Melatonin inhibits Benzo(a)pyrene-Induced apoptosis through activation of the Mir-34a/Sirt1/autophagy pathway in mouse liver

Therapeutic effects and molecular mechanisms of natural products in thrombosis

Thrombotic disorders, such as myocardial infarction and stroke, are the leading cause of death in the global population and have become a health problem worldwide. Drug therapy is one of the main antithrombotic strategies, but antithrombotic drugs are not completely safe, especially the risk of bleeding at therapeutic doses. Recently, natural products have received widespread interest due to their significant efficacy and high safety, and an increasing number of studies have demonstrated their antithrombotic activity. In this review, articles from databases, such as Web of Science, PubMed, and China National Knowledge Infrastructure, were filtered and the relevant information was extracted according to predefined criteria. As a result, more than 100 natural products with significant antithrombotic activity were identified, including flavonoids, phenylpropanoids, quinones, terpenoids, steroids, and alkaloids. These compounds exert antithrombotic effects by inhibiting platelet activation, suppressing the coagulation cascade, and promoting fibrinolysis. In addition, several natural products also inhibit thrombosis by regulating miRNA expression, anti-inflammatory, and other pathways. This review systematically summarizes the natural products with antithrombotic activity, including their therapeutic effects, mechanisms, and clinical applications, aiming to provide a reference for the development of new antithrombotic drugs.

Mechanisms and targeted reversion/prevention of hepatic fibrosis caused by the non-hereditary toxicity of benzo(a)pyrene

The effect of long term exposure to low concentrations of environmental pollutants on hepatic disorders is a major public health concern worldwide. Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants. In recent years, an increasing number of studies have focused on the deleterious effects of low concentrations of PAHs in the initiation or exacerbation of the progression of chronic liver disease. However, the underlying molecular mechanisms and effective intervention methods remain unclear. Here, we found that in hepatocytes, a low concentration of benzo(a)pyrene (B[a]P, an indicator of PAHs) chronic exposure continuously activated 14-3-3η via an epigenetic accumulation of DNA demethylation. As a "switch like" factor, 14-3-3η activated its downstream PI3K/Akt signal, which in turn promoted vascular endothelial growth factor (VEGF) production and secretion. As the characteristic fibrogenic paracrine factor regulated by B[a]P/14-3-3η, VEGF significantly induced the neovascularization and activation of hepatic stellate cells, leading to the development of hepatic fibrosis. Importantly, targeted 14-3-3η by using its specific inhibitor invented by our lab could prevent B[a]P-induced hepatic fibrosis, and could even reverse existent hepatic fibrosis caused by B[a]P. The present study not only revealed novel mechanisms, but also proposed an innovative approach for the targeted reversion/prevention of the harmful effects of exposure to PAHs on chronic liver disease.

MicroRNA-141-3p reduces pulmonary hypoxia/reoxygenation injury through suppression of Beclin-1-dependent autophagy

Alterations in autophagy are involved in pulmonary hypoxia/reoxygenation (H/R)-induced injury. Here, we intended to explain the function of microRNA-141-3p (miR-141-3p) in regulating autophagy under the H/R condition. Rat pulmonary microvascular endothelial cells (PMVECs) were applied for H/R cell model establishment, followed by tracing of autophagy formation. SIRT1 plays a critical role in controlling the lifespan of yeast, flies, and mice. Interaction between SIRT1 and Beclin-1, an indicator protein for autophagy, and between miR-141-3p and SIRT1 was assayed with their roles in PMVEC injury. Autophagy of PMVECs was activated after hypoxia treatment and further activated after H/R treatment. The binding of miR-141-3p and SIRT1 was verified. In H/R-treated PMVECs, the binding of miR-141-3p and SIRT1 was reduced. Furthermore, SIRT1 acted as a deacetylase to stabilize the Beclin-1 protein, promoting autophagy and PMVEC injury. H/R rat models were established, and in vivo, experiments further confirmed that miR-141-3p regulated autophagy and lung injury in H/R rats through SIRT1/Beclin-1 axis. The current study highlighted that reduced miR-141-3p in H/R-treated PMVECs promoted deacetylation of Beclin-1 by SIRT1, thus causing PMVEC injury.

Melatonin attenuates liver injury in arsenic-treated rats: The potential role of the Nrf2/HO-1, apoptosis, and miR-34a/Sirt1/autophagy pathways

Arsenic is a toxic metalloid found in the environment in different organic and inorganic forms. Molecular mechanisms implicated in arsenic hepatotoxicity are complex but include oxidative stress, apoptosis, and autophagy. The current study focused on the potential protective capacity of melatonin against arsenic-induced hepatotoxicity. Thirty-six male Wistar rats were allocated into control, arsenic (15 mg/kg; orally), arsenic (15 mg/kg) plus melatonin (10, 20, and 30 mg/kg; intraperitoneally), and melatonin alone (30 mg/kg) groups for 28 days. After the treatment period, the serum sample was separated to measure liver enzymes (AST and ALT). The liver tissue was removed and then histological alterations, oxidative stress markers, antioxidant capacity, the levels of Nrf2 and HO-1, apoptosis (Bcl-2, survivin, Mcl1, Bax, and caspase-3), and autophagy (Sirt1, Beclin-1, and LC3 II/I ratio) proteins, as well as the expression level of miR-34a, were evaluated on this tissue. Arsenic exposure resulted in the enhancement of serum AST, ALT, and substantial histological damage in the liver. Increased levels of malondialdehyde, a lipid peroxidation marker, and decreased levels of physiological antioxidants including glutathione, superoxide dismutase, and catalase were indicators of arsenic-induced oxidative damage. The levels of Nrf2, HO-1, and antiapoptotic proteins diminished, while proapoptotic and autophagy proteins were elevated in the arsenic group concomitant with a low level of hepatic miR-34a. The co-treatment of melatonin and arsenic reversed the changes caused by arsenic. These findings showed that melatonin reduced the hepatic damage induced by arsenic due to its antioxidant and antiapoptotic properties as well as its regulatory effect on the miR-34a/Sirt1/autophagy pathway.

The Hepatorenal Protective Potential of Caffeic Acid Consumption on the Arsenic-Exposed Syrian Mice

Arsenic can induce lethal hepatorenal insufficiency by inducing progressive cytotoxicity in the two main body's hemostatic regulators, the kidney and liver. In the current study, the hepatorenal protective impact of caffeic acid was investigated in arsenic-exposed Syrian mice. Twenty-four male Syrian mice (30 ± 8 g) were provided and randomly divided into 4 groups of 6 receiving nothing, arsenic, arsenic and caffeic, and caffeic acid. The mice passed the 21-day treatment program. The mice's blood was collected and analyzed by measuring the serum ALT/AST enzymes and creatinine/urea levels, respectively. Finally, the histopathological properties in both the kidney and liver organs of the mice were studied. Arsenic administration significantly increased aspartate aminotransferase (AST), alanine aminotransferase (ALT), LDH, urea, and creatinine concentrations (p < 0.05). Simultaneous administration of caffeic acid with arsenic decreased the serum AST and creatinine (p < 0.05). Moreover, the renal glomerulus and liver regeneration in the mice receiving caffeic acid supplements exhibited the caffeic acid hepatorenal protective potential. The histopathological changes caused by arsenic in the mice's liver and kidney tissue including degeneration, necrosis, hyperemia, and tissue hypotrophy were shifted to normal conditions following the caffeic acid administration dose, which was verified by the mice blood biochemical analysis results.

Azadirachtin Attenuates Carcinogen Benzo(a) Pyrene-Induced DNA Damage, Cell Cycle Arrest, Apoptosis, Inflammatory, Metabolic, and Oxidative Stress in HepG2 Cells

Azadirachtin (AZD), a limonoid from the versatile, tropical neem tree (Azadirachta indica), is well known for its many medicinal, and pharmacological effects. Its effects as an anti-oxidant, anti-inflammatory, and anti-cancer agent are well known. However, not many studies have explored the effects of AZD on toxicities induced by benzo(a)pyrene (B(a)P), a toxic component of cigarette smoke known to cause DNA damage and cell cycle arrest, leading to different kinds of cancer. In the present study, using HepG2 cells, we investigated the protective effects of Azadirachtin (AZD) against B(a)P-induced oxidative/nitrosative and metabolic stress and mitochondrial dysfunction. Treatment with 25 µM B(a)P for 24 h demonstrated an increased production of reactive oxygen species (ROS), followed by increased lipid peroxidation and DNA damage presumably, due to the increased metabolic activation of B(a)P by CYP 450 1A1/1A2 enzymes. We also observed intrinsic and extrinsic apoptosis, alterations in glutathione-dependent redox homeostasis, cell cycle arrest, and inflammation after B(a)P treatment. Cells treated with 25 µM AZD for 24 h showed decreased oxidative stress and apoptosis, partial protection from DNA damage, and an improvement in mitochondrial functions and bioenergetics. The improvement in antioxidant status, anti-inflammatory potential, and alterations in cell cycle regulatory markers qualify AZD as a potential therapeutic in combination with anti-cancer drugs.

The role of lncRNAs/miRNAs/Sirt1 axis in myocardial and cerebral injury

In recent years, researchers have begun to realize the importance of the role of non-coding RNAs in the treatment of cancer and cardiovascular and neurological diseases. LncRNAs and miRNAs are important non-coding RNAs, which regulate gene expression and activate mRNA translation through binding to diverse target sites. Their involvement in the regulation of protein function and the modulation of physiological and pathological conditions continues to be investigated. Sirtuins, especially Sirt1, have a critical function in regulating a variety of physiological processes such as oxidative stress, inflammation, apoptosis, and autophagy. The lncRNAs/miRNAs/Sirt1 axis may be a novel regulatory mechanism, which is involved in the progression and/or prevention of numerous diseases. This review focuses on recent findings on the crosstalk between non-coding RNAs and Sirt1 in myocardial and cerebral injuries and may provide some insight into the development of novel approaches in the treatment of these disorders.Abbreviation: BMECs, brain microvascular endothelial cells; C2dat1, calcium/calmodulin-dependent protein kinase type II subunit delta (CAMK2D)-associated transcript 1; EPCs, endothelial progenitor cells; FOXOs, forkhead transcription factors; GAS5, growth arrest-specific 5; HAECs, human aortic endothelial cells; HAND2-AS1, HAND2 Antisense RNA 1; HIF-1α, hypoxia-inducible factor-1α; ILF3-AS1, interleukin enhancer-binding factor 3-antisense RNA 1; KLF3-AS1, KLF3 antisense RNA 1; LncRNA, long noncoding RNA; LUADT1, Lung Adenocarcinoma Associated Transcript 1; MALAT1, Metastasis-associated lung adenocarcinoma transcript 1; miRNA, microRNA; NEAT1, nuclear enriched abundant transcript 1; NF-κB, nuclear factor kappa B; OIP5-AS1, Opa-interacting protein 5-antisense transcript 1; Sirt1-AS, Sirt1 Antisense RNA; SNHG7, small nucleolar RNA host gene 7; SNHG8, small nucleolar RNA host gene 8; SNHG12, small nucleolar RNA host gene 12; SNHG15, small nucleolar RNA host gene 15; STAT3, signal transducers and activators of transcription 3; TUG1, taurine up-regulated gene 1; VSMCs, vascular smooth muscle cells; XIST, X inactive specific transcript; ZFAS1, ZNFX1 Antisense RNA 1.

Benzo[a]pyrene induces epithelial tight junction disruption and apoptosis via inhibiting the initiation of autophagy in intestinal porcine epithelial cells

Ingestion of food contaminated with benzo[a]pyrene (B[a]P) poses health risks to animals and humans. However, the toxicity of B[a]P exposure on the intestinal barrier function and underlying mechanisms remain obscure. In the present study, intestinal porcine epithelial cells (IPEC-1) were challenged with different doses of B[a]P and its deleterious effects were determined. We found that B[a]P exposure led to impaired intestinal tight junction function as evidenced by reduced transepithelial electric resistance, increased permeability, and downregulated intestinal tight junction protein levels. Further study demonstrated that B[a]P treatment induced cell cycle arrest, and resulted in oxidative damage-related apoptosis in IPEC-1 cells. Intriguingly, we observed an inhibition of autophagy and an activation of unfolded protein response (UPR) in B[a]P-challenged cells, when compared with controls. To investigate the role of autophagy on B[a]P-induced epithelial tight junction disruption and apoptosis, cells were cotreated with B[a]P and rapamycin, and rapamycin dramatically improved intestinal tight junction and reduced apoptosis, indicating a protective effect of autophagy for the cells in response to B[a]P treatment. We also explored the role of UPR in B[a]P-induced cellular damage by using 4-phenylbutyric acid, an antagonist of UPR. Interestingly, B[a]P-induced apoptosis and dysfunction of the intestinal tight junction were exacerbated by 4-phenylbutyric acid, and the 4-phenylbutyric acid didn't ameliorate the inhibitory effects of B[a]P on microtubule-associated protein 1 light chain 3 (LC3-II) and lysosomal-associated membrane protein 2 (LAMP2) in IPEC-1 cells. These novel findings provided herein indicated that B[a]P induces intestinal epithelial tight junction disruption and apoptotic cell death via inhibiting autophagy in IPEC-1 cells.

Melatonin attenuates cardiopulmonary toxicity induced by benzo(a)pyrene in mice focusing on apoptosis and autophagy pathways

Benzo(a)pyrene (BaP) is a polycyclic aromatic hydrocarbon and a serious environmental pollutant. BaP is formed by the incomplete combustion of organic matter at high temperatures. In addition, tobacco smoke and many foods, especially charbroiled food and grilled meats, contain BaP and can cause it to enter human body. Melatonin, a pineal gland hormone, has antioxidant, anti-apoptosis, and autophagy regulatory properties. The possible protective impact of melatonin on cardiopulmonary toxicity induced by BaP was investigated by examining the antioxidant effects and the apoptosis and autophagy properties of melatonin. Thirty male mice were divided into 5 groups and treated for 28 days as follows: (I) control (BaP and melatonin solvent), (II) BaP (75 mg/kg, oral gavage), (III and IV) BaP (75 mg/kg) + melatonin (10 and 20 mg/kg, intraperitoneally), (V) melatonin (20 mg/kg). The oxidative stress factors (MDA and GSH content) were assessed in the heart and lung tissues. The levels of apoptotic (Caspase-3 and the Bax/Bcl-2 ratio) and autophagic (the LC3 ӀӀ/Ӏ, Beclin-1, and Sirt1) proteins were examined by using western blot analysis. Following the administration of BaP, MDA, the Bax/Bcl-2 ratio, and the Caspase-3 proteins increased in the heart and lung tissues, while GSH, Sirt1, Beclin-1, and the LC3 II/I ratio diminished. The coadministration of melatonin along with BaP, MDA, and apoptotic proteins returned to the control values, while GSH and the autophagy proteins were enhanced in both the heart and lungs. Melatonin exhibited a protective effect against BaP-induced heart and lung injury through the suppression of oxidative stress and apoptosis and the induction of the Sirt1/autophagy pathway.

Effect of benzo[a]pyrene on proliferation and metastasis of oral squamous cell carcinoma cells: A transcriptome analysis based on RNA-seq

Benzo[a]pyrene (BaP), a representative polycyclic aromatic hydrocarbon compound, is a carcinogen that causes head and neck cancers. Despite intensive research, the molecular mechanism of BaP in the development of oral squamous cell carcinoma (OSCC) remains largely unknown. In the present study, the SCC-9 human OSCC cell line was cultured in vitro, separated into treatment groups, and treated with dimethyl sulfoxide or BaP at various concentrations. The malignant behavior ascribed to the BaP treatment was investigated by cell proliferation, clony formation assay, and Transwell assays. Furthermore, transcriptome sequencing was performed to detect the differentially expressed genes, followed by quantitative real-time PCR to measure the expression levels of nine of these genes. Moreover, the Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed the biological processes and signaling pathways in which the target genes were involved. Significant effects on SCC-9 cell proliferation, tumorigenicity, cell migration, and invasion were observed after exposure to 8 μM BaP. Additional results revealed that BaP inhibited apoptosis in a dose-dependent manner. The transcriptome sequencing results showed 137 upregulated genes and 135 downregulated genes induced by BaP, associated with tumor-related biological processes and signaling pathways, mainly including transcriptional dysregulation in cancer, the tumor necrosis factor signaling pathway, metabolism of xenobiotics by cytochrome P450, mitogen-activated protein kinase signaling pathway, and so forth. Our study demonstrates that BaP may regulate the expression of certain genes involved in tumor-associated signaling pathways, thereby promoting the proliferative, tumorigenic, and metastatic behaviors of OSCC cells while suppressing their apoptosis.

Influences of polycyclic aromatic hydrocarbon on the epigenome toxicity and its applicability in human health risk assessment

The existence of polycyclic aromatic hydrocarbons (PAHs) in ambient air is an escalating concern worldwide because of their ability to cause cancer and induce permanent changes in the genetic material. Growing evidence implies that during early life-sensitive stages, the risk of progression of acute and chronic diseases depends on epigenetic changes initiated by the influence of environmental cues. Several reports deciphered the relationship between exposure to environmental chemicals and epigenetics, and have known toxicants that alter the epigenetic states. Amongst PAHs, benzo[a]pyrene (B[a]P) is accepted as a group 1 cancer-causing agent by the International Agency for the Research on Cancer (IARC). B[a]P is a well-studied pro-carcinogen that is metabolically activated by the aryl hydrocarbon receptor (AhR)/cytochrome P450 pathway. Cytochrome P450 plays a pivotal role in the stimulation step, which is essential for DNA adduct formation. Accruing evidence suggests that epigenetic alterations assume a fundamental part in PAH-promoted carcinogenesis. This interaction between PAHs and epigenetic factors results in an altered profile of these marks, globally and locus-specific. Some of the epigenetic changes due to exposure to PAHs lead to increased disease susceptibility and progression. It is well understood that exposure to environmental carcinogens, such as PAH triggers disease pathways through changes in the genome. Several evidence reported due to the epigenome-wide association studies, that early life adverse environmental events may trigger widespread and persistent variations in transcriptional profiling. Moreover, these variations respond to DNA damage and/or a consequence of epigenetic modifications that need further investigation. Growing evidence has associated PAHs with epigenetic variations involving alterations in DNA methylation, histone modification, and micro RNA (miRNA) regulation. Epigenetic alterations to PAH exposure were related to chronic diseases, such as pulmonary disease, cardiovascular disease, endocrine disruptor, nervous system disorder, and cancer. This hormetic response gives a novel perception concerning the toxicity of PAHs and the biological reaction that may be a distinct reliance on exposure. This review sheds light on understanding the latest evidence about how PAHs can alter epigenetic patterns and human health. In conclusion, as several epigenetic change mechanisms remain unclear yet, further analyses derived from PAHs exposure must be performed to find new targets and disease biomarkers. In spite of the current limitations, numerous evidence supports the perception that epigenetics grips substantial potential for advancing our knowledge about the molecular mechanisms of environmental toxicants, also for predicting health-associated risks due to environmental circumstances exposure and individual susceptibility.

Autophagy Dysregulation in Metabolic Associated Fatty Liver Disease: A New Therapeutic Target

Metabolic associated fatty liver disease (MAFLD) is one of the most common causes of chronic liver disease worldwide. To date, there is no FDA-approved treatment, so there is an urgent need to determine its pathophysiology and underlying molecular mechanisms. Autophagy is a lysosomal degradation pathway that removes damaged organelles and misfolded proteins after cell injury through endoplasmic reticulum stress or starvation, which inhibits apoptosis and promotes cell survival. Recent studies have shown that autophagy plays an important role in removing lipid droplets from hepatocytes. Autophagy has also been reported to inhibit the production of pro-inflammatory cytokines and provide energy for the hepatic stellate cells activation during liver fibrosis. Thyroid hormone, irisin, melatonin, hydrogen sulfide, sulforaphane, DA-1241, vacuole membrane protein 1, nuclear factor erythroid 2-related factor 2, sodium-glucose co-transporter type-2 inhibitors, immunity-related GTPase M, and autophagy-related gene 7 have been reported to ameliorate MAFLD via autophagic induction. Lipid receptor CD36, SARS-CoV-2 Spike protein and leucine aminopeptidase 3 play a negative role in the autophagic function. This review summarizes recent advances in the role of autophagy in MAFLD. Autophagy modulates major pathological changes, including hepatic lipid metabolism, inflammation, and fibrosis, suggesting the potential of modulating autophagy for the treatment of MAFLD.

Melatonin administration alleviates 2,2,4,4-tetra-brominated diphenyl ether (PBDE-47)-induced necroptosis and secretion of inflammatory factors via miR-140-5p/TLR4/NF-κB axis in fish kidney cells

2,2,4,4-tetra-brominated diphenyl ether (PBDE-47)-the dominant homologue of polybrominated diphenyl ethers-is a toxic environmental pollutant in the aquatic environment that continuously exists and bioaccumulates in the aquatic food chain. In experimental disease models, melatonin (MEL) has been reported to attenuate necroptosis and inflammatory responses. To further explore the mechanism underlying PBDE-47 toxicity and the mitigative impact of MEL detoxification, in this study, fish kidney cell models of PBDE-47 poisoning and/or MEL treatment were developed. The Ctenopharyngodon idellus kidney (CIK) cell line was treated with PBDE-47 (100 μM) and/or MEL (60 μM) for 24 h. Experimental data suggest that PBDE-47 exposure resulted in the enhancement of cytoplasmic Ca²⁺ concentration, induction of calcium dysmetabolism, decrease in the miR-140-5p miRNA level, upregulation of Toll-like Receptor 4 (TLR4) and nuclear factor-kappaB (NF-κB), triggering of receptor interacting serine/threonine kinase-induced necroptosis, and NF-κB pathway mediated secretion of inflammatory factors in CIK cells. PBDE-47-induced CIK cell damage could be mitigated by MEL through the regulation of calcium channels and the restoration of disorders of the miR-140-5p/TLR4/NF-κB axis. Overall, MEL relieved PBDE-47-induced necroptosis and the secretion of inflammatory factors through the miR-140-5p/TLR4/NF-κB axis. These findings enrich the current understanding of the toxicological molecular mechanisms of the PBDE-47 as well as the detoxification mechanisms of the MEL.

Ligustrazine prevents coronary microcirculation dysfunction in rats via suppression of miR-34a-5p and promotion of Sirt1

INTRODUCTION

The coronary microembolization contributes to coronary microvascular dysfunction (CMD), in which miR-34a-5p may play a critical role. Ligustrazine has been reported to improve CMD. The present study was designed to discuss the role of miR-34a-5p/Sirt1 pathway in CMD and explore the underlying mechanism of ligustrazine.

METHODS

Coronary microembolization (CME) was induced by left ventricle injection of sodium laurate in rats. CME formation and cardiac function were examined by HE staining and hemodynamic tests to evaluate CMD. The expressions of miR-34a-5p, Sirt1 and the downstream proteins were detected by RT-qPCR and western blot. Dual-luciferase reporter (DLR) assay was performed to confirm the connection between miR-34a-5p and Sirt1. The blood markers of endothelial dysfunction, platelet activation and inflammation were examined with ELISA.

RESULTS

Overt CME and cardiac dysfunction as well as up-regulated miR-34a-5p and down-regulated Sirt1 were observed in CME rats. Overexpressing miR-34a-5p aggravated while silencing miR-34a-5p inhibited CME formation. DLR assay confirmed that miR-34a-5p directly inhibited Sirt1 mRNA expression. Ligustrazine pretreatment suppressed miR-34a-5p and promoted Sirt1 expression, which alleviated endothelial dysfunction, inhibited platelet activation and inflammation, and in turn reduced CME. Overexpressing miR-34a-5p diminished the positive effects of ligustrazine; while after silencing miR-34a-5p, ligustrazine failed to further promote Sirt1 expression and inhibit CME formation.

CONCLUSION

MiR-34a-5p contributes to CMD by inhibiting Sirt1 expression. Ligustrazine exerts endothelial-protective, anti-platelet and anti-inflammatory effects to prevent CMD via suppressing miR-34a-5p and promoting Sirt1.

Modulation of autophagy by melatonin via sirtuins in stroke: From mechanisms to therapies

Sirtuins perform an important effect on the neural cell fate following stroke. Several mechanisms that have been correlated with stroke are oxidative stress, apoptosis, necrosis and autophagy. Autophagy is usually regarded as unitary of the neural cell survival mechanisms. Recently, the importance of the sirtuins effect on autophagy by antioxidant agents for stroke treatment mentioned in various studies. One of these agents is melatonin. Melatonin can modulate autophagy by changing on sirtuin pathways. Melatonin and its metabolites adjust various sirtuins pathways related to apoptosis, proliferation, metastases, autophagy and inflammation in case of stroke. In this review, we will discuss about the modulation of autophagy by melatonin via sirtuins in stroke.

Melatonin improves bisphenol A-induced cell apoptosis, oxidative stress and autophagy impairment via inhibition of the p38 MAPK signaling pathway in FLK-BLV cells

The aim of this study was to assess the protective effect and potential mechanism of melatonin against bisphenol A (BPA)-induced apoptosis and oxidative damage in FLK-BLV cells. The results showed that BPA reduced cell viability in a dose- and time-dependent manner, caused cell shrinkage and induced oxidative stress and apoptosis in FLK-BLV cells, which were effectively reversed by melatonin. In addition, BPA caused autophagy flux impairment, which was confirmed by the increased of LC3-II and p62 levels, whereas melatonin treatment effectively reduced p62 levels under BPA treatment, and reversed apoptosis-related protein expression patterns caused by BPA. However, inhibition of autophagy by CQ partially abolished the protective effect of melatonin on apoptosis, suggesting that melatonin against BPA-induced oxidative injury and apoptosis by activating autophagy pathway. Moreover, we found that melatonin inhibited BPA-induced the activation of p38 MAPK, which was comparable to SB203580 pretreatment, and companied by the activation of autophagy and decreases of apoptosis when compared to BPA alone, indicating that melatonin protected against BPA-induced apoptosis partially through the p38 MAPK-autophagy pathway. In conclusion, these results suggest that melatonin may prevent BPA-induced FLK-BLV cell damage by inhibiting p38/MAPK signaling pathway and activating autophagy, and it could be a potential therapeutic compound in preventing BPA-induced cell damage.

Melatonin improves arsenic-induced hypertension through the inactivation of the Sirt1/autophagy pathway in rat

Arsenic (As), a metalloid chemical element, is classified as heavy metal. Previous studies proposed that As induces vascular toxicity by inducing autophagy, apoptosis, and oxidative stress. It has been shown that melatonin (Mel) can decrease oxidative stress and apoptosis, and modulate autophagy in different pathological situations. Hence, this study aimed to investigate the Mel effect on As-induced vascular toxicity through apoptosis and autophagy regulation. Forty male rats were treated with As (15 mg/kg; oral gavage) and Mel (10 and 20 mg/kg, intraperitoneally; i.p.) for 28 days. The systolic blood pressure (SBP) changes, oxidative stress markers, the aorta histopathological injuries, contractile and relaxant responses, the level of apoptosis (Bnip3 and caspase-3) and autophagy (Sirt1, Beclin-1 and LC3 II/I ratio) proteins were determined in rats aorta. The As exposure significantly increased SBP and enhanced MDA level while reduced GSH content. The exposure to As caused substantial histological damage in aorta tissue and changed vasoconstriction and vasorelaxation responses to KCl, PE, and Ach in isolated rat aorta. The levels of HO-1 and Nrf-2, apoptosis markers, Sirt1, and autophagy proteins also enhanced in As group. Interestingly, Mel could reduce changes in oxidative stress, blood pressure, apoptosis, and autophagy induced by As. On the other hand, Mel led to more increased the levels of Nrf-2 and HO-1 proteins compared with the As group. In conclusion, our findings showed that Mel could have a protective effect against As-induced vascular toxicity by inhibiting apoptosis and the Sirt1/autophagy pathway.

MiR-34a-5p/Sirt1 axis: A novel pathway for puerarin-mediated hepatoprotection against benzo(a)pyrene

Benzo[a]pyrene (BaP) as a carcinogen induces oxidative stress and inflammation, causing health problems including liver damage. Puerarin (a natural flavonoid) is traditionally used to provide hepatoprotective effects. This research was established to meet the rising demand for effective therapies/treatments against hepatic diseases and investigate the mechanism underlying the protective actions of puerarin against BaP-induced liver damage. In mice, puerarin combated effectively the detrimental changes in liver weight, color and function indices caused by BaP. In HepG2 cells, puerarin alleviated BaP-induced cell death, oxidative stress and inflammation, and such effects were positively correlated with puerarin's concentration (12.5-50 μM). Mechanistic studies revealed that BaP induced low Sirt1 expression and high miR-34a-5p expression, and puerarin treatment alleviated these changes. Oxidative stress and inflammation induced by BaP were almost eliminated when miR-34a-5p was silenced. Inhibiting miR-34a-5p or overexpressing Sirt1 had a similar effect to puerain treatment. Overexpression of miR-34a-5p and inhibition of Sirt1 reduced the protective effect of puerarin. Collectively, miR-34a-5p participates in the regulation of puerarin's protective function against BaP-induced injury through targeting Sirt1. There is a novel pathway for suppressing oxidative stress and inflammation via miR-34a-5p/Sirt1 axis in puerarin-mediated hepatoprotection, which opens up a new avenue for alternative therapies.

Hepatotoxicity in young adult mouse offspring after prenatal exposure to benzo(a)pyrene, and protective effect of atorvastatin

OBJECTIVES

Benzo[a]pyrene (BaP) is an environmental contaminant that interrupts the antioxidant defense and thus leads to oxidative stress and DNA damage in the liver. Atorvastatin (ATV) for reducing cholesterol has antioxidant and anti-apoptotic activities. This study investigated the effects of prenatal exposure of BaP on liver toxicity and the protective role of ATV in reducing liver toxicity.

MATERIALS AND METHODS

In this study, rats were distributed randomly to seven groups: I. Saline control; II. ATV (10 mg/kg); III. Corn oil; IV and V. BaP (10 and 20 mg/kg); VI and VII. ATV + BaP (10 and 20 mg/kg). BaP and ATV were administrated from gestation day 7-16 (GD7-GD16), orally. Ten weeks after the birth, female offspring were examined for oxidative stress markers, liver enzymes, and histology.

RESULTS

Data revealed that BaP significantly induced oxidative stress (decreased glutathione and increased malondialdehyde level), and disrupted the tissue structure of the liver. Moreover, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase increased in the offspring. ATV treatment along with BaP during gestation was able to bring the antioxidant status and serum liver enzymes levels relatively close to normal. As well as, histological findings showed that ATV was able to improve liver tissue structure caused by BaP.

CONCLUSION

Based on the above studies we concluded that ATV at a low dose during gestation was able to reduce liver damage caused by BaP with antioxidant properties.

Effect of exercise and curcumin on cardiomyocyte molecular mediators associated with oxidative stress and autophagy in aged male rats

AIM

Aging can origin changes in the heart that may increase risk of developing cardiovascular disease. This study aimed to characterize autophagy alterations and related molecular mediators in the heart tissue in the aging alone or in combination with exercise and curcumin treatment.

METHODS

Seven young and twenty-eight elderly male Wistar rats were assigned into five groups, namely: young control, age, exercise, curcumin, and curcumin+exercise. Aged rats in exercise group run on treadmill (17 m/min) and in the curcumin group received curcumin (50 mg/kg) by gavage daily for 8 weeks for 2 months. At the end, heart samples were collected and used for determination of autophagy by immunostaining for LC3-phosphatidylethanolamine conjugate (LC3-II), apoptosis by TUNEL assay, Malondialdehyde (MDA) level by enzymatic assay and determination of mediators' molecules by ELISA for NADPH Oxidase 4 (NOX4), sirtuin 1 (SIRT-1), phosphorylated nuclear factor kappa-light-chain-enhancer of activated B cells (p-NF-Ƙb) protein levels and Sequestosome-1 (P62). Also, histological changes such as fibrosis evaluated by Masson trichrome staining.

RESULTS

Our results showed that autophagy, SIRT-1 level were significantly decreased and MDA, NOX4, p-NF-Ƙb and P62 levels were significantly increased in heart of aged group compared to young group. Also, significant increased apoptosis and fibrosis levels in the heart of aged rats were observed compared with young rats, whereas, these undesirable changes were improved by exercise and curcumin. Also, combination therapy of aged rats with curcumin and exercise showed more significant prominent effect on molecular mediators and histological changes in the heart compared with monotherapy.

CONCLUSION

These findings indicate that stress oxidative increase and autophagy decrease in the heart tissue of aged rats. The age induced the mentioned changes in the heart may in part be associated with down-expression of SIRT-1 and overexpression of NOX4 proteins. It was also showed that these age induced effects can be alleviated by treatment with exercise and curcumin. Since NF-Ƙb increased in both the age and treatment groups, it seems the age heart increased NF-Ƙb to be due to a compensatory mechanism.

Beneficial effects of melatonin on liver fibrosis: A systematic review of current biological evidence

Hepatic fibrosis is a reversible response to either acute or chronic cellular injury from a wide variety of etiologies, characterized by excessive deposition of extracellular matrix resulting in liver dysfunction and cirrhosis. Melatonin (N‐acetyl‐5‐methoxytryptamine), the main product secreted by the pineal gland, is a multitasking indolamine with important physiological functions such as anti‐inflammatory and antioxidant actions, modulation of circadian rhythms, and immune system enhancement. Among the numerous biological activities of melatonin, its antifibrotic effects have received increasingly more attention. In this study, we performed a systematic review of publications of the last 10 years evaluating the mechanisms of action of melatonin against liver fibrosis. The study protocol was registered at PROSPERO (CRD42022304744). Literature research was performed employing PubMed, Scopus, and Web of Science (WOS) databases, and after screening, 29 articles were included. Results from the selected studies provided denoted the useful actions of melatonin on the development, progression, and evolution of liver fibrosis. Melatonin antifibrotic effects in the liver involved the reduction of profibrogenic markers and modulation of several cellular processes and molecular pathways, mainly acting as an antioxidant and anti‐inflammatory agent. In addition, the indolamine influenced different molecular processes, such as hepatocyte apoptosis, modulation of autophagy and mitophagy, restoration of circadian rhythms, and modulation of microRNAs, among others. Although some limitations have been found regarding variability in the study design, the findings here summarized display the potential role of melatonin in ameliorating the development of liver fibrosis and its possible progression to liver cirrhosis and hepatocarcinoma.

Exposure to benzo(a)pyrene suppresses mitophagy via ANT1-PINK1-Parkin pathway in ovarian corpus luteum during early pregnancy

Exposure to benzo (a)pyrene (BaP) has been confirmed to interfere with embryo implantation. As the primary organ of progesterone synthesis during early pregnancy, the ovarian corpus luteum (CL) is essential for embryo implantation and pregnancy maintenance. We previously demonstrated that BaP impaired luteal function, but the molecular mechanism remains unclear. In CL cells, mitochondria are the main sites of progesterone synthesis. Mitophagy, a particular type of autophagy, regulates mitochondrial quality by degrading damaged mitochondria and ensuring the homeostasis of cell physiology. Therefore, the present study investigated the effects and the potential molecular mechanisms of BaP on ovarian mitophagy during early pregnancy. We found that BaP and its metabolite, BPDE, inhibited autophagy and PINK1/Parkin-mediated mitophagy in the pregnant ovaries and luteinized granulosa cell, KGN. Notably, adenine nucleotide translocator 1 (ANT1), a crucial mediator of PINK1-dependent mitophagy, was suppressed by BaP and BPDE both in vivo and in vitro. The inhibition of ANT1 leads to the decrease in the PINK1 bound to the outer membrane of mitochondria and consequently reduces recruitment of Parkin to the mitochondria, which is required for the subsequent clearance of mitochondria. Meanwhile, exposure to BPDE also damaged mitochondrial function, causing the reduction in mitochondrial potential and ATP production. Overexpression of ANT1 in KGN cells partially relieved the inhibition of mitophagy caused by BPDE, restored mitochondrial function and expression of hormone synthesis-associated genes. Collectively, our study firstly clarified that BaP and BPDE suppress mitophagy of CL cells via the ANT1-PINK1-Parkin pathway, which provides a new insight to explore the detailed mechanism of the BaP-induced ovarian toxicity.

Melatonin epigenetic potential on testicular functions and fertility profile in varicocele rat model is mediated by Silent information regulator1

BACKGROUND AND PURPOSE

Varicocele is a leading cause of male infertility. Melatonin is a highly pleiotropic neurohormone. We aimed to characterize the melatonin epigenetic potential in varicocele and the involved molecular mechanisms.

EXPERIMENTAL APPROACH

Fifty-two male albino rats were randomly divided into four groups (13 rats each): control (I), melatonin (II), varicocele (III) and melatonin treated varicocele (IV) groups. Left varicocele was induced by partial left renal vein ligation. Reproductive hormones, epididymal sperm functional parameters, testicular 3/17 β-hydroxysteroid dehydrogenases, antioxidant enzymes, malondialdehyde, nicotinamide adenine dinucleotide phosphate oxidase, 8-hydroxy-2'-deoxyguanosine and histopathological/Johnsen's score were evaluated. Flow cytometry and Comet were carried out to explore extent of sperm and testicular DNA damage. Testicular expression of silent information regulator 1 (SIRT1), forkhead transcription factors-class O (type1) (FOXO1), tumour suppressor gene, P53, cation channels of sperm (CatSper) and steroidogenic acute regulatory protein was evaluated by western blot technique. Testicular expression of Bcl-2 and its associated X protein and nuclear factor kappa-light-chain-enhancer of activated B cells were assayed by immunohistochemical staining. Testicular miR-34a expression was quantified by quantitative reverse transcription-polymerase chain reaction.

KEY RESULTS

The varicocele induced testicular histological injury, enhanced oxidative stress, P53-mediated apoptosis, DNA damage and increased testicular miR-34a expression paralleled with down-regulated SIRT1/FOXO axis. Melatonin treatment of varicocele rats displayed antioxidant/anti-apoptotic efficacy and improved reproductive hormones axis, CatSper expression and fertility parameters. MiR-34a/SIRT1/FOXO1 epigenetic axis integrates testicular melatonin mediated intracellular transduction cascades in varicocele.

CONCLUSION AND IMPLICATIONS

Melatonin can be used as an adjuvant therapy to improve varicocele and its complication.

Secoisolariciresinol diglucoside mitigates benzo[a]pyrene-induced liver and kidney toxicity in mice via miR-101a/MKP-1-mediated p38 and ERK pathway

Benzo[a]pyrene (BaP) can cause hepatorenal toxicity. Secoisolariciresinol diglucoside (SDG), a polyphenolic compound present in flaxseed, has shown a variety of biological activities including antioxidant, anti-inflammatory, anti-apoptotic effects. This study aimed to investigate the protective effects and working mechanisms of SDG against BaP-induced hepatorenal injury. Forty male mice were administrated daily (via gastric gavage; 4 weeks) with 0.9% saline (control), BaP (75 mg/kg body weight (b.w.)), SDG (100 mg/kg b.w.), SDG (100 mg/kg b.w.)+BaP (75 mg/kg b.w.). Results showed that the mice treated with SDG + BaP had significantly (P < 0.05) higher body weight, lower organ-to-body weight ratio, alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) activities, and less levels of serum creatinine (CRE) and blood urea nitrogen (BUN) than those treated with BaP alone. SDG administration alleviated BaP-induced oxidative damages, inflammation and apoptosis. Furthermore, it significantly (P < 0.05) downregulated phosphor-p38 (p-p38) and phosphor-extracellular regulated protein kinases (p-ERK) levels, upregulated mitogen-activated protein kinase phosphatase-1 (MKP-1) level, and suppressed miR-101a expression compared with BaP alone group. Taken together, these results showed for the first time that SDG has protective effects against BaP-induced liver and kidney toxicity in mice through regulating oxidative stress, inflammation and apoptosis via miR-101a/MKP-1-mediated p38 and ERK pathway.

The modulation of SIRT1 and SIRT3 by natural compounds as a therapeutic target in doxorubicin-induced cardiotoxicity: A review

Doxorubicin (DOX) is a potent antitumor agent with a broad spectrum of activity; however, irreversible cardiotoxicity resulting from DOX treatment is a major issue that limits its therapeutic use. Sirtuins (SIRTs) play an essential role in several physiological and pathological processes including oxidative stress, apoptosis, and inflammation. It has been reported that SIRT1 and SIRT3 can act as a protective molecular against DOX-induced myocardial injury through targeting numerous signaling pathways. Several natural compounds (NCs), such as resveratrol, sesamin, and berberine, with antioxidative, anti-inflammation, and antiapoptotic effects were evaluated for their potential to suppress the cardiotoxicity induced by DOX via targeting SIRT1 and SIRT3. Numerous NCs exerted their therapeutic effects on DOX-mediated cardiac damage via targeting different signaling pathways, including SIRT1/LKB1/AMPK, SIRT1/PGC-1α, SIRT1/NLRP3, and SIRT3/FoxO. SIRT3 also ameliorates cardiotoxicity by enhancing mitochondrial fusion.

miR-122-5p regulates hepatocytes damage caused by BaP and DBP co-exposure through SOCS1/STAT3 signaling in vitro

BaP and DBP are ubiquitously and contemporaneously present in the environment. However, Current studies largely concentrate on the effects of a single pollutant (BaP or DBP). The liver is vital for biogenic activities. The effects of BaP and DBP co-exposure on liver remain unclear. Thus, we treated human normal liver cell (L02 cell) with BaP or/and DBP. We found that compared to individual exposure, co-exposure to BaP and DBP induced further increased levels of AST and ALT. BaP and DBP co-exposure caused further increased levels of IL-2, IL-6, and TNF-α, decreased IL-10 level, and a higher percentage of apoptotic cells and S-phase arrest cells. BaP and DBP co-exposure worsen the decrease of miR-122-5p level and chaos of SOCS1/STAT3 signaling. Dual-luciferase reporter gene assays showed that SOCS1 was a validated target of miR-122-5p. miR-122-5p overexpression alleviated the increased SOCS1 expression, decreased phospho-STAT3 expression, decreased IL-10 level, increased TNF-α levels, increased percentage of apoptosis and S-phase arrest, and cytotoxicity induced by BaP and DBP co-exposure in hepatocytes. These results suggested that miR-122-5p negatively regulated the synergistic effects on apoptosis and disorder of inflammatory factor secretion involved in hepatocyte injury caused by BaP and DBP co-exposure through targeting SOCS1/STAT3 signaling.

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

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

miR‑34a increases inflammation and oxidative stress levels in patients with necrotizing enterocolitis by downregulating SIRT1 expression

The miR‑34a/SIRT1 signaling axis is an important signaling axis in tumors and diseases. Notably, low SIRT1 expression in the intestinal tissues of patients with necrotizing enterocolitis (NEC) has been reported. However, whether miR‑34a/SIRT1 signaling as a target to protect the intestines during the NEC process is unclear and remains to be elucidated. Blood samples were collected from 30 patients with NEC, and an NEC rat model was used. The miR‑34a and SIRT1 gene and protein expression levels were assayed by qPCR and Western blotting method. The inflammatory cytokine levels and oxidative stress levels were detected using the ELISA method. The results demonstrated that birth weight, albumin and glucose concentrations were significantly decreased in the NEC patient group compared with the control group, but the C‑reactive protein (CRP) and procalcitonin (PCT) concentrations were significantly increased. The miR‑34a expression level was notably increased in the NEC group, but the SIRT1 expression level was markedly decreased. Notably, the miR‑34a was significantly correlated with NEC severity and the concentrations of CRP, PCT, IL‑6, TNF‑α, IL‑1β, IL‑8, MCP‑1, VCAM1 and malondialdehyde (MDA), but was significantly negatively correlated with SIRT1 gene expression and the concentration of IL‑10. Intestinal villi damage in NEC rats was decreased with miR‑34a inhibition and SIRT1 activation treatment by decreasing the levels of inflammatory cytokines, including IL‑6, TNF‑α, IL‑1β and IL‑8, and oxidative stress proteins, including MCP‑1, VCAM1, and MDA, as well as increasing the level of the anti‑inflammatory cytokine IL‑10. In addition, the results indicated that miR‑34a inhibition and SIRT1 activation strongly protected the intestine and decreased the damage caused by NEC, not only by decreasing the protein levels of SIRT1, TNF‑α, IL‑1β, IL‑6 and IL‑8, but also by increasing the IL‑10 protein levels. The miR‑34a inhibition and SIRT1 activation may decrease the damage caused by NEC by decreasing proinflammatory cytokines and oxidative stress proteins and by increasing the anti‑inflammatory cytokine pathway. Based on the aforementioned analysis, the miR‑34a and SIRT1 proteins may be potential novel therapeutic targets in NEC.

Targeting epigenetics and lncRNAs in liver disease: From mechanisms to therapeutics

Early onset and progression of liver diseases can be driven by aberrant transcriptional regulation. Different transcriptional regulation processes, such as RNA/DNA methylation, histone modification, and ncRNA-mediated targeting, can regulate biological processes in healthy cells, as well also under various pathological conditions, especially liver disease. Numerous studies over the past decades have demonstrated that liver disease has a strong epigenetic component. Therefore, the epigenetic basis of liver disease has challenged our knowledge of epigenetics, and epigenetics field has undergone an important transformation: from a biological phenomenon to an emerging focus of disease research. Furthermore, inhibitors of different epigenetic regulators, such as m⁶A-related factors, are being explored as potential candidates for preventing and treating liver diseases. In the present review, we summarize and discuss the current knowledge of five distinct but interconnected and interdependent epigenetic processes in the context of hepatic diseases: RNA methylation, DNA methylation, histone methylation, miRNAs, and lncRNAs. Finally, we discuss the potential therapeutic implications and future challenges and ongoing research in the field. Our review also provides a perspective for identifying therapeutic targets and new hepatic biomarkers of liver disease, bringing precision research and disease therapy to the modern era of epigenetics.

MiR-34a/Sirt1/p53 signaling pathway contributes to cadmium-induced nephrotoxicity: A preclinical study in mice

Cadmium (Cd), as an environmental pollutant, can lead to nephrotoxicity. However, its nephrotoxicological mechanisms have not been fully elucidated. In this study, Cd (1.5 mg/kg body weight, gavaged for 4 weeks) was found to induce the renal damage in mice, based on indicators including Cd concentration, kidney index, serum creatinine and blood urea nitrogen levels, pro-inflammatory cytokines and their mRNA expressions, levels of Bcl-2, Bax and caspase9, and histopathological changes of the kidneys. Furthermore, Cd-caused detrimental changes through inducing inflammation and apoptosis via the miR-34a/Sirt1/p53 axis. This is the first report on the role of miR-34a/Sirt1/p53 axis in regulating Cd-caused apoptosis and nephrotoxicity in mice. The findings obtained in this study provide new insights into miRNA-based regulation of heavy metal induced-nephrotoxicity.

Multiple interactions between melatonin and non-coding RNAs in cancer biology

The melatonin hormone secreted by the pineal gland is involved in physiological functions such as growth and maturation, circadian cycles, and biological activities including antioxidants, anti-tumor, and anti-ischemia. Melatonin not only interacts with proteins but also has functional effects on regulatory RNAs such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs). In this study, we overview various physiological and pathological conditions affecting melatonin through lncRNA and miRNA. The information compiled herein will serve as a solid foundation to formulate ideas for future mechanistic studies on melatonin. It will also provide a chance to more clarify the emerging functions of the non-coding transcriptome.

Diabetes mellitus aggravates ranolazine-induced ECG changes in rats

PURPOSE

Diabetes mellitus (DM) is known to affect the pharmacokinetics of drugs. In this study, we evaluated the effect of DM on the liver content of CYP 3A2 enzyme. We also explored the ECG changes after administration of ranolazine in non-DM and DM rats.

METHODS

First phase: 24 male Wistar rats were separated into 4 groups. The control group (n = 6) received normal saline and the DM groups (n = 18) were treated with a single dose (55 mg/kg) of streptozocin (STZ; i.p. injection), then were held for 10, 20, and 30 days, respectively. After study duration for each group, the liver CYP 3A2 protein content was determined using western blotting. Second phase: 48 male Wistar rats were classified into two groups of non-DM and DM; and each group was divided into 4 subgroups (n: 6). Experimental groups received oral doses of 20, 40, and 80 mg/kg ranolazine. DM and non-DM control groups received normal saline. Treatment lasted for 28 days, and then the ECG was recorded.

RESULTS

Experimental DM induced by STZ caused a significant decrement in liver CYP3A2 protein content of rats on days 10 and 20 (P < 0.01), and 30 (P < 0.05) compared to the control animals. Significant increases in QT and corrected QT (QTc) intervals (P < 0.01), and bradycardia (P < 0.01) without any significant effect on PR and QRS intervals were observed in DM in comparison with non-DM groups after ranolazine treatment.

CONCLUSIONS

In summary, DM induction in animals resulted in CYP 3A2 inhibition and the prolongation of QT and QTc interval as well as bradycardia after ranolazine treatment.

Caffeic acid phenethyl ester mitigates cadmium-induced hepatotoxicity in mice: Role of miR-182-5p/TLR4 axis

Cadmium (Cd), an environmental pollutant, is evidenced to cause hepatotoxicity. In this study, the potential protective effect of caffeic acid phenethyl ester (CAPE) on cadmium-induced liver damage was investigated. Forty male mice were treated daily with either CdCl₂ (1.5 mg/kg body weight (b.w.), gavage) or CAPE (10 μmol/kg b.w., gavage) or both for 4 weeks. CAPE administration significantly reduced Cd level and liver and body weight, and increased AST, ALT and ALP level. Moreover, CAPE prevented CdCl₂-induced oxidative stress via PI3K/Akt/mTOR pathway and inhibited apoptosis by regulating apoptosis markers. CAPE also suppressed the CdCl₂-induced inflammation by reducing the inflammatory mediators, including TNF-α, IL-6 and IL-1β. Furthermore, CAPE alleviated CdCl₂-induced reduction of TLR4. It should be noted that this effect was achieved by targeting miR-182-5p, and CAPE improved miR-182-5p level. The improvement of the liver tissue histopathology by CAPE confirmed the biochemical data. These results show for the first time that miR-182-5p/TLR4 axis involved in CAPE's protection against CdCl₂-induced hepatotoxicity, and may provide novel insights into the treatment of cadmium-related diseases.

The protective effect of melatonin on benzo(a)pyrene-induced brain injury: role of apoptosis and autophagy pathways

Benzo(a)pyrene (BaP), a toxic polycyclic aromatic hydrocarbon, is spread in different ways as an environmental pollutant. It has been proposed that BaP can induce toxicity through oxidative stress and apoptosis in vital organs. The present study evaluated the protective effect of melatonin, a circadian hormone of the pineal gland, on BaP-induced neurotoxicity focused on oxidative stress, autophagy, and apoptosis pathways. Thirty male mice in 5 groups were treated daily for 28 consecutive days: (I) control group (BaP and melatonin solvent), (II) BaP (75 mg/kg, orally), (III) and (IV) BaP + melatonin (10 and 20 mg/kg, i.p.), (V) melatonin (20 mg/kg). The oxidative stress markers were determined in the brain. Western blot was conducted for the level of LC3 II/I and Beclin1, as autophagy markers, caspase3 and Bcl2, as apoptosis proteins, and Sirt1 in the brain. The exposure of mice to BaP caused a marked increase in the malondialdehyde (MDA) level and decrease of glutathione (GSH) content in the brain. Furthermore, the Sirt1 level upregulated as well as LC3 II/I, Beclin1, and cleaved caspase3 proteins, while the level of Bcl2 did not change. Melatonin at 20 mg/kg concurrently with BaP restored the BaP alteration in the brain compared with the BaP group. In conclusion, BaP induced brain toxicity via the induction of oxidative stress, apoptosis, and autophagy, whereas melatonin afforded neuroprotection against BaP due to inhibition of these mechanisms.