Metabolic Effects of Metformin
Metformin Is Used For, This article explores the metabolic effects of metformin on the immune system, the mechanism of action of metformin on endothelial function, and cancer. It also discusses the drug’s potential for use in the treatment of Alzheimer’s disease, a genetic disorder, and type 2 diabetes. It also outlines the potential side effects of metformin, as well as how to decide if metformin is the right choice for you.
Metabolic effects of metformin on the immune system
To address the question of whether metformin has any immunomodulating effect, researchers performed an IPA study. Gene sets associated with various auto-immune diseases and inflammatory diseases were significantly enriched for metformin-downregulated genes. These gene sets also included inflammatory and parasitic diseases. In addition, the metformin-downregulated genes were enriched for canonical pathways in atherosclerosis and cancer.
These results highlight the need to investigate metformin’s role in the immune system. Metformin reduces the Il1b transcript level in macrophage-like cells, both in the acute and chronic LPS responses. However, the drug does not inhibit the LPS response globally. Metformin increases IL10 and TN transcript levels, suggesting that metformin is able to regulate these genes and their levels.
Among its immune-modulatory activities, metformin inhibits the activity of mTORC1 and AMPK, which are responsible for the production of cytokines and nitric oxide. Metformin also inhibits the production of neutrophil extracellular traps and bone remodeling. These effects may help explain metformin’s anti-aging properties and the potential use of this drug in human trials.
The IPA identified 29 gene sets with enriched metformin-downregulated genes, ranging in size from six to sixty. These gene sets were associated with four broader functional categories and 11 disease categories. IPA revealed that metformin has a significant effect on immune-cell trafficking, morphology, and cellular movement. The results were summarized at the gene set level to generate a ‘directed global significance score’, which was calculated by calculating the square root of the mean signed squared t-statistics of all genes in a gene set.
Although metformin has a long history of clinical use, its mechanism of action is still not completely understood. It is thought to exert protective effects independent of its glucose-lowering effects. Metformin’s molecular mechanisms may involve the activation of the AMPK/mTOR signaling pathway when energy levels are low and nutrient intake is increased. The metabolic cross-talk between metformin and SGLT2is may be similar, leading to a potential overlapping of their effects.
Although these findings are preliminary, they show that chronic pretreatment of mice with metformin increases the number of tumour-infiltrating lymphocytes. Furthermore, metformin has been associated with enhanced antitumour activity in mice with a functional immune system. Furthermore, biguanide phenformin enhances immune function by inhibiting granulocytic myeloid-derived suppressor cells.
Although metformin’s immunomodulatory effects are well understood in experimental models, the evidence for clinical benefits of this medication is limited. While metformin appears to increase TILs, the effect of chronic exposure to metformin on immune function in type 2 diabetes patients is unclear. Further studies are necessary to determine whether metformin has any clinical significance. If metformin does indeed have any effect on the immune system, the results of this study would be helpful for patients who have diabetes.
Mechanism of action of metformin on endothelial function
This article reviews the mechanisms by which metformin inhibits the permeability transition pore and improves endothelial function in vitro. This drug also inhibits mTOR, PI3K-Akt and phospho-ERK1/2 pathways and down-regulates the transcription of TRX-interacting protein (TIP) and carbohydrate response element binding protein (CREBP). Furthermore, metformin inhibits endothelial cell apoptosis through an increase in the expression of VEGF receptors and fatty acid binding protein 4.
In healthy individuals, endothelium serves diverse biological functions. It regulates vascular tone, mediates mechanotransduction through mechanical sensors and maintains endothelial integrity. Furthermore, it regulates both procoagulant and anticoagulant regulatory mechanisms, regulating the activity of plasminogen and tissue-PA. Endothelial cells also promote endothelial remodeling (Eno MT) and reduce inhibition of plasmin.
ERK inhibitors inhibit caspase activation, preventing endothelial cell elimination in clusters. Moreover, endothelial progenitor cells in circulation participate in the repair process of endothelium. As endothelial cells are capable of repairing damage and maintaining endothelial integrity, these drugs may contribute to the development of vascular disease.
In addition to increasing eNOS activity, metformin also protects against the endothelial dysfunction caused by high-fat diet. Metformin also restores AMPK/PPARd signaling and inhibits oxidative stress, reducing superoxide generation. Metformin reverses these endothelial dysfunctions in diabetic obese mice. These effects are similar to those in humans.
Metformin is an insulin-sensitizing biguanide. It regulates glucose levels in the blood and improves endothelial function. Several vascular diseases result from endothelial dysfunction. Endothelial dysfunction leads to decreased arterial plasticity, increased vascular resistance, reduced tissue perfusion, and atherosclerosis. Metformin improves endothelial function and decreases ET-1 levels.
In obese mice, acetylcholine-induced relaxation of the aorta was impaired. Metformin improved this in obese mice, while metformin inhibited the effects of tunicamycin on aortic endothelial cells in KO mice. GSK0660, a PPARd inhibitor, blocked the effect of metformin on these mice.
Metformin ameliorates damaged islet endothelial cells by suppressing FXR/VEGF-A/eNOS signaling. Inhibiting FXR/VEGF-A and eNOS expression by siRNA also prevented metformin from ameliorating HG-induced injury. The reduced ROS levels in metformin-treated MS-1 cells were reversible when the proteins were inhibited by siRNA-FXR.
Mechanism of action of metformin on cancer
Metformin acts on several pathways that regulate metabolism. The first pathway is activated by insulin and is thought to affect AMPK, while the second one is associated with mTOR signaling. Both pathways are important for regulating growth factor and nutrient signals, and metformin inhibits mTOR activity by targeting TSC2, a tumor suppressor. AMPK and LKB1 also modulate mTOR, a crucial mediator of the PI3K/Akt signaling pathway in human cancer cells.
There are several theories underlying the mechanism of action of metformin. Some researchers believe metformin may affect the gut microbiome, a cellular factor related to inflammation and insulin resistance. However, this remains to be established. This research is ongoing, but it is likely that metformin has a number of mechanisms at play. Here are some of them:
Mechanisms of metformin’s antitumoral action are not fully understood, but there is evidence that the drug may inhibit the proliferation of tumor cells. This antitumoral activity has been demonstrated in liver, lung, and ovarian cancer cells. This review outlines the mechanism and suggests that metformin could be used as a cancer treatment in the future. However, further research is needed to understand the mechanism and improve metformin’s efficacy.
Metabolic profiling of tumors by serum metabolomics has revealed that patients who respond to metformin have greater levels of lipid metabolism than those who don’t respond to it. This suggests that metformin may influence tumor cell proliferation via an indirect mechanism. In a study involving four-weeks before surgery, patients were prescribed metformin dosages that were appropriate for their own tolerance. The tumors in the metformin-treated group decreased significantly in Ki-67 levels compared with their untreated historical control groups.
Metformin has been shown to inhibit tumor growth and promote differentiation of cells in non-obese patients. In addition, metformin has shown antitumor activity in various tumor types, including prostate cancer and colon cancer. In a study conducted by Jayalath et al., metformin also decreased serum prostate-specific antigen levels, delayed the progression of prostate cancer. Additionally, metformin has been shown to increase radiotherapy sensitivity and slow the metastasis of malignant gliomas.
Metformin inhibits mitochondrial function and activates AMP-activated protein kinase, which is a key regulator of cellular metabolism. It causes an increase in the AMP:ATP ratio and increases AMPK activity by disrupting complex I of mitochondrial respiratory chain. It also activates liver kinase B1, a tumor suppressor gene mutated in Peutz-Jeghers disease.
Using cells that exclusively rely on glycolysis for ATP, researchers were able to measure metformin’s effects on glycolytic output. This provided a simplified model for measuring the effect of metformin in cells that depend solely on glycolysis. Metformin and syrosingopine-metformin synergy suggests that inhibition of enolase may also result in synthetic lethality.