices such as hydrogen peroxide, reactive oxygen and nitrogen species, and lipid peroxidation with a respective improvement in the level of glutathione in the hypothalamic, testicular and epididymal tissues of DOX-treated rats. The activities of antioxidant enzymes such as catalase, superoxide dismutase, glutathione S-transferase and glutathione peroxidase were upregulated in the DPDS co-treated group. DPDS co-treatment alleviates the burden of DOX-induced inflammation by significant reductions in myeloperoxidase activity, levels of nitric oxide and tumor necrosis factor alpha with concomitant decline in the activity of caspase-3, an apoptotic biomarker. Consequently, significant improvement in the spermiogram, levels of reproductive hormones (follicle stimulating hormone, luteinizing hormone, prolactin, serum testosterone and intra-testicular testosterone) levels in the DPDS co-treatment group in comparison to DOX alone-treated group were observed. Histology results of the testes and epididymis showed that DPDS significantly alleviated pathological lesions induced by DOX in the animals.

CONCLUSION

DPDS may modulate reproductive toxicity associated with DOX therapy in male cancer patients.

Lycopene ameliorates aflatoxin B1-induced testicular lesion by attenuating oxidative stress and mitochondrial damage with Nrf2 activation in mice

Aflatoxin B₁ (AFB₁) is an extremely hazardous and unavoidable pollutant for cereals and feedstuff. AFB₁ can cause testicular lesion, and how to alleviate its testicular toxicity has received much attention in recent years. Lycopene (LYC), a foodborne nutrient derived from red fruits and vegetables, has protective effects against sperm abnormality and testicular lesions. To confirm the beneficial effects and mechanisms of LYC on AFB₁-induced testicular lesion, 48 male mice were exposed to 0.75 mg/kg AFB₁ or/and 5 mg/kg LYC for consecutive 30 days. Results demonstrated the LYC significantly restored the lesions of testicular microstructure and ultrastructure, and sperm abnormalities in AFB₁-exposed mice. Furthermore, LYC effectively attenuated AFB₁-induced oxidative stress and mitochondrial damage, including ameliorative mitochondrial structural, and elevated mitochondrial biogenesis for maintaining mitochondrial function. Meanwhile, LYC resisted AFB₁-induced mitochondrial-dependent apoptosis. In addition, LYC promoted nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation, and upregulated the Nrf2 signaling pathway. Collectively, our findings demonstrate LYC ameliorates AFB₁-induced testicular lesion by attenuating oxidative stress and mitochondrial damage, which is related to the activation of Nrf2.

Effect of troxerutin on the expression of genes regulating mitochondrial biogenesis and microRNA-140 in doxorubicin-induced testicular toxicity

Background

Application of doxorubicin (DOX) in cancer patients is limited due to its dose-dependent toxicity to nontarget tissues such as testis and subsequent infertility. Due to limitation of our knowledge about the mechanisms of DOX toxicity in the reproductive system, reduction of DOX-induced testicular toxicity remains an actual and primary clinical challenge. Considering the potentials of troxerutin (TXR) in generating a protective phenotype in many tissues, we aimed to examine the effect of TXR on DOX-induced testicular toxicity by evaluating the histological changes and the expression of mitochondrial biogenesis genes and microRNA-140 (miR-140).

Materials and Methods

Twenty-four adult male Wistar rats (250-300 g) were divided in groups with/without DOX and/or TXR. DOX was injected intraperitoneally at 6 consecutive doses over 12 days (cumulative dose: 12 mg/kg). TXR (150 mg/kg/day; orally) was administered for 4 weeks before DOX challenge. One week after the last injection of DOX, testicular histopathological changes, spermatogenesis activity, and expression of mitochondrial biogenesis genes and miR-140 were determined.

Results

DOX challenge significantly increased testicular histopathological changes, decreased testicular expression profiles of sirtuin 1 (SIRT-1) and nuclear respiratory factor-2 (NRF-2), and increased expression of miR-140 (P < 0.05 to P < 0.01). Pretreatment of DOX-received rats with TXR significantly reversed testicular histopathological changes, spermatogenesis activity index, and the expression levels of SIRT-1, peroxisome proliferator-activated receptor-γ coactivator 1-alpha (PGC-1α), NRF-2, and miR-140 (P < 0.05 to P < 0.01).

Conclusion

Reduction of DOX-induced testicular toxicity following TXR pretreatment was associated with upregulation of SIRT-1/PGC-1α/NRF-2 profiles and better regulation of miR-140 expression. It seems that improving microRNA-mitochondrial biogenesis network can play a role in the beneficial effect of TXR on DOX-induced testicular toxicity.

α-Bisabolol Attenuates NF-κB/MAPK Signaling Activation and ER-Stress-Mediated Apoptosis by Invoking Nrf2-Mediated Antioxidant Defense Systems against Doxorubicin-Induced Testicular Toxicity in Rats

The present study investigated the effects of α-bisabolol on DOX-induced testicular damage in rats. Testicular damage was induced in rats by injecting DOX (12.5 mg/kg, i.p., single dose) into rats. α-Bisabolol (25 mg/kg, i.p.) was administered to the rats along with DOX pre- and co-treatment daily for a period of 5 days. DOX-injected rats showed a decrease in absolute testicular weight and relative testicular weight ratio along with concomitant changes in the levels/expression levels of oxidative stress markers and Nrf2 expression levels in the testis. DOX injection also triggered the activation of NF-κB/MAPK signaling and increased levels/expression levels of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) and inflammatory mediators (iNOS and COX-2) in the testis. DOX triggered apoptosis, manifested by an increment in the expression levels of pro-apoptotic markers (Bax, Bcl2, cleaved caspase-3 and -9, and cytochrome-C) and a decline in the expression levels of anti-apoptotic markers (Bcl-xL and Bcl2) in the testis. Additionally, light microscopy revealed the changes in testicular architecture. α-Bisabolol rescued alterations in the testicular weight; restored all biochemical markers; modulated the expression levels of Nrf2-mediated antioxidant responses, NF-κB/MAPK signaling, endoplasmic reticulum (ER) stress, and apoptosis markers in DOX-injected testicular toxicity in rats. Based on our findings, it can be concluded that α-bisabolol has the potential to attenuate DOX-induced testicular injury by modifying NF-κB/MAPK signaling and the ER-stress-mediated mitochondrial pathway of apoptosis by invoking Nrf2-dependent antioxidant defense systems in rats. Based on the findings of the present study, α-bisabolol could be suggested for use as an agent or adjuvant with chemotherapeutic drugs to attenuate their deleterious effects of DOX on many organs including the testis. However, further regulatory toxicology and preclinical studies are necessary before making recommendations in clinical tests.

Exploring Nrf2 as a therapeutic target in testicular dysfunction

Testicular dysfunction, a major contributory factor to infertility, has received a lot of attention over the recent years. Several studies have linked abnormal sperm function and morphology with an enhanced generation of reactive oxygen species (ROS) and oxidative stress. The nuclear factor erythroid-derived 2 (Nrf2) is a transcriptional response to cellular stresses (intrinsic or extrinsic) that regulates the oxidative status, mitochondrial dysfunction, inflammation, and proteostasis. In this review, the therapeutic role of Nrf2 was explored. To do so, scientific data were retrieved from databases such as Elsevier, Wiley, Web of Science, Springer, PubMed, Taylor and Francis, and Google Scholar using search terms such as "Nrf2" and "testis," "sperm," "testicular function," and "testosterone." It has been noted that Nrf2 influences the physiology and pathology of testicular dysfunction, especially in the spermatogenic process, by regulating cellular resistance to oxidative stress, inflammation, and environmental toxicants. However, numerous compounds serve as activators and inhibitors of testicular Nrf2. Nrf2 activators might play a therapeutic role in the prevention and treatment of testicular dysfunction, while molecules that inhibit Nrf2 might induce dysfunction in testis components. Nrf2 activators protect cells against oxidative damage and activate Nrf2/KEAP1 signaling which promotes its movement to the nucleus, and increased Nrf2 function and expression, along with their downstream antioxidant gene. Nrf2 inhibitors facilitate oxidative stress via interfering with the Nrf2 signal pathway. The Nrf2 activation could serve as a promising therapeutic target for testicular dysfunction. This review explored the effect of Nrf2 on testicular function while highlighting potential activators and inhibitors of Nrf2.

Heavy metal and metalloid - induced reproductive toxicity

Heavy metals and metalloid exposure are among the most common factors responsible for reproductive toxicity in human beings. Several studies have indicated that numerous metals and metalloids can display severe adverse properties on the human reproductive system. Metals like lead, silver, cadmium, uranium, vanadium, and mercury and metalloids like arsenic have been known to induce reproductive toxicity. Moderate to minute quantities of lead may affect several reproductive parameters and even affect semen quality. The ecological and industrial exposures to the various heavy metals and metalloids have disastrous effects on the reproductive system ensuing in infertility. This work emphasizes the mechanism and pathophysiology of the aforementioned heavy metals and metalloids in reproductive toxicity. Additionally, this work aims to cover the classical protective mechanisms of zinc, melatonin, chelation therapy, and other trending methods to prevent heavy metal-induced reproductive toxicity.

Exploring the Pattern of Metabolic Alterations Causing Energy Imbalance via PPARα Dysregulation in Cardiac Muscle During Doxorubicin Treatment

Cardiotoxicity by anthracycline antineoplastic drug doxorubicin is one of the systemic toxicity of the cardiovascular system. The mechanism responsible for doxorubicin cardiotoxicity and lipid metabolism remains elusive. The current study tested the hypotheses that the role of peroxisome proliferator-activated receptor α (PPARα) in the progress of doxorubicin-induced cardiomyopathy and its mechanism behind lipid metabolism. In the present study, male rats were subjected to intraperitoneal injection (5-week period) of doxorubicin with different dosages such as low dosage (1.5 mg/kg body weight) and high dosage (15 mg/kg body weight) to induce doxorubicin cardiomyopathy. Myocardial PPARα was impaired in both low dosage and high dosage of doxorubicin-treated rats in a dose-dependent manner. The attenuated level of PPARα impairs the expression of the genes involved in mitochondrial transporter, fatty acid transportation, lipolysis, lipid metabolism, and fatty acid oxidation. Moreover, it disturbs the reverse triacylglycerol transporter apolipoprotein B-100 (APOB) in the myocardium. Doxorubicin elevates the circulatory lipid profile and glucose. Further aggravated lipid profile in circulation impedes the metabolism of lipid in cardiac tissue, which causes a lipotoxic condition in the heart and subsequently associated disease for the period of doxorubicin treatment. Elevated lipids in the circulation translocate into the heart dysregulates lipid metabolism in the heart, which causes augmented oxidative stress and necro-apoptosis and mediates lipotoxic conditions. This finding determines the mechanistic role of doxorubicin-disturbed lipid metabolism via PPARα, which leads to cardiac dysfunction.

Effects of chemotherapeutic agents on male germ cells and possible ameliorating impact of antioxidants

Treatment of cancer in young adults is associated with several side effects, particularly in the reproductive system. Detrimental effects of chemotherapy on the germ cells depend on many factors including primary semen parameters, the way of drug administration, the kind and dose of chemotherapeutic regimens, and the phase of spermatogenesis during the time of drug administration. Lack of appropriate fertility preservation treatments particularly in the affected children necessitates the introduction of methods to amend the harmful effects of chemotherapeutic agents on male germ cells. Several studies have assessed the toxic effects of chemotherapeutic agents in rodent models and tested a number of antioxidants to evaluate their possible impact on the preservation of sperm cells. In the present manuscript, we describe the effects of the mostly investigated chemotherapeutic drugs in this regard i.e., cisplatin, doxorubicin, paclitaxel, 5-fluorouracil, and cyclophosphamide. As several in vivo and in vitro studies have shown the impact of antioxidants on chemotherapy-induced damage of sperms, we also describe the protective effects of antioxidants in this regard.

Nuciferine Attenuates Doxorubicin-Induced Cardiotoxicity: An In Vitro and In Vivo Study

Chemotherapeutic drugs are a known factor that impairs the system of life due to their severe side effects. A more worrying fact is that the patients administered with doxorubicin fall under the risk of cardiotoxicity. The evolution of exploring plant-derived compounds is a possible way to combat health issues in therapeutic applications. Hence, this study focuses on the protective effect of plant-based compound nuciferine (NFN) against doxorubicin-induced cardiotoxicity in both in vitro and in vivo models. In this investigation, nuciferine significantly reduces DOX-mediated cardiotoxicity by mitigating reactive oxygen species, thereby preventing DNA fragmentation, regulating apoptosis genes and reducing the caspase 3/7 levels in vitro. Besides, nuciferine has shown significant protection against DOX-induced cardiac impairment and the upregulation of cardiogenic markers in vivo. The DOX-induced oxidative stress can be mitigated via enhancing the endogenous antioxidants, thereby controlling ROS-mediated apoptosis. In virtue of these potential features, nuciferine can be a budding candidate to address therapeutic needs.

Metabolomic Identification of Anticancer Metabolites of Australian Propolis and Proteomic Elucidation of Its Synergistic Mechanisms with Doxorubicin in the MCF7 Cells

The combination of natural products with standard chemotherapeutic agents offers a promising strategy to enhance the efficacy or reduce the side effects of standard chemotherapy. Doxorubicin (DOX), a standard drug for breast cancer, has several disadvantages, including severe side effects and the development of drug resistance. Recently, we reported the potential bioactive markers of Australian propolis extract (AP-1) and their broad spectrum of pharmacological activities. In the present study, we explored the synergistic interactions between AP-1 and DOX in the MCF7 breast adenocarcinoma cells using different synergy quantitation models. Biochemometric and metabolomics-driven analysis was performed to identify the potential anticancer metabolites in AP-1. The molecular mechanisms of synergy were studied by analysing the apoptotic profile via flow cytometry, apoptotic proteome array and measuring the oxidative status of the MCF7 cells treated with the most synergistic combination. Furthermore, label-free quantification proteomics analysis was performed to decipher the underlying synergistic mechanisms. Five prenylated stilbenes were identified as the key metabolites in the most active AP-1 fraction. Strong synergy was observed when AP-1 was combined with DOX in the ratio of 100:0.29 (w/w) as validated by different synergy quantitation models implemented. AP-1 significantly enhanced the inhibitory effect of DOX against MCF7 cell proliferation in a dose-dependent manner with significant inhibition of the reactive oxygen species (p < 0.0001) compared to DOX alone. AP-1 enabled the reversal of DOX-mediated necrosis to programmed cell death, which may be advantageous to decline DOX-related side effects. AP-1 also significantly enhanced the apoptotic effect of DOX after 24 h of treatment with significant upregulation of catalase, HTRA2/Omi, FADD together with DR5 and DR4 TRAIL-mediated apoptosis (p < 0.05), contributing to the antiproliferative activity of AP-1. Significant upregulation of pro-apoptotic p27, PON2 and catalase with downregulated anti-apoptotic XIAP, HSP60 and HIF-1α, and increased antioxidant proteins (catalase and PON2) may be associated with the improved apoptosis and oxidative status of the synergistic combination-treated MCF7 cells compared to the mono treatments. Shotgun proteomics identified 21 significantly dysregulated proteins in the synergistic combination-treated cells versus the mono treatments. These proteins were involved in the TP53/ATM-regulated non-homologous end-joining pathway and double-strand breaks repairs, recruiting the overexpressed BRCA1 and suppressed RIF1 encoded proteins. The overexpression of UPF2 was noticed in the synergistic combination treatment, which could assist in overcoming doxorubicin resistance-associated long non-coding RNA and metastasis of the MCF7 cells. In conclusion, we identified the significant synergy and highlighted the key molecular pathways in the interaction between AP-1 and DOX in the MCF7 cells together with the AP-1 anticancer metabolites. Further in vivo and clinical studies are warranted on this synergistic combination.

Nuciferine from Nelumbo nucifera Gaertn. attenuates isoproterenol-induced myocardial infarction in Wistar rats

The study explored the cardioprotective role of the methanolic leaf extract of Nelumbo nucifera and nuciferine against isoproterenol-induced myocardial infarction (MI) in Wistar rats. Pretreatment with leaf extract and nuciferine (200 and 20 mg/kg body weight, respectively) against MI induced by isoproterenol (85 mg/kg body weight) significantly decreased heart weight; levels of cardiac markers such as lactate dehydrogenase and creatine kinase-MB were similar to those in controls. The treatment significantly increased the content of endogenous antioxidants and decreased lipid peroxidation in all treated groups. Treated groups showed a significant reduction in heartbeats per minute as compared with the MI-induced positive control. The MI-induced group showed pathological implications such as tachycardia, left atrial enlargement, and anterolateral ST-elevated MI, which were absent in treated groups. Histology confirmed that the leaf extract and nuciferine prevented structural abnormality and inflammation in heart and liver tissues of treated groups. On in silico analysis, nuciferine showed stronger binding interaction with both β₁ and β₂ adrenergic receptors than isoproterenol. Hence, the leaf extract of N. nucifera and nuciferine could be used as plant-based cardioprotective agents.

Mechanisms of doxorubicin-mediated reproductive toxicity - A review

The anticancer drug doxorubicin has been associated with several adverse side-effects including reproductive toxicity in both genders. The current review has complied the mechanisms of doxorubicin induced reproductive toxicity. The articles cited in the review were searched using Google Scholar, PubMed, Scopus, Science Direct. Doxorubicin treatment has been found to cause a decrease in testicular mass along with histopathological deformities, oligospermia and abnormalities in sperm morphology. Apart from severely affecting the normal physiological role of both Leydig cells and Sertoli cells, doxorubicin also causes chromosome abnormalities and affects DNA methylase enzyme. Testicular lipid metabolism has been found to be negatively affected by doxorubicin treatment resulting in altered profile of sphingolipids glycerophospholipids and neutral lipids. Dysregulation of 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β- hydroxysteroid dehydrogenase (17β-HSD) are strongly linked to testicular exposure to doxorubicin. Further, oxidative stress along with endoplasmic reticulum stress are also found to aggravate the male reproductive functioning in doxorubicin treated conditions. Several antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase (GPx) are downregulated by doxorubicin. It also disturbs the hormones of the hypothalamic-pituitary-gonadal (HPG)-axis including testosterone, luteinizing hormone, follicle stimulating hormone etc. In females, the drug disturbs folliculogenesis and oogenesis leading to failure of ovulation and uterine cycle. In rodent model the drug shortens pro-estrous and estrous phases. It was also found that doxorubicin causes mitochondrial dysfunction in oocytes with impaired calcium signaling along with ER stress. The goal of the present review is to comprehends various pathways due to which doxorubicin treatment promotes toxicity in male and female reproductive system.

Nrf2 Signaling Pathway in Chemoprotection and Doxorubicin Resistance: Potential Application in Drug Discovery

Doxorubicin (DOX) is extensively applied in cancer therapy due to its efficacy in suppressing cancer progression and inducing apoptosis. After its discovery, this chemotherapeutic agent has been frequently used for cancer therapy, leading to chemoresistance. Due to dose-dependent toxicity, high concentrations of DOX cannot be administered to cancer patients. Therefore, experiments have been directed towards revealing underlying mechanisms responsible for DOX resistance and ameliorating its adverse effects. Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling is activated to increase levels of reactive oxygen species (ROS) in cells to protect them against oxidative stress. It has been reported that Nrf2 activation is associated with drug resistance. In cells exposed to DOX, stimulation of Nrf2 signaling protects cells against cell death. Various upstream mediators regulate Nrf2 in DOX resistance. Strategies, both pharmacological and genetic interventions, have been applied for reversing DOX resistance. However, Nrf2 induction is of importance for alleviating side effects of DOX. Pharmacological agents with naturally occurring compounds as the most common have been used for inducing Nrf2 signaling in DOX amelioration. Furthermore, signaling networks in which Nrf2 is a key player for protection against DOX adverse effects have been revealed and are discussed in the current review.

Comparison of the protective effects of curcumin and caffeic acid phenethyl ester against doxorubicin-induced testicular toxicity

Whether testicular toxicity is mediated by matrix metalloproteinases (MMPs) is an important question that has not been examined. This study investigated the suppressive effect of curcumin and caffeic acid phenethyl ester (CAPE) on oxidative stress, apoptosis, and whether MMPs mediate doxorubicin (DOX)-induced testicular injury. Male rats were randomly divided into eight groups (n = 8 per group). The groups were as follows: sham, dimethyl sulphoxide (100 µL), DOX (3 mg/kg), CAPE (2.68 mg/kg), curcumin (30 mg/kg), DOX+CAPE (3 mg/kg DOX and 2.68 mg/kg CAPE), DOX+curcumin (3 mg/kg DOX and 30 mg/kg curcumin) and DOX+CAPE+curcumin (3 mg/kg DOX, 2.68 mg/kg CAPE and 30 mg/kg curcumin). Injections were administered daily for 21 days. The oxidative stress, MMPs, proinflammatory cytokines and apoptotic markers in the DOX group were higher than the sham group (p < .05); these measures were lower in the groups treated with CAPE and curcumin together with DOX compared with the DOX group (p < .05). The results showed that MMPs mediated DOX-induced testicular injury, but CAPE and especially curcumin suppressed testis injury and cell apoptosis by suppressing DOX-induced increases in MMPs, oxidative stress and proinflammatory cytokines. However, curcumin exhibited more pronounced effects than CAPE in terms of all studied parameters.

Regulation of CAR and PXR Expression in Health and Disease

Pregnane X receptor (PXR, NR1I2) and constitutive androstane receptor (CAR, NR1I3) are members of the nuclear receptor superfamily that mainly act as ligand-activated transcription factors. Their functions have long been associated with the regulation of drug metabolism and disposition, and it is now well established that they are implicated in physiological and pathological conditions. Considerable efforts have been made to understand the regulation of their activity by their cognate ligand; however, additional regulatory mechanisms, among which the regulation of their expression, modulate their pleiotropic effects. This review summarizes the current knowledge on CAR and PXR expression during development and adult life; tissue distribution; spatial, temporal, and metabolic regulations; as well as in pathological situations, including chronic diseases and cancers. The expression of CAR and PXR is modulated by complex regulatory mechanisms that involve the interplay of transcription factors and also post-transcriptional and epigenetic modifications. Moreover, many environmental stimuli affect CAR and PXR expression through mechanisms that have not been elucidated.

Dissecting Chemical Composition and Cardioprotective Effects of Fuzhengkangfu Decoction against Doxorubicin-Induced Cardiotoxicity by LC-MS and Bioinformatics Approaches

Cardiotoxicity of doxorubicin (DOX) has gained increasing attention in clinical application. Fuzhengkangfu (FZK) decoction, a traditional Chinese herbal formula of replenishing Qi strengthening spleen, has been used to treat various cardiovascular diseases. However, the chemical composition, the protective effects of FZK, and the underlying mechanisms are yet unclear. In this study, an high-performance liquid chromatography-mass spectrometry (HPLC-MS) analytical method was established for the structural identification of constituents in FZK extracts. Target prediction and enrichment analysis of the identified ingredients were performed. The cell viability was measured via (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) (MTT) assay. The protective effects of FZK on cell survival, mitochondrial membrane potential, intracellular calcium homeostasis, and cell apoptosis were detected. The level of relevant proteins was measured by Western blot. The effect of FZK on the antitumor activity of DOX was evaluated in HeLa cells. A total of 42 major chemical constituents were identified in FZK extracts by HPLC-MS. A comprehensive target prediction of these constituents retrieved 46 pathways, of which several key pathways were related to mitochondrial dysfunction, including metabolic pathways and calcium signaling pathways. Furthermore, FZK ameliorated DOX-induced H9C2 cell apoptosis and increased the Bcl-2/Bax ratio. Also, it moderated the loss of mitochondrial membrane potential and reduced the intracellular calcium overload, which are the major targets of DOX-induced injury. These results confirmed that FZK ameliorates DOX-induced cardiotoxicity via antiapoptotic and mitochondrial protection but does not affect the antitumor activity of DOX.

New molecular and biochemical insights of doxorubicin-induced hepatotoxicity

Chemotherapeutic antibiotic doxorubicin belongs to the anthracycline class, slaughters not only the cancer cells but also non-cancerous cells even in the non-targeted organs thereby resulting in the toxicity. The liver is primarily involved in the process of detoxification and this mini-review we focused mainly to investigate the molecular mechanisms heading hepatotoxicity caused due to doxorubicin administration. The alterations in the doxorubicin treated liver tissue include vacuolation of hepatocytes, degeneration of hepatocyte cords, bile duct hyperplasia and focal necrosis. About the literature conducted, hepatotoxicity caused by doxorubicin has been explained by estimating the levels of liver serum biomarkers, ROS production, antioxidant enzymes, lipid peroxidation, and mitochondrial dysfunction. The liver serum biomarkers such as ALT and AST, elated levels of free radicals inducing oxidative stress characterized by a surge in Nrf-2, FOXO-1 and HO-1 genes and diminution of anti-oxidant activity characterized by a decline in SOD, GPx, and CAT genes. The augmented levels of SGOT, SGPT, LDH, creatine kinase, direct and total bilirubin levels also reveal the toxicity in the hepatic tissue due to doxorubicin treatment. The molecular insight of hepatotoxicity is mainly due to the production of ROS, ameliorated oxidative stress and inflammation, deteriorated mitochondrial production and functioning, and enhanced apoptosis. Certain substances such as extracts from medicinal plants, natural products, and chemical substances have been shown to produce an alleviating effect against the doxorubicin-induced hepatotoxicity are also discussed.