This study investigated the effect of ketogenic diet on monosodium glutamate (MSG)-induced testicular dysfunction. Forty-six male rats (180 ± 40 g) were grouped into two groups (23 rats each); control group and MSG-induced group (4 mg/kg bw) for 28 days. At the 29th day, 5 rats from both group were sacrificed to establish testicular dysfunction. The remaining animals from the control group was further divided into three sub-groups and treated for 42 days; untreated group, ketogenic diet only and curcumin only as the standard drug (150 mg/kg bw). In the pre-treatment, the administration of MSG resulted in a significant (p < 0.05) decrease in the testis-body weight ratio, alkaline phosphatase (ALP), acetylcholine esterase (AChE), cholesterol, triglycerides (TG), nitric oxide (NO), glycogen, protein and antioxidant enzymes in the testis. In the post treatment, the MSG only group significantly reduced testicular cholesterol, catalase (CAT) and NO. In contrast, MSG + ketogenic diet group showed a significant increase in levels of rat testicular acid phosphatase (ACP), ALP, cholesterol, HMG-CoA, TG, malondialdehyde (MDA), reduced glutathione (GSH) and NO. The ketogenic diet showed a significant increase (p < 0.05) in the levels of NO, ALP, cholesterol, HMG CoA reductase and (TG). In addition, significant increases in levels of rat testicular ACP, ALP, HMG-CoA, (CAT), SOD and GSH were recorded for MSG + Curcumin group. Taken together, the findings support the prospects of ketogenic diet to enhancethe testicular function in rats.

OBJECTIVES:The route of administration is an important factor in determining the action of some drugs. We previously demonstrated that subcutaneous monosodium glutamate (MSG) accelerated cortical spreading depression (CSD) in the rat and that treadmill exercise attenuated this effect. This study evaluated whether other routes of administration exert the same action by testing orogastric (gavage) and topical cortical MSG administration in treadmill-exercised and sedentary rats. Additionally, in the orogastric treatment we tested anxiety-like behavior.

METHODS:Exercised and sedentary rats received per gavage water or MSG (1 or 2 g/kg) daily from postnatal (P) day 7 to 27. Behavioral tests (open field and elevated plus-maze) occurred at P53 ± 3. At P56 ± 3, we analyzed CSD parameters (velocity, amplitude, and duration of the negative potential change). Other three groups of rats received an MSG solution (25, 50 or 75 mg/ml) topically to the intact dura mater during CSD recording.

RESULTS:MSG-gavage increased anxiety-like behavior and the CSD velocities compared with water-treated controls (P < 0.05). Exercise decelerated CSD. In contrast to gavage, which accelerated CSD, topical MSG dose-dependently and reversibly impaired CSD propagation, reduced CSD amplitude and increased CSD duration (P < 0.05).

CONCLUSIONS:The exercise-dependent attenuation of the effects of MSG confirms our previous results in rats treated subcutaneously with MSG. CSD results suggest two distinct mechanisms for gavage and topical MSG administration. Additionally, data suggest that exercise can help protect the developing and adult brain against the deleterious actions of MSG.

A case is reported in a 15-year-old white girl who had a swollen lower face and lips; a diagnosis of orofacial granulomatosis was made. It was suspected that her condition had an allergic basis because an increase in clinical signs and symptoms was shown to be related to the food additive monosodium glutamate. Treatment with a restricted diet resulted in resolution of the facial swelling.

NEW FINDINGS:Monosodium glutamate causes cognitive impairment. Resistance exercise is effective against monosodium glutamate induced memory impairment in male and female mice.

ABSTRACT:Monosodium glutamate (MSG), a flavor enhancer in diets, causes cognitive impairment in humans. Exercise has been reported to protect against impairment of memory in humans. This study investigated if resistance exercise improves the performance of male and female rats treated with MSG in tests of memory and motor coordination. Wistar rats received MSG (4g kg day(-1) , s.c.) from post natal day 1 to 10. At postnatal day 60, the animals started a resistance exercise protocol in an 80° inclined vertical ladder apparatus and performed it during 7 weeks. Rats performed object recognition and location memory tests. Resistance exercise reduced impairment in motor coordination of male and female rats treated with MSG. Resistance exercise was effective against the decrease in exploratory preference in the long-term recognition memory (LTM) for novel objects of male rats treated with MSG. In MSG-treated female rats, resistance exercise was effectiveagainst the decrease in exploratory preference in the novel object location test (OLT). The exploratory preference of female rats in the LTM test was similar in all groups. The short-term memory was not altered by MSG or resistance exercise in male and female rats. This study demonstrates that MSGaffected in a different way memory of male and female rats. Resistance exercise was effective against the decrease in recognition for male and in location memory for female rats treated with MSG. This report demonstrates the beneficial effects of resistance exercise against the prejudice of motor condition and impairment of memory induced by MSG in male and female rats. This article is protected by copyright. All rights reserved.

Despite resistance exercises being associated with health outcomes, numerous issues are still unresolved and further research is required before the exercise can faithfully be prescribed as medicine. The goal of this study was to investigate whether there are sex differences in resistance training effects on metabolic alterations induced by monosodium glutamate (MSG), a model of obesity, in male and female rats. Male and female Wistar rats received MSG (4 g/kg body weight/day, s.c.) from postnatal day 1 to 10. After 10 days from MSG administration, the rats were separated into two groups: MSG-sedentary and MSG-exercised. At postnatal day 60, the animals started a resistance training protocol in an 80 degrees inclined vertical ladder apparatus andperformed it for 7 weeks. Control rats received saline solution and were divided in saline-sedentary and saline-exercised. Resistance training restored all plasma biochemical parameters (glucose, cholesterol, triglycerides, aspartate aminotransferase, and alanine aminotransferase) increased in maleand female rats treated with MSG. The MSG administration induced hyperglycemia associated with a decrease in the skeletal muscle glucose transporter 4 (GLUT4) levels and accompanied by deregulation in proteins, G-6Pase, and tyrosine aminotransferase, involved in hepatic glucose metabolism of male and female rats. MSG induced dyslipidemia and lipotoxicity in the liver and skeletal muscle of male rats. Regarding female rats, lipotoxicity was found only in the skeletal muscle. The resistance training had beneficial effects against metabolic alterations induced by MSG in male and female rats, through regulation of proteins (GLUT2, protein kinase B, and GLUT4) involved in glucose and lipid pathways in the liver and skeletal muscle.

OBJECTIVES: To examine the effects of a challenge with monosodium glutamate (MSG) as compared to placebo on the symptoms of fibromyalgia (FM), in participants who initially experienced>30% remission of symptoms on an excitotoxin elimination diet.

METHODS: Fifty-seven FM patients who also had irritable bowel syndrome (IBS) were placed on a 4-week diet that excluded dietary additive excitotoxins including MSG and aspartame. Thirty-seven people completed the diet and 84% of those reported that>30% of their symptoms resolved, thus making them eligible to proceed to challenges. Subjects who improved on the diet were then randomised to a 2-week double-blind placebo-controlled crossover challenge with MSG or placebo for 3 consecutive days each week. The primary outcome measure was total symptom score. Secondary outcome measures included visual analogue pain scales (VAS for FM and IBS), an IBS Quality of Life Questionnaire (IBS QOL) and the Fibromyalgia Impact Questionnaire-Revised (FIQR). Repeated measures ANOVA was used to analyse crossover challenge results.

RESULTS: The MSG challenge, as compared to placebo, resulted in a significant return of symptoms (total symptom score, p<0.02); a worsening of fibromyalgia severity as determined by the FIQR (p<0.03); decreased quality of life in regards to IBS symptoms (IBS QOL, p<0.05); and a non-significant trend toward worsening FM pain based on visual analogue scale (VAS, p<0.07).

CONCLUSIONS: These findings suggest that dietary glutamate may be contributing to FM symptoms in some patients. Future research on the role of dietary excitotoxins in FM is warranted.