Table 7.

Summary of preclinical studies investigating the effect of MSG administration on fetal development

Mode of administration	Species	MSG dosage/day	Duration of administration	MSG effect (vs. control)	Reference
Intragastric	Swiss Albino mice	Maternal mice were given 1.0, 2.0, 4.0 g/kg MSG	Maternal mice received MSG for 3 consecutive days: at 17–19 days of pregnancy. Offspring were assessed.	MSG administration alters behavior, histopathology, genetic toxicity, and expression of apoptosis-related gene.	(Yu et al., 2006)
Oral	Kunming mice	Maternal mice were given 2.5 g/kg or 4.0 g/kg MSG	Maternal mice received MSG for 3 consecutive days: at 17–19 days of pregnancy. Offspring were assessed.	Decreased threshold of convulsion; Impaired discrimination learning; Increased rate of weight gain; No significant difference in spatial learning or pain thresholds assessed by tail flick latency; No impact on the reproductive capacity of the offspring.	(Yu et al., 1997)
Mixed with diet	Wistar rats male and female and their offspring	a) 2.5 g MSG/day representing 10% of dry weight of the average daily food ration b) 5 g MSG/day representing 20% of dry weight of the average daily food ration (in mother and offspring)	In utero life + 90 days after	Maternal feeding with 5 g MSG per day results in: Severe birth weight reduction of the offspring and of the weaned pup; Lower growth hormone and insulin-like growth factor 1 serum levels, which are maintained low in mice fed with high MSG diet (5 g MSG per day). Animals kept on medium MSG diet (2.5 g MSG per day) showed low serum growth hormone levels at day 30 of life but partially recover before day 90; Dose-dependent voracity. The animals fed 5 g MSG per day increased water uptake by threefold (p<0.01), and food uptake by almost two-fold (p<0.01).	(Hermanussen et al., 2006)