The Effect of Monosodium Glutamate on Neuronal Signaling Molecules in the Hippocampus and the Neuroprotective Effects of Omega-3 Fatty Acids

Modulating Multiple Molecular Trajectories by Nutraceuticals and/or Physical Activity in Attention-Deficit/Hyperactivity Disorder (ADHD)-Like Behaviors in Rat Pups

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental condition affecting cognitive and social functions all over childhood. Monosodium glutamate (MSG) is a common food additive associated with ADHD-like symptoms in children. Nutraceuticals, like sesamol (SE) and astaxanthin (AST), or physical activity (PHA) were reported to possess beneficial effects on human health. Meanwhile, still their neuroprotective effect against ADHD has been poorly investigated. This study aimed to investigate the impact of SE, AST and PHA either separately or combined on ADHD-like behaviors induced by MSG in rat pups. Eighty-four male Sprague Dawley rat pups were randomly allocated into seven groups; control, MSG, (PHA + MSG), (SE + MSG), (AST + MSG), (SE + AST + MSG), and (COMB [PHA + SE + AST] + MSG) and treated for eight weeks. MSG-induced ADHD-like behavior was evaluated, via assessing behavioral outcomes; neurotransmitters' levels; five pathway biomarkers, coupled with histopathological and immunohistochemical studies. Rats exposed to PHA or treated with SE or AST either separately or combined exhibited enhanced attention, locomotor, and cognitive abilities, compared to MSG-intoxicated group. All treatments remarkably improved MSG-induced abnormalities in neurotransmitters' levels; biochemical markers; along with histological findings, via modulating HMGB1/RAGE/JAK-2/STAT-3, PI3K/AKT/CREB/BDNF, AMPK/SIRT-1 and PERK/CHOP pathways. Nevertheless, the combination of PHA with nutraceuticals (SE and AST) elicited more favorable effects in all measured parameters and histological findings, compared to other treated groups. In conclusion, this study revealed the superiority of the combination of nutraceuticals with PHA, over other standalone treatments, in amelioration of MSG-induced ADHD-like behaviors in rat pups, via fine-tuning of HMGB1/RAGE, PI3K/AKT/CREB/BDNF, AMPK/SIRT-1 and PERK/CHOP pathways.

The Effect of Naringin on Cognitive-Behavioral Functions, CREB/BDNF Signaling, Cholinergic Activity, and Neuronal Density in the Hippocampus of an MSG-Induced Obesity Rat Model

The global rise in obesity and overweight over the past few decades has led to numerous associated disorders, including cognitive deficits. This study evaluate investigates the effects of Naringin (Nar) on memory and learning, anxiety-like behaviors, brain-derived neurotrophic factor (BDNF), cAMP responsive element binding protein (CREB), acetylcholinesterase (AChE) activity, and neuronal density in the CA₁/CA₃ subfields of the hippocampus in an MSG-induced obese obesity rat model. Forty-eight male Wistar rat pups were randomly divided into four groups: Control, MSG, MSG + Nar50, and MSG + Nar100. MSG (4 g/kg BW) was administered subcutaneously in the cervical region from PND 2 to PND10, while Nar (50 mg/kg BW and 100 mg/kg BW) was administered orally from PND30 to PND42. After the treatment period, cognitive (working memory and passive avoidance) and anxiety-related tests (elevated plus maze and novelty-suppressed feeding test) were performed. Subsequently, hippocampal protein level of BDNF and CREB/BDNF gene expression, AChE activity and neuronal density in the CA₁ and CA₃ regions of the hippocampus were measured. Relative to the MSG group, the Nar-treated rats demonstrated improvements in spatial working memory, reduced anxiety-related behaviors, elevated hippocampal CREB and BDNF genes and BDNF protein levels, and reduced AChE activity. Additionally, Nar treatment increased neuronal density in the CA₁/CA₃ subfields of the hippocampus. These findings suggest that Nar enhances cognitive function and mitigates anxiety in MSG-induced obese rats by modulating CREB/BDNF signaling pathway, inhibiting AChE, and exerting neuroprotective effects in the hippocampus.

Food additives for the central nervous system, useful or harmful? An evidence-based review

OBJECTIVES

This review examines how food additives impact the central nervous system (CNS) focusing on the effects of sugars, artificial sweeteners, colorings, and preservatives.

METHODS

A literature search of PubMed, Scopus, and Web of Science was conducted for studies published since 2010. Key search terms included, food additives, neurotoxicity, cognition, and behavior.

RESULTS

It summarizes research findings on additives such as aspartame, stevia, methylene blue, azo dyes, sodium benzoate, and monosodium glutamate. It also covers mechanisms such as oxidative stress, neuroinflammation, and disruptions in neurotransmitter systems. Furthermore, it emphasizes the properties of natural compounds such as garlic (Allium sativum), tetramethylpyrazine, curcumin, licorice root extract (glycyrrhizin), and polyphenols in mitigating CNS damage caused by food additives.

DISCUSSION

Although ongoing studies are expanding our knowledge on the effects of these additives, future CNS research should focus on long-term investigations involving subjects to provide a more comprehensive understanding of the cumulative impacts of different additives and update regulatory standards based on new scientific findings.

The Intersection of Ultra-Processed Foods, Neuropsychiatric Disorders, and Neurolaw: Implications for Criminal Justice

Over the last decade there has been increasing interest in the links between the consumption of ultra-processed foods and various neuropsychiatric disorders, aggression, and antisocial behavior. Neurolaw is an interdisciplinary field that seeks to translate the rapid and voluminous advances in brain science into legal decisions and policy. An enhanced understanding of biophysiological mechanisms by which ultra-processed foods influence brain and behavior allows for a historical reexamination of one of forensic neuropsychiatry's most famous cases-The People v. White and its associated 'Twinkie Defense'. Here in this Viewpoint article, we pair original court transcripts with emergent research in neurolaw, including nutritional neuroscience, microbiome sciences (legalome), pre-clinical mechanistic research, and clinical intervention trials. Advances in neuroscience, and related fields such as the microbiome, are challenging basic assumptions in the criminal justice system, including notions of universal free will. Recent dismissals of criminal charges related to auto-brewery syndrome demonstrate that courts are open to advances at the intersection of neuromicrobiology and nutritional neuroscience, including those that relate to criminal intent and diminished capacity. As such, it is our contention that experts in the neurosciences will play an increasing role in shaping research that underpins 21st-century courtroom discourse, policy, and decision-making.

The Role of Vitamin C on ATPases Activities in Monosodium Glutamate-Induced Oxidative Stress in Rat Striatum and Cerebellum

Monosodium glutamate (MSG) is a silent excitotoxin used as a flavour enhancer but exerts serious health hazards to consumers. MSG plays a role in neuronal function as the dominant excitatory neurotransmitter. It is transferred into the blood and ultimately increases brain glutamate levels, causing functional disruptions notably via oxidative stress. The study evaluated the toxic effect of high consumption of MSG and the modulatory role of vitamin C on ATPase activities in the striatum and cerebellum of male Wistar rats for five weeks. Rats were grouped into four (A-D): group A was fed with rat's show only; Group B was fed with diet containing 15% MSG; Group C was treated with vitamin C (200 mg/kg b.wgt orally in 0.9% saline solution) only for 3 weeks; and group D rats were fed with MSG and vitamin C. The findings show that MSG does not affect body and cerebellum weights but increases striatal weight. MSG increases the malondialdehyde (MDA) level and significantly decreases catalase (CAT) and superoxide dismutase (SOD) activities and glutathione (GSH) levels. MSG significantly impaired striatal and cerebellar ATPases activities (Na+/K+-, Ca2+-, Mg2+- and total ATPases). Vitamin C treatment abolishes MSG-induced oxidative stress and improves ATPase activities. The findings show that vitamin C has beneficial effects in improving the functions of membrane-bound ATPases against MSG toxicity in rat's striatum and cerebellum.

In silico and in vivo analysis of the relationship between ADHD and social isolation in pups rat model: Implication of redox mechanisms, and the neuroprotective impact of Punicalagin

Attention deficit hyperactivity disorder (ADHD) has high incidence rate among children which may be due to excessive monosodium glutamate (MSG) consumption and social isolation (SI).

AIM

We aimed to explore the relationships between MSG, SI, and ADHD development and to evaluate the neuroprotective potential of Punicalagin (PUN).

METHODS

Eighty male rat pups randomly distributed into eight groups. Group I is the control, and Group II is socially engaged rats treated with PUN. Groups III to VII were exposed to ADHD-inducing factors: Group III to SI, Group IV to MSG, and Group V to both SI and MSG. Furthermore, Groups VI to VIII were the same Groups III to V but additionally received PUN treatment.

KEY FINDINGS

Exposure to MSG and/or SI led to pronounced behavioral anomalies, histological changes and indicative of ADHD-like symptoms in rat pups which is accompanied by inhibition of the nuclear factor erythroid 2-related factor 2 (Nrf2)/Heme-oxygenase 1 (HO-1)/Glutathione (GSH) pathway, decline of the brain-derived neurotrophic factor (BDNF) expression and activation of the Toll-like receptor 4 (TLR4)/Nuclear factor kappa B (NF-kB)/NLR Family Pyrin Domain Containing 3 (NLRP3) pathway. This resulted in elevated inflammatory biomarker levels, neuronal apoptosis, and disrupted neurotransmitter equilibrium. Meanwhile, pretreatment with PUN protected against all the previous alterations.

SIGNIFICANCE

We established compelling associations between MSG consumption, SI, and ADHD progression. Moreover, we proved that PUN is a promising neuroprotective agent against all risk factors of ADHD.

Targeting Glutamate Neurotoxicity through Dietary Manipulation: Potential Treatment for Migraine

Glutamate, the main excitatory neurotransmitter in the central nervous system, is implicated in both the initiation of migraine as well as central sensitization, which increases the frequency of migraine attacks. Excessive levels of glutamate can lead to excitotoxicity in the nervous system which can disrupt normal neurotransmission and contribute to neuronal injury or death. Glutamate-mediated excitotoxicity also leads to neuroinflammation, oxidative stress, blood-brain barrier permeability, and cerebral vasodilation, all of which are associated with migraine pathophysiology. Experimental evidence has shown the protective effects of several nutrients against excitotoxicity. The current review focuses on the mechanisms behind glutamate's involvement in migraines as well as a discussion on how specific nutrients are able to work towards restoring glutamate homeostasis. Understanding glutamate's role in migraine is of vital importance for understanding why migraine is commonly comorbid with widespread pain conditions and for informing future research directions.

Investigation of the Effects of Monosodium Glutamate on the Embryonic Development of the Eye in Chickens

MSG is the most ubiquitous food additive in the food industry. The aim of this report was to investigate the effects of in ovo MSG administration on embryonic chicken eye development using histological and histometric methods. A total of 410 fertilized eggs obtained from Babcock Brown laying hens (Gallus gallus domesticus) were used and divided into 5 groups: I (untreated control), II (vehicle control), III (0.12 mg/g egg MSG), IV (0.6 mg/g egg MSG), and V (1.2 mg/g egg MSG), and injections were performed via the egg yolk. At incubation day 15, 18, and 21, 6 embryos from each group were sacrificed by decapitation and pieces of eye tissue were obtained. In all MSG groups, it was determined that both corneal epithelium thickness and total corneal thickness decreased at incubation time points 15, 18, and 21 days compared with the controls (p < 0.05). The total retinal thickness, thickness of the outer nuclear layer (ONL), inner nuclear layer (INL), ganglion cell layer (GL), and nerve fibre layers (NFL), as well as the number of ganglion cells decreased significantly at incubation days 15, 18, and 21 (p < 0.05), and degenerative changes such as vacuolar degeneration and retinal pigment epithelial detachment were also observed. In conclusion, MSG in ovo administration can affect the cornea and distinct layers of retinal cells.

The protective effect of thymoquinone or/and thymol against monosodium glutamate-induced attention-deficit/hyperactivity disorder (ADHD)-like behavior in rats: Modulation of Nrf2/HO-1, TLR4/NF-κB/NLRP3/caspase-1 and Wnt/β-Catenin signaling pathways in rat model

Both thymoquinone (TQ) and thymol (T) have been proved to possess a positive impact on human health. In this research, we aimed to investigate the effect of these compounds separately and together on the Attention-deficit/hyperactivity disorder (ADHD)-like behavior induced by monosodium glutamate (MSG) in rats. Forty male, Spargue Dawley rat pups (postnatal day 21), were randomly allocated into five groups: Normal saline (NS), MSG, MSG+TQ, MSG+T, and MSG+TQ+T. MSG (0.4 mg/kg/day), TQ (10 mg/kg/day) and T (30 mg/kg/day) were orally administered for 8 weeks. The behavioral tests proved that rats treated with TQ and/or T showed improved locomotor, attention and cognitive functions compared to the MSG group with more pronounced effect displayed with their combination. All treated groups showed improvement in MSG-induced aberrations in brain levels of GSH, IL-1β, TNF-α, GFAP, glutamate, calcium, dopamine, norepinephrine, Wnt3a, β-Catenin and BDNF. TQ and/or T treatment also enhanced the mRNA expression of Nrf2, HO-1 and Bcl2 while reducing the protein expression of TLR4, NFκB, NLRP3, caspase 1, Bax, AIF and GSK3β as compared to the MSG group. However, the combined therapy showed more significant effects in all measured parameters. All of these findings were further confirmed by the histopathological examinations. Current results concluded that the combined therapy of TQ and T had higher protective effects than their individual supplementations against MSG-induced ADHD-like behavior in rats.