The extract of the hortensia root, of the Hydrangea genre, which grows in Tibet and Nepal and is known by the name of Chang Shan, has been used for centuries by Chinese medicine to cure malaria.
Recent studies have shown that halofungione, a compound derived from this extract, could be used to treat autoimmune diseases.
Researchers at the Harvard School of Dental Medicine have discovered the molecular secrets at the base of the efficacy of this phytotherapic extract. Thanks to their study, researchers have demonstrated that halofungione (HF) activates a biochemical path that can block the development of a powerful class of immune cells called TH17.
“HF selectively inhibits the immune response without suppressing the entire immune system”, explains Malcolm Whitman, professor of developmental biology at the Harvard School of Dental Medicine and senior author of this new study. “This compound could inspire new therapeutic approaches to a large range of autoimmune diseases.”
A preceding study had demonstrated that HF can reduce the fibrosis of tissues and the symptoms of autoimmune diseases such as scleroderma or multiple sclerosis, and even the progress of tumors.
“ That research gave rise to the hypothesis that HF could act on sundry processes with ultimate final effects”, adds Keller. Thanks to the studies of Keller and colleagues in 2009 it was demonstrated that HF protects the organism from the dangerous Th17 cells, that are involved in various autoimmune diseases, without influencing in any significant way the benefits of other immune cells.
Researchers discovered that small doses of HF could reduce the symptoms of multiple sclerosis in laboratory mice and hypothesized that the same substance could represent the first example of a new class of pharmaceuticals that could selectively inhibit autoimmune diseases without diminishing the efficiency of the immune system.
Additional analyses have clarified that HF was able to activate genes in a new biochemical pathway, an aminoacidic response denominated AAR, crucial in regulating the immune response and metabolic signals.
In this last study, researchers were able to determine the role of a single aminoacid, proline, and discovered that HF was able to inhibit a particular enzyme tRNA synthetase, denominated EPRS, responsible for the integration of proline in other proteins.
The authors of the study believe that the precision with which the role of HF was determined could pave the way for new pharmacological experiments on a wide range of diseases.