Monoamine transporters playing major roles in regulating normal and abnormal synaptic activity are associated with various neuropsychological disorders. In spite of the discovery of a series of structurally different monoamine transporter antagonists for the therapy approach, no practical pharmaceutical can act as a transporter activator. Here, we isolated luteolin and apigenin from the fruit of Perilla frutescens (L.) Britt by using an activity-guided extraction technique, and proved that the two compounds possess actions of enhancing monoamine uptake either upon monoamine-transporter transgenic Chinese hamster ovary (CHO) cells or upon wild dopaminergic cell lines, with higher specificity for dopamine (DA) uptake than for norepinephrine (NE)- and serotonin (5HT)-uptake, as well as with more potency and greater efficacy for luteolin than for apigenin. Further, in the transgenic cells, the principal NE/DA uptake activation by luteolin was significantly prevented by respective transporter inhibitor, and the transmitter-uptake-enhancing action was independent of its ligands, which is in support of the compounds as monoamine transporter activators. Furthermore, luteolin evoked a marked disinhibition of cocaine-targeted effect in CHO cells overexpressing dopamine transporter. Thus, luteolin and apigenin function as monoamine transporter activators, which would improve several hypermonoaminergic neuropsychological disorders, especially cocaine dependence, through up-regulating monoamine transporter activity.

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