What science says about khat (Catha edulis Forsk)? Overview of chemistry, toxicology and pharmacology

Abstract

Catha edulis (khat) is a plant grown commonly in the horn of Africa. The leaves of khat are chewed by the people for its stimulant action. Khat is an evergreen shrub, which is cultivated as a bush or small tree. The leaves have an aromatic odour. The taste is astringent and slightly sweet. The plant is seedless and hardy, growing in a variety of climates and soils. Khat contains more than 40 alkaloids, glycosides, tannins, amino acids, vitamins and minerals. Many different compounds are found in khat including alkaloids, terpenoids, flavonoids, sterols, glycosides, tannins, amino acids, vitamins and minerals. The phenylalkylamines and the cathedulins are the major alkaloids which are structurally related to amphetamine. The major effects of khat include those on the gastro-intestinal system and on the nervous system. Constipation, urine retention and acute cardiovascular effects may be regarded as autonomic (peripheral) nervous system effects; increased alertness, dependence, tolerance and psychiatric symptoms as effects on the central nervous system. The main toxic effects include increased blood pressure, tachycardia, insomnia, anorexia, constipation, general malaise, irritability, migraine and impaired sexual potency in men. The purpose of this review is to summarize the chemistry, pharmacology, toxicology of khat (Catha edulis Forsk).