Action Of Monosodium Glutamate Research Articles

The Effect of Monosodium Glutamate Ingestion on Spatial Memory and Cognitive Behaviour in Wistar Rats

Monosodium glutamate (MSG), one of the most widely used food-additives in commercial foods gives a special aroma (umami) to processed foods. It’s vital to brain metabolism and function. Adverse effects of MSG have been widely reported. However, there is scarcity of literature on the action of MSG on spatial memory and cognition. Hence, there is need to assess the effect of MSG ingestion on spatial memory and cognitive behavior in Wistar rats. 25 Wistar rats were randomly selected into five groups and treated for three weeks thus: Group 1 (control), Group 2 (0.7 mL MSG), Group 3 (1 mL MSG), Group 4 (1.5 mL MSG) Group 5 (0.1 mL Epinephrine). Neurobehavioral (Barnes, navigation, and handgrip) activities exhibited by the various groups were recorded and analyzed using ANOVA. In the Barnes maze test, there was a significant decrease (p<0.05) in escape time in group 4 when compared to the control for weeks 1 and 3. In week 1 of the Navigation maze test, group 4 animals spent less time (p<0.05) to navigate the maze when compared to the control. In week 1 and 3 of the handgrip test, animals in groups 2, 3 and 5 had a significant decline (p<0.05) in grip strength when compared to the control group; However, in week 2, only the animals in group 5 had a decline in grip strength (p<0.05) when compared to control. MSG did not cause any form of neurotoxicity, cognitive or motor decline in rats.

Submicroscopic changes of the spleen in the action of monosodium glutamate and correction with melatonin

Background. Monosodium glutamate is one of the most common dietary supplements in the world. The aim of the study was to study the electron microscopic changes in the structural components of the spleen of rats under the action of monosodium glutamate and its correction with melatonin. Methods. The experimental study was performed on 66 white male rats and females of reproductive age. For six weeks, the animals received monosodium glutamate at a dose of 0.07 g/kg body weight daily with food, after which they switched to a standard diet with the addition of melatonin at a dose of 0.01 g/kg for two, four and six weeks. Sections of the spleen were made on an ultramicrotome UMTP-6M with a diamond knife (DIATOM) and double contrast was performed according to Reynolds and uranyl acetate. Submicroscopic examinations of the organ were performed using an electron transmission microscope TEM-100. The test material was documented using a SONY – H9 digital camera. Results. Daily consumption of monosodium glutamate for six weeks leads to profound destructive changes in the cellular composition of the spleen, causing disorders in the vascular bed. In particular, the number of lymphocytes with signs of apoptosis increases significantly, and the number of cells with signs of mitosis decreases, in the cytoplasm of dendritic cells organelles with signs of damage, in the periarterial zone signs of edema, a large number of active macrophages, the cytoplasm of which contains osmophilic inclusions and remnants of phagocytosed cells. The red pulp is full-blooded, contains areas of accumulation of deformed blood cells, polysegmental neutrophils and megakaryocytes. Blood capillaries with reduced lumen. The introduction of melatonin leads to a significant restoration of the structural organization and, consequently, the function of this organ. Conclusion. Melatonin has a positive effect on the restoration of changes in the spleen caused by the action of monosodium glutamate.

SUBMICROSCOPIC CHANGES OF STRUCTURAL COMPONENTS OF THE SPLEEN DUE TO THE ACTION OF MONOSODIUM GLUTAMATE

The results of an experimental study conducted on white male rats and females of reproductive age were analyzed in order to detect submicroscopic changes in the structural components of the spleen under the action of monosodium glutamate in the dynamics. For two, four, six and eight weeks, the animals received monosodium glutamate at a dose of 0.07 g / kg body weight daily with food. Sections of the spleen were made on a UMTP-6M ultramicrotome with a diamond knife (DIATOM) and double contrast was performed according to Reynolds and uranyl acetate. Submicroscopic examinations of the organ were performed using an electron transmission microscope TEM-100. The investigated material was photodocuted using a SONY – H9 digital camera. The first violations of the structural components of the spleen are observed after two weeks, namely the expansion of intercellular spaces in both white and red pulp of the spleen, which contain vacuole-like structures, an increase in plasma cells, the cytoplasm of which is filled with dilated tubules. In dynamics with increase in duration of reception changes deepen, reaching a maximum in 8 weeks of experiment. Electron microscopy revealed that the signs of adaptive-compensatory processes by the end of the experiment lead to a loss of regenerative function.

Electron microscopic changes of lymph nodes during correction of sodium glutamate action by melatonin

The effect of monosodium glutamate on lymphoid organs remains insufficiently studied. Also, no less relevant is the issue of correction of changes caused by the action of monosodium glutamate. The aim of the study was to study the electron microscopic changes in the parenchyma of the lymph nodes of rats under the action of monosodium glutamate for six weeks and during correction with melatonin. The experimental study was performed on 66 white male and female rats of reproductive age. The structure of mesenteric lymph nodes of white rats under the conditions of physiological norm at the electron microscopic level was studied in 10 intact animals. Experimental animals were divided into 4 groups, each with 10 animals. The control was 16 white rats, which instead of a high-calorie diet (HCD) received a standard diet of vivarium. HCD was achieved by adding to the diet of monosodium glutamate at a dose of 0.07 g/kg body weight of rats. The dose of melatonin was 10 mg/kg body weight of rats, administered orally daily at the same time in the afternoon. The electron microscopic structure of the mesenteric lymph nodes of male and female rats of reproductive age of the intact and control groups corresponds to the species norm. The study showed that monosodium glutamate causes changes in the parenchyma of the lymph nodes as in alimentary obesity. After six weeks of HCD, the number of apoptically altered lymphocytes increases. That part of lymphocytes, which has no signs of karyorrhexis or karyolysis, has a karyolemma with deep intussusception, the cytoplasm is enlightened, the tubules of the granular endoplasmic reticulum in cells with signs of edema, dilated, mitochondrial ridges swollen, damaged. There are profound destructive changes in the cellular composition of the organ and violations at the level of all parts of the vascular bed. After six weeks of melatonin correction, the number of macrophages and plasma cells decreased, in some lymphocytes the nucleolus is not clearly expressed, the karyolemma is uneven, the cytoplasm is enlightened, the number of osmophilic (fatty) inclusions decreases both in the intercellular space and in the cytoplasm of the cell. Therefore, the introduction of melatonin led to a significant restoration of the structural organization, and hence the function of this organ.

Determining Efficacy of Monosodium Glutamate for Salt Reduction in Plain and Spiced ‘Poories’ Through Sensory Responses

Palatability is considered as a major determinant of food selection and intake. Umami foods are being employed widely in savory food formulation for its greater potential for enhancing savory taste. In the present investigation, the role of monosodium glutamate (MSG) in salt reduction along with spices was investigated to understand the flavor potentiating effect and synergistic action of MSG. Deep fried unleavened wheat based traditional Indian bread (Poories) was chosen to study the acceptability. Control product was prepared with 2.0% salt. For experimental products, two levels of MSG viz, 75 and 100 mg/100 g and three levels of salt, namely, 1.5, 1.75 and 2.0% were selected. Spices, namely, chili (Capsicum annum L.) cumin (Cuminum cyminum)), pepper (Piper nigrum L) and omum (Trachyspermum ammi)) were incorporated into the product, either as single spice or in combination. The results revealed that the MSG added products were given a higher score for umami flavour in comparison to the control product. In general, MSG added products scored better for flavor in salt reduced products. Results of low sodium poories with single spices and different level of salt indicated that all products prepared with spices were equally liked for the selected sensory characteristics. The products prepared with 1.75% salt obtained highest scores. This is indicative of the flavour enhancing property of MSG. Similarly for products with mixture of spices; salt reduced products were also accepted well. PCA plot revealed the flavor potentiating effect of MSG in salt reduction. Thus it could be said that using MSG and spices combination would be a better option for achieving salt reduction in savory products.

Peculiar change in membrane potential of taste sensor caused by umami substances

Monosodium glutamate (MSG) induces a favorable taste, termed umami. The action of MSG on lipid membranes of a taste sensor was investigated. In general, food constituents monotonously increase the electric potential of the negatively charged membranes. Contrary to this, MSG decreases the potential at lower concentration and increases it at higher concentration, thus the effect of MSG on lipid membrane is biphasic. On the decrease of the membrane potential, a model was proposed in which the dissociated carboxyl group of MSG accelerates the dissociation of phosphate group of the membrane lipid.

Effects of Neonatal Administration of Octreotide, a Long-Lasting Somatostatin Analogue, on Growth Hormone Regulation in the Adult Rat

The pulsatile pattern of GH secretion slowly develop in the postnatal period concomitantly with the dual network of GHRH and somatostatin (SRIH) hypothalamic neurons. We investigated whether an early postnatal treatment with a long acting SRIH analogue, octreotide, could affect maturation and subsequent operation of those networks in the adult rat. Octreotide administration (5 mu g/rat SC) every other day during the first 10 days of life resulted in growth retardation in the adult. In parallel, the amplitude of plasma GH secretory episodes in free moving unanesthetized animals was markedly reduced. The numbers of arcuate GHRH mRNA-containing and periventricular SRIH-mRNA containing neurons were not affected by the treatment. GHRH mRNA levels per neuron however was decreased by 30%, and median eminence GHRH stores by 50%. SRIH expression in the arcuate nucleus was also diminished, as was the number of 125I-SRIH labeled neurons in that nucleus. The effects of octreotide were compared to the hyposomatotropinemia induced by administration of monosodium glutamate (MSG), every other day during the first 10 days of life. Growth retardation and inhibition of GH secretory episodes in adult rats neonatally treated with MSG were slightly more pronounced than after octreotide. In contrast to octreotide, MSG induced a massive loss of GHRH neurons and a concomitant decrease in 125I-SRIH binding. Somatostatin did not protect GHRH neurons against the neurotoxic action of MSG since octreotide treatment did not further affect any of the parameters impaired by MSG. In conclusion, these experiments demonstrate that neonatally injected octreotide cannot counteract the toxic effect of MSG on arcuate neurons. However, a neonatal treatment with the SRIH agonist affects permanently growth rate and GH pulsatility. This effect is mediated in the hypothalamus by permanently impairing the neural networks that control GH secretion.

The localization of phenolic and tyrosyl ring thyroxine deiodination in rat and mouse retina

To elucidate T(4) metabolism in various cell types of rat retina, 5-monodeiodinating and 5?-monodeiodinating activities were studied in retinal cell layers obtained by selective cytotoxic action of monosodium glutamate on bipolar and ganglion cell layers and by iodoacetate effect on photoreceptor cells. Concomitantly these enzyme activities were studied in C3H/HeN mouse retina genetically deprived of photoreceptor cells. Deiodinase activities were low in rat and mouse retina deprived of photoreceptors. The 5?-monodeiodination rate of T(4) was higher than T(4) tyrosyl ring deiodination in cell layers examined and the highest values were found in the photoreceptor cells. Data support the hypothesis that phenolic and tyrosyl ring deiodinase activities are present in the photoreceptor cells. Their reciprocal changes may regulate the nuclear function which in turn controls the rhythmical renewal of rod outer segments.