Preliminary study on the protective effect of vitamin C on monosodium glutamate-induced hepatotoxicity in rats

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.

Boldenone Undecylenate-Mediated Hepatorenal Impairment by Oxidative Damage and Dysregulation of Heat Shock Protein 90 and Androgen Receptors Expressions: Vitamin C Preventive Role

Boldenone Undecylenate (BLD) is a synthetic derivative of testosterone and a widely used anabolic androgenic steroid. The health risk of BLD use as a pharmaceutical or dietary supplement is still underestimated and under-reported. Vitamin C (VC) has been recognized as an antioxidant with prominent hepatorenal protective effects. This study investigated the possible preventive activity of VC against BLD-induced hepatorenal damage. Forty adult male Wistar rats were classified into five groups: control, vehicle control, VC (orally given 120 mg/kg b. wt./day), BLD (intramuscularly injected 5 mg/kg b. wt./week), and BLD + VC-treated groups. The experiment continued for eight weeks. Serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured. Serum contents of total protein (TP), albumin (ALB), globulin, total cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), and very-low-density lipoprotein-cholesterol (VLDL-C) were also assayed. Urea, creatinine, and uric acid levels were determined together with sodium and potassium electrolytes measuring. Moreover, oxidative stress indicators including reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione reductase (GSR) as well as malondialdehyde (MDA) levels were measured in both hepatic and renal tissues. Corresponding histological examination of renal and hepatic tissues was conducted. Besides, immunohistochemical evaluations for androgen receptors protein (AR) and heat shock protein 90 (Hsp 90) expressions were performed. BLD caused significant rises in serum ALT, AST, TP, ALB, TC, TG, LDL-C, VLDL-C, urea, creatinine, uric acid, potassium, and MDA levels. Further, BLD-injected rats showed significant declines in the serum levels of HDL-C, sodium, GSH, GPx, GST, and GSR. Besides, distinct histopathological perturbations were detected in renal and hepatic tissues of BLD-injected rats. AR and Hsp 90 immunoexpression were increased in hepatic and renal tissues. In contrast, VC significantly reversed the BLD-induced hepatorenal damage in co-treated rats but not ameliorated AR protein overexpression. VC could be an efficient preventive supplement for mitigating BLD-induced hepatorenal damage, possibly via controlling oxidative stress events.

Myrtle (Myrtus communis) leaf extract suppresses hepatotoxicity induced by monosodium glutamate and acrylamide through obstructing apoptosis, DNA fragmentation, and cell cycle arrest

A large number of plant extracts have demonstrated to provide health benefits and mitigate several disease conditions. However, at the molecular and cellular levels, few studies have been conducted. The present work was designed to study the effect of Myrtus communis leaf extract (ME) (300 mg/kg bw) against hepatotoxicity induced by monosodium glutamate (MSG) (100 mg/kg bw), and acrylamide (ACR) (20 mg/kg bw) in male rats and determining its molecular and cellular mechanisms. The data showed that the treatment with MSG and/or ACR induced significant changes in numerous biomarkers (Bcl-2 and the programmed cell death protein-1) related to liver damage, as recorded by genotoxicity, apoptosis, and histopathological changes. On the other side, the oral administration of ME (300 mg/kg bw) improved the hepatic conditions as confirmed by the improvement in cell viability, programmed cell death, and histopathological alterations. It can be concluded that the consumption of ME might be useful for minimizing the occurred hepatotoxicity through up-regulation of the key apoptotic regulators as well as the improvement of DNA content and cell cycle restoration. Graphical abstract.