Cell proliferation was assessed with the MTS assay. 
MTS assay
PC12 cells were pre-treated with 1 × 10-6 M LIG for 3 hours, cultured in 95% N2/5% CO2 in Dulbecco's modified Eagle's medium without glucose or serum for 4 hours, and then cultured normally for 16 hours, to simulate oxygen-glucose deprivation/reoxygenation (OGD/R). 
Dulbecco's modified Eagle's medium
The expression levels of apoptosis-related proteins, Bcl-2 and Bax, autophagy-related proteins, Beclin 1 and microtubule-associated protein l light chain 3B (LC3-II), and liver kinase B1 (LKB1)-5'-adenosine monophosphate-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) signaling pathway-related proteins were assessed by western blot assay. 
western blot assay
Autophagosome formation was observed by electron microscopy. 
electron microscopy