New insights into the brain protein metabolism of Gastrodia elata-treated rats by quantitative proteomics.

Gastrodia elata (tianma) is a traditional Chinese herbal medicine (TCM) often used for the treatment of cerebrovascular diseases. In this study, we investigated the effects of tianma on the brain protein metabolism by quantitative proteomics to gain evidence for a direct relationship between tianma treatment and brain functions. One-year-old rats were treated with tianma (~2.5 g/kg/day) for 3months and the brain tissue proteome was analyzed by using the iTRAQ (isobaric tag for relative and absolute quantification) technology. According to our results, the long-term treatment with tianma could modulate the brain protein metabolism at the proteome level by down-regulating the expressions of various proteins, such as Gnao1 and Dctn2, which are related to neuronal growth cone control and synaptic activities. In addition, tianma treatment also induced the up-regulation of molecular chaperons and proteins related to the misfolded protein response, like Anxa5, and also other proteins involved in Huntington's disease (HD) (e.g. Pacsin1 and Arf3). Concluding, tianma could eventually contribute to activities related to synaptic plasticity and neuro-restorative processes and thus might be a novel candidate agent for the treatment of neurodegenerative diseases by regulating the brain proteome.