Mesembrine ((+)-Mesembrine), a primary alkaloid distinguished by its aryloctahydroindole structure, acts as a potent 5-HT transporter inhibitor with an inhibition constant (K i) of 1.4 nM. Additionally, it demonstrates inhibitory activity against phosphodiesterase 4B (PDE4B) with an inhibitory concentration 50% (IC50) of 7.8 μM [1] [2].