Tree Bark Component Protects Neurons

A derivative of a traditional Chinese cancer treatment obtained from tree bark prevents neuronal cell death, or apoptosis, according to a new study by researchers at Emory University School of Medicine (Proc. Natl. Acad. Sci. USA, DOI: 10.1073/pnas.0706662104). Gambogic amide, a multiring compound with alkenyl side chains, could become a treatment for stroke and neurodegenerative diseases. The compound, derived from resin of the Garcinia hanburryi tree, provides protection by mimicking the behavior of nerve growth factor (NGF). When NGF docks to a receptor called TrkA, it causes the receptor to dimerize, thereby triggering a cascade of cell-signaling events that prevent apoptosis. Keqiang Ye and coworkers found gambogic amide while screening for small-molecule compounds that bind TrkA. Gambogic amide is able to do many of the things that NGF does, including initiating TrkA dimerization and tyrosine phosphorylation. In addition, gambogic amide triggers the growth of neurites, which are projections from the developing neuron's cell body.