Effect of monosodium glutamate on liver of pregnant rats and their fetuses (Histological and histochemical studies)

Effect of monosodium glutamate on fetal development and progesterone level in pregnant Wistar Albino rats

Monosodium glutamate (MSG) is a widespread flavor enhancer and stabilizer in manufactured or packaged foods that possess myriad adverse effects. This study aimed to evaluate the effect of MSG on placental progesterone receptors and fetal development. Thirty pregnant Wistar Albino rats were divided into three groups (ten/each). The control group (G1) gavaged distilled water only, low-dose treated group (G2) gavaged 3 g/kg MSG, and high-dose treated group (G3) gavaged 6 g/kg MSG from 1st to 18th days of gestation, and all pregnant rats were sacrificed on the 19th day of gestation. The effect of MSG on fetal weights, crown vertebral length (CVL), placental weight, placental ghrelin expression, and fetal skeleton examination were estimated. MSG induced a significant decrease in fetal weights, CVL lengths, placental weight, and ghrelin expression in both treatment groups compared to the control group. Several parts of the fetal skeleton showed incomplete ossification and delayed chondrification in which high-dose maternally treated fetuses were more affected. Many degenerative changes were detected in both maternal and fetal liver and kidney tissues in MSG-treated groups. Moreover, MSG caused a significant increase in serum ALT, ALP, and creatinine levels in pregnant rats' blood. Serum progesterone was only elevated in G3 on the 19th day of gestation. This study showed that the administration of MSG during pregnancy adversely influences fetal growth and skeletal development and caused several biochemical and histological changes in the maternal and fetal liver and kidney tissues which assure the toxic and teratogenic effects of MSG.

Assessment of changes in the liver of pregnant female rats and their fetuses following monosodium glutamate administration

Monosodium glutamate (MSG) is a common flavor enhancer and stabilizer for ready-made or packaged foods. This research investigated the impact of MSG on the maternal and fetal liver. The present study was carried out on sixteen mature female Albino rats and eight male rats of reproductive age. The control group was dissected on day 20 of gestation. MSG group was administrated MSG daily at a dosage of 1 g/5 mL/kg body weight from day 0 to day 20 of gestation. The liver function and lipid profile of the control and treated mothers were investigated in the blood sera. The levels of nitric oxide (NO), tumor necrosis factor (TNF-α), superoxide dismutase (SOD), and reduced glutathione (GSH) activities in the liver homogenate of maternal and fetal tissue were assayed, in addition to histopathological, histochemical and immunohistochemical studies were done to the liver tissue. The activities of liver functions and lipid profile significantly altered in the treated mothers with MSG. MSG significantly reduced the SOD and reduced GSH activities in addition to the elevated TNF-α and NO in liver tissue of pregnant mothers and their fetuses. Severe histopathological alterations were observed in both maternal and fetal liver tissues of MSG-treated groups. Moreover, histochemical observations showed a reduction of total polysaccharides in the liver of pregnant rats and fetuses. A significant increase in the percentage area of positive immunoreaction for caspase 3 was observed in the liver of treated rats with MSG compared to the liver of the control. The liver of fetuses treated with MSG revealed an alteration like their mother. This study showed that during the gestational period MSG exposure resulted in several biochemical, histological, and histochemical changes in the maternal and fetal liver tissues which emphasize the toxic effect of MSG.

Histomorphometric study on effects of monosodium glutamate in liver tissue of Wistar rats

OBJECTIVES

Thousands of food additives are being used by the food industries in ready to eat packed food. These food additives act as either preservatives or enhancers of palatability. Monosodium glutamate (MSG), a sodium salt of glutamic acid is a widely used food additive for enhancing taste. It gives the unique taste to the food called "Umami" or "Savory taste", which is different from four primary tastes namely, sweet, sour, salty, and bitter. The current experimental study was investigated by dose-related effects of MSG on adult Wistar rats using histological and histomorphometric techniques.

METHODS

Twenty-eight adult Wistar rats were divided into four groups i.e.; one control and three experimental groups. Rats were administered orally with different doses of MSG to the experimental groups and distilled water to the control groups consecutively for 45 days. At the end of the study, rats were sacrificed and tissues were collected for the examination.

RESULTS

Histomorphometric data of the nuclei diameter of hepatocytes showed significant variation between control and experimental groups. Less PAS-positive material found in a higher dose of MSG-induced rats in histochemical observation.

CONCLUSIONS

One of the challenges of the problem of animal experimental studies is the application of results to human dietary intake of MSG. Based on the dose-dependent findings of the current study; it is evident that the administration of MSG is hepatotoxic in adult Wistar rats.