Forensic Pharmacognosy

1. Khat (Catha edulis)
• Ass. Prof. Jilan A. Nazeam
• Pharmacognosy department, October 6 University

2. Catha edulis (Vahl) Endl. (Celastraceae), commonly known as “khat,”
It is a tree or a large shrub that is endogenously found in Arab region specially in Yemen, Saudi
Arabia and some African countries such as Ethiopia and Kenya, and in western Asia.
Khat is an ever- green shrub, which is cultivated as a small trees.
The leaves have an aromatic odor.
The taste is astringent and slightly sweet.
The plant is seedless and hardly growing in a variety of climates and soils.
In Yemen, about 44 different types of khat exist originating from different geographic areas of the
country.
Its young buds and tender twigs, young shoots or stem tips are chewed to attain a state of
euphoria and stimulation.
Khat contains more than forty alkaloids, and different glycosides, tannins, amino acids, vitamins,
and minerals.

5. BRIEF HISTORY
Khat's exact place of origin is uncertain.
One argument is that it was first grown in Ethiopia, with the explorer Si Richard Burton
suggesting that the plant was later introduced to Yemen from Ethiopia in the 15th
century.
the first time khat use in Yeman was 1237 The first time in Somalia was 1442
The Ethiopian Postal Authority
issued on September 9, 2008 three
Khat stamps in order to herald open
discussion and debate on the use
and abuse of this plant.

6. PURPOSES CHEWERS EAT KHAT
Khat use has increased steadily over the last 50 years and has become a
problem of significant social and medical importance. Because of its social
acceptability and euphoria effects.
khat chewing often plays a dominant role in celebrations, meetings.
Khat is harvested in the early morning hours and sold at markets in late morning to preserve its freshness,
khat is wrapped in banana leaves and sold as bundles (30-40cm) of twigs,stems, leaves
As a consequence of rapid and relatively inexpensive air transportation, khat has been
reported in Great Britain, Netherlands, Canada, Australia, New Zealand, USA and even in
Hungary.
It is estimated that 20 million people worldwide chew khat leaves regularly to enjoy its
psychostimulant effects (Balint et al., 2009).
In Yemen, khat-chewing is a widespread habit; approximately 80–85% of male and 10–60% of
female adults in Northern Yemen chew khat at least once a week (Bogale et al., 2016)

8. Folk use of Khat
Why might people use Khat?
To enhance social interaction
To improve performance, stay alert and to increase work capacity
Students chew khat in an attempt to improve mental performance before exams.
Yemeni khat chewers for minor ailments such as headaches, colds, body pains,
fevers, arthritis and also depression
Effects of khat
Modes of action: enhance dopamine and norepinephrine in the brain.
Subjective experiences: euphoria, excitement, increased energy levels, increased alertness, increased ability to
concentrate, improvement in self-esteem and an increase in libido.
Unpleasant after effects: insomnia, numbness, lack of concentration, low mood

10. Khat
• In ancient times, it was used for relieving the symptoms of depression.
• The young bud of leaves contain amphetamine like substances
Cathinone - a-aminopropiophenone
Cathine -D- norpseudoephedrine
Drug of abuse
WHO classified it into substance I abuse in 1980.
It is illegal in many countries
Legal in East Africa and Yemen

11. During maturation, cathinone is metabolized to cathine
and (-)-norephedrine.
Cathinone is mainly found in the young leaves and shoots.
The leaves contain [(+)-norpseudoephedrine] and (-)-
norephedrine in a ratio of approximately 4:1

12. Cathinone is also named (–)-alpha-aminopropio-
phenone.
It is considered to be the most active ingredient of khat.
It has been isolated and synthesised and its effects have
been shown to be similar to amphetamine, but with a
lower potency.
Cathinone is estimated to be 7–10 times more potent
than cathine.
It is difficult to synthesise, therefore it is unsuitable for
marketing as a pure substance for drug misuse.
Cathine is also named (+)-norpseudoephedrine
and phenylpropanolamine.
It had previously been isolated from the plant
ephedra, which has effects similar to those of
khat.
Cathine has a milder psychostimulant action than
cathinone and the effects last for only a short
time, so the user must chew leaves almost
continuously.
It plays only a minor role in the action of khat, but
it is cathine that is responsible for the unwanted
systemic effects.
Actions of cathinone and cathine

13. Modes of action
• The constituents of khat have been shown to exert their effects
on two main neurochemical pathways: dopamine and
noradrenalin.
• It has also been postulated that, like amphetamine, cathinone
releases serotonin in the central nervous system.
• Both cathinone and amphetamine induce release of dopamine
from central nervous system dopamine terminals and thus
increase the activity of the dopaminergic pathways.
• Cathinone has a releasing effect on noradrenalin storage sites,
which supports the conclusion that cathinone facilitates
noradrenalin transmission.
• Drake (1988) also proposed that cathinone and cathine cause
inhibition of noradrenalin uptake.

14. Pharmacokinetics
Cathine excreted unchanged in the urine within about 24
hours.
There is pharmacological synergism with drinks
containing methylxanthines (e.g. tea and cola), which
therefore enhances the effects of khat.
The euphoric effect appears shortly after the chewing
begins, suggesting absorption from the oral mucosa.
The effect of cathinone is maximum after 15–30
minutes.
Metabolism of cathinone is rapid, occurring mainly
during first passage through the liver.
Cathine has a slower onset of action, with a serum half-
life in humans of about 3 hours.
Only a small fraction cathinone (about 2%) appears
unchanged in the urine.
Most cathinone is metabolized to norephedrine and is
excreted in this form.

16. Short Term Effect
The major effects of khat include those on the gastro-intestinal system and on the nervous system.
o Constipation
o Urine retention
o Acute cardiovascular effects (Cathinone has vasoconstrictor activity )
o Autonomic (peripheral) nervous system effects; (stimulating effect on adrenocortical function)
o Increased alertness, dependence, tolerance and psychiatric symptoms.
o Anorexia, general malaise, irritability, migraine.
o Increased blood pressure and tachycardia,

17. Long Term Effect/ Regular use of khat may eventually cause:
o Worsening of existing mental health problems sleep-related issues/ psychological
dependence/ depression/ schizophreniform psychosis/ hallucinations/ on
occasions, been associated with self-harm and suicide.
o Impotence/ Fertility problems, such as impotence and lower sperm count and
motility, and an increase in the number of abnormal sperm, decrease in plasma
testosterone levels)/ Embryotoxic as well as teratogenic properties (animal
study).
o Inflamed mouth/ Mouth cancer/ GIT cancers
o 62% of chronic Khat chewers developed hemorrhoid.
o Cardiovascular irregular heart beats/ heart attacks/ hypertension/ CNS- strokes.
o Tuberculosis-caught through breathing.
o Liver disease
.

18. First, a manic illness with delusions.
second, a paranoid or schizophreniform psychosis with fear and
anxiety, resembling amphetamine psychosis.
Both reactions are exceptional and
associated with chewing large amounts
of khat
Hallucinations have been reported in
chronic khat users.
These consist of continuous visual
and/or auditory dreamlike experiences
that accompany daily life and are not
related to khat sessions.
Impairment of perceptual-visual memory and decision-speed cognitive functions

19. Khat chewing degrades the strength of healthy teeth.
Consecutive chewing and failure to brush off the teeth after chewing sessions
stains the teeth, creates cavities and gradually causes the teeth to decay and fall.
Prolonged khat chewing also causes mouth cancer affecting the gums and the
tongue.
KHAT ON DENTAL HYGIENE.
The vast majority of those ingesting khat do so by chewing.
Only a small number ingest it by making a drink from dried leaves, or, even more
rarely, by smoking dried leaves.
The chewer fills his or her mouth with leaves and stalks, and which is then
swallowed with saliva. then chews slowly and intermittently to release the active
components in the juice
The plant material is chewed into a ball, which is kept for a while in the cheek,
causing a characteristic bulge

20. In a survey that reviewed cancers in the Asir region of Saudi
Arabia,
28 patients with head and neck cancer were found/ 10 of these
presented with a history of khat chewing.
All were non-smoking chewers and all of them had used khat
over a period of 25 years or longer/ Eight of these ten presented
with oral cancers.
In some cases the malignant lesion occurred at exactly the same
site where the khat bolus was held.
The authors concluded that a strong correlation between
khat chewing and oral cancer existed.
In another study performed in Yemen, 30 of 36
patients suffering from squamous cell carcinoma (17
cases in the oral cavity, one in oropharynx, 15 in
nasopharynx and 3 cases in larynx) were habitual khat
chewers from childhood.
The authors considered khat as an important
contributing factor. It was reported that 50% of khat
chewers develop oral mucosal keratosis.
It was reported that 22.4% of khat chewers had oral
keratotic white lesions at the site of khat chewing,
The prevalence of these lesions and their severity
increased with frequency and duration of khat use.
Khat & Cancer

21. Initially, a rapid screen by immunoassay detects amphetamine-
related compounds/ Then gas chromatography mass
spectrometry is performed.
This cannot detect cathinone directly, but a positive result
indicates the presence of norephedrine, a cathinone
metabolite.
The test is highly sensitive, but not highly specific, and
there are some cross- reactions with other metabolites
(Lehmann et al, 1990).
However, in the context of the clinical presentation
together with the history of khat consumption, the
urinalysis is a useful additional test.
Detection of khat
Urinalysis
The test will give a positive result for up to about 48 hours after
consumption of khat, although this is dependent on many factors, for
example chronic consumption as opposed to a single episode of use, the
quantity taken, the user’s metabolism, and dilution of urine following
consumption of fluids.

22. Detecting cathine in urine sample:
Urine sample (60 ml) was basified using drops of NH3 solution till the indicator was
deep blue.
This was extracted with 60 ml of EtOAc using separatory funnel.
The EtOAc layer was dried with anhyd Na2SO4 (300 mg), filtered and concentrated.
ESA-Test is now marketing the UTS cathinone test to police and
customs agencies in Germany, and has also identified corrective
services, hospitals and health care environments elsewhere in
Europe as potential future markets.
https://phys.org/news/2019-04-cathinone.html
A colour test developed at the University of Technology Sydney (UTS) that can
accurately detect the presence of all cathinones has been commercialised by
Germany-based company ESA-Test.

23. Analysis of the different parts of the Khat plant revealed that the tender leaves, that are usually preferred by Khat chewers contain the
psychoactive alkaloid cathinone,
whereas the older and harder leaves contain cathine, also known as d-norpseudoephedrine.
In this study we used proton nuclear magnetic resonance method not only to establish presence or absence of these compounds in
the leaves, but also to determine their levels.
Using this method no cathine was detected in the fresh twigs and young leaves.
On the other hand the harder and older leaves from the branches gave upto 1.5% cathine. When the young leaves were dried in the sun
and analysed, cathine appeared to be the major component (1.5%), clearly showing the gradual conversion of cathinone to cathine.
The same analytical method was also used to establish presence or absence of cathine in urine of Khat chewers.

24. 3.5, m
4.5, d
In the case of one Khat chewed once, cathine could be detected in the urine after day 2, 3 and 4.
Key Proton signals

25. Upon drying and storage of the cut plant material, cathinone readily converts to the reduced
product, cathine, which necessitates rapid extraction and chemical analysis for cathinone
identification.
This study demonstrates that by air drying the young khat shoots at ambient temperature,
cathinone may be detected in khat samples that have been harvested for more than 10 days.
Refrigeration for two weeks and freezing for one month of the khat samples also yield identifiable
levels of cathinone.
Cathinone and cathine are both specifically determined and differentiated by vapor phase infrared
detection, which is the method of choice in relation to mass spectrometry.
THE IDENTIFICATION OF CATHINONE IN KHAT (CATHA EDULIS)
A TIME STUDY

26. 1.Extraction
Approximately 5 to 6 g of plant material was cut into small pieces, dimensions of approximately 0.5 cm
squares. The prepared sample was mixed with 15-20 mL of methanol, then sonicated for 15 min with
intermittent shaking and stirring.
2. Concentration
The green methanolic extract was decanted into a breaker which was then condensed to near dryness (<1
mL) using a stream of air.
3.Cleanup
A very dilute solution of 0.02 N H2SO4 was used to resuspend and acidify the plant residue.
The acidified solution acquired a reddish hue.
A chloroform extraction was performed to remove the neutral organic compounds as well as the remaining
plant solids.
THE IDENTIFICATION OF CATHINONE IN KHAT (CATHA EDULIS)
A TIME STUDY
https://chemistry.mdma.ch/hiveboard/rhodium/cathinone.khat.html

27. 4. Base Extraction
A small amount of a saturated sodium bicarbonate (NaHCO3) solution was added to the aqueous solution to basify the
extract. The pH change resulted in a light green solution.
Methylene chloride was used to extract cathinone and cathine.
5. GC/MS-Analysis
Gas Chromatograph, using a 12 m by 0.32 mm HP-5 (0.52 µm loading) capillary column and a temperature program of 70°C
for 1 min, 15°C/min to 270°C, with a final temperature hold for 5 min, equipped with a Hewlett-Packard Model 5965B
Infrared Detector. Equipped with a Hewlett-Packard 5970 Mass Selective Detector (electron impact mode).
6. Thin Layer Chromatography
The plant extract was spotted directly onto a precoated 5 by 10 cm silica gel 60 (Kieselgel F254) plate.
Cathinone and cathine drug standards (cathinone hydrochloride supplied by RSA Corporation, which were dissolved in
methanol also applied.
The plate was developed in ethyl acetate:methanol:aqueous ammonia (85:10:5), then viewed under an ultraviolet lamp.
The spots were visualized using a 0.5% ninhydrin solution, and then the plate was heated using a heat gun. Cathine
appeared purple, while cathinone was a burnt orange moving spot).
The Rf values obtained for cathinone and cathine were 0.46 and 0.25, respectively

28. Case reports of effective resolution of symptoms describe treatment with
thioridazine at doses of 300–600 mg per day for 1 week,
Haloperidol (doses not specified) and, in one case, electroconvulsive
therapy.
•Use of benzodiazepine and antipsychotic medication is often necessary
Khat Detoxification

29. Fictional case report
A 22-year-old Somali male was admitted via the accident and
emergency department. He had poor appetite, insomnia and
grandiose delusions. He had been talking and laughing to
himself, and admitted to experiencing visual hallucinations in
the form of scenes of people being tortured.
He admitted that he had chewed khat intermittently for about 6
years. His use of khat had increased for several weeks prior to
admission.
On the ward he was verbally and physically aggressive.
He was prescribed zuclopenthixol acetate.
Oral regular antipsychotic medication was started with
haloperidol and subsequently depot zuclopenthixol
dihydrochloride 200 mg intramuscularly weekly.
After initially responding with a decrease in his psychotic
symptoms, he absconded from the ward.
He returned later exhibiting bizarre behaviour and
worsening of his mental state.
His khat bundles were confiscated and disposed of.
He admitted to chewing khat during the period of
absconsion.
Continued regular depot medication led to a
gradual decrease and disappearance of his
psychotic symptoms over the next 4 weeks.
He abstained from further use of khat (confirmed
by negative urinalysis) and was discharged 8 weeks
after admission.

30. Albaser, N.A., Mohamad, A.W.H. and AL-Kamarany, M.A., 2021. Khat-drug interactions: A systematic
review. Journal of Pharmacy & Pharmacognosy Research, 9(3), pp.333-343.
Wabe, N.T., 2011. Chemistry, pharmacology, and toxicology of khat (catha edulis forsk): a
review. Addiction & health, 3(3-4), p.137.
Cox, G. and Rampes, H., 2003. Adverse effects of khat: a review. Advances in psychiatric treatment, 9(6),
pp.456-463.
Adugna, Y., Dagne, E., Kebede, E. and Atilaw, Y., 2010. Determination of Levels of Cathine in Khat (Catha
edulis) leaves and its detection in urine of khat chewers: a preliminary report. Ethiopian e-Journal for
Research and Innovation Foresight (Ee-JRIF), 2(1), pp.7-22.
References