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

Protective mechanism of apigenin in proton pump inhibitor-associated progressive cognitive impairment in adult zebrafish via targeting GSK-3β pathway

Cognitive impairment is characterized by memory loss and difficulty in focusing, remembering, adhering to directions, and solving problems; commonly seen in an elderly population. Apigenin (APG) (4', 5, 7-trihydroxyflavone) is a flavonoid with several positive health benefits, including chemoprevention, antioxidant and can suppress inflammatory responses by inhibiting TNF-α and IL-1β levels. In this experimental study, we observed the possible neuroprotective effects of APG in the zebrafish model exposed to Lansoprazole (LPZ), a proton pump inhibitor known to induce cognitive impairment through hyperactivation of GSK-3β pathway. This experiment involves 12 adult zebrafish per group, where one group received LPZ (100 mg) as a toxin for 7 days and APG (25, 50, and 100 mg/kg) as treatment, while DPZ (5 mg/kg) served as a standard comparison over the same period. Neurobehavioral tests such as T-Maze, Novel Tank Test (NTT), and Novel Object Recognition (NOR) were performed. Several biochemical assessments were also performed to evaluate the level of lipid peroxidation (LPO), glutathione (GSH), nitrite (NO), acetylcholinesterase activity (AChEs), catalase activity, neurotransmitters (GABA and glutamate), neuroinflammatory markers (IL-1β, TNF-α, and IL-10), and histopathological analysis. The results showed that apigenin enhanced memory function, improved neurotransmitter balance, decreased oxidative stress markers, regulated the production of proinflammatory cytokines, and inhibited GSK-3β activity. Additionally, the co-administration of a GSK-3β inhibitor further promoted neuroprotection and cognitive enhancement facilitated by apigenin, highlighting the importance of the GSK-3β signaling pathway. These findings highlight the potential of apigenin as a natural compound for mitigating cognitive dysfunction. However, this study should also include long-term toxicity assessments and deeper molecular analysis to elucidate Apigenin's mechanism of action fully. Future research should address these gaps to validate its therapeutic potential.

The protective efficacy of omega-3 polyunsaturated fatty acids on oxidative stress, inflammation, neurotransmitter perturbations, and apoptosis induced by monosodium glutamate in the brain of male rats

Exaggerated neuronal excitation by glutamate is a well-known cause of excitotoxicity, a key factor in numerous neurodegenerative disorders. This study examined the neurotoxic effect of monosodium glutamate (MSG) in the brain cortex of rats and focused on assessing the potential neuroprotective effects of omega-3 polyunsaturated fatty acids (ω-3 PUFAs). Four groups of adult male rats (n = 10) were assigned as follows; normal control, ω-3 PUFAs (400 mg/kg) alone, MSG (4 mg/g) alone, and MSG plus ω-3 PUFAs (4 mg/g MSG plus 400 mg/kg ω-3 PUFAs). Biochemical analysis, immunohistochemical, and histological examinations were conducted upon completion of the treatment protocol. Results revealed that MSG significantly increased malondialdehyde, nitric oxide, tumor necrosis factor-α, interleukin 1β, acetylcholinesterase, monoamine oxidase, and caspase-3. However, the MSG-treated group showed a decline in reduced glutathione, catalase, superoxide dismutase, dopamine, and serotonin. In addition, MSG caused histopathological changes in the cortical region which support the biochemical and immunohistochemical analysis. Supplementation of ω-3 PUFAs greatly improved the biochemical, immunohistochemical, and histopathological alterations induced by MSG administration in the brain cortex. Together, these findings revealed a neuroprotective effect of ω-3 PUFAs against MSG-induced toxicity in the brain cortex by attenuating oxidative damage, inflammation, neurochemical perturbations, and apoptosis.

The therapeutic potential of apigenin against atherosclerosis

Apigenin is a natural flavonoid abundantly found in fruits, vegetables, and medicinal plants. It possesses protective effects against cancer, metabolic syndrome, dyslipidemia, etc. Atherosclerosis, a chronic immune-mediated inflammatory disease, is the underlying cause of coronary heart disease, stroke, and myocardial infarction. Numerous in vivo and in vitro studies have shown a protective effect of apigenin against atherosclerosis, attributed to its antioxidant and anti-inflammatory properties, as well as its antihypertensive effect and regulation of lipid metabolism. This study aimed to review the effects and mechanisms of apigenin against atherosclerosis for the first time. Apigenin displays encouraging results, and this review confirms the potential value of apigenin as a candidate medication for atherosclerosis.

Combined bisoprolol and trimetazidine ameliorate arsenic trioxide -induced acute myocardial injury in rats: targeting PI3K/GSK-3β/Nrf2/HO-1 and NF-κB/iNOS signaling pathways, inflammatory mediators and apoptosis

BACKGROUND

Arsenic-trioxide (ATO) is an effective therapy for acute promyelocytic leukemia. Unfortunately, its utility is hindered by the risk of myocardial injury. Both bisoprolol (BIS) and trimetazidine (TMZ) have various pharmacological features, including anti-oxidant, anti-inflammatory, and anti-apoptotic properties.

AIM

The cardioprotective effects of BIS and TMZ were studied, and their mechanistic role in ameliorating ATO-induced myocardial injury.

MATERIALS AND METHODS

Forty male Wistar rats were randomly allotted into five groups as follows: normal control group (received normal saline, orally), ATO group (7.5 mg/kg, orally), BIS (8 mg/kg, orally), TMZ (60 mg/kg, orally), and finally combination group (BIS+TMZ+ATO). Following 21 days, samples of serum and cardiac tissues were obtained to perform biochemical, molecular, and histopathological investigations.

RESULTS

The present study showed that ATO caused myocardial injury evidenced by changes in serum biomarkers (Aspatate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, creatine kinase-MB, and cardiac troponin-1), electrolyte imbalance, and lipid profiles alongside histopathologic changes. In addition, ATO administration significantly elevated malondialdehyde, nicotinamide adenine dinucleotide phosphate hydrogen oxidase, myloperoxidase, total nitrite, inducible nitric oxide synthase, tumor necrosis factor-alpha, interleukin-1β, interleukin-6, 8-Hydroxy-2'-deoxyguanosine, nuclear factor NF-kappa-B p65 subunit, glycogen synthase kinase-3 beta, and caspase-3 expression contemporaneously with down-regulation of reduced glutathione, glutathione peroxidase, superoxide dismutase, catalase, heme oxygenase 1, nuclear factor erythroid 2-related factor 2, phosphatidylinositol-3 kinase, p-PI3K, and Bcl-2 expression. Interestingly, pretreatment with BIS and TMZ significantly reversed the detrimental effects of ATO-induced myocardial injury at both cellular and molecular levels. Otherwise, combining the two drugs displayed more enhancement than each drug alone.

CONCLUSION

The present research depicted that BIS and TMZ have the potential to protect the heart and provide therapeutic benefits by preventing acute heart injury induced by ATO. This is achieved by reversing the redox-sensitive pathway, reducing inflammation, and inhibiting apoptosis.

Evaluating the potential effects of apigenin on memory, anxiety, and social interaction amelioration after social isolation stress

Vigorous research confirmed the anti-inflammatory, antioxidant, and antidementia effects of apigenin (Api). The present study evaluated the beneficial impacts of Api administration on behaviour, brain-derived neurotrophic factor (BDNF), Interleukin 6 (IL-6), oxidative stress, and inflammation induced by social isolation (SI) stress in rats. For this purpose, rats underwent a 28-day SI period followed by a 4-week oral Api treatment (50 mg/kg/day, PO). On Day 56, behaviour tests were performed, including an elevated plus maze (EPM), Morris water maze (MWM), and three-chamber social tests. The oxidative stress markers, IL-6, and BDNF levels were measured in the hippocampus. Our results showed that SI stress caused an increase in anxiety and a decrease in spatial memory, sociability, and social preference index. In addition, SI stress increased hippocampal levels of IL-6 and malondialdehyde (MDA) content, whereas it reduced the hippocampal BDNF level and superoxide dismutase (SOD) activities. Our study indicated that Api attenuates anxiety and causes improvements in spatial memory and social interaction. These desirable effects of Api might be related to amelioration in the BDNF level, IL-6, and oxidative stress biomarkers in the hippocampus.

Apigenin and inflammation in the brain: can apigenin inhibit neuroinflammation in preclinical models?

Apigenin is a flavone-kind of flavonoid present in fruits and vegetables. Apigenin exhibits biological activities including neuropharmacological effects against different neurological disorders. In this study, we summarize and discuss the molecular mechanisms of the anti-neuroinflammatory effects of apigenin in neurological disorders. A systematic review was conducted by searching Google Scholar, Web of Science, Scopus and PubMed. A total of 461 records were retrieved from the search. After screening of the records based on the inclusion criteria, 16 articles were selected and discussed in this study. The results from the selected studies showed that apigenin exhibited anti-neuroinflammatory effect in preclinical studies. The anti-neuroinflammatory mechanisms exhibited by apigenin include inhibition of overproduction of pro-inflammatory cytokines, attenuation of microglia activation via reduction of CD-11b-positive cells, inhibition of ROCK-1 expression and upregulation of miR-15a, p-ERK1/2, p-CREB, and BDNF, downregulation of NLRP3 inflammasome, iNOS and COX-2 expression, reduction of Toll-like receptor-4 expression and inhibition of nuclear factor-kappa B (NF-kB) activation. Overall, apigenin inhibited neuroinflammation which suggests it confers neuroprotective effect against neuronal degeneration in some neurodegenerative conditions. This review provides important neuropharmacological information on the neuroprotective mechanisms of apigenin against neuroinflammation which may be useful for future preclinical and clinical studies.

Flavonoids as therapeutic agents for epilepsy: unveiling anti-inflammatory and antioxidant pathways for novel treatments

Epilepsy, a chronic neurological disorder affecting millions globally, is often exacerbated by neuroinflammation and oxidative stress. Existing antiepileptic drugs primarily manage symptoms, leaving the disease's progression largely unaddressed. Flavonoids, ubiquitous plant metabolites with potent anti-inflammatory and antioxidant properties, show promise in epilepsy treatment. Unlike conventional therapies, they target multiple pathophysiological processes simultaneously, offering a comprehensive approach to this complex neurological disorder. This review explores the dual role of flavonoids in mitigating neuroinflammation and reducing oxidative stress through various molecular pathways. By inhibiting key inflammatory mediators and pathways such as NF-κB, MAPK, JNK, and JAK, flavonoids offer neuronal protection. They enhance the body's natural antioxidant defenses by modulating enzyme activities, including superoxide dismutase, catalase, and glutathione peroxidase. Moreover, flavonoids influence crucial antioxidant response pathways like PI3K/AKT, Nrf2, JNK, and PKA. Despite their therapeutic promise, the low bioavailability of flavonoids poses a considerable challenge. However, cutting-edge strategies, including nanotechnology and chemical modifications, are underway to improve their bioavailability and therapeutic efficacy. These advancements support the potential of flavonoids as a valuable addition to epilepsy treatment strategies.

Boswellic acid and apigenin alleviate methotrexate-provoked renal and hippocampal alterations in rats: Targeting autophagy, NOD-2/NF-κB/NLRP3, and connexin-43

The neuronal and renal deteriorations observed in patients exposed to methotrexate (MTX) therapy highlight the need for medical interventions to counteract these complications. Boswellic acid (BA) and apigenin (APG) are natural phytochemicals with prominent neuronal and renal protective impacts in various ailments. However, their impacts on MTX-provoked renal and hippocampal toxicity have not been reported. Thus, the present work is tailored to clarify the ability of BA and APG to counteract MTX-provoked hippocampal and renal toxicity. BA (250 mg/kg) or APG (20 mg/kg) were administered orally in rats once a day for 10 days, while MTX (20 mg/kg, i.p.) was administered once on the sixth day of the study. At the histopathological level, BA and APG attenuated MTX-provoked renal and hippocampal aberrations. They also inhibited astrocyte activation, as proven by the inhibition of glial fibrillary acidic protein (GFAP). These impacts were partially mediated via the activation of autophagy flux, as proven by the increased expression of beclin1, LC3-II, and the curbing of p62 protein, alongside the regulation of the p-AMPK/mTOR nexus. In addition, BA and APG displayed anti-inflammatory features as verified by the damping of NOD-2 and p-NF-κB p65 to reduce TNF-α, IL-6, and NLRP3/IL-1β cue. These promising effects were accompanied with a notable reduction in one of the gap junction proteins, connexin-43 (Conx-43). These positive impacts endorse BA and APG as adjuvant modulators to control MTX-driven hippocampal and nephrotoxicity.

Investigating the effect of exposure to monosodium glutamate during pregnancy on development of autism in male rat offspring

In present study, we investigated the relationship between the pregnancy exposure to monosodium glutamate (MSG) and autism development in male offspring of rats. Pregnant Wistar rats were allocated into five groups. The first group was control group that pregnant animals received normal saline orally from day 1-18 of pregnancy. Group 2, 3 and 4 pregnant rats received different doses (1.5, 5 and 10 g/kg) of MSG by the same way respectively. Group 5 received 500 mg/kg of Valproic acid (VPA) on the 12.5th day of pregnancy. Different behavioral tests including marble burying, self-grooming, and Barnes maze test were performed on offspring. The levels of glutamate and GSH markers were also measured. The results showed that MSG similar to VPA led to induction of autistic anxiety and repetitive behaviors. It could also deteriorate the spatial memory. Besides we found that behavioral symptoms potentiated with increasing the MSG dosage. Similarly, we had an increase in glutamate and a reduction in GSH levels in offspring. Findings indicated that MSG was able to induce autism in offspring of rats in a dose-dependent way. This effect could be through increasing of glutamate and reduction of GSH. Consequently, MSG should be avoided during pregnancy.

Mechanism of Microglial Cell Activation in the Benzophenone-3 Exposure Model

Benzophenone-3 (BP-3) is the most commonly used UV filter in cosmetics, which is absorbed through the skin and crosses the blood-brain barrier. This compound increases extracellular glutamate concentrations, lipid peroxidation, the number of microglia cells and induces process of apoptosis. The aim of this study was to determine the effect of BP-3 on the activation and polarization of microglial cells in the frontal cortex and hippocampus of adult male rats exposed to BP-3 prenatally and then for two weeks in adulthood. It has been found, that exposure to BP-3 reduced the expression of the marker of the M2 phenotype of glial cells in both examined brain structures. An increase in the CD86/CD206 microglial phenotype ratio, expression of transcription factor NFκB and activity of caspase-1 were observed only in the frontal cortex, whereas BP-3 increased the level of glucocorticoid receptors in the hippocampus. The in vitro study conducted in the primary culture of rat frontal cortical microglia cells showed that BP-3 increased the LPS-stimulated release of pro-inflammatory cytokines IL-1α, IL-1β, TNFα, but in cultures without LPS there was decreased IL-1α, IL-6 and TNFα production, while the IL-18 and IP-10 was elevated. The obtained results indicate that differences in the level of immunoactivation between the frontal cortex and the hippocampus may result from the action of this compound on glucocorticoid receptors. In turn, changes in cytokine production in microglial cells indicate that BP-3 aggravates the LPS-induced immunoactivation.

Experimental evidence of the neurotoxic effect of monosodium glutamate in adult female Sprague Dawley rats: The potential protective role of Zingiber officinale Rosc. rhizomes

Strategies to prevent the health abnormalities associated with the extensive use of MSG (monosodium glutamate) as a flavoring booster are badly needed. The current study was conducted to investigate oxidative stress, inflammation, and abnormal lipid profile as the main risk factors of neurotoxicity in MSG-exposed female albino rats. Besides, the effect of concurrent consumption of Zingiber officinale rhizomes powder was studied at low doses. Twenty rats (total) were split into 4 separate groups. The 1st group was a negative control group (without any treatment), while the others received 6 mg MSG/kg. The 2nd group was left untreated, whereas the 3rd and 4th groups were given a regular laboratory diet that included ginger rhizome powder supplements (GRP, 0.5 & 1%, respectively) for six weeks. In brain tissue homogenates, exposure to MSG caused a significant depletion of gamma-aminobutyric acid (GABA) and total protein levels, while triglycerides and cholesterol contents were significantly elevated. Moreover, a noteworthy upsurge in oxidative load and inflammation markers was also noticed associated with a marked reduction of antioxidant levels, which histopathological staining verified further. The rat diet formulated with GRP, with a dose-dependent effect, resulted in increased GABA and total protein contents and attenuated inflammation, oxidative stress, abnormal lipid profile, and marked histological changes in cerebral cortical neurons of MSG-administered animals. Therefore, this study reveals that GRP shields rats against the neurotoxicity that MSG causes. The anti-inflammatory as well as antioxidant, and lipid-normalizing properties of rhizomes of ginger may be accountable for their observed neuroprotective action.

A systematic review of the neuropathology and memory decline induced by monosodium glutamate in the Alzheimer's disease-like animal model

This systematic review analyzes monosodium glutamate (MSG) in the Alzheimer's disease-like condition to enhance translational research. Our review seeks to understand how MSG affects the brain and causes degenerative disorders. Due to significant preclinical data linking glutamate toxicity to Alzheimer's disease and the lack of a comprehensive review or meta-analysis, we initiated a study on MSG's potential link. We searched PubMed, ScienceDirect, ProQuest, DOAJ, and Scopus for animal research and English language papers without time constraints. This study used the PRISMA-P framework and PICO technique to collect population, intervention or exposure, comparison, and result data. It was registered in PROSPERO as CRD42022371502. MSG affected mice's exploratory behaviors and short-term working memory. The brain, hippocampus, and cerebellar tissue demonstrated neuronal injury-related histological and histomorphometric changes. A total of 70% of MSG-treated mice had poor nesting behavior. The treated mice also had more hyperphosphorylated tau protein in their cortical and hippocampus neurons. Glutamate and glutamine levels in the brain increased with MSG, and dose-dependent mixed horizontal locomotor, grooming, and anxiety responses reduced. MSG treatment significantly decreased phospho-CREB protein levels, supporting the idea that neurons were harmed, despite the increased CREB mRNA expression. High MSG doses drastically lower brain tissue and serum serotonin levels. In conclusion, MSG showed AD-like pathology, neuronal atrophy, and short-term memory impairment. Further research with a longer time span and deeper behavioral characterization is needed. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier [CRD42022371502].

Exploring the impact of ketogenic diet on multiple sclerosis: obesity, anxiety, depression, and the glutamate system

Background

Multiple sclerosis (MS) is a neurodegenerative disorder. Individuals with MS frequently present symptoms such as functional disability, obesity, and anxiety and depression. Axonal demyelination can be observed and implies alterations in mitochondrial activity and increased inflammation associated with disruptions in glutamate neurotransmitter activity. In this context, the ketogenic diet (KD), which promotes the production of ketone bodies in the blood [mainly β-hydroxybutyrate (βHB)], is a non-pharmacological therapeutic alternative that has shown promising results in peripheral obesity reduction and central inflammation reduction. However, the association of this type of diet with emotional symptoms through the modulation of glutamate activity in MS individuals remains unknown.

Aim

To provide an update on the topic and discuss the potential impact of KD on anxiety and depression through the modulation of glutamate activity in subjects with MS.

Discussion

The main findings suggest that the KD, as a source of ketone bodies in the blood, improves glutamate activity by reducing obesity, which is associated with insulin resistance and dyslipidemia, promoting central inflammation (particularly through an increase in interleukins IL-1β, IL-6, and IL-17). This improvement would imply a decrease in extrasynaptic glutamate activity, which has been linked to functional disability and the presence of emotional disorders such as anxiety and depression.