Table 8.

Summary of preclinical studies investigating other effects of MSG administration

Mode of administration	Species	MSG dosage/day	Duration of administration	MSG effect (vs. control)	Reference
Mixed with diet	Male Wistar rats	a) 100 g/kg in standard diet b) 100 g/kg in high-fiber diet	45 days	Increase in voluntary food intake and decrease of feed efficiency; Metabolic dysfunction characterized by increased levels of glucose, triacylglycerol, insulin, leptin; Imbalance between the oxidant and antioxidant systems.	(Diniz et al., 2005)
Mixed with diet	Cats	Average intake 201.4 ± 18.65 mg/kg	In utero exposure and 9 months after birth	Increased adiposity, induction of hepatic steatosis and the expression of genes involved in cholesterol and steroid metabolism; Increase in fasting insulin and HOMA-IR values.	(Collison et al., 2011)
Subcutaneous	Newborn male Wistar rats	4 g/kg (n=10)	First 10 days of life (injection 5 times, every other day)	Impaired glucose tolerance; Insulin resistance to peripheral glucose uptake.	(Hirata et al., 1997)
Intravenous	Sprague-Dawley rats of either sex (n=16)	10 mg/kg 50 mg/kg	Single dose administration	MSG, 50 mg/kg, determined: 2- to 3-fold elevation in interstitial glutamate levels in the masseter muscle; Afferent mechanical sensitization through NMDA receptor activation.	(Cairns et al., 2007)
Oral	Male NMRI mice	150 mg/kg 300 mg/kg	ays	MSG, 300 mg/kg, determined: Reduced thermal nociceptive threshold and increased nociceptive behavior; Increased the nitrite concentration in brain tissue.	(Zanfirescu et al., 2017)