The effect of vitamin C administration on monosodium glutamate induced liver injury. An experimental study

Association between monosodium glutamate consumption with changes in gut microbiota and related metabolic dysbiosis-A systematic review

Monosodium glutamate (MSG) is used as a common food additive in some foods. However, based on our search and knowledge, no comprehensive study discussed the effect of MSG on the human gut microbiome. In this study, the effects of MSG on the gut microbiome, liver, and kidney were performed. Data were collected from databases including PubMed, Scopus, Web of Science, and ScienceDirect using the search strategy and keywords. Finally, 14 eligible studies were selected for systematic review. This study provides a new perspective on the effects of MSG on the gut flora, shedding light on the potential relationship between MSG intake and human health.

Disruptive consequences of monosodium glutamate on male reproductive function: A review

Monosodium glutamate (MSG) is one of the most extensively used flavour enhancers worldwide. Although it is widely regarded as a safe food additive with no recommended daily dosage, its over-consumption has been associated with notably pathophysiological events in various tissues and organs of the body. Previous studies have reported of the neuro- cardio- and hepato- toxic effects of its excessive exposure. Moreover, the food additive instigates metabolic dysfunction. It has been established that MSG damages male reproductive accessory organs like prostate glands and epididymis. In addition, it impairs serum enzymatic activities and serum levels of testosterone, gonadotropin-releasing hormone, luteinizing hormone and cholesterol. Reduced sperm count, sperm motility, sperm morphology, and sperm viability, imbalances in male reproductive hormones, alongside alteration in the histoarchitecture of the testes and other male reproductive tissues have also been connected with excessive exposure to MSG. Literature reports affirm the link between the over-consumption of MSG and reproductive organ weight and male sexual behaviour. This review article addresses the multi-systemic effects of exposure to MSG and the possible mechanism of action of the compound with a focus on the negative implications of the food additive on male reproductive functions and the possible role of natural antioxidants in male reproductive functions. carefully selected keywords were used during the literature search to gather credible and up-to-date information about the subject matter.

MORPHOLOGICAL PECULIARITIES OF THE PANCREAS OF MALE RATS AFTER PROLONGED ADMINISTRATION OF MONOSODIUM GLUTAMATE DURING THE RECOVERY PERIOD

OBJECTIVE

The aim: To study changes in the exocrine and endocrine parts of the pancreas of rats after abolition of monosodium glutamate (MSG) administered in the diet.

PATIENTS AND METHODS

Materials and methods: White male laboratory rats with a baseline weight of 120 ± 5 g were randomized into 3 groups: 1 - control, 2 - animals with daily feeding of 70 mg/ kg MSG for 8 weeks, 3 - abolition of MSG with transfer of animals to a standard diet and pancreatic examination after 8 weeks. We used histological studies with morphometric analysis and statistical processing of acini and acinar cell areas, Langerhans islets, connective tissue (according to Stolte M.) and adipose tissue. Preparations of pancreas were stained with hematoxylin and eosin and azan.

RESULTS

Results: The animals of groups 2 and 3 showed atrophic, degenerative and inflammatory disturbances in the exocrine and endocrine parts of the pancreas, which worsened after 8 weeks of MSG withdrawal (3 rd group). In the preparations, the Langerhans islets were of different shapes and sizes. Small islets predominated, as well as islets with low density of α- and β-cells, different capillary filling with blood and overgrowth of connective tissue in the capillary areas. The acinar cells and acini were reduced, and degenerative abnormalities were detected in the structures.

CONCLUSION

Conclusions: After daily administration of 70 mg/kg MSG for 8 weeks, atrophic and degenerative changes in the exocrine and endocrine parts of the pancreas were revealed. No recovery of pancreatic structures was observed 8 weeks after MSG withdrawal.

Microscopic study of potential toxic effects of monosodium glutamate on liver of chicken embryos aged 16 days

Background

This experimental study aimed to determine the changes caused by monosodium glutamate (MSG) on morphology and histology of liver of chicken embryos aged 16 days of incubation. In this research, 50 fertilized eggs were used. They were divided into two equal groups, one group was used as control with normal liver structure, while the other group (MSG) was treated with MSG in 0 day of incubation (0.1ml/egg).

Results

The results showed many harmful effects on hepatic cells, blood sinusoids, and bile ducts in MSG group. These changes included alterations in nuclei conformation and nuclear envelope. Chromatin distribution was associated with increased electronic intensity. Also, there were rupture in smooth endoplasm systems and malfunction of mitochondria and Golgi apparatus, with increased lysosomes and lipid droplets.

Conclusions

This study concluded that MSG had severe toxic effects on liver structure if it was given in pre-conception period as this period is considered critical for liver growth (organogenesis).

Glutamate - A multifaceted molecule: Endogenous neurotransmitter, controversial food additive, design compound for anti-cancer drugs. A critical appraisal

One of the most widely used flavour enhancers in the food industry is monosodium glutamate (MSG). MSG consumption has been on an upward trend, worrying in terms of potential toxic effects. This review is focused on the long-term toxicity of MSG and the experimental evidence that supports it. The article's primary purpose was to survey recently published data regarding the consumption of MSG within safe limits. The administered doses in animal models are very varied and have given rise to controversy. Also, the paper comprises pathways to lower MSG toxicity and highlight other underexploited biological effects, as anti-cancer potential. The administration of MSG, combined with various compounds, has been shown benefit against toxic effects. Several recent studies have identified a possible mechanism that recommends MSG and some derivatives as potential anti-cancer agents. New anti-cancer compounds based on the glutamic acid structure must be studied and further exploited. International regulations require harmonization of safe doses of MSG based on current scientific studies. Replacing MSG with other umami flavour enhancers may be a safer alternative for human health in the future. The biological consequences of MSG consumption or therapeutical administration have not been fully deciphered yet.

Worldwide flavor enhancer monosodium glutamate combined with high lipid diet provokes metabolic alterations and systemic anomalies: An overview

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Flavor enhancing high lipid diet acts as silent killer.

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Monosodium glutamate mixed with high lipid diet alters redox-status.

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Monosodium glutamate mixed with high lipid diet induces systemic anomalies.

In this fast-food era, people depend on ready-made foods and engage in minimal physical activities that ultimately change their food habits. Majorities of such foods have harmful effects on human health due to higher percentages of saturated fatty acids, trans-fatty acids, and hydrogenated fats in the form of high lipid diet (HLD). Moreover, food manufacturers add monosodium glutamate (MSG) to enhance the taste and palatability of the HLD. Both MSG and HLD induce the generation of reactive oxygen species (ROS) and thereby alter the redox-homeostasis to cause systemic damage. However, MSG mixed HLD (MH) consumption leads to dyslipidemia, silently develops non-alcoholic fatty liver disease followed by metabolic alterations and systemic anomalies, even malignancies, via modulating different signaling pathways. This comprehensive review formulates health care strategies to create global awareness about the harmful impact of MH on the human body and recommends the daily consumption of more natural foods rich in antioxidants instead of toxic ingredients to counterbalance the MH-induced systemic anomalies.

Natural products as safeguards against monosodium glutamate-induced toxicity

Monosodium glutamate is a sodium salt of a nonessential amino acid, L-glutamic acid, which is widely used in food industry. Glutamate plays an important role in principal brain functions including formation and stabilization of synapses, memory, cognition, learning, as well as cellular metabolism. However, ingestion of foodstuffs rich in monosodium glutamate can result in the outbreak of several health disorders such as neurotoxicity, hepatotoxicity, obesity and diabetes. The usage of medicinal plants and their natural products as a therapy against MSG used in food industry has been suggested to be protective. Calendula officinalis, Curcuma longa, Green Tea, Ginkgo biloba and vitamins are some of the main natural products with protective effect against mentioned monosodium glutamate toxicity through different mechanisms. This review provides a summary on the toxicity of monosodium glutamate and the protective effects of natural products against monosodium glutamate -induced toxicity.

The Interaction of Zinc Oxide/Green Tea Extract Complex Nanoparticles and its Effect on Monosodium Glutamate Toxicity in Liver of Rats

BACKGROUND

Zinc oxide nanoparticles (ZnO NPs) are increasingly utilized in both industrial and medical applications. Therefore, the study was aimed to investigate the effect of green nanoparticle complex (green tea extract/zinc oxide nanoparticles complex, GTE/ZnO NPs) on oxidative stress induced by monosodium glutamate (MSG) on the liver of rats.

METHODS

Wistar male rats (n=64) weighing between 200-250 g were divided randomly into eight groups: control group was given physiological saline (1 mg/kg), two groups were treated with two different doses of MSG (MSG-LD, MSG-HD; 6 and 17.5 mg/Kg, respectively), GTE was given 1 mg/mL, 5th group was treated with ZnO NPs and 6th group was treated with GTE/ZnO NPs complex while, 7th and 8th groups were treated with MSG-LD + GTE/ZnO NPs complex and MSG-HD + GTE/ZnO NPs complex, respectively. All substances were given orally for 30 consecutive days. At the end of the study, the liver was homogenized for measurement of the oxidative stress status and anti-inflammatory biomarkers as well as histological and transmission alternations.

RESULTS

Results showed that the antioxidant enzymes activity and glutathione level were significantly decreased in MSG groups than control in a dose-dependent manner. Conversely, the malondialdehyde and inflammatory cytokines levels were significantly increased in MSG groups than the control group. The liver indicated no evidence of alteration in oxidative status, anti-inflammatory and morphological parameters in GTE, ZnO NPs and GTE/ZnO NPs complex groups.

CONCLUSION

In conclusion, MSG at both doses caused oxidative stress and inflammation on liver after 28 days of exposure that supported histological analysis and transmission view of hepatic parenchyma. GTE/ZnO NPs act as partial hepato-protective against MSG.

A review of the alleged health hazards of monosodium glutamate

Monosodium glutamate (MSG) is an umami substance widely used as flavor enhancer. Although it is generally recognized as being safe by food safety regulatory agencies, several studies have questioned its long-term safety. The purpose of this review was to survey the available literature on preclinical studies and clinical trials regarding the alleged adverse effects of MSG. Here, we aim to provide a comprehensive overview of the reported possible risks that may potentially arise following chronic exposure. Furthermore, we intend to critically evaluate the relevance of this data for dietary human intake. Preclinical studies have associated MSG administration with cardiotoxicity, hepatotoxicity, neurotoxicity, low-grade inflammation, metabolic disarray and premalignant alterations, along with behavioral changes. Moreover, links between MSG consumption and tumorigenesis, increased oxidative stress and apoptosis in thymocytes, as well as genotoxic effects in lymphocytes have been reported. However, in reviewing the available literature, we detected several methodological flaws, which led us to conclude that these studies have limited relevance for extrapolation to dietary human intakes of MSG risk exposure. Clinical trials have focused mainly on the effects of MSG on food intake and energy expenditure. Besides its well-known impact on food palatability, MSG enhances salivary secretion and interferes with carbohydrate metabolism, while the impact on satiety and post-meal recovery of hunger varied in relation to meal composition. Reports on MSG hypersensitivity, also known as 'Chinese restaurant syndrome', or links of its use to increased pain sensitivity and atopic dermatitis were found to have little supporting evidence. Based on the available literature, we conclude that further clinical and epidemiological studies are needed, with an appropriate design, accounting for both added and naturally occurring dietary MSG. Critical analysis of existing literature, establishes that many of the reported negative health effects of MSG have little relevance for chronic human exposure and are poorly informative as they are based on excessive dosing that does not meet with levels normally consumed in food products.

The Ameliorating Effect of Sodium Selenite on the Histological Changes and Expression of Caspase-3 in the Testis of Monosodium Glutamate-Treated Rats: Light and Electron Microscopic Study

Monosodium glutamate (MSG) is a commonly used flavor enhancer that may contribute to male infertility. Sodium selenite is inorganic chemical form of selenium (Se). Se is best known as an antioxidant. This study was designed to investigate the possible ameliorating role of sodium selenite against MSG-induced testicular toxicity and histological changes. Forty male albino rats were allocated into four groups. Control group received distilled water, SE group received sodium selenite (0.25 mg/kg/day) dissolved in distilled water orally, MSG group received MSG (6 mg/g/day) dissolved in distilled water orally, and MSG + SE group received both MSG and sodium selenite for 45 days. Testicular samples were prepared for biochemical, light, and electron microscopic studies. Immunohistochemical staining for caspase-3 was done. MSG group demonstrated a significant increase in malondialdehyde level, marked damage of seminiferous tubules with a significant reduction in diameter and height of the lining epithelium. Spermatogenic cells showed disorganization, dark nuclei, reduction in number, and maturation arrest. Vacuolations of interstitial tissue and Leydig cells were also observed. Percent area of fibrosis and caspase-3 immunoexpression was significantly increased. Ultrastructurally, irregular tubular basement membrane and damaged germ cells were found. The spermatogenic, Sertoli, and Leydig cells showed irregular shrunken nuclei, cytoplasmic vacuolations, and swollen mitochondria. MSG + SE group showed much better histological and ultrastructural picture and improvement of the measured biochemical and morphometric parameters. Percent area of caspase-3 immunoexpression was significantly decreased. In conclusion, sodium selenite ameliorated the testicular damaging effect of MSG through reduction of oxidative stress and apoptosis.

Effects of Physalis peruviana L on Toxicity and Lung Cancer Induction by Nicotine Derived Nitrosamine Ketone in Rats

Nicotine-derived nitrosamine ketone (NNK) is considered a key tobacco smoke carcinogen inducing lung tumors. Physalis peruviana L (harankash) is considered one plant with marked health benefits. This study aimed to evaluate Physalis peruviana L effect on the toxic effect of NNK induced lung cancer in the rats by using pulmonary histopathological, immunohistochemical and DNA flow cytometric analyses. Sixty adult male rats were divided into four groups, each consisting of fifteen animals. The first group received saline, the second received two successive toxic doses of NNK only while the third received two successive toxic doses of NNK with a single daily dose of Physalis peruviana L. The fourth group received a single daily dose of Physalis peruviana L only. Toxic doses of NNK induced hyperplasia and adenocarcinoma in the lung and positive immunoreactivity for Ki-67 and p53 staining with disturbance of the lung DNA content. Administration of Physalis peruviana L with NNK led to a mild pulmonary hyperplasia and weak expression of Ki-67 and p53 with an improvement in the lung DNA content. Physalis peruviana L may protect against NNK induced lung carcinogenesis due to its antioxidant and anti-proliferative effects.

Monosodium glutamate induced testicular toxicity and the possible ameliorative role of vitamin E or selenium in male rats

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Monosodium glutamate induced testicular damage due to oxidative stress.

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Using of selenium and/or vitamin E to alleviate the toxicity of monosodium glutamate especially on testis.

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Increasing of MDA levels in MSG treated group while reduction in SOD, CAT and GPx activities.

Monosodium glutamate (MSG) has been recognized as flavor enhancer that adversely affects male reproductive systems. The present study was carried out to evaluate the potential protective role of vitamin E (vit E) or selenium against MSG induced oxidative stress and histopathological changes in testis tissues of rats. Mature male Wistar rats weighing 150–200 g BW were allocated to evenly twelve groups each group of ten animals, the first group was maintained as control group, the 2nd, 3rd and 4th groups were administered MSG in three different dose levels (low, medium and high) (6, 17.5 and 60 mg/kg BW), the 5th and 6th groups were given vit E in two doses (low and high) (150 and 200 mg/kg), the 7th and 8th groups were administered selenium in two doses (low and high) (0.25 and 1 mg/kg) daily via gavage for a period of 30 days. Meanwhile the 9th and 10th groups were given combinations of MSG (high dose) and vit E while, the 11th and 12th groups were given MSG (high dose) plus selenium in two recommended doses for each one. Monosodium glutamate caused an elevation in lipid peroxidation level parallel with significant decline in SOD, CAT as well as GPx activities in testis tissues. Administration of vit E or selenium to MSG-treated groups declined lipid peroxidation, increased SOD, CAT, GPx activities. Selenium or vit E significantly reduced MSG induced histopathological changes by the entire restoration of the histological structures and the testicular antioxidant status to great extent in treated rats. In conclusion, supplementation of selenium or vit E could ameliorate the MSG induced testicular toxicity to great extent and reduce the oxidative stress on testis tissues.