Halofuginone, sold under the brand name Halocur, is a

coccidiostat A coccidiostat is an antiprotozoal agent that acts upon Coccidia parasites. Examples include: * Amprolium * Arprinocid * Artemether * Clazuril * Clopidol * Decoquinate * Diclazuril * Dinitolmide * Ethopabate * Halofuginone * Lasalocid * Monens ...

used in veterinary medicine. It is a synthetic

halogen The halogens () are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts). In the modern IUPAC nomenclature, this group is ...

ated derivative of

febrifugine Febrifugine is a quinazolinone alkaloid first isolated from the Chinese herb ''Dichroa febrifuga'', but also found in the garden plant ''Hydrangea''. Laboratory synthesis of febrifugine determined that the originally reported stereochemistry was i ...

, a natural

quinazolinone Quinazolinone is a heterocyclic chemical compound, a quinazoline with a carbonyl group in the C4N2 ring. Two isomers are possible: 2-quinazolinone and 4-quinazolinone, with the 4-isomer being the more common. These compounds are of interest in med ...

alkaloid which can be found in the Chinese herb ''

Dichroa febrifuga ''Dichroa febrifuga'' is a flowering plant in the family Hydrangeaceae. National names * Chinese: ) * Indonesian language: ''gigil'', alternatively ''tataruman'' * Sundanese: ''ramram'' * Papua: ''Hom dong'' (ฮอมดง): * Thai: ''Yai k ...

'' (Chang Shan). Collgard Biopharmaceuticals is developing halofuginone for the treatment of

scleroderma Scleroderma is a group of autoimmune diseases that may result in changes to the skin, blood vessels, muscles, and internal organs. The disease can be either localized to the skin or involve other organs, as well. Symptoms may include areas of ...

and it has received

orphan drug An orphan drug is a pharmaceutical agent developed to treat medical conditions which, because they are so rare, would not be profitable to produce without government assistance. The conditions are referred to as orphan diseases. The assignment of ...

designation from the

U.S. Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food s ...

. Halofuginone inhibits the development of

T helper 17 cell T helper 17 cells (Th17) are a subset of pro-inflammatory T helper cells defined by their production of interleukin 17 (IL-17). They are related to T regulatory cells and the signals that cause Th17s to differentiate actually inhibit Treg different ...

s, immune cells that play an important role in autoimmune disease, but it does not affect other kinds of T cells which are involved in normal immune function. Halofuginone therefore has potential for the treatment of autoimmune disorders. * Halofuginone is also an inhibitor of

collagen type I Type I collagen is the most abundant collagen of the human body. It forms large, eosinophilic fibers known as collagen fibers. It is present in scar tissue, the end product when tissue heals by repair, as well as tendons, ligaments, the endomys ...

gene expression and as a consequence it may inhibit tumor cell growth. Halofuginone exerts its effects by acting as a high affinity inhibitor of the enzyme glutamyl-prolyl tRNA synthetase. Inhibition of prolyl tRNA charging leads to the accumulation of uncharged prolyl tRNAs, which serve as a signal to initiate the amino acid starvation response, which in turn exerts anti-inflammatory and anti-fibrotic effects.

References

{{reflist Antiparasitic agents Organobromides Chloroarenes Piperidines Secondary alcohols Quinazolinones Lactams