A review of the protective role of melatonin during phosphine-induced cardiotoxicity: focus on mitochondrial dysfunction, oxidative stress and apoptosis

The role of miRNA-21 and hypoxia inducible factor-1 in predicting post mortem interval in cardiac muscles of aluminum phosphide deaths

BACKGROUND

The assessment of the postmortem interval (PMI) represents one of the major challenges in forensic pathology. Because of their stability, microRNAs, or miRNAs, are anticipated to be helpful in forensic research.

OBJECTIVE

To see if estimation of PMI is possible using miRNA-21 and Hypoxia-inducible factor-1α (HIF-1α) expression levels in the heart samples from aluminum phosphide toxicity (Alpt).

METHODS

This was a cross sectional study on 60 post-mortem samples (heart tissues) collected at different intervals during forensic autopsies. The two groups were allocated equally according to the cause of death into Group I (non-toxicated deaths, n = 30): Deaths caused by other than toxicity, and Group II (toxicated deaths, n = 30): Deaths due to Alpt. MDA (Malondialdehyde) and GSH (Glutathione), were measured in heart tissues using ELIZA. MiRNA- 21and HIF-1α expression levels were measured in heart tissues at different PMI using RT-Q PCR. ROC curve for detection of toxicated deaths using miRNA-21 and HIF was carried out.

RESULTS

miRNA-21 and HIF-1α expression levels in Alp deaths were up regulated while GSH was downregulated with statistically significant difference. There was positive correlation between miRNA-21, HIF-1α and MDA with PMI while there was negative correlation between GSH and PMI in Alp deaths. In prediction of post mortem interval in Alp deaths miRNA-21 sensitivity and specificity were (75.9 %, 51.7 %, respectively) while HIF-1α sensitivity and specificity were 100 %.

CONCLUSION

PMI can be calculated using the degree to which particular miRNA-21 and HIF-1α are expressed in the heart tissue. The combination of miRNA-21 with HIF-1α in post mortem estimation is precious indicators.

Insight into the cardioprotective effects of melatonin: shining a spotlight on intercellular Sirt signaling communication

Cardiovascular diseases (CVDs) are the leading causes of death and illness worldwide. While there have been advancements in the treatment of CVDs using medication and medical procedures, these conventional methods have limited effectiveness in halting the progression of heart diseases to complete heart failure. However, in recent years, the hormone melatonin has shown promise as a protective agent for the heart. Melatonin, which is secreted by the pineal gland and regulates our sleep-wake cycle, plays a role in various biological processes including oxidative stress, mitochondrial function, and cell death. The Sirtuin (Sirt) family of proteins has gained attention for their involvement in many cellular functions related to heart health. It has been well established that melatonin activates the Sirt signaling pathways, leading to several beneficial effects on the heart. These include preserving mitochondrial function, reducing oxidative stress, decreasing inflammation, preventing cell death, and regulating autophagy in cardiac cells. Therefore, melatonin could play crucial roles in ameliorating various cardiovascular pathologies, such as sepsis, drug toxicity-induced myocardial injury, myocardial ischemia-reperfusion injury, hypertension, heart failure, and diabetic cardiomyopathy. These effects may be partly attributed to the modulation of different Sirt family members by melatonin. This review summarizes the existing body of literature highlighting the cardioprotective effects of melatonin, specifically the ones including modulation of Sirt signaling pathways. Also, we discuss the potential use of melatonin-Sirt interactions as a forthcoming therapeutic target for managing and preventing CVDs.

Ruthenium(II) Polypyridyl Complexes with Benzoxazole Derivatives and Non-Innocent Ligands as Effective Antioxidants in Human Neuroblasts

Ruthenium(II) polypyridyl complexes continue to raise increasing interest for the encouraging results in several biomedical areas. Considering their vast chemical-physical repertoire, in particular the possibility to switch from the sensitization of reactive oxygen species (ROS) to ROS-scavenging abilities by tuning the nature of their ligands, it is therefore surprising that their potential as antioxidants has not been largely investigated so far. Herein, we explored the antioxidant behaviour of the novel ruthenium compound [Ru(dbpy)(2,3-DAN)Cl]PF6 (Ru1), featuring a benzoxazole derivative (dpby=2,6-bis(4-methyl-2-benzoxazolyl)pyridine) and the non-innocent 2,3-diamminonaftalene (2,3-DAN) ligand, along with the reference tpy-containing analogue [Ru(tpy)(2,3-DAN)Cl]PF6 (Ru2) (tpy=2,2':6',2''-terpyridine). Following the synthesis and the electrochemical characterization, chemical antioxidant assays highlighted the beneficial role of dpby for the ROS-scavenging properties of Ru1. These data have been corroborated by the highest protective effect of Ru1 against the oxidative stress induced in SH-SY5Y human neuroblastoma, which exerts pro-survival and anti-inflammatory actions. The results herein reported highlight the potential of Ru1 as pharmacological tool in neurodegenerative diseases and specially prove that the antioxidant properties of such compounds are likely the result of a non-trivial synergetic action involving the bioactive ligands in their chemical architectures.

A Retrospective Review on Dysregulated Autophagy in Polycystic Ovary Syndrome: From Pathogenesis to Therapeutic Strategies

The main purpose of this article is to explore the relationship between autophagy and the pathological mechanism of PCOS, and to find potential therapeutic methods that can alleviate the pathological mechanism of PCOS by targeting autophagy. Relevant literatures were searched in the following databases, including: PubMed, MEDLINE, Web of Science, Scopus. The search terms were "autophagy", "PCOS", "polycystic ovary syndrome", "ovulation", "hyperandrogenemia", "insulin resistance", "inflammatory state", "circadian rhythm" and "treatment", which were combined according to the retrieval methods of different databases. Through analysis, we uncovered that abnormal levels of autophagy were closely related to abnormal ovulation, insulin resistance, hyperandrogenemia, and low-grade inflammation in patients with PCOS. Lifestyle intervention, melatonin, vitamin D, and probiotics, etc. were able to improve the pathological mechanism of PCOS via targeting autophagy. In conclusion, autophagy disorder is a key pathological mechanism in PCOS and is also a potential target for drug development and design.

The therapeutic effect of a novel parenteral formulation of dihydroxyacetone in aluminum phosphide-intoxicated patients

Background and objectives

Aluminum phosphide (AlP), known as "rice tablet," is widely used as an effective pesticide. However, AlP poisoning is a common cause of mortality in many countries, such as Iran. Unfortunately, there is no specific antidote for AlP toxicity to date. AlP releases phosphine gas when it is exposed to moisture or acid. Phosphine is a potent mitochondrial toxin that could significantly inhibit cellular energy metabolism. AlP poisoning is an emergency condition that needs instant and effective intervention. Dihydroxyacetone (DHA) is a simple saccharide used for several pharmacological as well as cosmetic purposes. Previously, we found that DHA could significantly prevent mitochondrial impairment induced by toxic agents such as cyanide and phosphine in various in vitro and in vivo experimental models.

Methods

Hospitalized patients (n = 111) were evaluated for eligibility criteria. Among these patients, n = 35 cases were excluded due to incomplete data (n = 11) and suspicion of poisoning with poisons other than AlP (n = 24). Meanwhile, n = 76 cases with confirmed AlP poisoning were included in the study. AlP-poisoned patients who did not receive DHA (n = 18) were used as the control group.Patients (n = 58) received at least one dose of DHA (500 ml of 5 % DHA solution w/v, i.v.) as an adjuvant therapy in addition to the routine treatment of AlP poisoning. Arterial blood gas (ABG), blood pH, bicarbonate levels, and other vital signs and biochemical measurements were monitored. Moreover, the mortality rate and hospitalization time were evaluated in DHA-treated and AlP-poisoned patients without DHA administration. Several biomarkers were assessed before (upon hospitalization) and after DHA treatment. The routine tests for AlP-poisoned patients in this study were the measurement of electrolytes (K+ and Na+), WBC, RBC, hemoglobin, INR, carbonate (HCO3), blood pH, PaCO2, and PaO2 and SGPT, SGOT, BUN, Cr.

Results

Upon patients' admission, significant decreases in blood pH (acidosis), blood PaO2, and HCO3 levels were the hallmarks of AlP poisoning. It was found that DHA significantly alleviated biomarkers of AlP poisoning and tremendously enhanced patients' survival rate (65.52 % in DHA-treated vs 33.34 % in the control group) compared to patients treated based on hospital routine AlP poisoning protocols (no DHA). No significant adverse effects were evident in DHA-treated patients in the current study.

Interpretation and conclusions

These data suggest that parenteral DHA is a novel and effective antidote against AlP poisoning to be used as an adjuvant in addition to routine supportive treatment.

Trial registration

IR.SUMS.REC.1394.102.

Melanogenesis Is Directly Affected by Metabolites of Melatonin in Human Melanoma Cells

Melatonin (N-acetyl-5-methoxytryptamine, MEL), its kynurenic (N1-acetyl-N2-formyl-5-methoxykynurenine, AFMK) and indolic derivatives (6-hydroxymelatonin, 6(OH)MEL and 5-methoxytryptamine, 5-MT) are endogenously produced in human epidermis. Melatonin, produced by the pineal gland, brain and peripheral organs, displays a diversity of physiological functions including anti-inflammatory, immunomodulatory, and anti-tumor capacities. Herein, we assessed their regulatory effect on melanogenesis using amelanotic (A375, Sk-Mel-28) and highly pigmented (MNT-1, melanotic) human melanoma cell lines. We discovered that subjected compounds decrease the downstream pathway of melanin synthesis by causing a significant drop of cyclic adenosine monophosphate (cAMP) level, the microphthalmia-associated transcription factor (MITF) and resultant collapse of tyrosinase (TYR) activity, and melanin content comparatively to N-phenylthiourea (PTU, a positive control). We observed a reduction in pigment in melanosomes visualized by the transmission electron microscopy. Finally, we assessed the role of G-protein-coupled seven-transmembrane-domain receptors. Obtained results revealed that nonselective MT1 and MT2 receptor antagonist (luzindole) or selective MT2 receptor antagonist (4-P-PDOT) did not affect dysregulation of the melanin pathway indicating a receptor-independent mechanism. Our findings, together with the current state of the art, provide a convenient experimental model to study the complex relationship between metabolites of melatonin and the control of pigmentation serving as a future and rationale strategy for targeted therapies of melanoma-affected patients.

Fucoidan/chitosan layered PLGA nanoparticles with melatonin loading for inducing intestinal absorption and addressing triple-negative breast cancer progression

Melatonin and fucoidan are naturally active compounds that have been reported to have therapeutic benefits for patients receiving cancer treatment. However, both compounds face significant challenges, including physical, chemical, and biological metabolisms in the gastrointestinal tract, which limit their ability to achieve therapeutic concentrations at the tumor site. Furthermore, the effectiveness of melatonin and fucoidan as adjuvants in vivo is influenced by the route of administration through the digestive system and their accumulation at the endpoint of the tumor. In this study, we developed an oral administration of nanoparticle, MNPs@C@F, that consisted of PLGA nanoparticles modified with chitosan, to promote intestinal microfold cell transcytosis for the delivery of melatonin and fucoidan into tumors. The experimental results indicated that melatonin and fucoidan in the tumors could regulate the tumor microenvironment by decreasing P-gp, Twist, HIF-1α, and anti-inflammatory immune cell expression, and increasing cytotoxic T cell populations following doxorubicin treatment. This resulted in an increase in chemo-drug sensitivity, inhibition of distant organ metastasis, and promotion of immunogenic cell death. This study demonstrates a favorable co-delivery system of melatonin and fucoidan to directly reduce drug resistance and metastasis in TNBC.

Melatonin Attenuates Oxidative Stress-Induced Apoptosis of Bovine Ovarian Granulosa Cells by Promoting Mitophagy via SIRT1/FoxO1 Signaling Pathway

Oxidative-stress-induced apoptosis of granulosa cells is considered to be a main driver of follicular atresia. Increasing evidence suggests a protective effect of melatonin against oxidative damage but the mechanism remains unclear. The aim of this study is to investigate the effects of melatonin on mitophagy and apoptosis of bovine ovarian granulosa cells under oxidative stress, and to clarify the mechanism. Our results indicate that melatonin inhibited H2O2-induced apoptosis and mitochondrial injury of bovine ovarian granulosa cells, as revealed by decreased apoptosis rate, reactive oxygen species (ROS) levels, Ca2+ concentration, and cytochrome C release and increased mitochondrial membrane potential (ΔΨm). Simultaneously, melatonin promoted mitophagy of bovine ovarian granulosa cells through increasing the expression of PTEN-induced putative kinase 1 (PINK1), PARKIN, BECLIN1, and LC3II/LC3I; decreasing the expression of sequestosome 1 (SQSMT1); and promoting mitophagosome and lysosome fusion. After treatment with a mitophagy inhibitor CsA, we found that melatonin alleviated apoptosis and mitochondrial injury through promoting mitophagy in bovine ovarian granulosa cells. Furthermore, melatonin promoted the expression of silent information regulator 1 (SIRT1) and decreased the expression level of forkhead transcription factors class O (type1) (FoxO1). By treatment with an SIRT1 inhibitor EX527 or FoxO1 overexpression, the promotion of melatonin on mitophagy as well as the inhibition on mitochondrial injury and apoptosis were reversed in bovine ovarian granulosa cells. In conclusion, our results suggest that melatonin could promote mitophagy to attenuate oxidative-stress-induced apoptosis and mitochondrial injury of bovine ovarian granulosa cells via the SIRT1/FoxO1 signaling pathway.

Repurposing of sevelamer as a novel antidote against aluminum phosphide poisoning: An in vivo evaluation

Aluminum phosphide (AlP) is widely used for protecting grains from pests. AlP releases toxic phosphine gas (PH₃) while exposed to humidity. Poisoning with these tablets is dangerous and can cause death or serious injuries. Up to now, no definite antidote has been introduced for specific treatment of this poisoning. Sevelamer carbonate or sevelamer hydrochloride (Renagel) is a polymeric pharmaceutical prescribed for treating hyperphosphatemia in patients with chronic kidney disease. Sevelamer can bind with phosphate groups and act as an anion exchanger. Herein, sevelamer is repurposed as a potent antidote agent in phosphine gas poisoning. In vivo evaluation was conducted on male Sprague Dawley rats. The evaluation was conducted on three groups of animals: control, AlP-poisoned, and AlP-poisoned treated with sevelamer. Survival percentage, serum biomarkers level of organ injury, and ATP level were recorded. The results indicate a high survival rate in sevelamer-treated animals compared with the AlP-poisoned group (75% vs. 0% respectively, 48 h after poisoning). The analysis of serum markers of organ injury also showed that sevelamer could reduce toxicity and organ injury in poisoned animals. ATP level of separate organs showed that sevelamer treated groups were recovered. The results showed that sevelamer could be a potent antidote for managing aluminum phosphide poisoning. Moreover, a mechanism is suggested for the interaction of sevelamer with phosphine gas.

Exogenous melatonin mediates radish (Raphanus sativus) and Alternaria brassicae interaction in a dose-dependent manner

Radish (Raphanus sativus L.) is an economically important vegetable worldwide, but its sustainable production and breeding are highly threatened by blight disease caused by Alternaria brassicae. Melatonin is an important growth regulator that can influence physiological activities in both plants and microbes and stimulate biotic stress resistance in plants. In this study, 0-1500 μM melatonin was exogenously applied to healthy radish seedlings, in vitro incubated A. brassicae, and diseased radish seedlings to determine the effects of melatonin on host, pathogen, and host-pathogen interaction. At sufficient concentrations (0-500 μM), melatonin enhanced growth and immunity of healthy radish seedlings by improving the function of organelles and promoting the biosynthesis of antioxidant enzymes, chitin, organic acid, and defense proteins. Interestingly, melatonin also improved colony growth, development, and virulence of A. brassicae. A strong dosage-dependent effect of melatonin was observed: 50-500 μM promoted host and pathogen vitality and resistance (500 μM was optimal) and 1500 μM inhibited these processes. Significantly less blight was observed on diseased seedlings treated with 500 μM melatonin, indicating that melatonin more strongly enhanced the growth and immunity of radish than it promoted the development and virulence of A. brassicae at this treatment concentration. These effects of MT were mediated by transcriptional changes of key genes as identified by RNA-seq, Dual RNA-seq, and qRT-PCR. The results from this work provide a theoretical basis for the application of melatonin to protect vegetable crops against pathogens.

Role of melatonin and quercetin as countermeasures to the mitochondrial dysfunction induced by titanium dioxide nanoparticles

AIM

Due to the growing commercialization of titanium dioxide nanoparticles (TNPs), it is necessary to use these particles in a manner that is safe, healthy and environmental friendly. Through reactive oxygen species (ROS) generation, it has been discovered that TNPs have a harmful effect on the brain. The aim of this study is to provide valuable insights into the possible mechanisms of TNPs induced mitochondrial dysfunction in brain and its amelioration by nutraceuticals, quercetin (QR) and melatonin (Mel) in in vitro and in vivo conditions.

MATERIALS AND METHODS

Whole brain mitochondrial sample was used for in-vitro evaluation. Pre-treatment of QR (30 μM) and Mel (100 μM) at 25 °C for 1 h was given prior to TNPs (50 μg/ml) exposure. For in-vivo study, male Wistar rats were divided into four groups. Group I was control and group II was exposed to TNPs (5 mg/kg b.wt., i.v.). QR (5 mg/kg b.wt.) and Mel (5 mg/kg b.wt.) were given orally as pre-treatment in groups III and IV, respectively. Biochemical parameters, neurobehavioural paradigms, mitochondrial respiration, neuronal architecture assessment were assessed.

KEY FINDINGS

QR and Mel restored the mitochondrial oxidative stress biomarkers in both the studies. Additionally, these nutraceuticals resuscitated the neurobehavioural alterations and restored the neuronal architecture alterations in TNPs exposed rats. The mitochondrial dysfunction induced by TNPs was also ameliorated by QR and Mel by protecting the mitochondrial complex activity and mitochondrial respiration rate.

SIGNIFICANCE

Results of the study demonstrated that QR and Mel ameliorated mitochondrial mediated neurotoxic effects induced by TNPs exposure.

Cell-penetrating peptide-mediated delivery of therapeutic peptides/proteins to manage the diseases involving oxidative stress, inflammatory response and apoptosis

OBJECTIVES

Peptides and proteins represent great potential for modulating various cellular processes including oxidative stress, inflammatory response, apoptosis and consequently the treatment of related diseases. However, their therapeutic effects are limited by their inability to cross cellular barriers. Cell-penetrating peptides (CPPs), which can transport cargoes into the cell, could resolve this issue, as would be discussed in this review.

KEY FINDINGS

CPPs have been successfully exploited in vitro and in vivo for peptide/protein delivery to treat a wide range of diseases involving oxidative stress, inflammatory processes and apoptosis. Their in vivo applications are still limited due to some fundamental issues of CPPs, including nonspecificity, proteolytic instability, potential toxicity and immunogenicity.

SUMMARY

Totally, CPPs could potentially help to manage the diseases involving oxidative stress, inflammatory response and apoptosis by delivering peptides/proteins that could selectively reach proper intracellular targets. More studies to overcome related CPP limitations and confirm the efficacy and safety of this strategy are needed before their clinical usage.

Inhibition of mitochondrial permeability transition pore and antioxidant effect of Delta-9-tetrahydrocannabinol reduces aluminium phosphide-induced cytotoxicity and dysfunction of cardiac mitochondria

Previous studies have demonstrated that phosphine gas (PH₃) released from aluminium phosphide (AlP) can inhibit cytochrome oxidase in cardiac mitochondria and induce generation of free radicals, oxidative stress, alteration in antioxidant defense system and cardiotoxicity. Available evidence suggests that cannabinoids have protective effects in the reduction of oxidative stress, mitochondrial and cardiovascular damages. The objective of this study was to evaluate the effect of trans-Δ-9-tetrahydrocannabinol (THC) on AlP-induced toxicity in isolated cardiomyocytes and cardiac mitochondria. Rat heart isolated cardiomyocytes and mitochondria were cotreated with different concentrations of THC (10, 50 and 100 μM) and IC50 of AlP, then cellular and mitochondrial toxicity parameters were assayed. Treatment with AlP alone increased the cytotoxicity, depletion of cellular glutathione (GSH), mitochondrial reactive oxygen species (ROS) generation, lipid oxidation, mitochondria membrane potential (ΔΨm) collapse and mitochondrial swelling, when compared to control group. However, incubation with THC (10, 50 and 100 μM) attenuated the AlP-induced changes in all these parameters in a THC concentration-dependent manner. Interestingly, the obtained results showed remarkably significant protective effects of THC by attenuation the different parameters of cytotoxicity, mitochondrial toxicity and oxidative stress induced by ALP in isolated cardiomyocytes and cardiac mitochondria. It is the first report showing the protective effects of THC against AlP-induced toxicity, and these effects are related to antioxidant potential and inhibition of mitochondria permeability transition (MPT) pore. Based on these results, it was hypothesized that THC may be used as a potential therapeutic agent for the treatment of AlP-induced mitochondrial dysfunction and cardiotoxicity.

The melatonin MT2 receptor is involved in the anti-apoptotic effects of melatonin in rats with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a widely prevalent chronic disease and risk factor for several other diseases, such as cardiovascular diseases, neuropathy, nephropathy, and retinopathy. Apoptosis is a homeostatic mechanism to maintain cell numbers at a certain level in tissues. Chronic high blood glucose levels might lead to mitochondrial dysfunction and trigger undesirable apoptosis in T2DM. The pineal hormone melatonin has been shown to regulate apoptosis. The aim of this study was to investigate the impact of the melatonin MT₂ receptor in the role of melatonin to prevent undesirable apotosis in different tissues of diabetic rats. Male Sprague Dawley rats were randomly divided into 4 groups; 1. Control group (only vehicle), 2. Diabetic group (streptozotozin/nicotinamide treated), 3. Diabetic group treated with melatonin (500μg/kg/day), and 4. Diabetic group treated with melatonin (500 μg/kg/day for 6 weeks) and the selective MT₂ receptor antagonist luzindole (0.25 g/kg/day for 6 weeks). Various tissue samples (kidney, liver, adipose tissue, pancreas) were removed after 6 weeks for immunohistochemistry and western blot analysis. Our results demonstrated an increased rate of apoptosis in different tissues of diabetic rats compared to controls with melatonin reducing the apoptotic rate in the tissues of rats with T2DM. Furthermore, the anti-apoptotic effects of melatonin were partly mediated by the melatonin MT₂ receptor.

The Role of Echocardiographic Findings in Estimating Survival Probability of Intensive Care Unit Admitted Aluminum Phosphide Poisoned Patients

INTRODUCTION

Cardiotoxicity represents the primary cause of death in acute aluminum phosphide (AlP) poisoning. Prompt supportive care can improve patient survival. This study assessed the role of echocardiography in estimating the survival probability of AlP-poisoned patients admitted to the intensive care unit.

METHODS

A prospective cohort study of symptomatic acute AlP poisoned patients was conducted between September 2019 and December 2020. Patients were subjected to history taking, clinical examination, To be included, patient evaluation needed to include electrocardiographic (ECG) and echocardiographic studies. The statistical analysis assessed the association between patient survival and relevant factors. Survival analysis was performed using the Kaplan-Meier survival curve and Cox proportional hazard regression.

RESULTS

A total of 90 patients met inclusion criteria. Electrocardiographic abnormalities were detected in 38.1% of survivors and 82.6% of non-survivors (p < 0.001). Survivors had a higher mean left ventricle ejection fraction (LVEF) (50.86 ± 6.30% vs. 26.52 ± 7.64%, respectively, p < 0.001) and a lower percentage of global LV hypokinesia (4.8% vs. 94.2%, p < 0.001). The mean survival time was higher among patients with LVEF ≥ 50% than those with LVEF = 41-49% and ≤ 40% (p = 0.014 and 0.001, respectively). The hazard of death was 4.42 and 5.40 times greater in patients with LVEF ≤ 40% or with global LV hypokinesia, respectively. Regression revealed that the global LV hypokinesia, ECG abnormalities, and decreased LVEF and oxygen saturation were significantly associated with the risk of death (hazard ratios: 4.382, 3.348, 0.957, and 0.971, respectively).

CONCLUSIONS

Echocardiography represents a valuable diagnostic tool to assess cardiac function in acute AlP poisoning. Both LVEF and global LV hypokinesia significantly impact the survival of AlP-poisoned patients. Echocardiography was superior to ECG changes in terms of accuracy for the prediction of mortality.

Sensing of oxidative stress biomarkers: The cardioprotective effect of taurine & grape seed extract against the poisoning induced by an agricultural pesticide aluminum phosphide

Aluminum phosphide is a well-known hazardous agent used as an agricultural pesticide to protect stored grains from insect damage. However, accidental consumption of a trivial amount of it caused irreversible damage to the human body or even death in acute cases. The present study used taurine and grape seed extract as a natural cardioprotective medicine against aluminum phosphide poisoning by decreasing oxidative stress. The activity of oxidative stress biomarkers (Malondialdehyde, Catalase, Protein carbonyl, and Superoxide dismutase) were evaluated in the cell line model on Human Cardiac Myocyte cells. In the beginning, to clarify the pure impact of aluminum phosphide poison, taurine, and grape seed extract on the human heart cells, their effects on the biomarkers quantity in cell line were measured. Subsequently, the effect of taurine and grape seed extract with various concentrations as a treatment on the oxidative stress biomarkers of the poisoned heart cells were studied. Data analysis reveals that taurine and grape seed extract treatment can successfully diminish the poisoning effect by their antioxidant properties. The oxidative markers values of the poisoned cells were recovered by taurine and grape seed extracts treatment. Taurine (2 g/l) can recover Malondialdehyde, Catalase, Protein carbonyl, and Superoxide dismutase by 56%, 78%, 88%, 78%, when the recovering power of grape seed extract (100 g/l) for the aforementioned enzymes are 56%, 0.71%,74%, 51%, respectively. Therefore, it is clear that the performance of taurine in the recovery of the biomarkers' value is better than grape seed extract.

Melatonin Enhances Anti-tumoral Effects of Menadione on Colon Cancer Cells

BACKGROUND

Colon cancer is one of the most important causes of death in the entire world. New pharmacological strategies are always needed, especially in resistant variants of this pathology. We have previously reported that drugs such as menadione (MEN), D, L-buthionine-S,R-sulfoximine or calcitriol, used in combination, enhanced cell sensibility of breast and colon tumour models, due to their ability to modify the oxidative status of the cells. Melatonin (MEL), a hormone regulating circadian rhythms, has anti-oxidant and anti-apoptotic properties at low concentrations, while at high doses, it has been shown to inhibit cancer cell growth.

OBJECTIVE

The objective of this study is to determine the antitumoral action of the combination MEN and MEL on colon cancer cells.

METHODS

Caco-2 cells were employed to evaluate the effects of both compounds, used alone or combined, on cellular growth/morphology, oxidative and nitrosative stress, and cell migration.

RESULTS

MEN plus MEL dramatically reduced cell proliferation in a time and dose-dependent manner. The antiproliferative effects began at 48 h. At the same time, the combination modified the content of superoxide anion, induced the formation of reactive nitrogen species and enhanced catalase activity. Cell migration process was delayed. Also, changes in nuclear morphology consistent with cell death were observed.

CONCLUSION

The enhanced effect of simultaneous use of MEN and MEL on Caco-2 cells suggests that this combined action may have therapeutic potential as an adjuvant on intestinal cancer acting in different oncogenic pathways.

On the mechanisms of taurine in alleviating electrocardiographic, hemodynamic, and biochemical parameters following aluminum phosphide cardiotoxicity

BACKGROUND

Aluminum phosphide (AlP) causes severe cardiotoxicity. Taurine has been chosen for the present study because of its positive known effects on cardiac injuries.

METHOD

To evaluate AlP-induced cardiotoxicity, the animals were divided into seven groups, including the control group, the taurine group (500 mg/kg), AlP with LD50 dose, AlP + taurine 20, 50, 100, and 200 mg/kg group. To assess cardiac hemodynamic parameters, Wistar rats received taurine intraperitoneally 60 min after AlP gavage. Cardiac hemodynamic parameters were evaluated for 180 min. To study biochemical parameters, 24 h after AlP treatment, the animals were sacrificed, and heart tissues were collected.

RESULT

ECG, BP, and HR abnormalities of AlP poisoning were improved by taurine treatment. AlP induced biochemical alterations including complexes I and IV activities, the ADP/ATP ratio, mitochondrial membrane potential, cytochrome C release, and oxidative stress biomarkers ameliorated by taurine. Moreover, taurine improved apoptosis, as well as lessened CK-MB and troponin I levels. Also, there were no significant changes between taurine 500 mg/kg and the control group in tests.

CONCLUSION

The present findings showed that taurine could be a possible candidate for AlP cardiotoxicity treatment via the effect on mitochondrial electron transfer chain and maintaining intracellular ATP balance.

Recent Progress in Environmental Toxins-Induced Cardiotoxicity and Protective Potential of Natural Products

Humans are unconsciously exposed to environmental toxins including heavy metals as well as various pesticides, which have deleterious effects on human health. Accumulating studies pointed out that exposure to environmental toxins was associated with various cardiopathologic effects. This review summarizes the main mechanisms of cardiotoxicity induced by environmental toxins (cadmium, arsenic and pesticides) and discusses the potential preventive effects of natural products. These findings will provide a theoretical basis and novel agents for the prevention and treatment of environmental toxins-induced cardiotoxicity. Furthermore, the limitations of current studies, future needs and priorities are discussed.

Acute aluminum phosphide poisoning: The menace of phosphine exposure

Aluminum phosphide (AlP) is a popular fumigant used widely for the safe storage of food grain. Although A1P is free from toxic residues, it releases phosphine which acts on mitochondrial components of almost all types of pests. Unfortunately A1P is also a common suicidal agent in developing countries with no known antidote. In addition, accidental exposure to phosphine may also occur. AlP poisoning affects cardiac and vascular tissue directly and can result in multiorgan system failure leading to death in severe cases. There is no specific biomarker for diagnosing AlP poisoning and management depends on a high level of clinical suspicion. Although acetylcholinesterase has been suggested as a surrogate biomarker of AlP exposure, there are opposing views. In this review, we analyzed the relevant published material with emphasis on the need to recognize and explore the use of plasma mitochondrial enzyme activity as a potential biomarker for AlP exposure.

Benomyl induced oxidative stress related DNA damage and apoptosis in H9c2 cardiomyoblast cells

Benomyl, benzimidazole group pesticide, has been prohibited in Europe and USA since 2003 due to its toxic effects and it has been still determined as food and environmental contaminant. In the present study, the toxic effect mechanisms of benomyl were evaluated in rat cardiomyoblast (H9c2) cells. Cytotoxicity was determined by MTT and NRU assay and, oxidative stress potential was evaluated by reactive oxygen species (ROS) production and glutathione levels. DNA damage was assessed by alkaline comet assay. Relative expressions of apoptosis related genes were evaluated; furthermore, NF-κB and JNK protein levels were determined. At 4 μM concentration (at which cell viability was >70%), benomyl increased 2-fold of ROS production level and 2-fold of apoptosis as well as DNA damage. Benomyl down-regulated miR21, TNF-α and Akt1 ≥ 48.75 and ≥ 97.90; respectively. PTEN, JNK and NF-κB expressions were upregulated. The dramatic changes in JNK and NF-κB expression levels were not observed in protein levels. These findings showed the oxidative stress related DNA damage and apoptosis in cardiomyoblast cells exposed to benomyl. However, further mechanistic and in vivo studies are needed to understand the cardiotoxic effects of benomyl and benzimidazol fungucides.

Melatonin Alleviates the Toxicity of High Nicotinamide Concentrations in Oocytes: Potential Interaction with Nicotinamide Methylation Signaling

Despite the numerous studies on melatonin and nicotinamide (NAM, the active form of vitamin B3), the linkage between these two biomolecules in the context of signaling pathways regulating preimplantation embryo development has not yet been investigated. In this study, we used bovine oocyte model to elucidate the effect of melatonin on the developmental competence of oocytes under the stress of high NAM concentrations. Results showed that NAM (20 mM) administration during in vitro maturation (IVM) significantly reduced oocyte maturation and actin distribution, while induced reactive oxygen species (ROS) accumulation and mitochondrial dysfunction, the multiple deleterious effects that were alleviated by melatonin (10⁻⁷ M). The RT-qPCR and/or immunofluorescence showed upregulation of the apoptosis (Caspase-3, Caspase-9, and BAX), autophagy (Beclin-1, LC3A, LC3B, ATG7, LAMP1, and LAMP2), cell cycle (P21, P27, and P53), and DNA damage (COX2 and 8-OxoG) specific markers in oocytes matured under NAM treatment, compared to NAM-melatonin dual-treated and the untreated ones. In addition, the total cleavage and blastocyst development rate, as well as the total number of cells and the inner cell mass (ICM) per blastocyst, were reduced, while DNA fragmentation was induced, in the group of NAM sole treatment than NAM-melatonin cotreatment and control. Inspecting the underlying mechanisms behind NAM-associated toxicity revealed an increase in transcription pattern of NAM methylation (NNMT and AHCY) genes in NAM-treated oocytes while the opposite profile was observed upon melatonin supplementation. In conclusion, to our knowledge, this is the first study reporting that melatonin can protect oocytes and embryos from NAM-induced injury through its ROS-scavenging activity together with potential interaction with NAM methylation signaling.

Melatonin protects the heart and pancreas by improving glucose homeostasis, oxidative stress, inflammation and apoptosis in T2DM-induced rats

Cardiomyopathy and pancreatic injury are health issues associated with type 2 diabetes mellitus (T2DM) and are characterized by elevated oxidative stress, inflammation and apoptosis. Melatonin (MLT) is a hormone with multifunctional antioxidant activity. The protective effects of MLT on the heart and pancreas during the early development of diabetic cardiomyopathy and pancreatic injury were investigated in male Wistar rats with T2DM. MLT (10 mg/kg) was administered daily by gavage for 15 days after diabetic induction. Treatment of diabetic rats with MLT significantly normalized the levels of serum glucose, HbA1-c, and the lipid profile and improved the insulin levels and insulin resistance compared with diabetic rats, affirming its antidiabetic effect. MLT significantly prevented the development of oxidative stress and sustained the levels of glutathione and glutathione peroxidase activity in the heart and pancreas of diabetic animals, indicating its antioxidant capacity. Additionally, MLT prevented the increase in proinflammatory cytokines and expression of Bax, caspase-3 and P53. Furthermore, MLT enhanced the anti-inflammatory cytokine IL-10 and antiapoptotic protein Bcl-2. MLT controlled the levels of troponin T and creatine kinase-MB and lactate dehydrogenase activity, indicating its anti-inflammatory and antiapoptotic effects. Histological examinations confirmed the protective effects of MLT on T2DM-induced injury in the myocardium, pancreas and islets of Langerhans. In conclusion, the protective effects of melatonin on the heart and pancreas during the early development of T2DM are attributed to its antihyperglycemic, antilipidemic and antioxidant influences as well as its remarkable anti-inflammatory and antiapoptotic properties.

Study of the cardioprotective effects of crocin on Human Cardiac Myocyte cells and reduction of oxidative stress produced by aluminum phosphide poisoning

OBJECTIVES

The effects of Crocin as a cardioprotective material against Aluminum phosphide poisoning by reducing the oxidative stress is investigated.

METHODS

The level of biomarkers of oxidative stress (Catalase, Superoxide dismutase, Malondialdehyde and Protein carbonyl) were measured in the cell culture model on Human Cardiac Myocyte cells to detect the protective effect of crocin. Initially, to define the pure impact of aluminum phosphide poison and crocin on the heart cells, their effects on the biomarkers quantity in cell line were measured, separately, using the standard related kits. Later the effect of crocin with different concentration as a treatment on the oxidative stress biomarkers of the poisoned heart cells were monitored. Note that in pre-treatment case, the crocin was initially added to the cells before poisoning them. Data were analyzed using the analysis of variance method.

KEY FINDINGS

Results showed that crocin treatment reduced the aluminum phosphide (AlP) poisoning effect significantly. The treatment resulted in substantial deviation in the biomarkers of oxidative stress at the pre- and post-treatment phases for all groups. The oxidative markers values of the poisoned cells were recovered by crocin treatment.

CONCLUSIONS

Crocin is proposed as a potentially powerful antioxidant to treat the cardiotoxicity caused by aluminum phosphide poisoning.

Flavonoid-rich fraction attenuates permethrin-induced toxicity by modulating ROS-mediated hepatic oxidative stress and mitochondrial dysfunction ex vivo and in vivo in rat

The present study explores the antioxidant, anti-microbial, and hepatoprotective potentials of flavonoid-rich fractions from Fumaria officinalis against permethrin-induced liver damage ex vivo/in vivo in rat. However, HPLC-DAD analysis revealed the richness of 6 components in ethyl acetate fraction (EAF) where ferulic acid, rosmarinic acid, and myricetin are the most abundant. The in vitro assays showed that EAFs have impressive antioxidant and anti-microbial properties. Ex vivo, permethrin (PER) (100 μM) induced a decrease of hepatic AST and ALT activities and 25-OH vitamin D and vitamin C levels and an increase of ALP and LDH activities, TBARS, and ϒ-GT levels with a disturbance of oxidative status. The hepatoprotective effect of EAF (1 mg/mL) against PER was confirmed by the amelioration of oxidative stress profile. In vivo, permethrin was found to increase absolute and relative liver weights, plasma transaminase activities, lactate-to-pyruvate ratio, hepatic and mitochondrial lipid peroxidation, and protein oxidation levels. This pesticide triggered a decrease of Ca²⁺ and Mg²⁺-ATPases and mitochondrial enzyme activities. The co-treatment with EAF reestablished the hepatic and mitochondrial function, which could be attributed to its richness in phenolic compounds.

Melatonin Alleviates Hypoxia-Induced Apoptosis of Granulosa Cells by Reducing ROS and Activating MTNR1B-PKA-Caspase8/9 Pathway

In mammalian ovaries, the avascular environment within follicular cavity is supposed to cause hypoxic status in granulosa cells (GCs), leading to apoptotic cell death accompanied by cumulative reactive oxygen species (ROS) production. Melatonin (N-acetyl-5-methoxytryptamine, MT), a broad-spectrum antioxidant that exists in porcine follicle fluid, was suggested to maintain GCs survival under stress conditions. In this study, using the established hypoxic model (1% O₂) of cultured porcine GCs, we explored the effect of MT on GCs apoptosis. The results showed that MT restored cell viability and reduced the apoptosis of GCs during hypoxia exposure. In addition, GCs treated with MT exhibited decreased ROS levels and increased expression of antioxidant enzymes including heme oxygenase-1 (HO-1), glutathione S-transferase (GST), superoxide dismutase 1 (SOD1), and catalase (CAT) upon hypoxia incubation. Moreover, the hypoxia-induced expression of cleaved caspase 3, 8, and 9 was significantly inhibited after MT treatment. In contrast, blocking melatonin receptor 2 (MTNR1B) with a competitive antagonist 4-phenyl-2-propionamidotetralin (4P-PDOT) diminished the inhibitory effects of MT on caspase 3 activation. By detecting levels of protein kinase (PKA), a downstream kinase of MTNR1B, we further confirmed the involvement of MT–MTNR1B signaling in mediating GCs protection during hypoxia stress. Together, the present data provide mechanistic evidence suggesting the role of MT in defending GCs from hypoxia-induced apoptosis.

Sudden Cardiac Arrest in an Asymptomatic Zinc Phosphide-Poisoned Patient: A Case Report

Zinc phosphide is a gray to black powder mainly used as a rodenticide. In contact with gastric fluid, it releases phosphine which is the main toxic material of this compound. Phosphine interferes with oxidative respiratory cycle of the cells, but is generally expected to manifest its toxicity with prodromal signs and symptoms including abdominal pain, nausea and vomiting, metabolic acidosis, and increased liver function tests. A 64-year-old man was referred to our center with the history of ingestion of three full table spoons of zinc phosphide powder with only a mild GI discomfort. Abdominal X-ray revealed radiopaque material in epigastric and abdominal right upper quadrant. Despite treatment with polyethylene glycol and completely normal vital signs and lab tests, he experienced sudden cardiac arrest 19 h after admission. Autopsy showed clues of focal myopathy and fibrosis with evidences of ischemia and congestion in cardiac tissue, pulmonary edema, shrunken bilateral kidneys, and nutmeg yellow liver. Toxicology panel confirmed the presence of phosphine and zinc phosphide in the gastric fluid. The patient deteriorated suddenly despite being completely symptom-free during the hours preceding cardiovascular arrest. Since the cardiopulmonary injury is the most rampant cause of early death, checking of the cardiac enzymes and cardiac monitoring could be beneficial for early detection and efficient management of these patients.

The Molecular Mechanism of Aluminum Phosphide poisoning in Cardiovascular Disease: Pathophysiology and Diagnostic Approach

Nowadays, poisoning with metal phosphides, especially aluminum phosphide (ALP), is one of the main health threats in human societies. Patients suffer from significant complications due to this type of poisoning, and the heart is one of the main organs targeted by ALP. Therefore, in this study, we discussed the effect of phosphine on cardiac function. This study is based on data obtained from PubMed, between 2002 and 2020. The key keywords included "Aluminum phosphide," "Oxidative Stress," "Mitochondria," "Cardiovascular disease," and "Treatment." The results showed that ALP produced reactive oxygen species (ROS) due to mitochondrial dysfunction. ROS production leads to red blood cell hemolysis, decreased ATP production, and induction of apoptosis in cardiomyocytes, which eventually results in cardiovascular disease. Since ALP has the most significant effect on cardiomyocytes, the use of appropriate treatment strategies to restore cell function can increase patients' survival.

Construction of homologous cancer cell membrane camouflage in a nano-drug delivery system for the treatment of lymphoma

BACKGROUND

Non-Hodgkin's lymphoma (NHL) possesses great heterogeneity in cytogenetics, immunophenotype and clinical features, and chemotherapy currently serves as the main treatment modality. Although employing monoclonal antibody targeted drugs has significantly improved its overall efficacy, various patients continue to suffer from drug resistance or recurrence. Chinese medicine has long been used in the treatment of malignant tumors. Therefore, we constructed a low pH value sensitivity drug delivery system based on the cancer cell membrane modified mesoporous silica nanoparticles loaded with traditional Chinese medicine, which can reduce systemic toxicity and improve the therapeutic effect for the targeted drug delivery of tumor cells.

RESULTS

Accordingly, this study put forward the construction of a nano-platform based on mesoporous silica nanoparticles (MSNs) loaded with the traditional Chinese medicine isoimperatorin (ISOIM), which was camouflaged by the cancer cell membrane (CCM) called CCM@MSNs-ISOIM. The proposed nano-platform has characteristics of immune escape, anti-phagocytosis, high drug loading rate, low pH value sensitivity, good biocompatibility and active targeting of the tumor site, blocking the lymphoma cell cycle and promoting mitochondrial-mediated apoptosis.

CONCLUSIONS

Furthermore, this study provides a theoretical basis in finding novel clinical treatments for lymphoma.

New insights into antimetastatic signaling pathways of melatonin in skeletomuscular sarcoma of childhood and adolescence

Melatonin is an indole produced by the pineal gland at night under normal light or dark conditions, and its levels, which are higher in children than in adults, begin to decrease prior to the onset of puberty and continue to decline thereafter. Apart from circadian regulatory actions, melatonin has significant apoptotic, angiogenic, oncostatic, and antiproliferative effects on various cancer cells. Particularly, the ability of melatonin to inhibit skeletomuscular sarcoma, which most commonly affects children, teenagers, and young adults, is substantial. In the past few decades, the vast majority of references have focused on the concept of epithelial-mesenchymal transition involvement in invasion and migration to allow carcinoma cells to dissociate from each other and to degrade the extracellular matrix. Recently, researchers have applied this idea to sarcoma cells of mesenchymal origin, e.g., osteosarcoma and Ewing sarcoma, with their ability to initiate the invasion-metastasis cascade. Similarly, interest of the effects of melatonin has shifted from carcinomas to sarcomas. Herein, in this state-of-the-art review, we compiled the knowledge related to the molecular mechanism of antimetastatic actions of melatonin on skeletomuscular sarcoma as in childhood and during adolescence. Utilization of melatonin as an adjuvant with chemotherapeutic drugs for synergy and fortification of the antimetastatic effects for the reinforcement of therapeutic actions are considered.

Chrysin ameliorates aluminum phosphide-induced oxidative stress and mitochondrial damages in rat cardiomyocytes and isolated mitochondria

Apart from the anticancer, antioxidant, anti-inflammatory effects, and inhibition of aromatase, chrysin is involved in the protection of cardiovascular disorders. Cardiovascular complications are the main cause of death induced by aluminum phosphide (AlP) which is related to oxidative stress and mitochondrial damages. For this purpose, we investigated the effect of chrysin as an antioxidant and mitochondrial protective agent against AlP-induced toxicity in isolated cardiomyocytes and mitochondria obtained from rat heart ventricular. Using by biochemical and flow cytometry, cell viability, reactive oxygen species (ROS) formation, mitochondria membrane potential (MMP), lysosomal membrane integrity, malondialdehyde (MDA) content, and glutathione (GSH) and oxidized glutathione (GSSG) content were measured in isolated cardiomyocytes. Also, mitochondrial toxicity parameters such as mitochondrial NADH/succinate dehydrogenase activity, mitochondrial swelling, ROS formation, MMP collapse, and lipid peroxidation were analyzed in isolated mitochondria. Our results showed that the administration of chrysin (up to 10 μM) efficiently decreased (P < 0.05) cytotoxicity, oxidative, lysosomal, and mitochondrial damages induced by AlP, in isolated cardiomyocytes. Also, our finding in isolated mitochondria showed that chrysin (up to 10 μM) significantly (P < 0.05) decreased AlP-induced mitochondrial toxicity. These findings demonstrated that chrysin as an antioxidant and mitochondrial protective agent exert protective effect in wild-type cardiomyocyte treated with AlP. It was concluded that chrysin significantly reduced the toxicity of AlP in isolated cardiomyocytes and mitochondria. Due to the very low toxicity of chrysin for humans, it could be a promising agent in treatment of AlP poisoning.

Targeting Host Defense System and Rescuing Compromised Mitochondria to Increase Tolerance against Pathogens by Melatonin May Impact Outcome of Deadly Virus Infection Pertinent to COVID-19

Fighting infectious diseases, particularly viral infections, is a demanding task for human health. Targeting the pathogens or targeting the host are different strategies, but with an identical purpose, i.e., to curb the pathogen's spreading and cure the illness. It appears that targeting a host to increase tolerance against pathogens can be of substantial advantage and is a strategy used in evolution. Practically, it has a broader protective spectrum than that of only targeting the specific pathogens, which differ in terms of susceptibility. Methods for host targeting applied in one pandemic can even be effective for upcoming pandemics with different pathogens. This is even more urgent if we consider the possible concomitance of two respiratory diseases with potential multi-organ afflictions such as Coronavirus disease 2019 (COVID-19) and seasonal flu. Melatonin is a molecule that can enhance the host's tolerance against pathogen invasions. Due to its antioxidant, anti-inflammatory, and immunoregulatory activities, melatonin has the capacity to reduce the severity and mortality of deadly virus infections including COVID-19. Melatonin is synthesized and functions in mitochondria, which play a critical role in viral infections. Not surprisingly, melatonin synthesis can become a target of viral strategies that manipulate the mitochondrial status. For example, a viral infection can switch energy metabolism from respiration to widely anaerobic glycolysis even if plenty of oxygen is available (the Warburg effect) when the host cell cannot generate acetyl-coenzyme A, a metabolite required for melatonin biosynthesis. Under some conditions, including aging, gender, predisposed health conditions, already compromised mitochondria, when exposed to further viral challenges, lose their capacity for producing sufficient amounts of melatonin. This leads to a reduced support of mitochondrial functions and makes these individuals more vulnerable to infectious diseases. Thus, the maintenance of mitochondrial function by melatonin supplementation can be expected to generate beneficial effects on the outcome of viral infectious diseases, particularly COVID-19.

Melatonin attenuates chemical-induced cardiotoxicity

Environmental chemicals and drugs can induce cardiotoxicity, mainly by generating free radicals. Reactive oxygen species play a critical role in the pathogenesis of cardiac tissue injury. This highlights a need for prevention of cardiotoxicity by scavenging free radicals. Melatonin has been shown to act as a protector against various conditions in which free radicals cause molecular and tissue injury. Some of the mechanisms by which melatonin operates as a free radical scavenger and antioxidant have been identified. The importance of endogenous melatonin in cardiovascular health and the benefits of melatonin supplementation in different cardiac pathophysiological disorders have been shown in a variety of model systems. Melatonin continues to attract attention for its potential therapeutic value for cardiovascular toxicity. The therapeutic potential of melatonin in treatment of cardiotoxicities caused by various chemicals along with suggested molecular mechanisms of action for melatonin is reviewed.

The role of melatonin in polycystic ovary syndrome: A review

Background

Polycystic ovary syndrome (PCOS) is a widespread endocrine disorder, affecting approximately 20% of women within reproductive age. It is associated with hyperandrogenism, obesity, menstrual irregularity, and anovulatory infertility. Melatonin is the main pineal gland hormone involved in the regulation of the circadian rhythm. In recent years, it has been observed that a reduction in melatonin levels of follicular fluid exists in PCOS patients. Melatonin receptors in the ovary and intra-follicular fluid adjust sex steroid secretion at different phases of ovarian follicular maturation. Moreover, melatonin is a strong antioxidant and an effective free radical scavenger, which protects ovarian follicles during follicular maturation.

Objective

In this paper, we conducted a literature review and the summary of the current research on the role of melatonin in PCOS.

Materials and Methods

Electronic databases including PubMed/MEDLINE, Web of Science, Scopus, and Reaxys were searched from their inception to October 2018 using the keywords “Melatonin” AND “Polycystic ovary syndrome” OR “PCOS.”

Results

Based on the data included in our review, it was found that the administration of melatonin can improve the oocyte and embryo quality in PCOS patients. It may also have beneficial effects in correcting the hormonal alterations in PCOS patients.

Conclusion

Since metabolic dysfunction is the major finding contributing to the initiation of PCOS, melatonin can hinder this process via its improving effects on metabolic functions.

Maintenance of mitochondrial function by astaxanthin protects against bisphenol A-induced kidney toxicity in rats

Bisphenol A (BPA), a global environmental pollutant, has been reported to have the potential to induced organs toxicity. This study explored the potential benefits of astaxanthin (ATX), a natural antioxidant, against BPA toxicity in the kidney, and explored whether mitochondria are involved in this condition. Male Wistar rats were fed with a vehicle, BPA, BPA plus ATX, ATX and were evaluated after five weeks. ATX treatment significantly reversed BPA-induced changes in body weight, kidney/body weight, and renal function related markers. When treated simultaneously with ATX, the imbalance of the oxidative-antioxidant status caused by BPA was also alleviated. The high expression of BPA-induced pro-inflammatory cytokines were inhibited by ATX treatment. ATX treatment also lessened the effects of BPA-induced caspase-3, -8, -9 and -10 gene expression and enzyme activity. The benefits of ATX were associated with enhanced mitochondrial function, which led to increased mitochondrial-encoded gene expression, mitochondrial copy number, and increased mitochondrial respiratory chain complex enzyme activity. Our results demonstrate the efficacy of ATX in protecting BPA-induced kidney damage, in part by regulating oxidative imbalance and improving mitochondrial function. Collectively, these findings provide a new perspective for the rational use of ATX in the treatment of BPA-induced kidney disease.

Immunoregulatory role of melatonin in cancer

Melatonin is a ubiquitous indole amine that plays a fundamental role in the regulation of the biological rhythm. Disrupted circadian rhythm alters the expression of clock genes and deregulates oncogenes, which finally promote tumor development and progression. An evidence supporting this notion is the higher risk of developing malignancies among night shift workers. Circadian secretion of the pineal hormone also synchronizes the immune system via a reciprocal association that exists between the immune system and melatonin. Immune cells are capable of melatonin biosynthesis in addition to the expression of its receptors. Melatonin induces big changes in different immune cell proportions, enhances their viability and improves immune cell metabolism in the tumor microenvironment. These effects might be directly mediated by melatonin receptors or indirectly through alterations in hormonal and cytokine release. Moreover, melatonin induces apoptosis in tumor cells via the intrinsic and extrinsic pathways of apoptosis, while it protectsthe immune cells. In general, melatonin has a profound impact on immune cell trafficking, cytokine production and apoptosis induction in malignant cells. On such a basis, using melatonin and resynchronization of sleep cycle may have potential implications in immune function enhancement against malignancies, which will be the focus of the present paper.

NLRP inflammasome as a key role player in the pathogenesis of environmental toxicants

Exposure to environmental toxicants (ET) results in specific organ damage and auto-immune diseases, mostly mediated by inflammatory responses. The NLRP3 inflammasome has been found to be the major initiator of the associated pathologic inflammation. It has been found that ETs can trigger all the signals required for an NLRP3-mediated response. The exaggerated activation of the NLRP3 inflammasome and its end product IL-1β, is responsible for the pathogenesis caused by many ETs including pesticides, organic pollutants, heavy metals, and crystalline compounds. Therefore, an extensive study of these chemicals and their mechanisms of inflammasome (INF) activation may provide the scientific evidence for possible targeting of this pathway by proposing possible protective agents that have been previously shown to affect INF compartments and its activation. Melatonin and polyunsaturated fatty acids (PUFA) are among the safest and the most studied of these agents, which affect a wide variety of cellular and physiological processes. These molecules have been shown to suppress the NLRP3 inflammasome mostly through the regulation of cellular redox status and the nuclear factor-κB (NF-κB) pathway, rendering them potential promising compounds to overcome ET-mediated organ damage. In the present review, we have made an effort to extensively review the ETs that exert their pathogenesis via the stimulation of inflammation, their precise mechanisms of action and the possible protective agents that could be potentially used to protect against such toxicants.

Melatonin Abrogates the Anti-Developmental Effect of the AKT Inhibitor SH6 in Bovine Oocytes and Embryos

Melatonin, a nighttime-secreted antioxidant hormone produced by the pineal gland, and AKT, a serine/threonine-specific protein kinase, have been identified as regulators for several cellular processes essential for reproduction. The current study aimed to investigate the potential interplay between melatonin and AKT in bovine oocytes in the context of embryo development. Results showed that the inclusion of SH6, a specific AKT inhibitor, during in vitro maturation (IVM) significantly reduced oocyte maturation, cumulus cell expansion, cleavage, and blastocyst development that were rescued upon addition of melatonin. Oocytes treated with SH6 in the presence of melatonin showed lower levels of reactive oxygen species (ROS) and blastocysts developed exhibited low apoptosis while the mitochondrial profile was significantly improved compared to the SH6-treated group. The RT-qPCR results showed up-regulation of the mRNA of maturation-, mitochondrial-, and cumulus expansion-related genes including GDF-9, BMP-15, MARF1, ATPase, ATP5F1E, POLG2, HAS2, TNFAIP6, and PTGS2 and down-regulation of Bcl-2 associated X apoptosis regulator (BAX), caspase 3, and p21 involved in apoptosis and cell cycle arrest in melatonin-SH6 co-treated group compared to SH6 sole treatment. The immunofluorescence showed high levels of caspase 3 and caspase 9, and low AKT phosphorylation in the SH6-treated group compared to the control and melatonin-SH6 co-treatment. Taken together, our results showed the importance of both melatonin and AKT for overall embryonic developmental processes and, for the first time, we report that melatonin could neutralize the deleterious consequences of AKT inhibition, suggesting a potential role in regulation of AKT signaling in bovine oocytes.

Low-to-moderate fluoride exposure, relative mitochondrial DNA levels, and dental fluorosis in Chinese children

BACKGROUND

The alteration of mitochondrial DNA (mtDNA) content contributes to many diseases, however, little is known about its effect on the prevalence of dental fluorosis (DF).

OBJECTIVES

We conducted a cross-sectional study to investigate the association of low-to-moderate fluoride exposure with relative mtDNA levels in relation to DF in children.

METHODS

We recruited 616 resident children, aged 7-13 years, randomly from low-to-moderate fluoride areas in Tianjin, China. We measured the fluoride concentrations in drinking water and urine using the national standardized ion selective electrode method, and determined the relative levels of mtDNA using a quantitative real-time polymerase chain reaction assay. The association among fluoride exposure, relative mtDNA levels, and the prevalence of DF were examined using multivariable linear and logistic regression models. We also performed stratified and mediation analyses.

RESULTS

The relative mtDNA levels of participants in the DF group were significantly lower than in the non-DF group (0.95 ± 0.44 vs. 1.12 ± 0.45, P < 0.001). In the adjusted models, we found that a 1 mg/L increment in water fluoride concentration was associated with a 0.10-unit decrease in circulating relative mtDNA levels (95% CI: -0.14, -0.06) and a 2.85-fold increase (95% CI: 2.01, 3.92) in moderate DF prevalence. A 1 mg/L increment in urinary fluoride level was associated with a 0.12-unit decrease in circulating relative mtDNA levels (95% CI: -0.14, -0.09) and a 1.85-fold increase (95% CI: 1.39, 2.39) in moderate DF prevalence. Stratified analysis indicated a weaker positive association of DF prevalence with fluoride exposure, while a stronger inverse relationship with relative mtDNA levels in boys than in girls. Assuming causality, we estimated that circulating mtDNA levels mediated 13.0% (95% CI: 5.2, 28.7%) and 9.6% (95% CI: 4.7, 18.5%) of the estimated effect of a 1 mg/L increment in water fluoride and urinary fluoride on prevalence of moderate DF, respectively.

CONCLUSIONS

Gender potentially modifies the associations of DF prevalence with relative mtDNA levels and low-to-moderate fluoride exposure. The reduced circulating mtDNA levels may partly mediate the elevated prevalence of moderate DF in children under such exposure.

The protective effect of melatonin on the in vitro development of yak embryos against hydrogen peroxide-induced oxidative injury

SummaryMelatonin plays a critical role in several types of cells as an antioxidant to protect intracellular molecules from oxidative stress. The anti-oxidation effect of melatonin in yak embryos is largely unknown. We report that melatonin can protect the development of yak preimplantation embryos against oxidative stress induced by hydrogen peroxide (H2O2). Therefore, the quality of blastocysts developed from zygotes exposed to H2O2 was promoted. In addition, we observed that melatonin reduced H2O2-induced intracellular reactive oxygen species (ROS) levels and prevented mitochondrial dysfunction in zygotes. These phenomena revealed the effective antioxidant activity of melatonin to prevent oxidative stress in yak embryos. To determine the underlying mechanism, we further demonstrated that melatonin protected preimplantation embryos from oxidative damage by preserving antioxidative enzymes. Collectively, these results confirmed the anti-oxidation effect of melatonin in yak embryos that significantly improved the quantity and quality of blastocysts in the in vitro production of embryos in yaks.

Melatonin attenuates caspase-dependent apoptosis in the thoracic aorta by regulating element balance and oxidative stress in pinealectomised rats

The aim of this study was to explain the possible mechanisms by which melatonin deficiency results in cardiovascular injury and to investigate the effects of melatonin administration on important signalling pathways and element equilibrium in the thoracic aorta (TA). For this purpose, we analysed the cellular and molecular effects of melatonin deficiency or administration on oxidative stress, DNA damage, molecular chaperone response, and apoptosis induction in TA tissues of pinealectomised rats using ELISA, RAPD, qRT-PCR, and Western blot assays. The results showed that melatonin deficiency led to an imbalance in essential element levels, unfolded or misfolded proteins, increased lipid peroxidation, and selectively induced caspase-dependent apoptosis in TA tissues without significantly affecting the Bcl-2/BAX ratio (2.28 in pinealectomised rats, 2.73 in pinealectomised rats treated with melatonin). In pinealectomised rats, the genomic template stability (80.22%) was disrupted by the significantly increased oxidative stress, and heat shock protein 70 (20.96-fold), TNF-α (1.73-fold), caspase-8 (2.03-fold), and caspase-3 (2.87-fold) were markedly overexpressed compared with the sham group. Melatonin treatment was protective against apoptosis and inhibited oxidative damage. In addition, melatonin increased the survivin level and improved the regulation of element equilibrium in TA tissues. The results of the study indicate that melatonin deficiency induces TNF-α-related extrinsic apoptosis signals and that the administration of pharmacological doses of melatonin attenuates cardiovascular toxicity by regulating the increase in the rate of apoptosis caused by melatonin deficiency in TA tissue of Sprague–Dawley rats.

Resveratrol attenuates high fat diet-induced mouse cardiomyopathy through upregulation of estrogen related receptor-α

Resveratrol reportedly promotes the improvement of cardiac dysfunction and other cardiovascular diseases. Studies demonstrate resveratrol exhibits a set of benefits, including anti-oxidative property, anti-apoptosis and anti-inflammation. However, the molecular mediators of resveratrol-induced cardiac benefits are still not fully disclosed. Present study aims to investigate whether estrogen-related receptor (ERR)-α, an orphan nuclear receptor, determines the protective benefits of resveratrol in obesity-related cardiomyopathy. Through high fat diet-fed mouse model, our results show resveratrol increases cardiac ERR-α level and attenuates diet-induced cardiac hypertrophy, mitochondrial inactivity and inflammatory response. Co-administration of lentivirus encoding Err-α siRNA abolishes these benefits, such as enlargement of cardiomyocyte size, induction of left ventricular dysfunction and structural disorders. More importantly, we firstly find resveratrol stimulates the cardiac mitochondrial activities, but silencing Err-α decreased mitochondrial function on ATP production, oxygen consumption and complex I activity. Besides, Err-α deficiency also reverses resveratrol-mediated suppression of inflammatory response in cardiac tissues. Present study not only shows resveratrol enhances cardiac mitochondrial activities, but also supports ERR-α at least partially controls the pharmacological benefits of resveratrol in obese mouse cardiomyopathy.

Melatonin protects against myocardial ischemia-reperfusion injury by elevating Sirtuin3 expression and manganese superoxide dismutase activity

Myocardial ischemia-reperfusion (MI/R) injury is a crucial cause for mortality throughout the world. Recent studies indicated that melatonin might exert profound cardio-protective effect in MI/R injury. However, the underlying mechanisms are not completely understood. In the current study, we aimed to explore the potential effect of melatonin in the pathological process of MI/R. Both in vivo MI/R model and in vitro H9c2 cell line simulated I/R (SIR) model were applied with or without melatonin supplementation. We found that Sirtuin3 (Sirt3) expression and activity were markedly decreased under MI/R and SIR conditions. Melatonin treatment significantly increased myocardial Sirt3 expression, and alleviated MI/R-induced cardiac morphology changes and cardiac dysfunction, as well as myocardial apoptosis level. In addition, DHE and JC-1 staining results demonstrated that melatonin reduced mitochondrial reactive oxygen species (ROS) generation and restored ATP production after SIR injury via elevating Sirt3 expression. By using siRNA targeting Sirt3, we confirmed that the beneficial effects of melatonin were dependent on Sirt3, which in turn deacetylated and activated manganese superoxide dismutase (MnSOD). Collectively, the current study demonstrated the protective effect of melatonin against MI/R injury via alleviating myocardial oxidative stress. Moreover, these beneficial effects were associated with the deacetylation modification of Sirt3 on MnSOD.

Dihydroxyacetone as a definitive treatment for aluminium phosphide poisoning in rats

Aluminium phosphide (AlP), a very toxic pesticide also known as the rice tablet, releases phosphine gas upon contact with water, moisture, or gastric acid. Its mortality rate in humans is 70-100 % due to cardiogenic shock and refractory hypotension. Dihydroxyacetone (DHA) is a simple ketonic carbohydrate, mainly used for sunless skin tanning. It also plays a beneficial role in the treatment of hypotension and cardiogenic shock by restoring blood volume and cellular respiration. The aim of this study was to investigate the its effect on the haemodynamics and electrocardiogram (ECG) in male rats poisoned with AlP. The animals were divided into the following groups: control (received 1 mL corn oil, orally), AlP (received 15 mg kg-1 AlP solved in corn oil, orally), AlP plus DHA (treated with 50 mg kg-1 of DHA 30 min after receiving AlP), and AlP plus N-acetyl cysteine (NAC) (treated with 200 mg kg-1 of NAC 30 min after receiving AlP). The animals were then anaesthetised and ECG, blood pressure, and heart rate were recorded for 120 min. Treatment with AlP alone and in combination with NAC was associated with progressive hypotension, tachycardia, and ECG disturbances in rats, resulting in 100 % mortality 3 h after poisoning. However, DHA achieved 100 % survival in the poisoned rats and prevented AlP-induced ECG and haemodynamic abnormalities. The main mechanism of DHA in the treatment of AlP poisoning is unclear, but the findings suggest the promising therapeutic potential of DHA against AlP poisoning.

Antidotes for aluminum phosphide poisoning - An update

Aluminum phosphide (AlP), an inexpensive solid fumigant, is frequently used for grain conservation despite its alleged high toxicity. Increased utilization of AlP for agricultural and non-agricultural purposes during the last four decades has resulted in increment of AlP-attributed poisoning numbers. Moreover, due to its limitless accessibility in developing countries, AlP has been increasingly used for suicide. Moisture-exposed AlP undergoes a chemical reaction producing phosphine gas, which in turn inhibits cytochrome oxidase and impedes cellular oxygen consumption. Lethality remains elevated reaching rates of >50% and no effective antidote is available. Nevertheless, experimental and clinical studies suggested that magnesium sulfate, melatonin, N-acetylcysteine, glutathione, sodium selenite, vitamin C and E, triiodothyronine, liothyronine, vasopressin, milrinone, Laurus nobilis L., 6-aminonicotinamide, boric acid, acetyl-L-carnitine and coconut oil, may serve as antidotes by reducing the deleterious oxidative properties of AlP. This article reviews the afore-mentioned chemicals suggested to specifically treat AlP poisoning and discusses their protective mechanisms and main outcomes.

Quercetin attenuates hypertension induced by sodium fluoride via reduction in oxidative stress and modulation of HSP 70/ERK/PPARγ signaling pathways

Hypertension is one of the silent killers in the world with high mortality and morbidity. The exposure of humans and animals to fluoride and/or fluoride containing compounds is almost inevitable. This study investigated the modulatory effects of quercetin on sodium fluoride (NaF)-induced hypertension and cardiovascular complications. Forty male rats were randomly separated into four groups (n =10). Group A animals served as the control, rats in Group B were exposed to 300 ppm of NaF, Groups C and D animals were exposed to 300 ppm of NaF along with quercetin orally at 50 mg/kg and 100 mg/kg orally by gavage, while NaF was administered in drinking water, respectively, for a week. Administration of NaF caused severe hypertension as indicated with significant increases in the systolic, diastolic, and mean arterial blood pressure, together with prolonged ventricular depolarization (QRS) and the time between the start of the Q wave and the end of the T wave in the heart's electrical cycle (QT) intervals when compared with controls. NaF significantly decreased the activities of antioxidant enzymes, caused increase in markers of oxidative stress and renal damage when compared with controls. Immunohistochemical staining revealed lower expressions of Hsp70, ERK, and PPARγ in the heart, kidney, and aorta of rats-administered NaF relative to the controls. Together, quercetin co-treatment with NaF restored blood pressure, normalized QRS interval, and improved antioxidant defense system. © 2018 BioFactors, 44(5):465-479, 2018.

Melatonin Mitigates Mitochondrial Meltdown: Interactions with SIRT3

Melatonin exhibits extraordinary diversity in terms of its functions and distribution. When discovered, it was thought to be uniquely of pineal gland origin. Subsequently, melatonin synthesis was identified in a variety of organs and recently it was shown to be produced in the mitochondria. Since mitochondria exist in every cell, with a few exceptions, it means that every vertebrate, invertebrate, and plant cell produces melatonin. The mitochondrial synthesis of melatonin is not photoperiod-dependent, but it may be inducible under conditions of stress. Mitochondria-produced melatonin is not released into the systemic circulation, but rather is used primarily in its cell of origin. Melatonin's functions in the mitochondria are highly diverse, not unlike those of sirtuin 3 (SIRT3). SIRT3 is an NAD+-dependent deacetylase which regulates, among many functions, the redox state of the mitochondria. Recent data proves that melatonin and SIRT3 post-translationally collaborate in regulating free radical generation and removal from mitochondria. Since melatonin and SIRT3 have cohabitated in the mitochondria for many eons, we predict that these molecules interact in many other ways to control mitochondrial physiology. It is predicted that these mutual functions will be intensely investigated in the next decade and importantly, we assume that the findings will have significant applications for preventing/delaying some age-related diseases and aging itself.

Pesticides and cardiotoxicity. Where do we stand?

Cardiovascular diseases are among the most significant causes of mortality in humans. Pesticides toxicity and risk for human health are controlled at a European level through a well-developed regulatory network, but cardiotoxicity is not described as a separate hazard class. Specific classification criteria should be developed within the frame of Regulation (EC) No 1272/2008 in order to classify chemicals as cardiotoxic, if applicable to avoid long-term cardiovascular complications. The aim of this study was to review the cardiac pathology and function impairment due to exposure to pesticides (i.e. organophosphates, organothiophisphates, organochlorines, carbamates, pyrethroids, dipyridyl herbicides, triazoles, triazines) based on both animal and human data. The majority of human data on cardiotoxicity of pesticides come from poisoning cases and epidemiological data. Several cardiovascular complications have been reported in animal models including electrocardiogram abnormalities, myocardial infarction, impaired systolic and diastolic performance, functional remodeling and histopathological findings, such as haemorrhage, vacuolisation, signs of apoptosis and degeneration.