Berberine alleviates monosodium glutamate induced postnatal metabolic disorders associated vascular endothelial dysfunction in newborn rats: possible role of matrix metalloproteinase-1

Reconsideration of the health effects of monosodium glutamate: from bench to bedside evidence

Monosodium glutamate (MSG) is a food additive that enhances the palatability of foods, thus its frequent use both domestically and industrially. Based on the dose-factor, frequency, and duration of exposure, MSG may provoke adverse health outcomes both in animals and humans. The present report aims at providing a comprehensive analysis of the scientifically proven untoward health effects of MSG. To achieve our aim, we adopted the PRISMA guidelines and checklist and searched four databases (Scopus, Web of Science, PubMed, and Google Scholar) from 2014 to 2024. Retrieved research papers were critically appraised for quality using the ARRIVE and Joanna Briggs (JB) checklists and data analysis was conducted via the narrative synthesis method. Our analysis reveals that though MSG is generally considered safe at low doses; however, high doses and repeated exposure to MSG are associated with embryotoxicity and teratogenicity, obesity, cardiotoxicity, hepatotoxicity, kidney toxicity, neurotoxicity, endothelial dysfunction, reproductive toxicities, alteration of lipid, and glucose metabolism. Thus, chronic exposure to MSG may be of human pathological importance. The findings of the present narrative synthesis provide a rationale for informed decisions on the use and labeling of this widely used food additive.

Effects of in utero exposure to monosodium glutamate on locomotion, anxiety, depression, memory and KCC2 expression in offspring

In pregnancy, there is a significant risk for developing embryos to be adversely affected by everyday chemicals such as food additives and environmental toxins. In recent times, several studies have documented the detrimental effect of exposure to such chemicals on the behaviour and neurodevelopment of the offspring. This study evaluated the influence of the food additive, monosodium glutamate (MSG), on behaviour and development in mice. Pregnant dams were exposed to MSG 2 or 4 g/kg or distilled water from gestation day 10-20. On delivery, postnatal day 1 (PN 1), 3 pups were sacrificed and whole brain samples assayed for KCC2 expression by western blot. The remaining pups were housed until PN 43 before commencing behavioural assessment. Their weights were measured at birth and at 3 days intervals until PN 42. The impact of prenatal exposure to MSG on baseline exploratory, anxiety and depression behaviours as well as spatial and working memory was assessed. In utero exposure to 4 g/kg MSG significantly reduced exploratory drive and increased depression-like behaviours but did not exert any significant impact on anxiety-like behaviours (p < 0.01). Additionally, there was a two-fold increase in KCC2 expression in both 2 and 4 g/kg MSG-exposed offspring. CONCLUSION: This study indicates that, in utero exposure to MSG increases the expression of KCC2 and causes significant effect on locomotion and depression-like behaviours but only marginally affects memory function.