Central nervous system cathinones

The major effects of khat on the central nervous system can be attributed to cathinone (S-(-)-alpha-aminopro-priophenone) in fresh khat leaves and cathine (norpseu-doephedrine) in dried khat leaves and stems. Cathinone, a phenylalkylamine, is the major active component and is structurally similar to amfetamine. It degrades to norp-seudoephedrine and norephedrine within days of leaf picking. Cathinone increases dopamine release and reduces dopamine re-uptake (1). 

Khat is purchased as bundles of dried and fresh leaves and buds. For transport purposes, it is usually wrapped in plastic bags or banana skins to preserve its moisture content - loss of activity is observed after 48 h if the plant material dries out. However, the drug can also be obtained as dried crushed leaves or in powdered form. These materials are either chewed or used to prepare an infusion which is drunk like tea. The major part of the pharmacological action is due to cathinone, which acts as a central nervous system (CNS) stimulant, promoting excitation, reducing the need to sleep and enhancing communication. 

The pharmacologic properties of (—)-cathinone are similar to those of (+)-amphetamine, and both alkaloids possess central nervous system (CNS) excitatory activity and indirect neuronal excitement activity. That is to say, both alkaloids are incorporated at the sympathetic nerve ending and expel noradrenaline (NAdr = norepinephrine, NE) from the amine storage granule, and the expelled NE works as the effector. These activities seem to be the effects caused by chewing khat [11]. Cathine also possesses CNS excitatory activity, but the activity of cathine is less than that of cathinone [12]. 

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