Stimulatory effect of eurycomanone from <i>Eurycoma longifolia</i> Jack roots on dopamine secretion in human neuroblastoma SH-SY5Y cell line.

Eurycomanone has been identified as the major bioactive compound contributing to <i>Eurycoma longifolia</i> (EL) aphrodisiac activity, however, its mechanism of action remains obscured. Presently, eurycomanone was isolated from EL root extract and its molecular structure was identified. The human neuroblastoma SH-SY5Y cell line was differentiated into human dopaminergic neuron-like cells. Exogenous dopamine levels from the differentiated SH-SY5Y cells were quantified following the treatment of 5, 10, 15 μM of eurycomanone and 10 μM clorgyline as positive control. Dopamine secretion was significantly increased in a dose-dependent manner, compared to the vehicle control (<i>p</i> < .01) in differentiated SH-SY5Y cells. Dopamine concentration stimulated by 15 μM eurycomanone was significantly higher than clorgyline (<i>p</i> < .05), an inhibitor of monoamine oxidase A that suppresses dopamine catabolism. In conclusion, eurycomanone stimulated dopamine release of human SH-SY5Y neuron-like cells, which could be one of the mechanisms that underpin the aphrodisiac properties of the plant.