Metformin (The Miracle Drug) Kinetics in Different Diseases such as Cancer

Metformin, a miracle drug that was introduced a century ago, could be considered for various aspects of diseases such as diabetes (type 1 and 2), cancer prevention or chemotherapy, and metabolic and neurodegenerative disease. It is well known that the frequency of cancer is higher in patients with type 2 diabetes mellitus. This review aims to provide updated information regarding clinical pharmacokinetics and the mechanism of action of Metformin in different diseases such as cancer. Diabetes type 1 is another chronic autoimmune disease detected usually in early childhood due to immune-mediated devastation of insulin-producing pancreatic beta-cells. Because of the lack of effective therapeutic approaches, its prevalence is increasing. Regarding cancer, an estimated 19.3 million new cancer cases and almost 10.0 million cancer deaths were reported in 2020 worldwide. By 50-60% bioavailability, the main route of metformin excretion is through urine. Its mechanism of action is based on 1) initiation of adenosine monophosphate-activated kinase, 2) block proinflammatory paths in perivascular adipose tissue, 3) decrease in monocyte-to-macrophage differentiation in vascular tissues, and 4) improvement in endothelial function. Metformin induces adenosine monophosphate-activated protein kinase signaling and suppresses gluconeogenesis. Antitumor properties of Metformin include a decrease in reactive oxygen species generation and inducing autophagy. In addition to glucose-lowering effects, Metformin has moderate anti-inflammatory and antioxidative effects. It could improve lipid profile and reduce overweight individuals' body mass and arterial blood pressure. In type 1 diabetes, Metformin reduces the requirement for daily insulin and improves glycemia. Its long-term use decreases cardiovascular events. In addition to inhibiting the synthesis of lipids via a reduction in oxidative stress, Metformin inhibits inflammation and increases energy metabolism. Finally, by reducing micro- and macro-vascular consequences, mortality-related diabetes and cancer decline by metformin administration. Therefore, in addition to diabetes, Metformin could reduce the proliferation of cancer cells and the possibility of malignancies in different types of cancer.