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Psychoactive Plants. Stimulants - III: Other Stimulants. Stimulants. Cocaine Ephedrine Nicotine Khat - cathonine Betel nuts - arecoline Caffeine. Khat. Khat: stimulant from Catha Edulis. Alkaloids.
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Psychoactive Plants Stimulants - III: Other Stimulants
Stimulants • Cocaine • Ephedrine • Nicotine • Khat - cathonine • Betel nuts - arecoline • Caffeine
Alkaloids • Khat contain cathinone and cathine, two phenylisopropylamine alkaloids which resemble amphetamine – • Cathinone is the main alkaloid • Produces amphetamine-like action - effects not distinguishable from amphetamine - a naturally occurring amphetamine- carbonyl group replaces methylene side chain • Drug conditioned animals cannot distinguish cathinone from amphetamines • Khat consumption induces mild euphoria and excitement, reduces appetite, increases heart rate and blood pressure • Withdrawal symptoms can follow prolonged khat use include lethargy, depression, nightmares and tremor
Cathinone • Functions by releasing catecholamines (esp. dopamine) from presynaptic storage sites • Cathinone only present in fresh leaves – it degrades within 48 hrs • After this time only cathine left • Cathine also a stimulant but has a lower potential for abuse
Amphetamine Meth-amphetamine Cathinone Cathine Ephedrine Pseudoephedrine
Traditional Use • Long history of use in Asia - recorded in 4th century in China • Traditionally chewed • Crushed betel nuts (from the betel palm) wrapped in pieces of betel leaf from the betel vine, Piper betel (in the pepper family - Piperaceae) along with lime and sometimes other flavorings • Lime (CaCO3) needed to release alkaloid
Arecoline • Many active ingredient in betel nuts is the alkaloid arecoline - although betel nuts have several other alkaloids • Arecoline has also been shown to improve learning and memory • Also traditional use for intestinal worms • Used as an antihelminthic in veternary medicine today
Mode of Action • Not completely understood • Believed to affect the central and autonomic nervous systems - increases plasma concentrations of norepinephrine and epinephrine • Evidence suggests also an inhibitor of GABA (gamma aminobutryc acid) uptake • Also Piper betel leaf contains aromatic phenolic compounds which have been found to stimulate the release of catecholamines in vitro
Effects of Betel Chewing • Stains mouth • Possible carcinogen • Betel chewing associated with throat, mouth, and esophagal cancers • Betel chewing spreading • Lime (CaCO3) needed to release arecoline • However some chew it only for flavor not stimulating effect • Also mixed with tobacco and it strongly interacts with tobacco
Coffee and Caffeine • Made from seeds of Coffea arabica in the Rubiaceae • Seeds occur in coffee berries (cherries of commerce)
Ethnobotany and history • Long history of use in Arab world • Introduced to Europe in 1615 • By 1700 coffee houses popular throughout Europe • Dutch established plantations in East Indies late in 17th century • East Indies Paris and Amsterdam Caribbean Islans South America
Caffeine • Caffeine occurs naturally in the leaves, seeds or fruit of more than 60 plant species, of which coffee, cocoa-beans, tea, cola and guarana are the best known • Like other stimulates, caffeine acts on CNS - noradrenergic receptors (norepinephrine) • Promotes alertness and endurance • Constricts blood vessels • Increase heart beat
H = theophylline H = theobromine
Drip coffee.....115 mg Tea..................40 mg Cocoa..............13 mg Coca Cola........46 mg Diet Coke.........46 mg Dr. Pepper........40 mg Mr. Pibb............41 mg Mt. Dew............54 mg Pepsi...............38 mg Surge...............51 mg Jolt Cola...........71 mg Excedrin...........65 mg Anacin..............32 mg NoDoz............100 mg Vivarin............200 mg Midol...............60 mg Caffeine Content of Common Products