ABSTRACT
Effects of a flavor enhancer, monosodium glutamate (MSG) was evaluated in female albino rats during the gestational period. Thirty two rats were divided into 4 equal groups (each having 8 rats), Group I, control; Group II, treated with 6 g/kg/day of MSG, Group III, treated group with 8 g/kg/day and Group IV received 10 g/kg/day of MSG. Different doses of MSG (6 g/kg, 8 g/kg and 10 g/kg body weight) were administered orally from 7 -15th day of gestational period on completion of the treatment period. The Dams were allowed to deliver their pups. Sixty four pups were used for histology and the remaining were used for motor activity. Morphometric results of the fetal weight ,crown rump length, head of the pups, brain weight, weight of the cerebral cortex, cerebral width (narrow area) and cerebral width (broad area) of the developing cerebral cortex showed that high dose group rats demonstrated significant reduction in all the parameters when compared to the control. MSG also induced some abnormal changes in gestation such as tincture in the stomach of group III animals, dead of the pups, macrocephaly as well as ulceration in the thoracic region among the group IV animals. Cerebral tissues were obtained and processed to prepare sections stained with H&E and toluidine blue. Histological examination of group II showed degenerative changes present on the stellate cells. However, group III showed pyramidal cells, stellate cells and degenerated pyramidal cells with disintegrated nuclei while group IV showed a lot of vacoulation and clumped cells with some degenerating cells. The glial fibrillary acidic protein (GFAP) was detected immunohistochemically in the developing cerebral cortex of the pups. The result from montoya staircase test showed reduced exploratory motor activity in rats exposed to high concentration of monosodium glutamate that was statistically significant in the second and third week. There was significant motor xix exploratory activity impairment due to monosodium glutamate consumption even at low doses. The present study suggested that MSG has neurotoxic effect leading to degenerative changes in neurons and adversely affected the fetal development of the offsprings.