Faculty of Science Bulletin, 24 (2012) 103-109 © 2012 Sana’a UniversityISSN 1684-100X

103

INFLUENCE OF KHAT ON THE LEVEL OFCLINICAL BIOMARKERS IN BLOOD OFKHAT CHEWERS

Khalid Mohammed Naji1*, Maher Ali Al-Maqtari1, Qais Yusuf Abdullah2

1Department of Chemistry, Faculty of Science, Sana'a University2Department of Biology, Faculty of Science, Sana’a University

*Correspondence author; email: khalid.m.naji@gmail.com

(Received 19August 2012)

Abstract

Leaves and buds of Catha edulis plant (Khat) that contain Cathinone were consumed dailyin Yemen as a social habit for the mild stimulant effect of cathinine. Chewing Khat hassocio-cultural tradition in which consumers spend part of their time ranging between 4-8hours per day, in chewing khat. This study aimed to investigate the changes in biochemicalmarkers and antioxidants associated with chewing khat. The results showed a majoralteration in the estimated biochemical and the antioxidant markers. It reveal that chewingkhat has a toxic effect, on blood constituents, and induce the oxidative stress. The alterationin the clinical biomarkers could be an indicator for liver and kidney toxicity. These proposedthat; the daily chewing khat for long time leads to alter in the biochemical composition ofblood and enhancing oxidative state, these may contribute in the failure of the body organs,further detailed studies are recommended.

Keywords: Khat chewing, Glutathione, lipid peroxidation, antioxidants, Catha edulis.

INTRODUCTION

The khat plant (Catha edulis Forsk) is a tree, frequently cultivated in certain areas ofEast Africa and the Arabian Peninsula. Worldwide about ten million People chew khatdaily. Several authors have argued that regular consumption of khat seriously affects thesocial and economic life of the chewing khat [1]. Usually, a person consumes 100–200g of the leaves per day; young leaves are preferred because these have the higheststimulant activity. The leaves of the khat plant contain alkaloids structurally related toamphetamine. They are chewing daily by a high proportion of the adult population inYemen for the pleasant mild stimulant effect. Khat has been used first as a drinkprepared from dry leaves, but its effect is weak compared with coffee [2]. It was foundlater that drying the leaves results in loss of some active constituents [3] therefore thehabit of chewing the green leaves was adopted. For many hundreds of years the customof chewing khat leaves has been practiced for the resulting central stimulant effects [4].In Yemen, the habit is widespread with a deep-rooted socio-cultural tradition, forty four

INFLUENCE OF KHAT ON THE LEVEL OF CLINICAL BIOMARKERS….. K M. Naji, et al.

104

different types of khat in different regions, each has different cathinon constituent [5].The pleasurable central stimulant properties of khat are commonly believed to improvework capacity, and are used on journeys and by students preparing for examinations tocounteract fatigue. In recent years, because of improved air transport, the consumptionof fresh khat leaves has expanded considerably, even to communities in Europe.Early clinical observation suggested that khat had amphetamine-like properties [6].Such as coffee, tea, khat has a stimulating dependence affect and no withdrawalsymptoms. The active ingredient is alkaloid (cathinone)-pharmacological effect isincrease energy, euphoria, concentration motivation and decreased appetite, increasesmetabolism decreases appetite CNS stimulant acts on adrenergic receptors. It may causeelevation of arterial blood pressure and pulse rate with subsequent increasedcardiovascular risk, particularly in hypertensive patients [7].It seems to be a common cause of stomatitis and other problems in the mouth as well asgastro-esophageal reflux. It may be associated with increased risk of carcinoma of themouth and esophagitis, may interfere with absorption of some orally administeredantibiotics 0[8]. It may have a toxic effect on the liver, possibly as a result of pesticidesused in khat cultivation [9]. It is associated with an increased risk of low birth weightinfants in khat-chewing pregnant women. Subsequent chemical analysis confirmed thatthe fresh leaves contain a number of compounds, including phenylalkylaminecompounds (alkaloids) such as nor pseudoephedrine(cathine) and alphaaminopropiophenone (cathinone), the latter being structurally related andpharmacologically similar to amphetamine [7] [8].khat leaves also contain considerable amounts of tannins (7–14% in dried material),vitamins, minerals and flavonoids [5] [8]0. As a plant containing amphetamine-likesubstances, the main effects of khat are on the cardiovascular system, GastrointestinalSystem, and nervous system, much of the concern raised about the harmful effects ofkhat are related to excessive use.Recent review [1] came to a similar conclusion: state that is khat dependence is low tomild, craving and tolerance to khat effects exists but there is no definite withdrawalsyndrome. There is no strong, and even contradictory, evidence for a causal relationbetween khat use and psychiatric morbidity”. As oral administration of khat in rats wasassociated with decreased serum free radicals metabolizing enzymes such as superoxidedismutase (SOD) and catalase (CAT) [8]. The widespread chewing of khat in Yemen isa habit in which consumers spend part of their time chewing khat. There is an extensiveliterature on khat. Only a few studies, however, have investigated the effect of khatchewing on blood constituents.In this investigation, we measure the biochemical changes associated with chewing andstudy the associated health factors.

Materials and Methods

SubjectsThis study involved random selection of 50 individual's educated male daily chewingkhat since long time at least 4 years consuming at least 200 gram of fresh leaves. Theage of the subject between 20-40 years old and 20 individuals never chew khat used ascontrol from the community of the Sana’a University. All of individual's were adultmale healthy and do not suffer from any hereditary diseases or chronic symptoms.

Faculty of Science Bulletin, 24 (2012) 103-109

105

Sample preparationBlood Sample of 2 ml has been collected in a pair of tubes, from each subject afterovernight fasting one tube is heparinized tube, the second tube did not containsanticoagulant agent. The tests were carried out within 30 minutes using the facilities inbiochemistry and the medical lab in military hospital Sana’a Yemen.

Clinical Biochemical AssaysCholesterol, glucose, albumin, uric acid, Urea, Creatinine, and Total protein in theserum and plasma were estimated using chemistry analyzer (Automatic Analyzer,Japan).

Lipid peroxidation and GSH determinationEstimation of Lipid Peroxidation in serum collected was conducted by measuring theconcentration of TBARS using the method described by Okhawa and others [10]. TheGSH content of serum collected was measured at 412 nm according to Buetler andother [11].

Catalase activity AssayCatalase activity of samples (chewing and non-chewing kath) was assayed by themethod of [12]. The samples were mixed in 50 mM phosphate buffer (pH: 7.0),Decomposition of H2O2 was determined by the decrease in absorbance at 240 nm. Oneunit of this activity was defined as the amount of enzyme decomposing 1mol/ H2O2

/per min (U/mg of protein). The amount of protein was determined by the method ofLowry. [13].

Statistical analysisThe results of three separated replicates were subjected to statistical analysis, whichperformed using one way analysis of variance (ANOVA) by using Graph Pad prismsoftware Version 6. The results were expressed as means ± SD.

RESULTS

The results of clinical parameters in blood showed a significant increment in the levelsof urea, bilirubin and creatinine, in khat chewer group compared with control (non-chewer) group (Table 1.). However glucose, albumin and total protein weresignificantly decreased

Table 1: Levels of blood biochemical assay of chewing and no-chewing khat.

Parameters Control Treatment

Glucose mg/dl 95 ± 1.56 65.96 ± 4.32 **

Total cholesterol mg/dl 185 ± 0.22 188. 01 ± 8.28 *

Albumin (g/dl) 3. 63 ± 0.219 3.021 ± 0.11 *

Uric acid mg/dl 6.76 ± 0.23 9.543 ± 0.965 **

Creatinine mg/dl o.83 ± 0.32 2.3 ± 0.675 *

Urea (mg/dl) 32.3 ± 1.92 43.643 ± 6.93 **

Total protein (g/dl) 6.05 ± 0.206 4.563 ± 0.81 *

All values are means ± SD and statistically significant at * P<0.05 , ** P < 0.01

A CAT C

TBARS 80 50 GSH 3

E

00- 2 40

2 46 2

I 40-

30 E E t% 20

20- 10

0 control

Treatment

control treatment control .

INFLUENCE OF KHAT ON THE LEVEL OF CLINICAL BIOMARKERS….. K M. Naji, et al.

106

In khat chewer group. Furthermore, significant increase in lipid peroxidationbiomarkers thiobarbituric acid reactive substances (TBARS) was indicated in the khatchewers group (Fig. 1). In contrast, khat chewer group showed significant reduction inthe level of reduced Glutathione (GSH) and Catalase activity (Fig 1).

DISCUSSIONIn this study, there was a significant decrease in serum total protein and albumin of khatchewing in both groups as compared to control khat non-chewing, which may indicatesdecrease in liver function, decreased protein synthesis, either primary as in liver celldamage or secondary to diminished protein intake and reduced absorption of aminoacids [14]. Some constituents of the Catha edulis might be been converted to pro-oxidant metabolites or the extract during chewing might have induced decreasedsynthesis or activity of the antioxidant system in khat chewing groups suggesting thatthe extract generated free radicals or directly inhibited synthesis of antioxidantenzymes. Oxidative stress is often defined as an imbalance of pro-oxidants andantioxidants, which can be quantified in humans as the redox state of plasmaGSH/GSSG. The increase in serum urea, creatinine, and uric acid has been linked tokidney disease in much research [14].

Figure 1. Levels of oxidative biomarkers including: (A) specific activity of serumCatalase; (B) reduced Glutathine antioxidant; and (C) Thiobarbeturic acid reactivesubstances (TBARS).

Both groups of khat chewing had significantly increased serum creatinine, impairedrenal function due to a reduced ability to excrete these products could originate fromchanges in the threshold of tubular re-absorption, renal blood flow and glomerularfiltration rate [14] [15]. These results are in broad agreement with previous studies thatreported the khat induced cytotoxicity in livers and kidneys after oral administration ofkhat to animals [16] [17].

In the khat chewer group the activities of CAT were decreased, this suggest that thefresh extract generated by chewing fresh leaves may release free radicals or directlyinhibited synthesis of antioxidant enzymes, or may reflect the damage of protein byreactive oxygen species produced.Glutathione is a strong antioxidant peptide contains thiol group, therefore Glutathioneplay an important role as a protective agent against oxidative organ damage has to be

Faculty of Science Bulletin, 24 (2012) 103-109

107

subjecting to extensive studies [18] [19]. The decrease in the control group renalactivity was significant which might suggest the decrease in the renal activity could beaccompanied with many co-founder factors. From the results presented in this paper inthe biochemical constituent in most of the khat chewers. The decrease in glucose andlipid per oxidation could be related to oxidative stress in hepatic and renal tissues,which indicated by the significant increase in lipid peroxidation marker (TBARS) and asignificant decrease in levels of the antioxidant components.

CONCLUSION

A harmful activity of chewing khat on health has been reported in several studies. Studythe effect of daily dose intake of this plant in Yemen as the first country in which themost of the people are chewing khat in continuous manner. The study reveal thatchewing khat have a toxic effect where it alter the clinical biomarkers of bloodconstituents and inducing the oxidative stress. These could be an indicator for liver andthe kidney toxicity. Further studies regarding the effect of khat on each organ functionand studying the co-founder that might affect the toxicity of the plant is recommended.

Acknowledgements

We would like to thank all the subjects and the other participants for allowing us tocollect blood many times during the period of this study.

REFERENCES

[1]. Pennings EJM, Opperhuizen A, van Amsterdam JGC (2008). Risk assessment of

khat use in the Netherlands: A review based on adverse health effects, prevalence,

criminal involvement and public order. Regulatory toxicology and pharmacology.

52:199–207.

[2]. El-Mahi T (1962). A preliminary study on khat together with institutional history

of coffee as a beverage in relation to khat. Alexandria, WHO Regional Office for

Eastern Mediterranean. 2-3(EM/RC 11/10 MS).

[3]. Revir R (1983). Catha Edulis Forsk, Geographical dispersal, botanical, ecological,

and agronomical aspects with special reference to Yemen Arab Republic.

Gottingen Publications. 30-110.

[4]. Luqman W, Danowski T (1976). The use of khat (Catha edulis) in Yemen: social

and Medical Observations. Annals of internal medicine. 85: 246-9.

[5]. Halbach H (1980). Medical aspects of the chewing of khat leaves. Bulletin of the

World Health Organization. 47:21-9.

[6]. Szendrei K (1980). The chemistry of khat. Bulletin on narcotics. 32(3):5-35.

[7]. Al-Motarreb A, Al-Habori M, Broadley KJ (2010). Khat chewing, cardiovascular

diseases and other internal medical problems: the current situation and directions

for future research. J Ethnopharmacol. 132(3): 540–548.

doi:10.1016/j.jep.2010.07.001.

INFLUENCE OF KHAT ON THE LEVEL OF CLINICAL BIOMARKERS….. K M. Naji, et al.

108

[8]. Valko M, Leibfritz D, Moncol J, Cronin M, Mazur T, Telser M (2007). Freeradicals and antioxidants in normal physiological functions and human disease. IntJ Biochem Cell Biol. 39:44–84.

[9]. Masoud AM, Al-Shehari BA, Al-Hattar LN, Altaezzi MA, Al-khadher WA,

Zindal YN (2012). Alterations in Antioxidant Defense System in the Plasma of

Female Khat Chewers of Thamar City, Yemen. Jordan Journal of Biological

Sciences. 5(2):129 – 133.

[10]. Ohkawa H, Ohishi N, Yagi K (1979). Assay for lipid peroxides. In: Animal

tissue by thiobarbituric acid reaction. Anal Biochem. 95:351–8.

[11]. Buetler E, Duron O, Kelly BM (1963) Improved method for determination of

blood glutathione. J Lab Clin Med. 61:882–8.

[12]. Aebi H, (1984) Catalase in vitro. Methods of Enzymology. 105: 121–126.

[13]. Lowry OH, Rosenbrough NJ, Far AL, Randel RJ (1951). Protein measurement

with Folin-phenol reagent. J Biol Chem. 193: 265-275.

[14]. Carvalho F (2003). The Toxicological Potential of Khat. J Ethnopharmacol. 87

(1): 1-2.

[15]. Al-Motarreb A, Baker K, Broadley KJ (2002). Khat: Pharmacological and

Medical Aspects and Its Social Use in Yemen. Phytother Res. 16: 403-13.

[16]. Dimba E, Gjertsen BT, Francis G, Johannessen AC, Vintermyr OK (2003). Catha

edulis (khat) induces cell death by apoptosis in leukemia cell lines. Ann N Y A S.

1010: 384 - 398.

[17]. Gunaid AA, Nasher TM, El-Guneid, et al. (1997). Acute Sporadic Hepatitis in theRepublic of Yemen. J Med Virol. 51: 64-6.

[18]. Nasher AA, Qirbi AA, Ghafoor MA, Catterall A, Thompson A, Ramsay JW,Murray-Lyon IM (1995). Khat chewing and bladder neck dysfunction. Arandomized control trial of -adrenergic blockade. British Journal of Urology 75:597–598.

[19]. Baynes JW (1995). Reactive Oxygen in the Aetiology and Complications of

Diabetes. In: Ioannides C, Flatt PR, eds. Drug, Diet and Disease: Mechanistic

Approach to Diabetes. Hertfordshire: Ellis Horwood Limited, (vol. 2): 203-31

Faculty of Science Bulletin, 24 (2012) 103-109

109

القاتدم ماضغي في والسریریةالحیویةالمؤشراتمستوى على القاتتأثیر

2وسف عبدهللاقیس یو1المقطريماھر عليو1اجيخالد محمد ن

الیمن –جامعة صنعاء –كلیة العلوم –قسم الكیمیاء 1.الیمن – جامعة صنعاء – كلیة العلوم–علوم الحیاةقسم 2

ملخص

كعادةالیمن في یومیاالكاثینونمادة على تحتويالتي)كاثا ایدلیوس(القاتنباتوبراعمأوراقستھلكت

حیث یقضيوالثقافياالجتماعيتقلیدالمنالقات مضغویعتبر .خفیفالمنبھالالكاثینونلتأثیرجتماعیةا

ھذهھدفتوقد .القات مضغ في یومیاساعات8-4بینتتراوحلفترة وقتھممنجزءاالمستھلكون

حیث .القات ضغموارتباطھا باألكسدةومضاداتحیویةالكیمالمؤشرات في التغیرمعرفةإلىالدراسة

لھالقات مضغ أنتكشفولألكسدة المقدرةالمضادةوالحیویةالمؤشرات في كبیرتغییر نتائجالأظھرت

السریریة،الحیویةالمؤشرات في لتغییرإن ا.التأكسدياإلجھادكما تسببالدم،مكونات على سامة آثار

إلىیؤديطویلةلفترةالیومیةالقات غمضیقترح بأن ذلك.والكلىالكبدلتسمممؤشرایكونأنیمكن

ولذا الجسم،أجھزةفشل في سھمیقدوھذاة،یأكسدتالویعزز الحالةحیویةالكیموالدممكونات في تغییر

.تفصیالأكثردراساتبإجراء نصحن