**2.1 Discovery of hepcidin**

The hepcidin molecule ("hep" hepatic origin, "cidin" antimicrobial activity) was described in the year 2000; it is an antimicrobial peptide that acts in parts in innate immunity and iron metabolism [8]. It is a peptide hormone the liver produces, and it works as a regulator of iron [9]. Hepcidin is a regulator of iron homeostasis. Its production is increased by iron excess and inflammation and decreased by hypoxia and anemia. Hepcidin inhibits the flow of iron into the plasma from duodenal enterocytes that absorb dietary iron, macrophages that recycle iron from senescent erythrocytes, and iron-storing hepatocytes. Iron-loading anemias are diseases in which hepcidin is controlled by ineffective erythropoiesis and concurrent iron overload impacts [10]. Hepcidin was isolated from the human urine and blood, especially from plasma after filtration [8]. Hepcidin was produced by macrophages, adipocytes, neutrophils, lymphocytes, renal cells, and β-cells [11].

Hepcidin is produced by macrophages, adipocytes, neutrophils, lymphocytes, renal cells, and β-cells [11]. In the studies of experiment on mice used for the determination of hepcidin regulation, the expression, function, and structure showed that severe iron overload is occurring due to the gene responsible for hepcidin production, and the gene has the role of iron regulation. Hepcidin has several functions such as inflammation, hypoxia, hypoxia, and iron stores [12]. Hepcidin reacts with ferroportin, and the ferroportin is found in spleen, duodenum, and placenta. If the ferroportin decreases, it results in reduced iron intake and macrophage release of iron and using of the iron, which is stored in the liver [13].
