Modulation of cholinergic contractions of airway smooth muscle by cathinone: potential beneficial effects in airway diseases.

Infusion of khat leaves is an African traditional remedy used to treat airway diseases. The beneficial effects of khat are thought to be due to the activity of its main active component, cathinone. Cathinone inhibited electric field stimulation-induced acetylcholine release and the contractions of smooth muscle, which could be responsible for the beneficial effects seen in airway disease. The mechanism of action of this natural product appears to be via the activation of both pre-junctional alpha(2) adrenergic and 5-hydroxytryptamine 7 receptors. The present novel study describes how cathinone modulates airway tone, and may go some way to explaining the traditional use of khat as a remedy for the alleviation of respiratory disease symptoms. In conclusion, cathinone may have beneficial effects in airway diseases with heightened cholinergic tone. There is some rationale for follow-up of these observations, given previous experience of other traditional remedies being developed for therapeutic use.