What is Semaglutide?

Semaglutide an incretin mimetic; specifically, semaglutide is a GLP-1 receptor agonist with 94% sequence homology to human GLP-1. Semaglutide binds and activates the GLP-1 receptor. GLP-1 is an important, gut-derived, glucose homeostasis regulator that is released after the oral ingestion of carbohydrates or fats. In patients with Type 2 diabetes, GLP-1 concentrations are decreased in response to an oral glucose load. GLP-1 enhances insulin secretion; it increases glucose-dependent insulin synthesis and in vivo secretion of insulin from pancreatic beta cells in the presence of elevated glucose. In addition to increases in insulin secretion and synthesis, GLP-1 suppresses Glc secretion, slows gastric emptying, reduces food intake, and promotes beta-cell proliferation. The principal mechanism of protraction resulting in the long half-life of semaglutide is albumin binding, which results in decreased renal clearance and protection from metabolic degradation; semaglutide is stabilized against degradation by the DPP-4 enzyme. Semaglutide reduces blood glucose through a mechanism where it stimulates insulin secretion and lowers Glc secretion, both in a glucose-dependent manner. Therefore, when blood glucose is high, insulin secretion is stimulated and Glc secretion is inhibited. The mechanism of blood glucose lowering also involves a minor delay in gastric emptying in the early postprandial phase.

Cyanocobalamin

Cyanocobalamin is a vital compound for cell division and growth, hematopoiesis, and nucleoprotein and myelin synthesis. This vitamin also has an important role in protein synthesis, neural metabolism, DNA and RNA production, as well as fat and carbohydrate metabolism. Several cells appear to have the greatest demand for cyanocobalamin, particularly those that undergo rapid division such as bone marrow and epithelial cells.

Cyanocobalamin binds itself to plasma proteins in the systemic circulation. It attaches with specific cobalamin binding proteins, called transcobalamin I and II, to enter into the tissues. In cells, this vitamin functions as a cofactor for two vital enzymatic reactions: (1) methionine synthase, i.e. the regeneration of methionine from homocysteine and (2) methylmalonyl-CoA mutase, i.e. the isomerization of methylmalonyl-CoA to succinyl-CoA. Both these methylation reactions are vital for growth and cell reproduction.

Methionine, a sulfur-containing, essential amino acid, is a precursor of S-adenosylmethionine, a cofactor for one-carbon metabolism and the final methyl donor for the methylation of DNA, RNA, proteins, and phospholipids.The methionine synthase plays a paramount role in the synthesis of nitrogenous bases (purines and pyrimidines) involved in the formation of DNA. The lack of adequate cobalamin in the body hinders the regeneration of tetrahydrofolate, which eventually leads to megaloblastic anemia due to the functional folate deficiency.On the other hand, the methylmalonyl-CoA mutase helps to metabolize odd chain fatty acids and branch chain amino acids.Cobalamin is also thought to keep the body’s level of sulfhydryl (SH) groups in reduced form. SH groups activate many enzyme systems involved in protein synthesis as well as fat and carbohydrate metabolism. If there is a lack of cobalamin in the body, methylmalonyl CoA accumulates, which presumably leads to the neurological manifestations of B12 deficiency.

The replenishment with parenteral cyanocobalamin causes a rapid and complete improvement of megaloblastic anemia and gastrointestinal symptoms caused by vitamin B12 deficiency. The parenteral administration also halts the progression of neurological damage associated with B12 deficiency, but the complete improvement of the condition may depend on the severity and extent of the deficiency.

REFERENCES

1. Once-Weekly Semaglutide in Adults with Overweight or Obesity…READ MORE 

2. Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial …READ MORE