Low concentrations of monosodium glutamate (MSG) are safe in male Drosophila melanogaster

Abstract

ObjectiveMonosodium glutamate (MSG) has been marred by a lot of controversy on its safety. In a majority of experimental studies, administration of the compound has been parenteral, and yet little is known about MSG safety consumed as a food supplement. In this study, we assessed the effects of low concentrations of MSG on the activity of hydrogen scavenging, catalase activity and climbing as well as lifespan in male Drosophila melanogaster over a 30 days period since this has been sparsely studied.ResultsNo significant differences were associated with MSG at 5%, 1%, 0.2%, 0.04% on hydrogen peroxide scavenging, negative geotaxis and lifespan in W1118 male D. melanogaster. Significant differences were found in 5% MSG on catalase activity, showing that high MSG concentrations would affect tissue health in male D. melanogaster. MSG consumed as a food supplement would be safe at concentrations below 5% MSG.

Synergistic action of propolis with levodopa in the management of Parkinsonism in Drosophila melanogaster

“…A low survival rate was characterized with all flies having Parkinsonism (Figure 3) due to defective coordination of the skeletomuscular system, leading to decreased ability to look for food, starvation and death ( Figure 1). These findings are in agreement with several studies in Drosophila melanogaster, demonstrating the importance of an efficient neuromuscular connection to improve on survival [30,31]. These findings are in agreement with epidemiological studies in humans with Parkinsonism who have been associated with a lower lifespan than healthy individuals [45].…”

“…Wild type (W 1118 ) and PTEN-induced putative kinase 1 (PINK1 B9 ) mutant Drosophila melanogaster flies were obtained from the Bloomington Stock Center as previously described [27][28][29][30][31]. These flies that were obtained had the red eye balancer, meaning they appeared phenotypically normal but were genetically modified to express parkinsonian symptoms.…”

“…The flies in each vial were counted every 3 days interval and live flies were transferred to new vials while the dead flies were recorded. Flies of the same genealogy were used, to minimize differences arising from genetic backgrounds [30,31]. The number of flies used in this experiment was 51 × 6 groups = 306 flies.…”

High concentration of MSG alters antioxidant defence system in lobster cockroach Nauphoeta cinerea (Blattodea: Blaberidae)

“…The brain is known to be susceptible to free radical damage because of its high concentration of polyunsaturated fatty acids, relatively low antioxidant capacity, high rate of oxygen use, and high concentration of transition metals in some of its' regions [30]. Reports differ on the effect of MSG on Drosophila melanogaster antioxidant response [8,9] we herein show reduced CAT and GST activities in N. Cinerea exposed to 4% MSG, suggesting that MSG might overwhelm the antioxidant and detoxification capabilities of insects. It is clear that at high concentration, MSG may disrupt antioxidant defence systems, nevertheless, nymphs exposed to 1% MSG showed no significant alterations in all parameters evaluated.…”

“…Recently, studies have shown an adaptive response to oxidative stress in Drosophila melanogaster and a reduction in life span after short exposure to MSG diet [8]. However, another study in D. melanogaster showed that MSG could be safe at extremely low concentrations, though high concentration caused alterations in catalase activity [9].…”