Purity: > 98%
Halofuginone(cas 55837-20-2) inhibits the development of T
helper 17 cells, 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 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.
In vitro: The addition of halofuginone can significantly inhibit the migratory and invasive trend induced by irradiation, and the TGF-β pathway was also inhibited. In the study, we observed the strong inhibitory activity of halofuginone on HepG2 cell growth and the cell cycle and apoptosis assays showed that halofuginone arrested the cell cycle and inhibited the induction. And we found that halofuginone inhibits tumor cell cycle possibly by up-regulating p15 and p21 of expression. Then, we found that the proportion of cleaved PARP, caspase-3, 8 and 9 in HepG2 cells increased after halofuginone treatment. And the results showed that halofuginone down-regulated Mcl-1 and c-IAP1 expression. Finally, our results showed halofuginone regulated the activities of JNK and MEK/ERK signaling pathways in hepatocellular carcinoma cells.
In vivo: In animal xenograft model, the addition of halofuginone to irradiation inhibited the growth of subcutaneously implanted xenografts, reduced hepatic and pulmonary metastases, and improved survival of the mice. C57BL/6 recipient mice received an orthotopic left lung transplant, and Lung transplant recipients received daily intraperitoneal injections of 2.5 μg halofuginone or vehicle alone. Lung grafts were assessed on Days 7, 14, and 28 post-transplant. Compared with control mice, on Day 28 post-transplant, lung grafts of mice treated with halofuginone showed a significant reduction in the percentage of obliterated airways (6.8 ± 4.7% vs 52.5 ± 13.8%, p < 0.01), as well as significantly reduced parenchymal fibrosis (5.5 ± 2.3% vs 35.9 ± 10.9%, p < 0.05).
1. J Leukoc Biol. 2017 Dec;102(6):1333-1345. doi: 10.1189/jlb.3RU0417-148RR. Epub
2017 Oct 6.
The role of halofuginone in fibrosis: more to be explored?
Luo Y(1), Xie X(1), Luo D(2), Wang Y(1), Gao Y(3).
(1)Department of Stomatology, The Second Xiangya Hospital, Central South
University, Changsha, Hunan Province, China; and.
(2)Xiangya School of Stomatology, Central South University, Changsha, Hunan
(3)Department of Stomatology, The Second Xiangya Hospital, Central South
University, Changsha, Hunan Province, China; and firstname.lastname@example.org.
Fibrosis, which can be defined as an abnormal or excessive accumulation of
extracellular matrix (ECM), particularly fibrillar collagens, is a key driver of
progressive organ dysfunction in many inflammatory and metabolic diseases,
including idiopathic pulmonary fibrosis (IPF), cirrhosis, nephropathy, and oral
submucous fibrosis (OSF). It has been estimated to contribute to ～45% of deaths
in the developed world. Therefore, agents that target specific fibrotic pathways,
with the consequence of slowing, arresting, or even reversing the progression of
tissue fibrogenesis, are urgently needed.
(halofuginone), an analog of febrifugine, which specifically targets the
pathogenesis of ECM proteins, inhibits tissue fibrosis and regeneration and even
affects the development of tumors in various tissues. Four modes of actions of
halofuginone against fibrosis have been presented: 1) Inhibition of mothers
against decapentaplegic homolog 3 (Smad3) phosphorylation downstream of the TGF-β
signaling pathway, 2) reduction of collagen amounts, 3) decreases in ECM protein,
and 4) selective prevention of Th17 cell differentiation. In this review, we will
mainly focus on the rationale for halofuginone against fibrosis.
2. Histol Histopathol. 2011 Jan;26(1):135-46. doi: 10.14670/HH-26.135.
Halofuginone and muscular dystrophy.
Pines M(1), Halevy O.
(1)Institute of Animal Sciences, Volcani Center, Bet Dagan, Israel.
Muscular dystrophies (MDs) include different inherited diseases that all result
in progressive muscle degeneration, impaired locomotion and often premature
death. The major focus of MD research has been on alleviating the primary genetic
deficit - using gene therapy and myoblast-transfer approaches to promote
expression of the deficient or mutated genes in the muscle fibers. Although
promising, these approaches have not yet entered into clinical practice and
unfortunately for MD patients, there is currently no cure. Thus, the development
of complementary and supportive therapies that slow disease progression and
improve patients/' quality of life is critically important. The main features of
MDs are sarcolemmal instability and increased myofiber vulnerability to
mechanical stress, resulting in myofiber degeneration. Fibrosis, with progressive
replacement of muscle tissue, is a prominent feature in some MDs, preventing
complete regeneration and hampering muscle functions. TGFβ is the leading
candidate for activating fibroblasts and eliciting overproduction of
extracellular matrix (ECM) proteins. Halofuginone, an inhibitor of Smad3
phosphorylation downstream of TGFβ signaling, inhibits the activation of
fibroblasts and their ability to synthesize ECM, regardless of their origin or
location. In animal models of MDs with prominent muscle fibrosis, halofuginone
treatment has resulted in both prevention of collagen production in young animals
and resolution of established fibrosis in older ones: the reduction in muscle
collagen content was associated with improved muscle histopathology and major
improvements in muscle function. Recently, these halofuginone-dependent
improvements were also observed in MD with minor fibrosis involvement, probably
due to a direct effect of halofuginone on muscle cells, resulting in myotube
fusion that is dependent on Akt and MAPK pathway activation. In summary,
halofuginone improves muscle histopathology and muscle functions in various MDs,
via inhibition of muscle fibrosis on the one hand, and increased myotube fusion
on the other.
3. Biol Blood Marrow Transplant. 2003 Jul;9(7):417-25.
Halofuginone to treat fibrosis in chronic graft-versus-host disease and
Pines M(1), Snyder D, Yarkoni S, Nagler A.
(1)Institute of Animal Science, ARO, the Volcani Center, Bet Dagan, 50250,
Chronic graft-versus-host disease (cGvHD) and systemic sclerosis (scleroderma
[SSc]) share clinical characteristics, including skin and internal organ
fibrosis. Fibrosis, regardless of the cause, is characterized by extracellular
matrix deposition, of which collagen type I is the major constituent. The
progressive accumulation of connective tissue results in destruction of normal
tissue architecture and internal organ failure. In both SSc and cGvHD, the
severity of skin and internal organ fibrosis correlates with the clinical course
of the disease. Thus, there is an unmet need for well-tolerated antifibrotic
therapy. Halofuginone is an inhibitor of collagen type I synthesis in cells
derived from various tissues and species and in animal models of fibrosis in
which excess collagen is the hallmark of the disease. Halofuginone decreased
collagen synthesis in the tight skin mouse (Tsk) and murine cGvHD, the 2
experimental systems that show many features resembling those of human GvHD.
Inhibition of collagen synthesis by halofuginone is achieved by inhibiting
transforming growth factor beta-dependent Smad3 phosphorylation. Dermal
application of halofuginone caused a decrease in collagen content at the treated
site of a cGvHD patient, and reduction in skin scores was observed in a pilot
study with SSc patients. The results of the human studies provide basis for using
halofuginone treatment for dermal fibrosis. As a first step toward future
treatment of internal organ involvement, an oral administration study was
performed in which halofuginone was well tolerated and plasma levels surpassed
the predicted therapeutic exposure.