Protocatechuic acid mitigates cadmium-induced neurotoxicity in rats: Role of oxidative stress, inflammation and apoptosis

Protective effect of naringenin on cadmium chloride-induced renal injury via alleviating oxidative stress, endoplasmic reticulum stress, and autophagy in chickens

Cadmium (Cd) is a highly hazardous toxic substance that can cause serious harm to animals. Previous studies have indicated that cadmium chloride (CdCl2) can damage organs, such as the liver, ovaries, and testicles. Naringenin (Nar) represents a flavonoid with various properties that promote the alleviation of Cd-induced damage. In this experiment, 60 chickens were divided into the control group, 150 mg/kg CdCl2 treatment group, 250 mg/kg Nar treatment group, and 150 mg/kg CdCl2 + 250 mg/kg Nar co-treatment group, which were treated for 8 weeks. Kidney tissues samples were collected to investigate kidney function, including oxidative stress (OS), endoplasmic reticulum (ER) stress, and autophagy activity. Experimental results showed the decreased weight of chickens and increased relative weight of their kidneys after CdCl2 treatment. The increase in NAG, BUN, Cr, and UA activities, as well as the increase in MDA and GSH contents, and the decrease activities of T-AOC, SOD, and CAT in the kidney, manifested renal injury by OS in the chickens. TUNEL staining revealed that CdCl2 induced apoptosis in renal cells. CdCl2 upregulates the mRNA and protein expression levels of GRP78, PERK, eIF2α, ATF4, ATF6, CHOP, and LC3, and inhibited the mRNA and protein expression levels of P62 proteins, which leads to ER stress and autophagy. The CdCl2 + Nar co-treatment group exhibited alleviated CdCl2-induced kidney injury, OS, ER stress, and autophagy. Research has demonstrated that Nar reduces CdCl2-induced kidney injury through alleviation of OS, ER stress, and autophagy.

Caffeic acid attenuates memory dysfunction and restores the altered activity of cholinergic, monoaminergic and purinergic in brain of cadmium chloride exposure rats

OBJECTIVES

This study aims to evaluate the neuroprotective effect of caffeic acid (CAF) against cadmium chloride (CdCl2) in rats via its effect on memory index as well as on altered enzymatic activity in the brain of CdCl2-induced neurotoxicity.

METHODS

The experimental rats were divided into seven groups (n=6 rats per group) of healthy rats (group 1), CdCl2 -induced (CD) (3 mg/kg BW) rats (group 2), CD rats + Vitamin C (group 3), CD rats + CAF (10 and 20 mg/kg BW respectively) (group 4 & 5), and healthy rat + CAF (10 and 20 mg/kg BW respectively) (group 6 & 7). Thereafter, CdCl2 and CAF were administered orally to the experimental rats in group 2 to group 5 on daily basis for 14 days. Then, the Y-maze test was performed on the experimental rats to ascertain their memory index.

RESULTS

CdCl2 administration significantly altered cognitive function, the activity of cholinesterase, monoamine oxidase, arginase, purinergic enzymes, nitric oxide (NOx), and antioxidant status of Cd rats (untreated) when compared with healthy rats. Thereafter, CD rats treated with vitamin C and CAF (10 and 20 mg/kg BW) respectively exhibited an improved cognitive function, and the observed altered activity of cholinesterase, monoamine oxidase, arginase, purinergic were restored when compared with untreated CD rats. Also, the level of brain NOx and antioxidant status were significantly (p<0.05) enhanced when compared with untreated CD rats. In the same vein, CAF administration offers neuro-protective effect in healthy rats vis-à-vis improved cognitive function, reduction in the activity of some enzymes linked to the progression of cognitive dysfunction, and improved antioxidant status when compared to healthy rats devoid of CAF.

CONCLUSIONS

This study demonstrated the neuroprotective effect of CAF against CdCl2 exposure and in healthy rats.

Pharmacological Potential of Kaempferol, a Flavonoid in the Management of Pathogenesis via Modulation of Inflammation and Other Biological Activities

Natural products and their bioactive compounds have been used for centuries to prevent and treat numerous diseases. Kaempferol, a flavonoid found in vegetables, fruits, and spices, is recognized for its various beneficial properties, including its antioxidant and anti-inflammatory potential. This molecule has been identified as a potential means of managing different pathogenesis due to its capability to manage various biological activities. Moreover, this compound has a wide range of health-promoting benefits, such as cardioprotective, neuroprotective, hepatoprotective, and anti-diabetic, and has a role in maintaining eye, skin, and respiratory system health. Furthermore, it can also inhibit tumor growth and modulate various cell-signaling pathways. In vivo and in vitro studies have demonstrated that this compound has been shown to increase efficacy when combined with other natural products or drugs. In addition, kaempferol-based nano-formulations are more effective than kaempferol treatment alone. This review aims to provide detailed information about the sources of this compound, its bioavailability, and its role in various pathogenesis. Although there is promising evidence for its ability to manage diseases, it is crucial to conduct further investigations to know its toxicity, safety aspects, and mechanism of action in health management.

Neuroprotective Assessment of Betaine against Copper Oxide Nanoparticle-Induced Neurotoxicity in the Brains of Albino Rats: A Histopathological, Neurochemical, and Molecular Investigation

Copper oxide nanoparticles (CuO-NPs) are commonly used metal oxides. Betaine possesses antioxidant and neuroprotective activities. The current study aimed to investigate the neurotoxic effect of CuO-NPs on rats and the capability of betaine to mitigate neurotoxicity. Forty rats; 4 groups: group I a control, group II intraperitoneally CuO-NPs (0.5 mg/kg/day), group III orally betaine (250 mg/kg/day) and CuO-NPs, group IV orally betaine for 28 days. Rats were subjected to neurobehavioral assessments. Brain samples were processed for biochemical, molecular, histopathological, and immunohistochemical analyses. Behavioral performance of betaine demonstrated increasing locomotion and cognitive abilities. Group II exhibited significantly elevated malondialdehyde (MDA), overexpression of interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α). Significant decrease in glutathione (GSH), and downregulation of acetylcholine esterase (AChE), nuclear factor erythroid 2-like protein 2 (Nrf-2), and superoxide dismutase (SOD). Histopathological alterations; neuronal degeneration, pericellular spaces, and neuropillar vacuolation. Immunohistochemically, an intense immunoreactivity is observed against IL-1β and glial fibrillary acidic protein (GFAP). Betaine partially neuroprotected against CuO-NPs associated alterations. A significant decrease at MDA, downregulation of IL-1β, and TNF-α, a significant increase at GSH, and upregulation of AChE, Nrf-2, and SOD. Histopathological alterations partially ameliorated. Immunohistochemical intensity of IL-1β and GFAP reduced. It is concluded that betaine neuroprotected against most of CuO-NP neurotoxic effects through antioxidant and cell redox system stimulating efficacy.

The protective effects of protocatechuic acid against natural and chemical toxicants: cellular and molecular mechanisms

Protocatechuic acid (PCA) is a water-soluble polyphenol compound that is extracted from certain fruits and plants or obtained from glucose fermentation. Several in vivo and in vitro studies have determined that PCA has protective effects against the toxicity of natural and chemical toxicants. We searched these articles in PubMed, Google Scholar, and Scopus with appropriate keywords from inception up to August 2023. Forty-nine studies were found about protective effects of PCA against drug toxicity, metal toxicity, toxins, chemical toxicants, and some other miscellaneous toxicants. PCA indicates these protective effects by suppression of oxidative stress, inflammation, and apoptosis. PCA reduces reactive oxygen/nitrogen species (RONS) and enhances the level of antioxidant parameters mainly through the activation of the Nrf-2 signaling pathway. PCA also decreases the levels of inflammatory mediators via downregulating the TLR-4-mediated IKBKB/NF-κB and MAPK/Erk signaling pathways. In addition, PCA inhibits apoptosis by lowering the expression of Bax, caspase-3, and caspase-9 along with enhancing the level of the antiapoptotic protein Bcl-2. Further evaluation, especially in humans, is necessary to confirm PCA as a potential therapeutic approach to intervene in such toxicities.

Heavy Metal Mediated Progressive Degeneration and Its Noxious Effects on Brain Microenvironment

Heavy metals, including lead (Pb), cadmium (Cd), arsenic (As), cobalt (Co), copper (Cu), manganese (Mn), zinc (Zn), and others, have a significant impact on the development and progression of neurodegenerative diseases in the human brain. This comprehensive review aims to consolidate the recent research on the harmful effects of different metals on specific brain cells such as neurons, microglia, astrocytes, and oligodendrocytes. Understanding the potential influence of these metals in neurodegeneration is crucial for effectively combating the ongoing advancement of these diseases. Metal-induced neurodegeneration involves molecular mechanisms such as apoptosis induction, dysregulation of metabolic and signaling pathways, metal imbalance, oxidative stress, loss of synaptic transmission, pathogenic peptide aggregation, and neuroinflammation. This review provides valuable insights by compiling the supportive evidence from recent research findings. Additionally, we briefly discuss the modes of action of natural neuroprotective compounds. While this comprehensive review aims to consolidate the recent research on the harmful effects of various metals on specific brain cells, it may not cover all studies and findings related to metal-induced neurodegeneration. Studies that are done using bioinformatics tools, microRNAs, long non-coding RNAs, emerging disease models, and studies based on the modes of exposure to toxic metals are a future prospect to be explored.

Dietary Polyphenols: Review on Chemistry/Sources, Bioavailability/Metabolism, Antioxidant Effects, and Their Role in Disease Management

Polyphenols, as secondary metabolites ubiquitous in plant sources, have emerged as pivotal bioactive compounds with far-reaching implications for human health. Plant polyphenols exhibit direct or indirect associations with biomolecules capable of modulating diverse physiological pathways. Due to their inherent abundance and structural diversity, polyphenols have garnered substantial attention from both the scientific and clinical communities. The review begins by providing an in-depth analysis of the chemical intricacies of polyphenols, shedding light on their structural diversity and the implications of such diversity on their biological activities. Subsequently, an exploration of the dietary origins of polyphenols elucidates the natural plant-based sources that contribute to their global availability. The discussion extends to the bioavailability and metabolism of polyphenols within the human body, unraveling the complex journey from ingestion to systemic effects. A central focus of the review is dedicated to unravelling the antioxidant effects of polyphenols, highlighting their role in combating oxidative stress and associated health conditions. The comprehensive analysis encompasses their impact on diverse health concerns such as hypertension, allergies, aging, and chronic diseases like heart stroke and diabetes. Insights into the global beneficial effects of polyphenols further underscore their potential as preventive and therapeutic agents. This review article critically examines the multifaceted aspects of dietary polyphenols, encompassing their chemistry, dietary origins, bioavailability/metabolism dynamics, and profound antioxidant effects. The synthesis of information presented herein aims to provide a valuable resource for researchers, clinicians, and health enthusiasts, fostering a deeper understanding of the intricate relationship between polyphenols and human health.

Chronic cadmium exposure impairs flight behavior by dampening flight muscle carbon metabolism in bumblebees

Cadmium pollution affects the global ecosystem because cadmium can be transferred up the food chain. The bumblebee, Bombus terrestris, is an important insect pollinator. Their foraging activity on flowers exposes them to harmful heavy metals, which damages their health and leads to massive population declines. However, the effects of chronic exposure to heavy metals on the flight performance of bumblebees have not yet been characterized. Here, we studied variation in the flight capacity of bumblebees induced by chronic cadmium exposure at field-realistic concentrations using behavioral, physiological, and molecular approaches. Chronic cadmium exposure caused a significant reduction in the duration, distance, and mean velocity of bumblebee flight. Transcriptome analysis showed that the impairment of carbon metabolism and mitochondrial dysfunction in the flight muscle were the primary causes. Physiological, biochemical, and metabolomic analyses validated disruptions in energy metabolism, and impairments in mitochondrial respiratory chain complexes activities. Histological analysis revealed muscle fiber damage and mitochondrial loss. Exogenous decanoic acid or citric acid partially restored sustained flight ability of bumblebees by mitigating muscle fiber damage and increasing energy generation. These findings provide insights into how long-term cadmium stress affects the flight ability of insects and will aid human muscle or exercise-related disease research.

Effects of postweaning cadmium exposure on socioemotional behaviors in adolescent male mice

Exposure to cadmium (Cd), a toxic heavy metal classified as an environmental endocrine disruptor, can exert significant toxicity in both animals and humans. However, the potential effects of Cd exposure on socioemotional behaviors are still poorly understood, as are the underlying mechanisms. In the present study, employing a series of behavioral tests as well as 16 S rRNA sequencing analysis, we investigated the long-term effects of Cd exposure on socioemotional behaviors and their associated mechanisms in mice based on the brain-gut interaction theory. The results showed that postweaning exposure to Cd reduced the ability to resist depression, decreased social interaction, subtly altered sexual preference, and changed the composition of the gut microbiota in male mice during adolescence. These findings provided direct evidence for the deleterious effects of exposure to Cd in the postweaning period on socioemotional behaviors later in adolescence, and suggested that these effects of Cd exposure may be linked to changes in the gut microbiota.

Azithromycin induces neurotoxicity in zebrafish by interfering with the VEGF/Notch signaling pathway

Azithromycin (AZM) is a widely used antibiotic in both human and veterinary medicine, and its use has significantly increased during the COVID-19 pandemic. However, potential adverse effects of AZM on aquatic organisms have not been well studied. In this study, we explored the neurotoxicity of AZM in zebrafish and delved into its underlying mechanisms. Our results showed that AZM exposure resulted in a spectrum of detrimental effects in zebrafish, encompassing abnormal behaviors, damaged neuronal development, aberrant lateral line nervous system development, vascular malformations and perturbed expression of genes related to neural development. Moreover, we observed a concentration-dependent exacerbation of these neurotoxic manifestations with increasing AZM concentrations. Notably, AZM induced excessive cell apoptosis and oxidative stress damage. In addition, alterations in the expression levels of the genes involved in the VEGF/Notch signaling pathway were evident in AZM-exposed zebrafish. Consequently, we hypothesize that AZM may induce neurotoxicity by influencing the VEGF/Notch signaling pathway. To validate this hypothesis, we introduced a VEGF signaling inhibitor, axitinib, and a Notch signaling agonist, valproic acid, alongside AZM exposure. Remarkably, the administration of these rescue compounds significantly mitigated the neurotoxic effects induced by AZM. This dual verification provides compelling evidence that AZM indeed induces neurotoxicity during the early developmental stages of zebrafish, primarily through its interference with the VEGF/Notch pathway. Innovatively, our study reveals the molecular mechanism of AZM-induced neurotoxicity from the perspective of the close connection between blood vessels and nervous system. These findings provide new insights into the potential mechanisms underlying the neurotoxic effect of antibiotics and highlight the need for further investigation into the ecotoxicological effects of antibiotics on aquatic organisms and the potential risks to human health.

Chronic cadmium exposure induces Parkinson-like syndrome by eliciting sphingolipid disturbance and neuroinflammation in the midbrain of C57BL/6J mice

Cadmium (Cd) is known as a widespread environmental neurotoxic pollutant. Cd exposure is recently recognized as an etiological factor of Parkinson's disease (PD) in humans. However, the mechanism underlying Cd neurotoxicity in relation to Parkinsonism pathogenesis is unclear. In our present study, C57BL/6 J mice were exposed to 100 mg/L CdCl2 in drinking water for 8 weeks. It was found Cd exposure caused motor deficits, decreased DA neurons and induced neuropathological changes in the midbrain. Non-targeted lipidomic analysis uncovered that Cd exposure altered lipid profile, increased the content of proinflammatory sphingolipid ceramides (Cer), sphingomyelin (SM) and ganglioside (GM3) in the midbrain. In consistency with increased proinflammatory lipids, the mRNA levels of genes encoding sphingolipids biosynthesis in the midbrain were dysregulated by Cd exposure. Neuroinflammation in the midbrain was evinced by the up-regulation of proinflammatory cytokines at mRNA and protein levels. Blood Cd contents and lipid metabolites in Parkinsonism patients by ICP-MS and LC-MS/MS analyses demonstrated that elevated blood Cd concentration and proinflammatory lipid metabolites were positively associated with the score of Unified Parkinson's Disease Rating Scale (UPDRS). 3 ceramide metabolites in the blood showed good specificity as the candidate biomarkers to predict and monitor Parkinsonism and Cd neurotoxicity (AUC>0.7, p < 0.01). In summary, our present study uncovered that perturbed sphingomyelin lipid metabolism is related to the Parkinsonism pathogenesis and Cd neurotoxicity, partially compensated for the deficiency in particular metabolic biomarkers for Parkinsonism in relation to Cd exposure, and emphasized the necessity of reducing Cd exposure at population level.

Coenzyme Q10-Loaded Albumin Nanoparticles Protect against Redox Imbalance and Inflammatory, Apoptotic, and Histopathological Alterations in Mercuric Chloride-Induced Hepatorenal Toxicity in Rats

Exposure to mercuric chloride (HgCl2), either accidental or occupational, induces substantial liver and kidney damage. Coenzyme Q10 (CoQ10) is a natural antioxidant that also has anti-inflammatory and anti-apoptotic activities. Herein, our study aimed to investigate the possible protective effects of CoQ10 alone or loaded with albumin nanoparticles (CoQ10NPs) against HgCl2-induced hepatorenal toxicity in rats. Experimental animals received CoQ10 (10 mg/kg/oral) or CoQ10NPs (10 mg/kg/oral) and were injected intraperitoneally with HgCl2 (5 mg/kg; three times/week) for two weeks. The results indicated that CoQ10NP pretreatment caused a significant decrease in serum liver and kidney function markers. Moreover, lowered MDA and NO levels were associated with an increase in antioxidant enzyme activities (SOD, GPx, GR, and CAT), along with higher GSH contents, in both the liver and kidneys of intoxicated rats treated with CoQ10NPs. Moreover, HgCl2-intoxicated rats that received CoQ10NPs revealed a significant reduction in the hepatorenal levels of TNF-α, IL-1β, NF-κB, and TGF-β, as well as an increase in the hepatic level of the fibrotic marker (α-SMA). Notably, CoQ10NPs counteracted hepatorenal apoptosis by diminishing the levels of Bax and caspase-3 and boosting the level of Bcl-2. The hepatic and renal histopathological findings supported the abovementioned changes. In conclusion, these data suggest that CoQ10, alone or loaded with albumin nanoparticles, has great power in reversing the hepatic and renal tissue impairment induced by HgCl2 via the modulation of hepatorenal oxidative damage, inflammation, and apoptosis. Therefore, this study provides a valuable therapeutic agent (CoQ10NPs) for preventing and treating several HgCl2-induced hepatorenal disorders.

Mediation analysis of urinary metals and stroke risk by inflammatory markers

BACKGROUND

The association between metals and stroke has been reported, but the mediating role of inflammation between metals and stroke remains unclear.

METHODS

We included 9326 adults from the National Health and Nutrition Examination Survey in this study. Through least absolute selection and shrinkage operator (LASSO) regression, weighted quantile sum (WQS) regression, logistic regression, linear regression, restricted cubic spline analysis, and mediation analysis, we explored the association between metals and stroke, as well as the association between metals and inflammatory indicators, and further evaluated the mediating effect of inflammatory indicators on the association between selected metals and stroke risk.

RESULTS

The results of the present study suggested positive associations between mixed metals, cadmium and uranium and stroke risk. There is a positive correlation and dose‒response relationship between cadmium and C-reactive protein (CRP). Moreover, CRP mediates 10.1% of the association between cadmium and stroke.

CONCLUSIONS

At the epidemiological level, CRP mediates the association between cadmium and stroke risk, suggesting that inflammation may be a potential mechanism for metal-induced stroke.

Beta-Caryophyllene, a Plant-Derived CB2 Receptor Agonist, Protects SH-SY5Y Cells from Cadmium-Induced Toxicity

Cadmium (Cd) is a transition heavy metal that is able to accumulate in the central nervous system and may induce cell death through reactive oxygen species (ROS)-mediated mechanisms and inactivating the antioxidant processes, becoming an important risk factor for neurodegenerative diseases. The antioxidant effects of cannabinoid receptor modulation have been extensively described, and, in particular, β-Caryophyllene (BCP), a plant-derived cannabinoid 2 receptor (CB2R) agonist, not only showed significant antioxidant properties but also anti-inflammatory, analgesic, and neuroprotective effects. Therefore, the aim of the present study was to evaluate BCP effects in a model of Cd-induced toxicity in the neuroblastoma SH-SY5Y cell line used to reproduce Cd intoxication in humans. SH-SY5Y cells were pre-treated with BCP (25, 50, and 100 μM) for 24 h. The day after, cells were challenged with cadmium chloride (CdCl2; 10 μM) for 24 h to induce neuronal toxicity. CdCl2 increased ROS accumulation, and BCP treatment significantly reduced ROS production at concentrations of 50 and 100 μM. In addition, CdCl2 significantly decreased the protein level of nuclear factor erythroid 2-related factor 2 (Nrf2) compared to unstimulated cells; the treatment with BCP at a concentration of 50 μM markedly increased Nrf2 expression, thus confirming the BCP anti-oxidant effect. Moreover, BCP treatment preserved cells from death, regulated the apoptosis pathway, and showed a significant anti-inflammatory effect, thus reducing the pro-inflammatory cytokines increased by the CdCl2 challenge. The results indicated that BCP preserved neuronal damage induced by Cd and might represent a future candidate for protection in neurotoxic conditions.

Encapsulation of Selenium Nanoparticles and Metformin in Macrophage-Derived Cell Membranes for the Treatment of Spinal Cord Injury

Spinal cord injury is an impact-induced disabling condition. A series of pathological changes after spinal cord injury (SCI) are usually associated with oxidative stress, inflammation, and apoptosis. These pathological changes eventually lead to paralysis. The short half-life and low bioavailability of many drugs also limit the use of many drugs in SCI. In this study, we designed nanovesicles derived from macrophages encapsulating selenium nanoparticles (SeNPs) and metformin (SeNPs-Met-MVs) to be used in the treatment of SCI. These nanovesicles can cross the blood-spinal cord barrier (BSCB) and deliver SeNPs and Met to the site of injury to exert anti-inflammatory and reactive oxygen species scavenging effects. Transmission electron microscopy (TEM) images showed that the SeNPs-Met-MVs particle size was approximately 125 ± 5 nm. Drug release assays showed that Met exhibited sustained release after encapsulation by the macrophage cell membrane. The cumulative release was approximately 80% over 36 h. In vitro cellular experiments and in vivo animal experiments demonstrated that SeNPs-Met-MVs decreased reactive oxygen species (ROS) and malondialdehyde (MDA) levels, increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, and reduced the expression of inflammatory (TNF-α, IL-1β, and IL-6) and apoptotic (cleaved caspase-3) cytokines in spinal cord tissue after SCI. In addition, motor function in mice was significantly improved after SeNPs-Met-MVs treatment. Therefore, SeNPs-Met-MVs have a promising future in the treatment of SCI.

The protective effect of apigenin against inorganic arsenic salt-induced toxicity in PC12 cells

Poisoning by arsenic affects people worldwide, and many human illnesses and health issues, including neurotoxicity, have been linked to chronic exposure to arsenic. When exposed to arsenic, the body produces intracellular reactive oxygen species (ROS), which influence a variety of alterations in cellular activity and directly harm molecules through oxidation. Arsenic-induced lesions are improved by antioxidants with the ability to lower ROS levels. Therefore, the current research aimed to assess how well apigenin protected PC12 cells from the toxicity caused by inorganic arsenic salt (iAs). For 24 and 48 h, iAs and/or apigenin were applied to PC12 cells. Then, oxidative stress indicators like malondialdehyde (MDA), nitric oxide (NO), and ROS in addition to the enzymatic and non-enzymatic antioxidant molecules such as catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD) were assessed. Moreover, after exposure to iAs, PC12 was examined for nuclear factor erythroid 2-related factor 2 (Nrf2) expression to clarify how apigenin manifests its neuroprotection. Furthermore, NF-kB p65 concentration and IL-1B, IL-6, and TNF-α mRNA expression were measured to assess neuroinflammation. Bax, caspase-3, and Bcl-2 levels were measured to investigate apigenin's potential to protect PC12 cells from iAs poisoning. The obtained results revealed that, the cell survival rate in the iAs group was significantly lower (P < 0.05), and the number of viable cells steadily increased after apigenin treatment. Furthermore, the study found that iAs decreased GSH, CAT, and SOD in the PC12 cells while increasing ROS, MDA, and NO levels. In PC12 cells, the capacity of iAs to cause oxidative stress was linked to the induction of neuroinflammation and apoptosis. Interestingly, apigenin pre-treatment of PC12 cells resulted in exceptional protection against iAs-induced neuroinflammation, oxidative stress, and apoptotic cell death. Nrf2 upregulation in PC12 cells may explain the neuroprotection effect of apigenin against iAs toxicity. In conclusion, the obtained results of the present study have clinical significance and indicate that apigenin is a promising candidate for shielding the nervous system from toxic effects caused by arsenic. These findings require further investigation using in vivo experimental models.

Inulin alleviates neuroinflammation and oxidative stress induced by perinatal 2-ethylhexyl diphenyl phosphate (EHDPHP) exposure in female mice and offspring

Organophosphorus flame retardants (OPFRs), including 2-ethylhexyl diphenyl phosphate (EHDPHP), are prevalent in everyday life due to their broad usage in fields such as healthcare, electronics, industry, and sports. These compounds, added to polymers through physical mixing, can leach into the environment, posing a risk to humans through direct contact or the food chain. Despite known associations with health issues like endocrine disruption, neurotoxicity, and reproductive toxicity, the implications of perinatal EHDPHP exposure on both mothers and offspring are still unclear. This study aimed to investigate the neuroinflammatory effects of EHDPHP and the potential mitigating role of inulin. Pregnant C57 mice were administered either a corn oil control or an EHDPHP solution (300 μg/kg bw/d) from gestation day 7 (GD7) to postnatal day 21 (PND21). Concurrently, mice were provided either regular drinking water or water supplemented with 1% inulin. We found that EHDPHP significantly increased the serum levels of IL-1β, IL-6, and MDA, but decreased SOD levels in both mothers and pups. These effects were reversed by inulin supplementation. RNA-sequencing revealed that EHDPHP induced inflammation and oxidative stress through the TLR4/NF-κB pathway, which was mitigated by inulin. In conclusion, inulin ameliorated EHDPHP-induced neuroinflammation and oxidative stress in both mothers and offspring, highlighting its potential therapeutic role.

Involvement of the heat shock response (HSR) regulatory pathway in cadmium-elicited cerebral damage

The heat shock response (HSR) is a cellular protective mechanism that is characterized by the induction of heat shock transcription factors (HSFs) and heat shock proteins (HSPs) in response to diverse cellular and environmental stressors, including cadmium (Cd). However, little is known about the relationship between the damaging effects of Cd and the HSR pathway in the chicken cerebrum following Cd exposure. To explore whether Cd exposure elicits cerebral damage and triggers the HSR pathway, chicks were exposed to Cd in the daily diet at different concentrations (35, 70, or 140 mg/kg feed) for 90 days, while a control group was fed the standard diet without Cd. Histopathological examination of cerebral tissue from Cd-exposed chickens showed neuronal damage, as evidenced by swelling and degeneration of neurons, loss of neurons, and capillary damage. Cd exposure significantly increased mRNA expression of HSF1, HSF2, and HSF3, and mRNA and protein expression of three major stress-inducible HSPs (HSP60, HSP70, and HSP90). Moreover, Cd exposure differentially modulated mRNA expression of small HSP (sHSPs), most notably reducing expression of HSP27 (HSPB1). Furthermore, Cd exposure increased TUNEL-positive neuronal apoptotic cells and up-regulated protein expression of caspase-1, caspase-8, caspase-3, and p53, leading to apoptosis. Taken together, these data demonstrate that activation of the HSR and apoptotic pathways by Cd exposure is involved in Cd-elicited cerebral damage in the chicken. Synopsis for the graphical abstract Cadmium (Cd)-induced neuronal damage triggers the heat shock response (HSR) by activating heat shock transcription factors (HSFs) and subsequent induction of major heat shock proteins (notably, HSP60, HSP70, and HSP90). Moreover, Cd exposure activates caspase-1, caspase-8, caspase-3, and p53 protein, thereby resulting in neuronal apoptosis in the chicken brain.

A dietary polyphenol metabolite alters CA1 excitability ex vivo and mildly affects cortico-hippocampal field potential generators in anesthetized animals

Dietary polyphenols have beneficial effects in situations of impaired cognition in acute models of neurodegeneration. The possibility that they may have a direct effect on the electrical activity of neuronal populations has not been tested. We explored the electrophysiological action of protocatechuic acid (PCA) on CA1 pyramidal cells ex vivo and network activity in anesthetized female rats using pathway-specific field potential (FP) generators obtained from laminar FPs in cortex and hippocampus. Whole-cell recordings from CA1 pyramidal cells revealed increased synaptic potentials, particularly in response to basal dendritic excitation, while the associated evoked firing was significantly reduced. This counterintuitive result was attributed to a marked increase of the rheobase and voltage threshold, indicating a decreased ability to generate spikes in response to depolarizing current. Systemic administration of PCA only slightly altered the ongoing activity of some FP generators, although it produced a striking disengagement of infraslow activities between the cortex and hippocampus on a scale of minutes. To our knowledge, this is the first report showing the direct action of a dietary polyphenol on electrical activity, performing neuromodulatory roles at both the cellular and network levels.

Mapping the metabolic characteristics of probiotic-fermented Ganoderma lucidum and its protective mechanism against Cd-induced nephrotoxicity

An animal model of Cd-induced kidney damage was designed to investigate the nephroprotective potential of the probiotic-fermented Ganoderma lucidum (FGL) via metabonomic analysis. The results showed that FGL enhanced sugar and amino acid metabolism. The interaction of Ganoderma lucidum (GL) and probiotics efficiently elevated short-chain fatty acid production following gut microbiota fermentation. The current data revealed that the FGL intervention alleviated Cd-induced nephrotoxicity via elevating the activity of antioxidant enzymes and decreasing the levels of pro-inflammatory and apoptotic factors. Based on transcriptome analysis, FGL intervention mediated renal dysfunction via decreasing the expressions of Nos2, Tnfsf14, S100a9, Map3k6 and Hk3, which were involved in oxidative stress, inflammatory response and the apoptosis process. The current study highlights a new approach for achieving positive nephroprotection via natural product intervention.

Procyanidin B2 alleviates uterine toxicity induced by cadmium exposure in rats: The effect of oxidative stress, inflammation, and gut microbiota

Environmental exposure to hazardous materials causes enormous socioeconomic problems due to its deleterious impacts on human beings, agriculture and animal husbandry. As an important hazardous material, cadmium can promote uterine oxidative stress and inflammation, leading to reproductive toxicity. Antioxidants have been reported to attenuate the reproductive toxicity associated with cadmium exposure. In this study, we investigated the potential protective effect of procyanidin oligosaccharide B2 (PC-B2) and gut microbiota on uterine toxicity induced by cadmium exposure in rats. The results showed that the expression levels of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were reduced in utero. Proinflammatory cytokines (including tumor necrosis factor-α, interleukin-1β and interleukin-6), the NLRP3 inflammasome, Caspase-1 and pro-IL-1β were all involved in inflammatory-mediated uterine injury. PC-B2 prevented CdCl2-induced oxidative stress and inflammation in uterine tissue by increasing antioxidant enzymes and reducing proinflammatory cytokines. Additionally, PC-B2 significantly reduced cadmium deposition in the uterus, possibly through its significant increase in MT1, MT2, and MT3 mRNA expression. Interestingly, PC-B2 protected the uterus from CdCl2 damage by increasing the abundance of intestinal microbiota, promoting beneficial microbiota, and inhibiting harmful microbiota. This study provides novel mechanistic insights into the toxicity of environmental cadmium exposure and indicates that PC-B2 could be used in the prevention of cadmium exposure-induced uterine toxicity.

Alternations in interleukin-1β and nuclear factor kappa beta activity (NF-kB) in rat liver due to the co-exposure of Cadmium and Arsenic: Protective role of curcumin

Cadmium chloride (Cd) and sodium arsenite (As) are two prominent examples of non-biodegradable substances that accumulate in ecosystems, pose a serious risk to human health and are not biodegradable. Although the toxicity caused by individual use of Cd and As is known, the toxicity of combined use (Cd+As) to mammals is poorly understood. The present study aims to investigate the hepatoprotective effect of curcumin (CUR), a naturally occurring bioactive component isolated from the root stem of Curcuma longa Linn., in preventing liver damage caused by a Cd+As mixture. A group of 30 Sprague-Dawley rats were subjected to intraperitoneal administration of Cd+As (0.44 mg/kg+5.55 mg/kg i.p.) and CUR (100 or 200 mg/kg) for a period of 14 days. The experimental results showed that the animals treated with Cd+As exhibited changes in liver biochemical parameters, inflammation and oxidative stress at the end of the experiment. Administration of CUR significantly reduced inflammation, oxidative stress and lipid peroxidation in the Cd+As plus CUR groups compared to the Cd+As group. Furthermore, histological examination of the liver tissue showed that administration of CUR had led to a significant reduction in the liver damage observed in the Cd+As group. The present study provides scientific evidence for the protective effects of CUR against lipid peroxidation, inflammation, oxidative stress and liver damage induced by Cd+As in the liver of rats. The results of our in vivo experiments were confirmed by those of our molecular modelling studies, which showed that CUR can enhance the diminished antioxidant capacity caused by Cd+As.

Cadmium-induced pyroptosis is mediated by PERK/TXNIP/NLRP3 signaling in SH-SY5Y cells

Cadmium (Cd) is a hypertoxic heavy metal that may be exposed to environmental pollutants by humans and animals. It can lead to cognitive disfunction, and is linked to neurodegenerative diseases. Cadmium reportedly can induce endoplasmic reticulum (ER) stress, but few studies have concentrated on it in nerve cells, and the connection between ER stress and neuroinflammation. In this study, in vitro experiments on SH-SY5Y neuroblastoma cells were carried out. We aimed at exploring whether Cd attributed to the cell pyroptosis and the role of PERK in promoting this form of cell damage which can induce strong inflammatory responses. Our results demonstrated that CdCl2 treatment induced excess reactive oxygen species (ROS) production, caused significant modifications in the expression of PERK and increased TXNIP, NLRP3, IL-1β, IL-18, and caspase1 in SH-SY5Y cells. In addition, scavenging ROS with N-acetylcysteine or inhibiting the expression of PERK by using GSK2606414, rescued the SH-SY5Y cells from cadmium-induced pyroptosis. In conclusion, the results suggest that Cd induces pyroptotic death of SH-SY5Y cells through ER stress, and this may be the potential mechanism of Cd incurring neurological diseases.

Pharmacological bioactivity of Ceratonia siliqua pulp extract: in vitro screening and molecular docking analysis, implication of Keap-1/Nrf2/NF-ĸB pathway

Inflammation is interfaced with various metabolic disorders. Ceratonia siliqua (CS) has a higher pharmaceutical purpose. The research aimed to investigate the biofunction of CS pulp aqueous extract (CS-PAE) with an emphasis on its integrated computational approaches as opposed to different specific receptors contributing to inflammation. The extract was assessed for its chemical and phenolic components via GC-MS, LC-MS, HPLC, and total phenolic and flavonoid content. In vitro, bioactivities and molecular docking were analyzed. Findings indicate that CS-PAE demonstrated higher scavenging activities of nitric oxide, 1,1-diphenyl-2-picrylhydrazyl radical, superoxide anion, hydrogen peroxide, and anti-lipid peroxidation (IC₅₀ values were 5.29, 3.04, 0.63, 7.35 and 9.6 mg/dl, respectively). The extract revealed potent inhibition of RBCs hemolysis, acetylcholine esterase, monoamine oxidase-B, and α-glucosidase enzymes (IC₅₀ was 13.44, 9.31, 2.45, and 1.5 mg/dl, respectively). The extract exhibited a cytotoxic effect against prostate cancer Pc3, liver cancer HepG2, colon cancer Caco2, and lung cancer A549 cell lines. Moreover, CS-PAE owned higher antiviral activity against virus A and some bacteria. When contrasting data from molecular docking, it was reported that both apigenin-7-glucoside and rutin in CS-PAE have a good affinity toward the Keap-1/Nrf2/ NF-ĸB pathway. In conclusion, CS-PAE showed promise in therapeutic activity in metabolic conditions.

Curcumin derived from medicinal homologous foods: its main signals in immunoregulation of oxidative stress, inflammation, and apoptosis

It has been for thousands of years in China known medicinal homologous foods that can be employed both as foods and medicines to benefit human and animal health. These edible herbal materials perform divert roles in the regulation of metabolic disorders, cancers, and immune-related diseases. Curcumin, the primary component derived from medicinal homologous foods like curcuma longa rhizome, is reported to play vital actions in organic activities, such as the numerous pharmacological functions including anti-oxidative stress, anti-inflammation and anti/pro-apoptosis in treating various diseases. However, the potential mechanisms of curcumin-derived modulation still need to be developed and attract more attention worldwide. Given that these signal pathways are enrolled in important bioactive reactions, we collected curcumin's last achievements predominantly on the immune-regulation signals with the underlying targetable strategies in the last 10 years. This mini-review will be helpful to accelerate curcumin and other extracts from medicinal homologous foods use in future human clinical applications.

Cadmium-promoted thyroid hormones disruption mediates ROS, inflammation, Aβ and Tau proteins production, gliosis, spongiosis and neurodegeneration in rat basal forebrain

Cadmium (Cd) produces cognition decline following single and repeated treatment, although the complete mechanisms are still unrevealed. Basal forebrain (BF) cholinergic neurons innervate the cortex and hippocampus, regulating cognition. Cd single and repeated exposure induced BF cholinergic neuronal loss, partly through thyroid hormones (THs) disruption, which may cause the cognition decline observed following Cd exposure. However, the mechanisms through which THs disruption mediate this effect remain unknown. To research the possible mechanisms through which Cd-induced THs deficiency may mediate BF neurodegeneration, Wistar male rats were treated with Cd for 1- (1 mg/kg) or 28-days (0.1 mg/kg) with or without triiodothyronine (T3, 40 μg/kg/day). Cd exposure promoted neurodegeneration, spongiosis, gliosis and several mechanisms related to these alterations (increased H₂0₂, malondialdehyde, TNF-α, IL-1β, IL-6, BACE1, Aβ and phosphorylated-Tau levels, and decreased phosphorylated-AKT and phosphorylated-GSK-3β levels). T3 supplementation partially reversed the effects observed. Our results show that Cd induces several mechanisms that may be responsible for the neurodegeneration, spongiosis and gliosis observed in the rats' BF, which are partially mediated by a reduction in THs levels. These data may help to explain the mechanisms through which Cd induces BF neurodegeneration, possibly leading to the cognitive decline observed, providing new therapeutic tools to prevent and treat these damages.

Minocycline Protects PC12 Cells Against Cadmium-Induced Neurotoxicity by Modulating Apoptosis

Cadmium (Cd) is a well-known heavy metal and a neurotoxic agent. Minocycline (Mino) is an anti-microbial agent with a lipophilic structure that crosses the blood-brain barrier and enters the cerebral tissue. In recent studies, Mino has been introduced as an antioxidant and anti-apoptotic chemical compound, and therefore, it was examined as a protective candidate against Cd-induced neurotoxicity. In this study, PC12 cells were exposed to Cd alone, or after being pre-treated with Mino. Initially, the cell viability and oxidative stress were analyzed using the MTT assay and fluorimetry, respectively. Then, Cd-induced apoptosis and Mino anti-apoptotic effect were evaluated in both intrinsic and extrinsic pathways using western blot analysis. Exposing PC12 cells to Cd for 24 h decreased cell viability and increased production of reactive oxygen species in comparison with the control group. Cd (35 μM) also elevated the level of caspase-8, Bax/Bcl-2, and caspase-3 proteins in the cells. Mino pre-treatment for 2 h (100 nM) increased the number of viable cells and decreased the production of reactive oxygen species, and the level of all apoptotic markers in comparison to Cd-treated cells. Considering all the evidence, it appears that Mino holds promising antioxidant and anti-apoptotic activity and can protect cells against Cd-induced oxidative stress and prevent apoptotic cell death.

Anthocyanins-gut microbiota-health axis: A review

Anthocyanins are a subclass of flavonoids responsible for color in some fruits and vegetables with potent antioxidative capacity. During digestion, a larger proportion of dietary anthocyanins remains unabsorbed and reach the large intestine where they interact with the gut microbiota. Anthocyanins can modulate gut microbial populations to improve diversity and the proportion of beneficial populations, leading to alterations in short chain fatty acid and bile acid production. Some anthocyanins can be degraded into colonic metabolites, such as phenolic acids, which accumulate in the body and regulate a range of biological activities. Here we provide an overview of the effects of dietary anthocyanin consumption on gut microbial interactions, metabolism, and composition. Progression of chronic diseases has been strongly associated with imbalances in gut microbial populations. We therefore focus on the role of the gut microbiota as the 'mediator' that facilitates the therapeutic potential of anthocyanins against various chronic diseases, including obesity, type II diabetes, cardiovascular disease, neurodegenerative disease, inflammatory bowel disease, cancer, fatty liver disease, chronic kidney disease and osteoarthritis.

Protocatechuic acid reverses myocardial infarction mediated by β-adrenergic agonist via regulation of Nrf2/HO-1 pathway, inflammatory, apoptotic, and fibrotic events

Myocardial infarction (MI) is an instant ischemic death of cardiomyocytes that remains a major global cause of mortalities. MI is accompanied by oxidative, inflammatory, apoptotic, and fibrotic insults. Protocatechuic acid (PCA) is a polyphenolic compound with various potent biological activities. In this study, we explored the possible cardioprotective role of PCA against isoproterenol (ISO)-mediated MI. Rats were either injected with ISO (85 mg/kg, subcutaneously) or pretreated with PCA (100 or 200 mg/kg, orally). PCA supplementation markedly normalized ISO-induced disturbed cardiac function markers (creatine kinase-MB, lactate dehydrogenase, and troponin T). Notably, PCA administration exerted remarkable increases in glutathione and its derived enzymes, superoxide dismutase, and catalase, as well as decreases in malondialdehyde and nitric oxide levels in the injured cardiac tissue. The molecular findings validated the augmented cellular antioxidative capacity by PCA via increasing the gene expressions of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1. The cardioprotective efficacy of PCA extended to suppress cardiac inflammation as demonstrated by the decreased levels of tumor necrosis factor-alpha, interleukin-1 beta, and nuclear factor kappa B. Additionally, PCA prevented cardiomyocyte loss and fibrosis by decreasing Bax, caspase-3, transforming growth factor-β1 and matrix metalloproteinase-9, and enhancing B-cell lymphoma 2 and tissue inhibitors of metalloproteinase-3. The cardiac histological screening further confirmed the PCA's protective action. The obtained data recommend PCA as an alternative therapeutic agent to attenuate the molecular, biochemical, and histological alterations associated with MI development.

Bee Pollen as Functional Food: Insights into Its Composition and Therapeutic Properties

Bee pollen is a hive product made up of flower pollen grains, nectar, and bee salivary secretions that beekeepers can collect without damaging the hive. Bee pollen, also called bee-collected pollen, contains a wide range of nutritious elements, including proteins, carbs, lipids, and dietary fibers, as well as bioactive micronutrients including vitamins, minerals, phenolic, and volatile compounds. Because of this composition of high quality, this product has been gaining prominence as a functional food, and studies have been conducted to show and establish its therapeutic potential for medical and food applications. In this context, this work aimed to provide a meticulous summary of the most relevant data about bee pollen, its composition—especially the phenolic compounds—and its biological and/or therapeutic properties as well as the involved molecular pathways.

Therapeutic Potential of Phenolic Compounds in Medicinal Plants-Natural Health Products for Human Health

Phenolic compounds and flavonoids are potential substitutes for bioactive agents in pharmaceutical and medicinal sections to promote human health and prevent and cure different diseases. The most common flavonoids found in nature are anthocyanins, flavones, flavanones, flavonols, flavanonols, isoflavones, and other sub-classes. The impacts of plant flavonoids and other phenolics on human health promoting and diseases curing and preventing are antioxidant effects, antibacterial impacts, cardioprotective effects, anticancer impacts, immune system promoting, anti-inflammatory effects, and skin protective effects from UV radiation. This work aims to provide an overview of phenolic compounds and flavonoids as potential and important sources of pharmaceutical and medical application according to recently published studies, as well as some interesting directions for future research. The keyword searches for flavonoids, phenolics, isoflavones, tannins, coumarins, lignans, quinones, xanthones, curcuminoids, stilbenes, cucurmin, phenylethanoids, and secoiridoids medicinal plant were performed by using Web of Science, Scopus, Google scholar, and PubMed. Phenolic acids contain a carboxylic acid group in addition to the basic phenolic structure and are mainly divided into hydroxybenzoic and hydroxycinnamic acids. Hydroxybenzoic acids are based on a C6-C1 skeleton and are often found bound to small organic acids, glycosyl moieties, or cell structural components. Common hydroxybenzoic acids include gallic, syringic, protocatechuic, p-hydroxybenzoic, vanillic, gentistic, and salicylic acids. Hydroxycinnamic acids are based on a C6-C3 skeleton and are also often bound to other molecules such as quinic acid and glucose. The main hydroxycinnamic acids are caffeic, p-coumaric, ferulic, and sinapic acids.

Cerebellar injury induced by cadmium via disrupting the heat-shock response

Cadmium (Cd) is a food contaminant that poses serious threats to animal health, including birds. It is also an air pollutant with well-known neurotoxic effects on humans. However, knowledge on the neurotoxic effects of chronic Cd exposure on chicken is limited. Thus, this study assessed the neurotoxic effects of chronic Cd on chicken cerebellum. Chicks were exposed to 0 (control), 35 (low), and 70 (high) mg/kg of Cd for 90 days, and the expression of genes related to the heat-shock response was investigated. The chickens showed clinical symptoms of ataxia, and histopathology revealed that Cd exposure decreased the number of Purkinje cells and induced degeneration of Purkinje cells with pyknosis, and some dendrites were missing. Moreover, Cd exposure increased the expression of heat-shock factors, HSF1, HSF2, and HSF3, and heat-shock proteins, HSP60, HSP70, HSP90, and HSP110. These changes indicate that HSPs improve the tolerance of the cerebellum to Cd. Conversely, the expressions of HSP10, HSP25, and HSP40 were decreased significantly, which indicated that Cd inhibits the expression of small heat-shock proteins. However, HSP27 and HSP47 were upregulated following low-dose Cd exposure, but downregulated under high-dose Cd exposure. This work sheds light on the toxic effects of Cd on the cerebellum, and it may provide evidence for health risks posed by Cd. Additionally, this work also identified a novel target of Cd exposure in that Cd induces cerebellar injury by disrupting the heat-shock response. Cd can be absorbed into chicken's cerebellum through the food chain, which eventually caused cerebellar injury. This study provided a new insight that chronic Cd-induced neurotoxicity in the cerebellum is associated with alterations in heat-shock response-related genes, which indicated that Cd through disturbing heat-shock response induced cerebellar injury.

Monosodium glutamate induces cortical oxidative, apoptotic, and inflammatory challenges in rats: the potential neuroprotective role of apigenin

Monosodium glutamate (MSG) is used as a flavor, and a taste enhancer was reported to evoke marked neuronal impairments. This study investigated the neuroprotective ability of flavonoid apigenin against neural damage in MSG-administered rats. Adult male rats were allocated into four groups: control, apigenin (20 mg/kg b.wt, orally), MSG (4 g/kg b.wt, orally), and apigenin + MSG at the aforementioned doses for 30 days. Regarding the levels of neurotransmitters, our results revealed that apigenin augmented the activity of acetylcholinesterase (AChE) markedly, and levels of brain monoamines (dopamine, norepinephrine, and serotonin) accompanied by lessening the activity of monoamine oxidase (MAO) as compared to MSG treatment. Moreover, apigenin counteracted the MSG-mediated oxidative stress by decreasing the malondialdehyde (MDA) levels together with elevating the glutathione (GSH) levels. In addition, pretreatment with apigenin induced notable increases in the activities of cortical superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). Furthermore, apigenin attenuated the cortical inflammatory stress as indicated by lower levels of pro-inflammatory mediators such as interleukin-1 b (IL-1b), tumor necrosis factor-α (TNF-α), and nitric oxide (NO) as well as downregulated inducible nitric oxide synthase (iNOS) expression levels. Histopathological screening validated the abovementioned results and revealed that apigenin restored the distorted cytoarchitecture of the brain cortex. Thus, the present findings collectively suggest that apigenin exerted significant protection against MSG-induced neurotoxicity by enhancing the cellular antioxidant response and attenuating inflammatory machineries in the rat brain cortex.

Antioxidant and in vitro cytogenotoxic properties of Amburana cearensis (Allemão) A.C.Sm. leaf extract

Amburana cearensis leaves have been used in folk medicine to treat respiratory diseases and inflammations. This study aimed to evaluate the biological potential of A. cearensis leaves by antioxidant and in vitro cytogenotoxic analyses of ethanolic crude extract (EE) and its fractions in healthy human cells. The EE was obtained by percolation, followed by fractionation using dichloromethane, cyclohexane, ethyl acetate (EtOAc), and methanol (MeOH) as organic solvents. Extract and all fractions were evaluated for their antioxidant potential by DPPH and reducing power tests. In vitro cytotoxic activity was determined in human peripheral blood mononuclear cells by MTT assay for the extract, EtOAc and MeOH fractions. In turn, the genotoxic activity was determined in human lymphocytes by the Cytokinesis Block Micronucleus assay only for the EtOAc fraction. Only EtOAc fraction was analyzed via gas chromatography coupled to mass spectrometry due to its higher biological activity. Considering the antioxidant potential, the EtOAc fraction was most effective in DPPH (EC₅₀ 43.37 µg/mL) and reducing power (EC₅₀ 89.80 µg/mL) assays. GC-MS analysis of the EtOAc fraction led to the identification of guaiacol, 2,3-dihydro-benzofuran, 2-methoxy-4-vinylphenol, isovanillic acid methyl ester, 4-hydroxybenzaldehyde, and 4-(ethoxymethyl)-phenol. The EE (400-1000 µg/mL), EtOAc (≤150 µg/mL) and MeOH (50 and 150-600 µg/mL) fractions were not cytotoxic by MTT test. Additionally, the EtOAc fraction (100-400 µg/mL) did not induce significant genotoxic damage. Concentrations of the EtOAc fraction with antioxidant activity showed no cytotoxicity, nor genotoxicity potential, indicating them as a nontoxic natural antioxidant source.

Puerarin alleviates cadmium-induced rat neurocyte injury by alleviating Nrf2-mediated oxidative stress and inhibiting mitochondrial unfolded protein response

Cadmium (Cd) is a highly neurotoxic environmental pollutant. Puerarin (Pur) is a natural antioxidant isolated from Kudzu root that exhibits a powerful neuroprotective effect. Herein, we illustrated the mechanism underlying the protective effect of Pur on Cd-induced rat neurocyte injury in an in vivo rat model as well as in vitro using PC12 cells and primary rat cerebral cortical neurons. First, the results showed that Pur alleviated Cd-induced cerebral cortical pathological damage and decreased the viability of neurocytes. Furthermore, Cd activated the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, which plays a negative role in Cd-induced rat neurocyte injury. In addition, Pur alleviated Cd-induced oxidative stress by enhancing antioxidant defense, reducing reactive oxygen species (ROS) accumulation and lipid peroxidation, and inhibiting activation of the Nrf2 signaling pathway in rat neurocytes. Moreover, Pur inhibited the Cd-induced mitochondrial unfolded protein response (UPRmt) in rat neurocytes. Overall, Pur alleviated Cd-induced rat neurocyte injury by alleviating Nrf2-mediated oxidative stress and inhibiting UPRmt.

Alpha-mangostin Protects PC12 Cells Against Neurotoxicity Induced by Cadmium and Arsenic

Arsenic and cadmium are nonessential elements that are of importance in public health due to their high toxicity. Contact with these toxic elements, even in very small amounts, can induce various side effects, including neurotoxicity. Oxidative stress and apoptosis are part of the main mechanisms of arsenic- and cadmium-induced toxicity. Alpha-mangostin is the main xanthone derived from mangosteen, Garcinia mangostana, with anti-oxidative properties.In this study, PC12 cells were selected as a nerve cell model, and the protective effects of alpha-mangostin against neurotoxicity induced by arsenic and cadmium were investigated. PC12 cells were exposed to cadmium (5-80 µM) and arsenic (2.5-180 µM) for 24 h. Cytotoxicity, reactive oxygen species (ROS) production, and the protein expression of Bax, Bcl2, and cleaved caspase 3 were determined using MTT assay, fluorimetry, and western blot, respectively.Arsenic (10-180 µM) and cadmium (50-80 µM) significantly reduced cell viability. IC₅₀ values were 10.3 ± 1.09 and 45 ± 4.63 µM, respectively. Significant increases in ROS, Bax/Bcl-2 ratio, and cleaved caspase-3 were observed after arsenic and cadmium exposures. Cell viability increased and ROS production decreased when cells were pretreated with alpha-mangostin for 2 h. Alpha-mangostin reduced the increased level of cleaved caspase-3 induced by cadmium and decreased the elevated level of the Bax/Bcl-2 ratio after arsenic exposure.Alpha-mangostin significantly increased cell viability and reduced oxidative stress caused by cadmium and arsenic in PC12 cells. Moreover, alpha-mangostin reduced cadmium-induced apoptosis through the reduction in the level of cleaved caspase 3. Further studies are required to determine the different mechanisms of alpha-mangostin against neurotoxicity induced by these elements.

Bromelain Modulates Liver Injury, Hematological, Molecular, and Biochemical Perturbations Induced by Aluminum via Oxidative Stress Inhibition

Aluminum (Al) is an important factor in the environment as it is used in agriculture and several industries leading to hazardous effects via oxidative stress. Bromelain is a cheap extract from the byproduct waste of Ananas comosus stem. It has been used in several biological and therapeutic applications. So, this study was undertaken to assess the hepatoprotective potential of bromelain versus oxidative stress induced by aluminum chloride in rats. Results revealed that administration of AlCl₃ reduced the body and liver weights and increased Al concentration in the blood and liver tissue. Also, AlCl₃ caused valuable changes in hematological parameters and increased TBARS and H₂O₂ concentrations in rat liver. Enzymatic (SOD, CAT, GPx, GR, and GST) and nonenzymatic (GSH) antioxidants and protein content were significantly decreased. Furthermore, alterations in liver biomarkers such as bilirubin level and enzyme activities in both serum and liver homogenate (LDH, ALP, AST, and ALT) were detected. AlCl₃ also caused inflammation as indicated by upregulation of the inflammation-related genes [interleukin 1 beta (IL-1β)], tumor necrosis factor-alpha (TNF-α), as well as matrix metalloproteinase (MMP9), and downregulation of nuclear factor erythroid 2 (Nrf2) expression. In addition, histopathological examination showed significant variations in the liver that confirms the biochemical results. Otherwise, bromelain intake alone slumped lipid peroxidation and gotten better antioxidant status significantly. Moreover, supplementation with bromelain before AlCl₃ intoxication restores enzymatic and nonenzymatic antioxidants as well as biochemical indices and tissue architecture with respect to the AlCl₃ group. In conclusion, bromelain proved its remarkable protective power to abolish AlCl₃ toxicity. So, it might represent a new strategy in the therapy of metal toxicity by its antioxidant capacity.

Synthesis and characterization of protocatechuic acid grafted carboxymethyl chitosan with oxidized sodium alginate hydrogel through the Schiff's base reaction

Excessive accumulation of free radicals is closely related to the occurrence and development of various neurodegenerative diseases. In this study, a novel protocatechuic acid grafted carboxymethyl chitosan with oxidized sodium alginate (PCA-g-CMCS/OSA) hydrogel was developed to maintain the oxidation-antioxidation balance activities. By optimizing the pH-soluble range (pH > 6.4) of CMCS, PCA was grafted onto CMCS skeleton via EDC/NHS, and then conjugated with aldehyde group of OSA to form Schiff's base hydrogel at physiological temperature. The gelation time can be adjusted rapidly within 1-3 min by controlling the content of OSA. The shaped hydrogel exhibited porous network structure with high porosity (>90 %), swelling ratio (2000-3000 %) and rheological property, which is beneficial to cell growth and proliferation. The conjugates preserved excellent DPPH and ABTS radicals scavenging abilities and adequate biodegradability within 5 weeks. Moreover, with the release of PCA monomer due to degradation of the PCA-g-CMCS/OSA, the hydrogel also exhibited excellent biocompatibility and protective effect on H2O2-induced oxidative damage in PC12 cells. These results suggested that the PCA-g-CMCS/OSA hydrogel would appear to be a more attractive candidate for potential biomedical applications such as antioxidant drug release and tissue engineering implant material.

Cadmium exposure causes mitochondrial fission and fusion disorder in the pig hypothalamus via the PI3K/AKT pathway

Cadmium (Cd) is the main environmental pollutant causing endocrine and nervous system dysfunction in animals. High doses of Cd cause cytotoxicity, including programmed necrosis and apoptosis, which has aroused widespread concern. Mitochondrial dynamics plays a key role in programmed necrosis and apoptosis of endocrine organs. Nevertheless, there is a lack of information on the relationship between Cd-induced programmed necrosis/apoptosis of the hypothalamus and the mitochondrial fusion-fission balance. Therefore, a hypothalamic injury model of Cd exposure was established by adding 20 mg/kg CdCl₂ to the basic pig diet for 40 days. Analysis of the Cd toxicity mechanism was conducted by inductively coupled plasma mass spectrometry, hematoxylin and eosin staining, the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, and quantitative reverse transcription-polymerase chain reaction, as well as western blot analyses. The results suggested that exposure to Cd inhibited the expression of PI3K and AKT, interfered with the balance of mitochondrial fusion and division, downregulated the expression of Mfn2, Mfn1, and OPA1, and upregulated the expression of Drp1 and Mff, which led to cell apoptosis and programmed necrosis in the pig hypothalamus. This study finds that cadmium exposure leads to mitochondrial fission and fusion dysfunction in porcine hypothalamus via the PI3K/AKT pathway.

Protocatechuic acid counteracts oxidative stress and inflammation in carrageenan-induced paw edema in mice

Protocatechuic acid (PCA), a phenolic compound found in teas, fruits, and vegetables, is widely recognized with its antioxidant and anti-inflammatory activities. Here, we verified the protective role of PCA on carrageenan (CGN)-induced paw edema in mice. Forty-five male Swiss albino mice were assigned into five groups: control group, CGN-injected group (1% w/v), PCA (25 mg/kg) + CGN group. PCA (50 mg/kg) + CGN group and diclofenac sodium (20 mg/kg) + CGN group. PCA and diclofenac sodium were administered orally for 5 consecutive days prior to the CGN injection. PCA pretreatment notably decreased the volume of the developed edema and alleviated the histopathological alterations induced by carrageenan. Additionally, PCA administration enhanced the cellular antioxidant capacity as demonstrated by the increased levels of catalase, superoxide dismutase, and reduced glutathione, in addition to the decreased malondialdehyde level in the edematous tissue. Interestingly, PCA administration was able significantly to suppress the developed inflammatory response upon carrageenan injection as indicated by the decreased levels and expression of pro-inflammatory cytokines and mediators including tumor necrosis factor alpha, interleukin-1 beta, interleukin-6, inducible nitric oxide synthase, nitric oxide, cyclooxygenase-II, prostaglandin E2, monocyte chemoattractant protein-1, myeloperoxidase and nuclear factor kappa B. These results collectively confirm the protective effect of PCA against carrageenan-induced paw edema owing to its antioxidant and anti-inflammatory characteristics.

Protective effects of tree peony seed protein hydrolysate on Cd-induced oxidative damage, inflammation and apoptosis in zebrafish embryos

The objective of this study was to investigate protective effects of tree peony seed protein hydrolysate by Alcalase (AL-TPSPH) on oxidative damage, inflammation and apoptosis using Cd-induced zebrafish embryos. Zebrafish embryos were treated with either Cd (2 μg/L) or AL-TPSPH (25, 50 and 75 μg/mL) alone or in combination of both from 4 to 144 h post fertilization (hpf). The effects of these treatments on developments, antioxidant parameters and mRNA expression of genes related to oxidative damage, inflammation and apoptosis were examined. The results showed that co-treatment with Cd and AL-TPSPH significantly increased hatching and survival rates and decreased malformation rates of zebrafish embryos compared with Cd treatment alone group (P < 0.05). Cd-induced increase of MDA content, decreases of T-AOC content, GSH/GSSG ratio and activities of SOD, CAT and GPx in zebrafish embryos were modified upon treatment with AL-TPSPH. AL-TPSPH treatment significantly suppressed Cd-induced down-regulations of the antioxidant gene expressions (Mn-sod, Cat and GPx1a) in zebrafish embryos (P < 0.05). AL-TPSPH also prevented Cd-induced up-regulations of pro-inflammatory cytokine (TNF-α, IL-1β and IFN-γ) expressions. Moreover, AL-TPSPH inhibited Cd-induced up-regulations of pro-apoptotic genes (C-jun, Caspase-3 and Caspase-9) in zebrafish embryos. Collectively, these results indicated that AL-TPSPH could reduce Cd-induced oxidative damage, inflammation and apoptosis in zebrafish embryos, suggesting its future applications as functional food or pharmaceutical ingredient.

Neurotoxicity and transcriptome changes in embryonic zebrafish induced by halobenzoquinone exposure

Halobenzoquinones (HBQs) are emerging disinfection byproducts (DBPs) with a widespread presence in drinking water that exhibit much higher cytotoxicity than regulated DBPs. However, the developmental neurotoxicity of HBQs has not been studied in vivo. In this work, we studied the neurotoxicity of HBQs on zebrafish embryos, after exposure to varying concentrations (0-8 µmol/L) of three HBQs, 2,5-dichloro-1,4-benzoquinone (2,5-DCBQ), 2,6-dichloro-1,4-benzoquinone (2,6-DCBQ), and 2,5-dibromo-1,4-benzoquinone (2,5-DBBQ) for 4 to 120 hr post fertilization (hpf). HBQ exposure significantly decreased the locomotor activity of larvae, accompanied by significant reduction of neurotransmitters (dopamine and γ-aminobutyric acid) and acetylcholinesterase activity. Furthermore, the expression of genes involved in neuronal morphogenesis (gfap, α1-tubulin, mbp, and syn-2α) were downregulated by 4.4-, 5.2-, 3.0-, and 4.5-fold in the 5 µmol/L 2,5-DCBQ group and 2.0-, 1.6-, 2.1-, and 2.3-fold in the 5 µmol/L 2,5-DBBQ group, respectively. Transcriptomic analysis revealed that HBQ exposure affected the signaling pathways of neural development. This study demonstrates the significant neurotoxicity of HBQs in embryonic zebrafish and provides molecular evidence for understanding the potential mechanisms of HBQ neurotoxicity.

Physical activity reduces the role of blood cadmium on depression: A cross-sectional analysis with NHANES data

Cadmium (Cd) exposure is recognized as an important risk factor for psychological health, but suitable physical activity may relieve depression. However, it remains unknown whether physical activity (PA) can reduce the effect of cadmium exposure on depression. Therefore, a cross-sectional data from National Health and Nutrition Examination Survey (NHANES) 2015-2018 was used. The Nine-item Patient Health Questionnaire (PHQ-9) was used to assess depression among the participants. PA was calculated according to the metabolic equivalent (MET), weekly frequency, and duration of each activity. Logistic regression and restricted cubic spline models were used to examine the associations of Cd and depression. A total of 5560 adults aged 20 years and above were finally included in this study. The results indicated a positive correlation between blood Cd and depression. The multivariate-adjusted ORs (95% CI) of the highest quartile were 2.290 (1.754-2.990) for depression, which was still significant after controlling other heavy metals (P < 0.05). Under Cd exposure, the high intensity of physical activity group had the lowest risk of depression (OR = 2.226, 95%CI: 1.447-3.425), while the group with no physical activity had the highest risk (OR = 2.443, 95%CI: 1.382-4.318). Our results indicate that inner Cd exposure may be a risk factor for depression, and physical activity can moderate this relationship to some degree.

Use of Generalized Weighted Quantile Sum Regressions of Tumor Necrosis Factor Alpha and Kidney Function to Explore Joint Effects of Multiple Metals in Blood

Exposure to heavy metals could lead to adverse health effects by oxidative reactions or inflammation. Some essential elements are known as reactors of anti-inflammatory enzymes or coenzymes. The relationship between tumor necrosis factor alpha (TNF-α) and heavy metal exposures was reported. However, the interaction between toxic metals and essential elements in the inflammatory response remains unclear. This study aimed to explore the association between arsenic (As), cadmium (Cd), lead (Pb), cobalt (Co), copper (Cu), selenium (Se), and zinc (Zn) in blood and TNF-α as well as kidney function. We enrolled 421 workers and measured the levels of these seven metals/metalloids and TNF-α in blood; kidney function was calculated by CKD-EPI equation. We applied weighted quantile sum (WQS) regression and group WQS regression to assess the effects of metal/metalloid mixtures to TNF-α and kidney function. We also approached the relationship between metals/metalloids and TNF-α by generalized additive models (GAM). The relationship of the exposure−response curve between Pb level and TNF-α in serum was found significantly non-linear after adjusting covariates (p < 0.001). Within the multiple-metal model, Pb, As, and Zn were associated with increased TNF-α levels with effects dedicated to the mixture of 50%, 31%, and 15%, respectively. Grouped WQS revealed that the essential metal group showed a significantly negative association with TNF-α and kidney function. The toxic metal group found significantly positive associations with TNF-α, serum creatinine, and WBC but not for eGFR. These results suggested Pb, As, Zn, Se, and mixtures may act on TNF-α even through interactive mechanisms. Our findings offer insights into what primary components of metal mixtures affect inflammation and kidney function during co-exposure to metals; however, the mechanisms still need further research.

Effect of cadmium administration on the antioxidant system and neuronal death in the hippocampus of rats

Cadmium (Cd) is a heavy metal classified as a carcinogen whose exposure could affect the function of the central nervous system. Studies suggest that Cd modifies neuronal morphology in the hippocampus and affects cognitive tasks. The oxidative stress pathway is proposed as a mechanism of toxicity. However, this mechanism is not precise yet. This study aimed to evaluate the effect of Cd administration on oxidative stress markers in the male rat's hippocampus. Male Wistar rats were divided into (1) control (drinking water) and (2) treatment with Cd (32.5 ppm of cadmium chloride (CdCl₂ ) in water). The Cd was administered for 2, 3, and 4 months. The results show that the oral administration of CdCl₂ increased the concentration of Cd in plasma and hippocampus, and this response is time-dependent on its administration. Likewise, it caused an increase in lipid peroxidation and nitrosative stress markers. Moreover, it increased reactive astrogliosis and antioxidant enzyme activity. Consequently, the progression of the oxidative response exacerbated neurodegeneration in hippocampal cells. Our results suggest that Cd exposure induces a severe oxidative response that contributes critically to hippocampal neurodegeneration. It is suggested that exposure to Cd increases the risk of developing neurological diseases, which contributes to a decrease in the quality of life of the human and the environment in which it lives.

Hepatoprotective role of vitexin against cadmium-induced liver damage in male rats: A biochemical, inflammatory, apoptotic and histopathological investigation

Cadmium (Cd) is one of the potent occupational and environmental toxicants, which induces oxidative stress to the multiple organs of the body, including liver. The present investigation was planned to evaluate the protective role of vitexin against Cd-prompted hepatotoxicity in rats. 24 male rats were divided into 4 groups viz. control, Cd-induced group (5 mg/kg), Cd + vitexin-treated group (2 mg/kg + 30 mg/kg), and vitexin-treated group (30 mg/kg). After 30 days of treatment, it was indicated that Cd escalated the level of liver function enzymes namely alanine transaminase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) as well as total bilirubin. Whereas the levels of albumin and total proteins were decreased in the rats. Additionally, it reduced the enzymatic activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GSR) and glutathione-S-transferase (GST), in addition to glutathione (GSH) content, whereas levels of malondialdehyde (MDA) and reactive oxygen species (ROS) were escalated. Furthermore, level of nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) as well as the activity of cyclooxygenase-2 (COX-2) were increased. Besides, the level of Bax, caspase-9 and caspase-3 were elevated, while the Bcl-2 level was reduced following the Cd intoxication. Histopathological observation revealed significant hepatic tissue damage in Cd-administered rats. However, treatment of rats with vitexin significantly (p < 0.05) improved the Cd-induced disruptions in biochemical parameters as well as histological damages. Therefore, it is concluded that vitexin could be used as a therapeutic agent to counter the Cd-generated hepatic toxicity in rats owing to its anti-oxidant, anti-apoptotic and anti-inflammatory potential.

Neuroprotective effects of carvacrol against cadmium-induced neurotoxicity in rats: role of oxidative stress, inflammation and apoptosis

Cadmium (Cd), is a heavy metal reported to be associated with oxidative stress and inflammation. In this paper, we investigated the possible protective effects of carvacrol against Cd-induced neurotoxicity in rats. Adult male Sprague Dawley rats were treated orally with Cd (25 mg/kg body weight) and with carvacrol (25 and 50 mg/kg body weight) for 7 days. Carvacrol decreased the levels of malondialdehyde (MDA), glial fibrillary acidic protein (GFAP) and monoamine oxidase (MAO), and significantly increased the levels of glutathione (GSH) and activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in brain tissue. Additionally, carvacrol alleviated the in levels of inflammation and apoptosis related proteins involving p38 mitogen-activated protein kinase (p38 MAPK), cyclooxygenase-2 (COX-2), nuclear factor kappa B (NF-κB), B-cell lymphoma-3 (Bcl-3), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), myeloperoxidase (MPO), prostaglandin E2 (PGE2), neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), cysteine aspartate specific protease-3 (caspase-3) and Bcl-2 associated X protein (Bax) in the Cd-induced neurotoxicity. Carvacrol also decreased the mRNA expression of matrix metalloproteinases (MMP9 and MMP13), as well as 8-hydroxy-2'-deoxyguanosine (8 - OHdG) level, a marker of oxidative DNA damage. Collectively, our findings indicated that carvacrol has a beneficial effect in ameliorating the Cd-induced neurotoxicity in the brain of rats.

Etanercept Mitigates Cadmium Chloride-induced Testicular Damage in Rats "An Insight into Autophagy, Apoptosis, Oxidative Stress and Inflammation"

RATIONALE

Cadmium (Cd) is an environmental and occupational toxin that represents a serious health hazard to humans and other animals. One of the negative consequences of cadmium exposure is testicular injury.

OBJECTIVE

This study aimed to investigate the therapeutic effect of etanercept against cadmium chloride-induced testicular damage and the probable underlying mechanisms of its action.

METHODS

A total of sixty rats were divided into six groups: control, cadmium chloride (CdCl₂) (7 mg/ kg i.p.), and CdCl₂ treated with etanercept (5,10 and 15 mg/kg s.c.) and etanercept only (15 mg/kg s.c.). CdCl₂ was administrated as a single dose, while etanercept was administered every 3 days for 3 weeks.

RESULTS

CdCl₂ reduced serum testosterone, testicular glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). However, it elevated the levels of malondialdehyde (MDA) and microtubule-associated protein light chain 3B (LC3B) in the testes. Cadmium caused pathogenic alterations as well as increased levels of inflammatory biomarkers such as tumor necrosis factor-alpha (TNF-α) and nuclear factor-kappa B (NF-κB). Besides, the gene expressions of caspase-3 and inducible nitric oxide synthase (i-NOS) and Beclin-1 protein increased with CdCl₂ exposure. Interestingly, etanercept relieved the previous toxic effects induced by CdCl₂ in a dose-dependent manner as evidenced by inhibition of oxidative stress, inflammatory markers, Beclin-1, LC3B, and caspase-3 accompanied by improvement in histopathological changes.

CONCLUSION

Etanercept provides a potential therapeutic approach to treat testicular tissue against the damaging effects of Cd by reducing oxidative stress, inflammation, apoptosis, and autophagy.