Irbesartan reprofiling for the amelioration of ethanol-induced gastric mucosal injury in rats: Role of inflammation, apoptosis, and autophagy

The Impact of Tobacco Smoking and Alcohol Consumption on the Development of Gastric Cancers

Chronic infection of Helicobacter pylori is considered the principal cause of gastric cancers, but evidence has accumulated regarding the impact of tobacco smoking and alcohol consumption on the development of gastric cancers. Several possible mechanisms, including the activation of nicotinic acetylcholine receptors, have been proposed for smoking-induced gastric carcinogenesis. On the other hand, local acetaldehyde exposure and ethanol-induced mucosal inflammation have been proposed as the mechanisms involved in the development of gastric cancers in heavy alcohol drinkers. In addition, genetic polymorphisms are also considered to play a pivotal role in smoking-related and alcohol-related gastric carcinogenesis. In this review, we will discuss the molecular mechanisms involved in the development of gastric cancers in relation to tobacco smoking and alcohol consumption.

Atractylenolide I Alleviates Indomethacin-Induced Gastric Ulcers in Rats by Inhibiting NLRP3 Inflammasome Activation

Atractylodes macrocephala Koidz, a traditional Chinese medicine, contains atractylenolide I (ATR-I), which has potential anticancer, anti-inflammatory, and immune-modulating properties. This study evaluated the therapeutic potential of ATR-I for indomethacin (IND)-induced gastric mucosal lesions and its underlying mechanisms. Noticeable improvements were observed in the histological morphology and ultrastructures of the rat gastric mucosa after ATR-I treatment. There was improved blood flow, a significant decrease in the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β, and IL-18, and a marked increase in prostaglandin E2 (PGE2) expression in ATR-I-treated rats. Furthermore, there was a significant decrease in the mRNA and protein expression levels of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), apoptosis-associated speck-like protein (ASC), cysteinyl aspartate specific proteinase-1 (caspase-1), and nuclear factor-κB (NF-κB) in rats treated with ATR-I. The results show that ATR-I inhibits the NLRP3 inflammasome signaling pathway and effectively alleviates local inflammation, thereby improving the therapeutic outcomes against IND-induced gastric ulcers in rats.

Gastroduodenal injury and repair mechanisms

PURPOSE OF REVIEW

Although the mucosal barrier serves as a primary interface between the environment and host, little is known about the repair of acute, superficial lesions or deeper, persistent lesions that if not healed, can be the site of increased permeability to luminal antigens, inflammation, and/or neoplasia development.

RECENT FINDINGS

Studies on acute superficial lesions have been sparse in the past year, with more focus given to novel mechanisms of mucosal protection, and the way in which mature epithelial cells or committed stem cells dedifferentiate, reprogram, proliferate, and then regenerate the gastroduodenal mucosa after injury. For this, adenoviral therapy showed organ specific targeting with mRNA and protein expression of effectors to protect against mucosal injury and ulceration. A large database of plant-based agents known to protect against injury and ulceration was published, along with studies using plant-based compounds delivered with alginates, polysaccharide/gel floating rafts, or incorporated into nanoparticles or green carbon dots to improve targeting and retention at the ulcerated lesion. With RNA technology developing rapidly, particularly single-cell RNA sequencing, important and novel data was forthcoming on mucosal regeneration. In particular, the role of interleukin-17 hub proteins in mucosal healing was highlighted. The presence and role of injury reserve cells was determined, as was the composition of ligand gradients for cell differentiation in both stomach and duodenum. The role of amphiregulin in parietal cell differentiation from lineage-restricted stem cells and the Yap1 gene signature in metaplasia vs. healing ulcers were of particular importance. Additionally, studies unveiled the important role of mesenchymal stromal cells in differentiation and repair mechanisms, in Muse cells as an exciting new therapy for mucosal repair after injury, and the role of sympathetic neurons in activating the immune system to regulate mucosal repair mechanisms.

SUMMARY

Recent studies highlight novel mechanisms that promote mucosal regeneration after injury of the gastroduodenal mucosa.

Cilostazol protects against gastric ulcers by regulating PPAR-γ, HO-1, PECAM-1, pErk-1, NF-κB, Bcl-2, and cleaved caspase-3 protein expression

Millions of individuals worldwide, across all age groups, suffer from the widespread health issue of gastric ulcers. In many experiments, cilostazol (Cls), a phosphodiesterase-3 inhibitor, was recently shown to have anti-ulcer activity. Notably, Cls increases the expression and transcriptional activity of PPAR-γ in vitro and in vivo. This study aimed to evaluate the protective effect of Cls against ethanol-induced gastric ulcers and clarify the possible underlying mechanisms with an emphasis on the role of PPAR-γ. Male albino rats were treated with ethanol to induce gastric ulcers, or they were pretreated with Cls, omeprazole (Omp), GW9662, or Cls + GW9662 for 14 consecutive days before receiving ethanol. Cls protects against ethanol-induced gastric ulcers. Cls treatment significantly reduced ethanol-induced upregulation of the pro-inflammatory markers (IL-1β, IL-6, TNF-α, and NF-κB), MDA (a marker of lipid peroxidation), and caspase-3 and cleaved caspase-3 (apoptotic markers). On the other hand, Cls treatment counteracted ethanol-induced downregulation of PPAR-γ, pErk-1, HO-1 and GSH (antioxidant markers), PECAM-1 and NO (healing markers), and Bcl-2 (antiapoptotic marker). However, when combined with GW9662, a potent antagonist of PPAR-γ, Cls loses its effects. In conclusion, these results suggest that PPAR-γ and pErk-1 are essential for Cls's protective effects against ethanol-induced gastric ulcers.

Gastroprotective effect of vanillic acid against ethanol-induced gastric injury in rats: involvement of the NF-κB signalling and anti-apoptosis role

BACKGROUND

Vanillic acid (VA; 4-hydroxy-3-methoxybenzoic acid) is a flavouring agent found in various natural sources such as olives, fruits, and green tea. While VA exhibits numerous pharmacological effects, its potential protective effects against gastric injury warrants further investigation. Therefore, the primary objective of this study is to elucidate investigate the gastroprotective properties of VA against ethanol-induced gastric injury.

METHODS AND RESULTS

Rats were orally administered either saline or VA at different doses (50, 100, and 200 mg/kg/day), with omeprazole (20 mg/kg) serving as a positive control, for fourteen consecutive days before ethanol administration. Blood and gastric tissue samples were collected one hour after ethanol administration for biochemical, molecular, and histological analyses. Pre-treatment with VA before ulcer induction alleviated both macroscopic and microscopic damage. It also increased antioxidant glutathione levels and decreased malondialdehyde and myeloperoxidase activity, along with reducing inflammatory markers such as tumour necrosis factor (TNF)-α, interleukin (IL)-6, and nuclear factor kappa B (NF-κB). Additionally, VA pre-treatment reversed the elevation of Bax mRNA expression and gastric caspase-3 levels induced by gastric damage. It also mitigated the reduction in Bcl-2 mRNA expression.

CONCLUSION

These findings suggest that VA exerts protective effects against ethanol-induced gastric injury in rats. It achieves this by augmenting gastric antioxidant capacity and mitigating oxidative, inflammatory, and apoptotic damage.

Activation of SIRT1/Nrf2/HO-1 and Beclin-1/AMPK/mTOR autophagy pathways by eprosartan ameliorates testicular dysfunction induced by testicular torsion in rats

Testicular torsion carries the ominous prospect of inducing acute scrotal distress and the perilous consequence of testicular atrophy, necessitating immediate surgical intervention to reinstate vital testicular perfusion, notwithstanding the paradoxical detrimental impact of reperfusion. Although no drugs have secured approval for this urgent circumstance, antioxidants emerge as promising candidates. This study aspires to illustrate the influence of eprosartan, an AT1R antagonist, on testicular torsion in rats. Wistar albino rats were meticulously separated into five groups, (n = 6): sham group, eprosartan group, testicular torsion-detorsion (T/D) group, and two groups of T/D treated with two oral doses of eprosartan (30 or 60 mg/kg). Serum testosterone, sperm analysis and histopathological examination were done to evaluate spermatogenesis. Oxidative stress markers were assessed. Bax, BCL-2, SIRT1, Nrf2, HO-1 besides cleaved caspase-3 testicular contents were estimated using ELISA or qRT-PCR. As autophagy markers, SQSTM-1/p62, Beclin-1, mTOR and AMPK were investigated. Our findings highlight that eprosartan effectively improved serum testosterone levels, testicular weight, and sperm count/motility/viability, while mitigating histological irregularities and sperm abnormalities induced by T/D. This recovery in testicular function was underpinned by the activation of the cytoprotective SIRT1/Nrf2/HO-1 axis, which curtailed testicular oxidative stress, indicated by lowering the MDA content and increasing GSH content. In terms of apoptosis, eprosartan effectively countered apoptotic processes by decreasing cleaved caspase-3 content, suppressing Bax and stimulating Bcl-2 gene expression. Simultaneously, it reactivated impaired autophagy by increasing Beclin-1 expression, decreasing the expression of SQSTM-1/p62 and modulate the phosphorylation of AMPK and mTOR proteins. Eprosartan hold promise for managing testicular dysfunction arising from testicular torsion exerting antioxidant, pro-autophagic and anti-apoptotic effect via the activation of SIRT1/Nrf2/HO-1 as well as Beclin-1/AMPK/mTOR pathways.

Activation of AMPK/mTOR-Driven Autophagy and Suppression of the HMGB1/TLR4 Pathway with Pentoxifylline Attenuates Doxorubicin-Induced Hepatic Injury in Rats

Despite being an effective chemotherapeutic agent, the clinical use of doxorubicin (DOX) is limited by several organ toxicities including hepatic injury. Pentoxifylline (PTX) is a methylxanthine derivative with marked anti-inflammatory and anti-apoptotic features. It is unknown, however, whether PTX can mitigate DOX-evoked hepatotoxicity. This study aims to explore the potential hepatoprotective impact of PTX in DOX-induced hepatic injury and the underlying molecular mechanisms. Histopathology, immunohistochemistry, and ELISA were used to examine liver tissues. The current findings revealed that PTX administration to DOX-intoxicated rats mitigated the pathological manifestations of hepatic injury, reduced microscopical damage scores, and improved serum ALT and AST markers, revealing restored hepatic cellular integrity. These favorable effects were attributed to PTX's ability to mitigate inflammation by reducing hepatic IL-1β and TNF-α levels and suppressing the pro-inflammatory HMGB1/TLR4/NF-κB axis. Moreover, PTX curtailed the hepatic apoptotic abnormalities by suppressing caspase 3 activity and lowering the Bax/Bcl-2 ratio. In tandem, PTX improved the defective autophagy events by lowering hepatic SQSTM-1/p62 accumulation and enhancing the AMPK/mTOR pathway, favoring autophagy and hepatic cell preservation. Together, for the first time, our findings demonstrate the ameliorative effect of PTX against DOX-evoked hepatotoxicity by dampening the hepatic HMGB1/TLR4/NF-κB pro-inflammatory axis and augmenting hepatic AMPK/mTOR-driven autophagy. Thus, PTX could be utilized as an adjunct agent with DOX regimens to mitigate DOX-induced hepatic injury.

An injectable polyacrylamide/chitosan-based hydrogel with highly adhesive, stretchable and electroconductive properties loaded with irbesartan for treatment of myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) significantly contributes to the high incidence of complications and mortality associated with acute myocardial infarction. Recently, injectable electroconductive hydrogels (IECHs) have emerged as promising tools for replicating the mechanical, electroconductive, and physiological characteristics of cardiac tissue. Herein, we aimed to develop a novel IECH by incorporating irbesartan as a drug delivery system (DDS) for cardiac repair. Our approach involved merging a conductive poly-thiophene derivative (PEDOT: PSS) with an injectable dual-network adhesive hydrogel (DNAH) comprising a catechol-branched polyacrylamide network and a chitosan-hyaluronic acid covalent network. The resulting P-DNAH hydrogel, benefitting from a high conducting polymer content, a chemically crosslinked network, a robust dissipative matrix, and dynamic oxidation of catechol to quinone exhibited superior mechanical strength, desirable conductivity, and robust wet-adhesiveness. In vitro experiments with the P-DNAH hydrogel carrying irbesartan (P-DNAH-I) demonstrated excellent biocompatibility by cck-8 kit on H9C2 cells and a rapid initial release of irbesartan. Upon injection into the infarcted hearts of MIRI mouse models, the P-DNAH-I hydrogel effectively inhibited the inflammatory response and reduced the infarct size. In conclusion, our results suggest that the P-DNAH hydrogel, possessing suitable mechanical properties and electroconductivity, serves as an ideal IECH for DDS, delivering irbesartan to promote heart repair.

Azilsartan improves doxorubicin-induced cardiotoxicity via inhibiting oxidative stress, proinflammatory pathway, and apoptosis

Azilsartan, a known angiotensin receptor blocker, has shown potential in reducing 24-hour blood pressure and may have protective effects against cardiac complications. Increased oxidative stress in cardiac tissue is directly related to the cardiac complications of doxorubicin. This study investigated whether azilsartan could mitigate doxorubicin-induced cardiotoxicity. We divided 28 male rats into four groups: the control group receiving a standard diet and water, the vehicle group given DMSO orally for two weeks, doxorubicin group receiving 2.5 mg/kg of doxorubicin three times a week for two weeks, and azilsartan group treated with 5 mg/kg/day of azilsartan orally and doxorubicin. Doxorubicin-induced cardiotoxicity was evidenced by a significant increase in TNF-α, IL-1β, MDA, and caspase-3 levels and significantly decreased TAC and Bcl-2 levels in the cardiac tissues of treated rats compared to the DMSO and control groups. Azilsartan significantly decreased doxorubicin-induced cardiotoxicity, as evidenced by a decline in serum levels of both TNF-α and IL-1β. Additionally, MDA significantly decreased in the cardiac tissue, although TAC was significantly increased when comparing the azilsartan group to the group receiving doxorubicin-only. These results suggest that azilsartan effectively reduced doxorubicin-induced cardiotoxicity, likely by mitigating apoptosis, inflammation, and oxidative stress in cardiac tissues.

Pathophysiology updates: gastroduodenal injury and repair mechanisms

PURPOSE OF REVIEW

Although the mucosal barrier serves as a primary interface between the environment and host, little is known about the repair of acute, superficial lesions or deeper, persistent lesions that if not healed, can be the site of increased permeability to luminal antigens, inflammation, and/or neoplasia development.

RECENT FINDINGS

Recent studies on acute superficial lesions have focused on calcium signaling and focal adhesion kinase, which regulate cell migration and controlled matrix adhesion during restitution. Microfluidic organ-on-a-chip and gut-on-a-chip models continued in development to support reductionist studies of epithelial-bacterial and/or epithelial-immune cell interactions during mucosal barrier disruption. In fact, these models may allow personalized medicine studies in the future using patient-derived cells to evaluate injury and repair mechanisms. Work done in the past year evaluated the safety and efficacy of acid blocking drugs on ulcer healing, with new animal studies providing evidence that each drug affects the microbiome in a different way that can be correlated with its efficacy in ulcer healing. Lastly, work to understand the way in which mature epithelial cells or committed stem cells dedifferentiate, reprogram, proliferate, and then regenerate the gastroduodenal mucosa after injury was a major focus of studies in the past year.

SUMMARY

Recent studies highlight novel mechanisms that promote restitution and mucosal regeneration after injury of the gastroduodenal mucosa.

Targeting Autophagy, Apoptosis, and SIRT1/Nrf2 Axis with Topiramate Underlies Its Neuroprotective Effect against Cadmium-Evoked Cognitive Deficits in Rats

Cadmium is an environmental toxicant that instigates cognitive deficits with excessive glutamate excitatory neuroactivity in the brain. Topiramate, a glutamate receptor antagonist, has displayed favorable neuroprotection against epilepsy, cerebral ischemia, and Huntington's disease; however, its effect on cadmium neurotoxicity remains to be investigated. In this study, topiramate was tested for its potential to combat the cognitive deficits induced by cadmium in rats with an emphasis on hippocampal oxidative insult, apoptosis, and autophagy. After topiramate intake (50 mg/kg/day; p.o.) for 8 weeks, behavioral disturbances and molecular changes in the hippocampal area were explored. Herein, Morris water maze, Y-maze, and novel object recognition test revealed that topiramate rescued cadmium-induced memory/learning deficits. Moreover, topiramate significantly lowered hippocampal histopathological damage scores. Mechanistically, topiramate significantly replenished hippocampal GLP-1 and dampened Aβ42 and p-tau neurotoxic cues. Notably, it significantly diminished hippocampal glutamate content and enhanced acetylcholine and GABA neurotransmitters. The behavioral recovery was prompted by hippocampal suppression of the pro-oxidant events with notable activation of SIRT1/Nrf2/HO-1 axis. Moreover, topiramate inactivated GSK-3β and dampened the hippocampal apoptotic changes. In tandem, stimulation of hippocampal pro-autophagy events, including Beclin 1 upregulation, was triggered by topiramate that also activated AMPK/mTOR pathway. Together, the pro-autophagic, antioxidant, and anti-apoptotic features of topiramate contributed to its neuroprotective properties in rats intoxicated with cadmium. Therefore, it may be useful to mitigate cadmium-induced cognitive deficits.

Gastroprotective Effects of the Aqueous Extract of Finger Citron Pickled Products against Ethanol-Induced Gastric Damage: In Vitro and In Vivo Studies

Finger citron pickled products (FCPP), as folk remedies, are famous in southern China for protecting gastric mucosa. However, the gastric mucosa protection of FCPP has not been reported yet, and its effective mechanism is unclear. In this study, the protective mechanism of FCPP aqueous extract on gastric mucosa was investigated in vitro and in vivo for the first time, using human gastric mucosa epithelial cells (GES-1) and acute alcoholic gastric ulcer rat model respectively. Furthermore, we also investigated the main substances in the aqueous extract that exert gastroprotective activity using a GES-1 scratch test and basic chemical composition analysis. FCPP aqueous extract was found to play a protective and reparative role in GES-1 by promoting the secretion of trefoil factor thyroid transcription factor 2 (TFF2) and inhibiting the secretion of tumor necrosis factor-α (TNF-α) in cells damaged by alcohol. The ulcer index of gastric tissue induced by alcohol was significantly decreased (p < 0.01) after pretreatment with FCPP aqueous extract, indicating that FCPP aqueous extract had a good protective effect on the stomach mucosa. Moreover, FCPP aqueous extract could increase superoxide dismutase (SOD) activity and inhibit malondialdehyde (MDA) content, exhibiting good antioxidant capacity. Aqueous extract of FCPP could also effectively inhibit the increase of cytokines TNF-α, interleukin-1β (IL-1β) and interleukin-6 (IL-6) in serum of rats, and promote the increase of anti-inflammatory cytokines interleukin-10 (IL-10) to some extent. Furthermore, FCPP aqueous extract could inhibit the expression of nuclear factor kappa-B (NF-κB/P65) protein, caspase-1 protein and IL-1β protein in the gastric tissue of rats, while promoting the expression of IκBα protein, indicating that the gastric mucosa protection effects of FCPP aqueous extract were mainly dependent on the NF-κB/caspase-1/IL-1β axis. The polysaccharides in FCPP aqueous extract might be the main components that exerted gastroprotective activity, as demonstrated by GES-1 cell scratch assay. This study confirmed that FCPP aqueous extract presented promising potential in protecting gastric mucosa and avoiding gastric ulcers, which could provide an experimental basis for further utilizing the medicinal value and developing new products of FCPP.

Meloxicam Targets COX-2/NOX1/NOX4/Nrf2 Axis to Ameliorate the Depression-like Neuropathology Induced by Chronic Restraint Stress in Rats

Meloxicam has shown significant neuroprotection in experimental models of stroke, Alzheimer's disease, and Parkinson's disease. However, the potential of meloxicam to treat depression-like neuropathology in a chronic restraint stress (CRS) model and the associated molecular changes has been insufficiently explored. The current work aimed to explore the potential neuroprotective actions of meloxicam against CRS-evoked depression in rats. In the current experiments, animals received meloxicam (10 mg/kg/day; i.p.) for 21 days, and CRS was instigated by restraining the animals for 6 h/day during the same period. The sucrose preference test and the forced swimming test were used to explore the depression-linked anhedonia/despair, whereas the open-field test examined the animals' locomotor activity. The current findings revealed that CRS elicited typical depression behavioral anomalies in the animals, including anhedonia, despair, and diminished locomotor activity; these findings were reinforced with Z-normalization scores. These observations were corroborated by brain histopathological changes and increased damage scores. In CRS-exposed animals, serum corticosterone spiked, and the hippocampi revealed decreased monoamine neurotransmitter levels (norepinephrine, serotonin, and dopamine). Mechanistically, neuroinflammation was evident in stressed animals, as shown by elevated hippocampal TNF-α and IL-1β cytokines. Moreover, the hippocampal COX-2/PGE₂ axis was activated in the rats, confirming the escalation of neuroinflammatory events. In tandem, the pro-oxidant milieu was augmented, as seen by increased hippocampal 8-hydroxy-2'-deoxyguanosine alongside increased protein expression of the pro-oxidants NOX1 and NOX4 in the hippocampi of stressed animals. In addition, the antioxidant/cytoprotective Nrf2/HO-1 cascade was dampened, as evidenced by the lowered hippocampal protein expression of Nrf2 and HO-1 signals. Interestingly, meloxicam administration mitigated depression manifestations and brain histopathological anomalies in the rats. These beneficial effects were elicited by meloxicam's ability to counteract the corticosterone spike and hippocampal neurotransmitter decrease while also inhibiting COX-2/NOX1/NOX4 axis and stimulating Nrf2/HO-1 antioxidant pathway. Together, the present findings prove the neuroprotective/antidepressant actions of meloxicam in CRS-induced depression by ameliorating hippocampal neuroinflammation and pro-oxidant changes, likely by modulating COX-2/NOX1/NOX4/Nrf2 axis.

Targeting SIRT1/FoxO3a/Nrf2 and PI3K/AKT Pathways with Rebamipide Attenuates Acetic Acid-Induced Colitis in Rats

Rebamipide is a quinolone derivative that has been commonly used for the treatment of gastric and duodenal ulcers. However, the molecular mechanisms of rebamipide against acetic acid-evoked colitis have not been adequately examined. Hence, the current study aimed to investigate the ameliorative effect of rebamipide in a rat model of acetic acid-evoked ulcerative colitis and the linked mechanisms pertaining to SIRT1/FoxO3a/Nrf2 and PI3K/AKT pathways. Herein, colitis was induced by the intrarectal administration of 3% acetic acid solution in saline (v/v) while rebamipide was administered by oral gavage (100 mg/kg/day) for seven days before the colonic insult. The colonic injury was examined by macroscopical and microscopical examination. The current findings demonstrated that rebamipide significantly improved the colonic injury by lowering the colonic disease activity index and macroscopic mucosal injury score. Moreover, it mitigated the histopathological aberrations and microscopical damage score. The favorable outcomes of rebamipide were driven by combating inflammation evidenced by dampening the colonic expression of NF-κBp65 and the pro-inflammatory markers CRP, TNF-α, and IL-6. In the same context, rebamipide curtailed the colonic pro-inflammatory PI3K/AKT pathway as seen by downregulating the immunostaining of PI3K and p-AKT(Ser473) signals. In tandem, rebamipide combated the colonic pro-oxidant events and augmented the antioxidant milieu by significantly diminishing the colonic TBARS and replenishing GSH, SOD, GST, GPx, and CAT. In the same regard, rebamipide stimulated the colonic upstream SIRT1/FoxO3a/Nrf2 axis by upregulating the expression of SIRT1, FoxO3a, and Nrf2, alongside downregulating Keap-1 gene expression. These antioxidant actions were accompanied by upregulation of the protein expression of the cytoprotective signal PPAR-γ in the colons of rats. In conclusion, the present findings suggest that the promising ameliorative features of rebamipide against experimental colitis were driven by combating the colonic inflammatory and oxidative responses. In perspective, augmentation of colonic SIRT1/FoxO3a/Nrf2 and inhibition of PI3K/AKT pathways were engaged in the observed favorable outcomes.

Targeting the Endoplasmic Reticulum Stress-Linked PERK/GRP78/CHOP Pathway with Magnesium Sulfate Attenuates Chronic-Restraint-Stress-Induced Depression-like Neuropathology in Rats

Magnesium sulfate has demonstrated marked neuroprotection in eclampsia, hypoxia, stroke, and post-traumatic brain injury rodent models. However, its potential impact against chronic-restraint-stress (CRS)-induced depression-like neuropathology and associated alterations in endoplasmic reticulum (ER) stress have not been adequately examined. The present study aimed to investigate the neuroprotective potential of magnesium sulfate in a rat model of CRS-triggered depression-like behavioral disturbance and the underlying molecular mechanisms. Herein, CRS was induced by placing rats into restraining tubes for 6 h/day for 21 days and the animals were intraperitoneally injected with magnesium sulfate (100 mg/kg/day) during the study period. After stress cessation, the depression-like behavior was examined by the open-field test, sucrose preference test, and forced swimming test. The present data demonstrated that CRS triggered typical depression-like behavioral changes which were confirmed by the Z-normalization scores. Mechanistically, serum circulating corticosterone levels spiked, and the hippocampi of CRS-exposed animals demonstrated a significant decline in serotonin, norepinephrine, and dopamine neurotransmitters. At the molecular level, the hippocampal pro-inflammatory TNF-alpha and IL-1β cytokines and the oxidative stress marker 8-hydroxy-2'-deoxyguanosine (8-HG) increased in stressed animals. In tandem, enhancement of hippocampal ER stress was evidenced by the activation of iNOS/PERK/GRP78/CHOP axis seen by increased protein expression of iNOS, PERK, GRP78, and CHOP signal proteins in the hippocampi of stressed rats. Interestingly, magnesium sulfate administration attenuated the depression-like behavioral outcomes and the histopathological changes in the brain hippocampi. These favorable actions were driven by magnesium sulfate's counteraction of corticosterone spike, and hippocampal neurotransmitter decline, alongside the attenuation of neuroinflammation, pro-oxidation, and ER stress. In conclusion, the current results suggest the promising neuroprotective/antidepressant actions of magnesium sulfate in CRS by dampening inflammation, ER stress, and the associated PERK/GRP78/CHOP pathway.