PDR for Herbal Medicines

448/KHAT PDR FOR HERBAL MEDICINES

rine (cathine), (-)-norephedrine, merucathinone, pseudome-

' rucathinone, (-)-formyl norephedrine

Sesquiterpene polyester alkaloids: cathaedulines Kl to K15

• Catechin tannins

Volatile oil

EFFECTS

The alkaloid-containing drug (chief active ingredient cathi-

none) is centrally stimulating and indirectly sympathomimet-

ic (amphetamine-like effect). In addition, the leaf

preparations have ulcer-protective and insecticidal effects,

and the drug's high tannin content makes it constipating.

INDICATIONS AND USAGE

Unproven Uses: Khat has been used for centuries in Islamic

culture to improve communicative abilities, performance and

to suppress feelings of hunger. The leaves can be chewed or

administered as an infusion (Yemen) or paste (Ethiopia/

Somalia). Khat leaves are said to have an aphrodisiac effect

and are used for depression, headache, gonorrhea, gastric

complaints, coughs, asthma and fever.

The medicinal use of Khat preparations is obsolete today.

PRECAUTIONS AND ADVERSE REACTIONS

The fresh shoot tips may lead to central excitation, suppres-

sion of appetite, widening of the pupils, increased motor

activity, hypertonia and hyperthermia through the sympatho-

mimetic effect of cathinone (the other constituents account

for only approximately 10% of the effect) and its ability to

bypass the blood-brain barrier. Moderate dosages (100 to

300 g of the fresh leaves) lead to a state of general well

being, mental alertness and exaggerated self-regard. Physical

ability is temporarily enhanced and the need for sleep is

reduced. Depression and anxiety states can follow once the

effect wears off. Diabetics could experience hyperglycemia.

The tannin content of the drug leads to constipation and

digestive disorders. Acute poisonings have not been

recorded.

Chronic use can lead to such long-term ill effects as

emaciation (through appetite suppression), increased suscep-

tibility to infection, nervousness, insomnia and disturbances

of the circadian rhythm. In addition, Khat preparations have

been associated with ulcers in the digestive tract and liver

and kidney damage. When the drug is used over periods of

years, it can lead to personality disorders.

DOSAGE

Mode of Administration: Available as whole herb and

powdered drug

Storage: Can be kept for several months deep-frozen

LITERATURE

Al-Ahdal MN, McGarry TJ, Hannan MA Cytotoxicity of Khat

(Catha edulis) extract on cultured mammalian cells: effects on

macromolecule biosynthesis. Mutat Res, 204:317-22, 1988 Feb

Al-Meshal I A, Tariq M, Parmar NS, Ageel AM Anti-

inflammatory activity of the flavonoid fraction of khat (Catha

edulis Forsk). Agents Actions, 19:379-80, 1986 Jan

Balint GS, Balint E Kath (Catha edulis) - a plant containing an

amphetamine-like substance Orv Hetil, 136:1063-6, 1995 May

14

Dhadphale M, Mengech A, Chege SW Miraa (catha edulis) as

a cause of psychosis. East Afr Med J, 19:130-5, 1981 Feb

Geisshiisler S, Brenneisen R The content of psychoactive

phenylpropyl and phenylpentenyl khatamines in Catha edulis

Forsk. of different origin. J Ethnopharmacol. 19:269-77, 1987

May

Geisshiisler S, Brenneisen R The presumed neurotoxic effects of

Catha edulis - an exotic plant now available in the United

Kingdom. Br J Ophthalmol, 19:779-81. 1986 Oct

Hansel R, Keller K, Rimpler H, Schneider G (Ed) Hagers

Handbuch der Pharmazeutischen Praxis. 5. Aufl.. Bde 4-6

(Drogen), Springer Verlag Berlin, Heidelberg, New York, 1992-

1994

Kalix P Catha edulis, a plant that has amphetamine effects.

Pharm World Sci, 18:69-73, 1996 Apr

Kalix P Hyperthermic response to (-)-cathinone, an alkaloid of

Catha edulis (khat). J Pharm Pharmacol, 11:662-3, 1980 Sep

Nabil Z, Saleh M, Mekkawy H, Allah GA Effects of an extract

of khat (Catha edulis) on the toad heart. J Ethnopharmacol,

18:245-56, 1986 Dec

Nencini P, Amiconi G, Befani O, Abdullahi MA, Anania MC

Possible involvement of amine oxidase inhibition in the

sympathetic activation induced by khat (Catha edulis) chewing

in humans. J Ethnopharmacol, 11:79-86, 1984 Jun

Tariq M, Al-Meshal I, Al-Saleh A Toxicity studies on Catha

edulis. Dc Toxicol Environ Sci, 11:337-40, 1983

Knautia arvensis

See Field Scabious

Knotweed

Polygonum aviculare

DESCRIPTION

Medicinal Parts: The medicinal parts are the herb, some-

times with the root, collected during the flowering season

and dried, as well as the fresh aerial parts collected during

the flowering season.

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