Areca catechu
Chewing areca nut (seeds from the "Areca catechu" palm) with slaked lime (calcium hydroxide) – a common practice in South- and Southeast Asia – produces stimulant effects and euphoria. The major psychoactive ingredients – arecoline (a muscarinic receptor partial agonist) and arecaidine (a GABA reuptake inhibitor) – are responsible for the euphoric effect.