Trigonelline-induced neurite outgrowth in human neuroblastoma SK-N-SH cells

Extension of dendrites and axons in neurons may compensate and rescue damag ed neuronal networks in the dementia brain. Our aim is to isolate and ident ify constituents of coffee beans exhibiting neurite outgrowth activity. Amo ng the extracts of raw and roasted coffee beans, a methanol fraction of the ethanol extract (1 mu g/ml) of raw beans increased significantly the perce ntage of cells with neurites in human neuroblastoma SK-N-SH cells. Among su bfractions of this methanol fraction was a basic fraction (5 mu g/ml) which exhibited significant neurite outgrowth activity. Finally, trigonelline in the basic fraction was identified to be active as far neurite extension wa s concerned. Treatment with trigonelline (30 mu M) increased the percentage of cells with neurites at 3 and 6 d after treatment. In addition, the numb er of neurites reacting positively to phosphorylated neurofilament-H was in creased by treatment with 30 mu M trigonelline for 6 d, suggesting enhancem ent of axonal extension. These results show that trigonelline promotes func tional neurite outgrowth.