Effects of Angelica Oil and the Isolated Butylphthalides on Glutamate-induced Neurotoxicity in PC12 Cells

ngelica sinensis contains a large amount of essential oil (angelica oil), which is rich in phthalide derivatives with a lot of bioactivities. In vitro activity screening of angelica oil from the roots of A. sinensis found that it had concentration-dependent effect on glutamate-induced injury in PC12 cells. Further phytochemical investigation on this angelica oil led to the isolation of nine butylphthalides (1 –9) including two new compounds (1 and 2). Their structures were elucidated by extensive spectroscopic analyses. It is noteworthy that most of the isolated butylphthalides also displayed protective activity at low concentrations and cytotoxicity at high concentrations. These results imply that angelica oil and its main chemical components have protective effect for injured neurons only in appropriate concentration range.