The interplay between monosodium glutamate (MSG) consumption and metabolic disorders.

Monosodium glutamate (MSG) is one of the most popular food additives in the world and is often ingested with commercially processed foods. It can be described as a sodium salt of glutamic acid with the IUPAC name - Sodium 2-aminopentanedioate and is ionized by water to produce free sodium ions and glutamic acid. MSG use has significantly increased over the past 30 years, its global demand stands huge at over three million metric tons which is worth over $4.5 billion. Asia was responsible for more than three quarter of world MSG consumption with the country China also leading in global consumption as well as production and export to other countries. Prior to year 2020, global demand for MSG increased by almost four percent each year with the highest significant increase in demand for MSG predicted to rise in Thailand, Indonesia, Vietnam and China, followed by Brazil and Nigeria. However, several researches featured in this review has identified MSG consumption as a major contributor to the development and progression of some metabolic disorders such as obesity, which is a risk factor for other metabolic syndromes like hypertension, diabetes mellitus and cancer initiation. The mechanism by which MSG induce obesity involves induction of hypothalamic lesion, hyperlipidemia, oxidative stress, leptin resistance and increased expression of peroxisome proliferator-activated receptors (PPARs) Gamma and Alpha. Similarly for induction of diabetes mellitus, MSG consumption resulted in decreased pancreatic beta cell mass, increased oxidative stress and metabolic rates, reduced glucose and insulin transport to adipose tissue and skeletal muscles, insulin insensitivity, reduced insulin receptors and induced severe hyperinsulinemia. Dietary salt, an active component of MSG is also found to be a major risk factor for high blood pressure (which may lead to hypertension). MSG is used to enhance the taste of tobacco, causing smokers to consume the product in excess and thereby increasing the risk of cancer development. Depending on the amount consumed, MSG has both positive and negative effects. Despite the controversy surrounding MSG's safety and its probable contribution to risk of development and progression of metabolic disorders, its global consumption is still very high. Therefore, this article will sensitize the public on the need for cautious use of MSG in foods and also aid regulatory agencies to further review the daily MSG consumption limit based on metabolic toxicities observed at the varied dosages reported in this review.

Novel ketogenic diet formulation improves sucrose-induced insulin resistance in canton strain Drosophila melanogaster.

This study investigates the antidiabetic effect of a ketogenic diet (KD) on sucrose-induced insulin resistance in the fruit fly model. The fruit flies were divided and grouped into four: Group A, B, C, and D, representing the control, high-sucrose diet (HSD), KD, and HSD + KD, respectively. The administration of the various treatments to the groups proceeded for 7 days. The flies were thereafter immobilized, homogenized, and the homogenates used for biochemical parameters determination. This includes glucose concentration, antioxidant status, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, total cholesterol (TC), triglycerides (TG), and protein concentration. There was a significant increase (p < .05) in weight gain, glucose concentration, TG, HMG-CoA reductase activity, TC, and lipid peroxidation status of the HSD group compared with the control and KD groups. The antioxidant enzymes measured (superoxide dismutase, catalase, and reduced glutathione) and protein concentrations were repressed significantly (p < .05) in the HD groups but significantly elevated (p < .05) in the KD, HSD + KD, and the control groups. The KD improved biochemical parameters altered during the onset of sucrose-induced insulin resistance. With further research on this, KD may emerge as the much-awaited treatment option for diabetes mellitus type 2 (T2DM) with almost reduced toxicity concerns. PRACTICAL APPLICATIONS: Novel KD are sources of dietary phytocompounds with proven antioxidant activities. The antidiabetic activity of the KD was investigated. The results showed that the KD proves to serve as a better effective antidiabetic option in Drosophila melanogaster. The observed results could provide the potential application of the KD as an alternative therapy for diabetes management.

Contraceptive and biochemical effect of juice extract of Allium cepa, Allium sativum, and their combination in Canton S fruit flies.

This study determines the contraceptive activity of Allium sativa (Garlic) and Allium cepa (Onion) juices on reproductive output and development of Drosophila melanogaster. The fruit flies were divided and grouped into 5, group A serves as the control, group B serves as the onion group, group C serves as the garlic group, group D serves as the onion + garlic group, while group E serves as the standard contraceptive group. Biochemical parameters measured were superoxide dismutase (SOD), Catalase (CAT), Glutathione-S-transferase (GST), malondialdehyde (MDA), nitric oxide (NO), total cholesterol (TC), triglyceride, mating test, and negative geotaxis. There was a significant reduction in the levels of MDA in onion, garlic, onion + garlic groups when compared with the control, in contrast, a significant increase was observed in SOD, CAT, and GST activities. Furthermore, there was a significant reduction in nitric oxide levels in garlic, onion + garlic extract with a corresponding increase in the standard contraceptive group. There was a significant reduction in the concentration of TC and HMG-CoA in garlic and standard contraceptive groups when compared with the control while triglyceride revealed a considerable increase in the garlic group when compared with the control. The mating test showed there was a considerable reduction in the onion, garlic, onion + garlic, and standard contraceptive when compared with the control. Taken together, Allium sativum proved to serve as a better contraceptive in D. melanogaster as a possible effective option for contraceptives, which is further, supported by their strong antioxidant activity. PRACTICAL APPLICATIONS: A. cepa and A. sativum are sources of dietary phytocompounds with proven antioxidant activities. The contraceptive activity of A. cepa and A. sativum juice extract was investigated. The results showed that A. cepa and A. sativum and their combination prove to serve as a better effective option for contraceptives in D. melanogaster. The observed results could provide the potential application of A. cepa and A. sativum as an alternative therapy for contraceptives.

Monosodium Glutamate (MSG)-Induced Male Reproductive Dysfunction: A Mini Review.

Reproductive dysfunction is often characterized by malfunction of the reproductive tissues, which may lead to disruption of the synergistic rhythm that should bring about a progression of sexual events and the conception of new life. This may therefore result in the sexual dysfunction and infertility that can be seen in couples having prolonged biological difficulty in reproducing their offspring after having unrestricted sexual intercourse for at least twelve months. Several factors have been implicated in the cause and progression of reproductive dysfunction, including poor nutrition, drug side effects, disease states, and toxicant ingestion. A well-known food additive that has been found to be potent at initiating reproductive anomalies in males is monosodium glutamate (MSG). This regular flavor enhancer is widely used as a taste enhancer in several diets. The different mechanisms by which it may induce reproductive dysfunctions include spermatogenic alteration resulting in a low sperm count, high sperm abnormality, reduced live sperm and decreased sperm pH, oxidative damage (increased lipid peroxidation and reduced antioxidant enzyme activities), histological alteration (blood hemorrhage, distorted germ and Sertoli cells), as well as gonadotropin imbalance (reduced testosterone, luteinizing hormone, and follicle-stimulating hormone concentrations). Therefore, this review discusses various established mechanisms through which MSG may induce reproductive dysfunction and the treatment strategies to ameliorate its toxic effects.