Agomelatine protects heart and aorta against lipopolysaccharide-induced cardiovascular toxicity via inhibition of NF-kβ phosphorylation

Agomelatine prevented depression in the chronic restraint stress model through enhanced catalase activity and halted oxidative stress

BACKGROUND

Agomelatine (AGO) is an antidepressant with unique pharmacological effects; however, its underlying mechanisms remain unknown. In this study, we examined agomelatine's effects on catalase activity, oxidative stress, and inflammation.

METHODS

Chronic restraint stress (CRS) model mice were established over 4 weeks, and AGO 50 mg/kg was administered to different groups alongside a deferasirox (DFX) 10 mg/kg gavage treatment. Behavioral tests were performed to assess the effect of AGO on the remission of depression-like behaviors. Meanwhile, the expression of CAT, the oxidative stress signaling pathway and inflammatory protein markers were assessed using ELISA, qRT-PCR, Western blot, and immunohistochemistry.

RESULTS

Four weeks of AGO treatment significantly improved depression-like behavior in mice through the activation of catalase in the hippocampus and serum of the model mice, increased superoxide dismutase expression, reduced malondialdehyde expression, and reduced oxidative stress damage. Deferasirox was found to offset this therapeutic effect partially. In addition, the inflammatory pathway (including nuclear factor-κB and nuclear factor of kappa light polypeptide gene enhancer in B cells inhibitor, alpha) was not significantly altered.

CONCLUSIONS

AGO can exert antidepressant effects by altering oxidative stress by modulating catalase activity.

The melatonin receptor agonist agomelatine protects against acute pancreatitis induced by cadmium by attenuating inflammation and oxidative stress and modulating Nrf2/HO-1 pathway

Pancreatitis is a serious effect of the heavy metal cadmium (Cd) and inflammation and oxidative stress (OS) are implicated in Cd-induced pancreatic injury. This study evaluated the effect of the melatonin receptor agonist agomelatine (AGM) on Cd-induced acute pancreatitis (AP), pointing to its modulatory effect on inflammation, OS, and Nrf2/HO-1 pathway. Rats were supplemented with AGM orally for 14 days and a single injection of cadmium chloride (CdCl2) on day 7. Cd increased serum amylase and lipase and caused pancreatic endocrine and exocrine tissue injury. Malondialdehyde (MDA), nitric oxide (NO) and myeloperoxidase (MPO) were elevated, nuclear factor (NF)-kB p65, inducible NO synthase (iNOS), interleukin (IL)-6, tumor necrosis factor (TNF)-α and CD40 were upregulated, and antioxidants were decreased in the pancreas of Cd-administered rats. AGM ameliorated serum amylase and lipase and pancreatic OS, NF-kB p65, CD40, pro-inflammatory mediators and caspase-3, prevented tissue injury and enhanced antioxidants. AGM downregulated Keap1 and enhanced Nrf2 and HO-1 in the pancreas of Cd-administered rats. In silico findings revealed the binding affinity of AGM with Keap1, HO-1, CD40L and caspase-3. In conclusion, AGM protected against AP induced by Cd by preventing inflammation, OS and apoptosis and modulating Nrf2/HO-1 pathway.

Cadmium cardiotoxicity is associated with oxidative stress and upregulated TLR-4/NF-kB pathway in rats; protective role of agomelatine

Cardiotoxicity is one of the hazardous effects of the exposure to the heavy metal cadmium (Cd). Inflammation and oxidative injury are implicated in the cardiotoxic mechanism of Cd. The melatonin receptor agonist agomelatine (AGM) showed promising effects against oxidative and inflammatory responses. This study evaluated the effect of AGM on Cd-induced cardiotoxicity in rats, pointing to its modulatory effect on TLR-4/NF-kB pathway and HSP70. Rats received AGM for 14 days and a single dose of Cd on day 7 and blood and heart samples were collected for analyses. Cd increased serum CK-MB, AST and LDH and caused cardiac tissue injury. Cardiac malondialdehyde (MDA), nitric oxide (NO) and MPO were elevated and GSH, SOD and GST decreased in Cd-administered rats. AGM ameliorated serum CK-MB, AST and LDH and cardiac MDA, NO and MPO, prevented tissue injury and enhanced antioxidants. AGM downregulated serum CRP and cardiac TLR-4, NF-kB, iNOS, IL-6, TNF-α and COX-2 in Cd-administered rats. HSP70 was upregulated in the heart of Cd-challenged rats treated with AGM. In silico findings revealed the binding affinity of AGM with TLR-4 and NF-kB. In conclusion, AGM protected against Cd cardiotoxicity by preventing myocardial injury and oxidative stress and modulating HSP70 and TLR-4/NF-kB pathway.

Zataria multiflora and its constituent, carvacrol, counteract sepsis-induced aortic and cardiac toxicity in rat: Involvement of nitric oxide and oxidative stress

BACKGROUND

Zataria multiflora and carvacrol showed various pharmacological properties including anti-inflammatory and anti-oxidant effects. However, up to now no studies have explored its potential benefits in ameliorating sepsis-induced aortic and cardiac injury. Thus, this study aimed to investigate the effects of Z. multiflora and carvacrol on nitric oxide (NO) and oxidative stress indicators in lipopolysaccharide (LPS)-induced aortic and cardiac injury.

METHODS

Adult male Wistar rats were assigned to: Control, lipopolysaccharide (LPS) (1 mg/kg, intraperitoneal (i.p.)), and Z. multiflora hydro-ethanolic extract (ZME, 50-200 mg/kg, oral)- and carvacrol (25-100 mg/kg, oral)-treated groups. LPS was injected daily for 14 days. Treatment with ZME and carvacrol started 3 days before LPS administration and treatment continued during LPS administration. At the end of the study, the levels of malondialdehyde (MDA), NO, thiols, and antioxidant enzymes were evaluated.

RESULTS

Our findings showed a significant reduction in the levels of superoxide dismutase (SOD), catalase (CAT), and thiols in the LPS group, which were restored by ZME and carvacrol. Furthermore, ZME and carvacrol decreased MDA and NO in cardiac and aortic tissues of LPS-injected rats.

CONCLUSIONS

The results suggest protective effects of ZME and carvacrol on LPS-induced cardiovascular injury via improved redox hemostasis and attenuated NO production. However, additional studies are needed to elucidate the effects of ZME and its constituents on inflammatory responses mediated by LPS.

Agomelatine improves streptozotocin-induced diabetic nephropathy through melatonin receptors/SIRT1 signaling pathway

INTRODUCTION

Diabetic nephropathy (DN) is a major cause of end-stage renal disease (ESRD). Agomelatine, a melatonin receptor agonist, has a potent anti-inflammatory activity. The current study aimed to determine the ameliorative anti-inflammatory effect of agomelatine against DN.

METHODS

We used 10 % fructose with streptozotocin (STZ) to induce DN in male Wistar rats. Diabetic rats were treated with agomelatine in presence or absence of melatonin receptor antagonist (luzindole) or Sirtuin1 (SIRT1) inhibitor (EX527). SIRT1 expression was measured by qRT-PCR and immunohistochemical analysis. The expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), 5'adenosine monophosphate-activated protein kinase (AMPK), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion protein-1 (VCAM-1), and monocyte chemoattractant protein-1 (MCP-1) were measured using ELISA. Histological assessment was performed using hematoxylin and eosin-stained renal sections.

RESULTS

Fructose and STZ treatment induced diabetes, insulin resistance, and renal damage accompanied by reduced SIRT1 expression, increased NFκB activation, and decreased AMPK phosphorylation in the kidney. Agomelatine treatment improved kidney histology and function and upregulated SIRT1 expression (2-fold). Inhibition of melatonin receptors and SIRT1 activity increased NFκB phosphorylation (2.13 and 1.98-folds, respectively), reduced AMPK activation (0.51 and 0.53-folds, respectively), increased inflammatory markers ICAM-1 (2.16 and 2.23-folds, respectively), VCAM-1 (2.19 and 2.26-folds, respectively), and MCP-1(2.84 and 3.12-folds, respectively), and inhibited the ameliorative effect of agomelatine on kidney structure and function.

CONCLUSION

Our findings reveal the ameliorative anti-inflammatory activity of agomelatine against STZ-induced DN and this effect is SIRT1- and melatonin receptor-dependent. Therefore, agomelatine may be beneficial to prevent the development of ESRD from diabetes mellitus.

Agomelatine ameliorates cadmium-induced toxicity through the modification of HMGB-1/TLR-4/NFκB pathway

Cadmium (Cd) has potential hazards on human beings. Consequently, this study was performed to explore the protective effects of agomelatine (AGO), a melatonin receptor agonist, against Cd-induced toxicity in rats. AGO (40 mg/kg/day) was administered orally concomitant with intra peritoneal injection of Cd (0.4 mg/kg/day) for 14 days. Then, blood, biochemical parameters and histological examination of affected organs including, heart and testis, were evaluated. Interestingly, AGO significantly counteracted Cd-induced elevation of serum cardiac enzymes. Similarly, AGO significantly improved the deterioration of serum testosterone level with Cd administration. The oxidative balance was corrected by AGO, as evidenced by decrease malondialdehyde (MDA), and superoxide dismutase activity in cardiac and testicular tissues. Additionally, AGO increased silent information regulator 1 protein (SIRT-1) and decreased High mobility group box 1 (HMGB1), Toll like receptor-4 (TLR-4), and Myd88 levels that subsequently reduced expression of nuclear factor-κB (NF-κB). Moreover, level of apoptotic marker; caspase-3 was inhibited by AGO. In accordance with the biochemical and molecular results, AGO restored structure of cardiac myofibers and seminiferous tubules. Collectively, AGO mitigated cardiac and testicular toxicity of Cd via modulation of SIRT-1/HMGB1 and its downstream pathway.

Agomelatine rescues lipopolysaccharide-induced neural injury and depression-like behaviors via suppression of the Gαi-2-PKA-ASK1 signaling pathway

BACKGROUND

Agomelatine has been shown to be effective in the treatment of depression, but the molecular mechanisms underlying its antidepressant effects have yet to be elucidated. Identification of these molecular mechanisms would not only offer new insights into the basis for depression but also provide the foundation for the development of novel treatments for this disorder.

METHODS

Intraperitoneal injection of LPS was used to induce depression-like behaviors in rats. The interactions of the 5-HT2C reporter and Gαi-2 were verified by immunoprecipitation or immunofluorescence assay. Inflammatory related proteins, autophagy related proteins and apoptosis markers were verified by immunoblotting or immunofluorescence assay. Finally, electron microscopy analysis was used to observe the synapse and ultrastructural pathology.

RESULTS

Here, we found that the capacity for agomelatine to ameliorate depression and anxiety in a lipopolysaccharide (LPS)-induced rat model of depression was associated with an alleviation of neuroinflammation, abnormal autophagy and neuronal apoptosis as well as the promotion of neurogenesis in the hippocampal dentate gyrus (DG) region of these rats. We also found that the 5-HT2C receptor is coupled with G alphai (2) (Gαi-2) protein within hippocampal neurons and, agomelatine, acting as a 5-HT2C receptor antagonist, can up-regulate activity of the Gαi-2-cAMP-PKA pathway. Such events then suppress activation of the apoptosis signal-regulating kinase 1 (ASK1) pathway, a member of the mitogen-activated protein kinase (MAPK) family involved in pathological processes of many diseases.

CONCLUSION

Taken together, these results suggest that agomelatine plays a neuroprotective role in regulating neuroinflammation, autophagy disorder and apoptosis in this LPS-induced rat model of depression, effects which are associated with the display of antidepressant behaviors. These findings provide evidence for some of the potential mechanisms for the antidepressant effects of agomelatine.

Agomelatine prevents angiotensin II-induced endothelial and mononuclear cell adhesion

Agomelatine is a non-selective melatonin receptor agonist and an atypical antidepressant with anti-inflammatory, neuroprotective, and cardioprotective effects. The renin-angiotensin system modulates blood pressure and vascular homeostasis. Angiotensin II (Ang II) and its receptor Ang II type I receptor (AT₁R) are recognized as contributors to the pathogenesis of cardiovascular and cardiometabolic diseases, including diabetes, obesity, and atherosclerosis. The recruitment and attachment of monocytes to the vascular endothelium is a major event in the early stages of atherosclerosis and other cardiovascular diseases. In the present study, we demonstrate that agomelatine reduced Ang II-induced expression of AT₁R while significantly inhibiting the attachment of monocytes to endothelial cells induced by Ang II and mediated by ICAM-1 and VCAM-1. Additionally, Ang II inhibited the expression of the chemokines CXCL1, MCP-1, and CCL5, which are critical in the process of immune cell recruitment and invasion. Agomelatine also suppressed the expression of TNF-α, IL-8, and IL-12, which are proinflammatory cytokines that promote endothelial dysfunction and atherogenesis. Importantly, we demonstrate that the inhibitory effect of agomelatine against the expression of adhesion molecules is mediated through the downregulation of Egr-1 signaling. Together, our findings provide evidence of a novel mechanism of agomelatine that may be practicable in the treatment and prevention of cardiovascular diseases.

Agomelatine prevents gentamicin nephrotoxicity by attenuating oxidative stress and TLR-4 signaling, and upregulating PPARγ and SIRT1

Kidney injury is a relatively common complication of the use of aminoglycosides. Inflammation and oxidative stress play a key role in gentamicin (GM) nephrotoxicity. We investigated the protective effect of the melatonergic agonist agomelatine (AGM) on GM nephrotoxicity, emphasizing the involvement of TLR-4 signaling, SIRT1 and PPARγ. Rats received 25 mg/kg AGM for 15 days and 100 mg/kg GM for eight days starting at day 7. Elevated serum creatinine, urea and Kim-1 along with multiple histological alterations in the kidney were observed in GM-intoxicated rats. Malondialdehyde (MDA), TNF-α, IL-1β, nitric oxide (NO) and myeloperoxidase (MPO) were increased, and GSH, SOD and catalase were decreased in the kidney of GM-intoxicated rats. Treatment with AGM significantly ameliorated the kidney function biomarkers, prevented tissue injury, decreased inflammatory cytokines, MDA, NO and MPO, and boosted antioxidants. In addition, AGM suppressed the expression of TLR-4, NF-κB p65, p38 MAPK, ERK-1, VCAM-1 and iNOS, whereas upregulated SIRT1 and PPARγ in the kidney of GM-intoxicated rats. In conclusion, AGM prevented GM nephrotoxicity in rats by attenuating oxidative injury and inflammation. AGM suppressed TLR-4 signaling, enhanced antioxidants and upregulated SIRT1 and PPARγ in the kidney of GM-induced rats.

Agomelatine prevents macrophage infiltration and brain endothelial cell damage in a stroke mouse model

Background and purpose: Ischemic/reperfusions are regarded as the clinical consensus for stroke treatment, which results in secondary injury of brain tissues. Increased blood-brain barrier (BBB) permeability and infiltration of inflammatory cells are responsible for the ischemic/reperfusion injury. In the present study, we aimed to investigate the effects of Agomelatine on brain ischemic/reperfusions injury and the underlying mechanism.

Methods: MCAO model was established in mice. The expressions of CD68 and claudin-5 in the cerebral cortex were determined using an immunofluorescence assay. Brain permeability was evaluated using Evans blue staining assay. A two-chamber and two-cell trans-well assay was used to detect the migration ability of macrophages through endothelial cells. The expression levels of claudin-5 and MCP-1 in the endothelial cells were determined using qRT-PCR and ELISA.

Results: CD68 was found to be up-regulated in the cerebral cortex of MCAO mice but was down-regulated by treatment with Agomelatine. The expression level of down-regulated claudin-5 in the cerebral cortex of MCAO mice was significantly suppressed by Agomelatine. Deeper staining of Evans blue was found in the MCAO group, which was however faded significantly in the Agomelatine treated MCAO mice. The migrated macrophages were significantly increased by hypoxia incubation but were greatly suppressed by the introduction of Agomelatine. The down-regulated claudin-5 by hypoxic incubation in endothelial cells was up-regulated by treatment with Agomelatine. Furthermore, the increased expression of MCP-1 in endothelial cells under hypoxic conditions was significantly inhibited by Agomelatine.

Conclusion: Agomelatine prevents macrophage infiltration and brain endothelial cell damage in a stroke mouse model.

A protective effect of curcumin on cardiovascular oxidative stress indicators in systemic inflammation induced by lipopolysaccharide in rats

Objective

Inflammation has been considered as an important factor in cardiovascular diseases (CVD). Curcumin has been well known for its anti-inflammatory effects. In current research, protective effect of curcumin on cardiovascular oxidative stress indicators in systemic inflammation induced by lipopolysaccharide (LPS) was investigated in rats.

Material and methods

The animals were divided into five groups and received the treatments during two weeks [1]: Control in which vehicle was administered instead of curcumin and saline was injected instead of LPS [2], LPS group in which vehicle of curcumin plus LPS (1 mg/kg) was administered [3-5], curcumin groups in them three doses of curcumin (5, 10 and 15 mg/kg) before LPS were administered.

Results

Administration of LPS was followed by an inflammation status presented by an increased level of white blood cells (WBC) (p < 0.001). An oxidative stress status was also occurred after LPS injection which was presented by an increased level of malondialdehyde (MDA) while, a decrease in thiols, superoxide dismutase (SOD) and catalase(CAT) in all heart, aorta and serum (p < 0.001). The results also showed that curcumin decreased WBC (doses: 10 and 15 mg/kg) (p < 0.001) accompanying with a decrease in MDA (P < 0.01 and P < 0.001). Curcumin also improved the thiols and the activities of SOD and catalase (P < 0.05, P < 0.01 and P < 0.001).

Conclusion

Based on our findings, curcumin can ameliorates oxidative stress and inflammation induced by LPS in rats to protect the cardiovascular system.

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The aim of the present study was to investigate the cardiovascular protective effects of curcumin in lipopolysaccharide (LPS) challenged rats

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Lipopolysaccharide (LPS) induced inflammation model in rats

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LPS injection was followed by inflammation and induced oxidative stress status in the serum, aorta and heart.

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Administration of curcumin attenuated oxidative stress and inflammation in the serum, aorta and heart tissues induced by LPS.

Ameliorative effects of pregabalin on LPS induced endothelial and cardiac toxicity

We investigated the antioxidant, anti-inflammatory and anti-apoptotic effects of pregabalin (PREG) on lipopolysaccharide (LPS) induced sepsis related cardiotoxicity via NF-kβ pathways. We used 24 female Wistar albino rats divided into three groups: control, LPS treated and LPS + PREG treated. Total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), tumor necrosis factor alpha (TNF-α), nuclear factor kappa beta (NF-kβ)/p65, p-NF-kβ/p65, caspase-3 (Cas-3) and cleaved Cas-3 were measured in cardiac tissues and creatine kinase MB (CKMB), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) levels were measured in blood samples. Also, Cas-3, granulocyte-colony stimulating factors (G-CSF), interleukin-6 (IL-6), serum amyloid A (SAA) and inducible nitric oxide synthase (iNOS) were measured immunohistochemically in heart and aorta tissue. In the LPS group; the levels of CKMB, AST, LDH, TOS, OSI increased and TAS decreased. TNF-α, p-NF-kβ/p65 and Cas-3 protein levels also increased in the LPS group. Immunohistochemical evaluation of the heart and aorta revealed a significant increase in the levels of Cas-3, G-CSF, SAA, IL-6 and iNOS in the LPS group. PREG treatment restored all measurements to near normal. LPS induced cardiovascular toxicity was due to inflammation, oxidative stress and apoptosis. PREG ameliorated the damage by inhibition of NF-kβ phosphorylation.