Khat chewing, cardiovascular diseases and other internal medical problems: the current situation and directions for future research

Is Khat (Catha edulis) chewing a risk factor for periodontal diseases? A systematic review

Background

Khat (Catha edulis) chewing is a highly prevalent habit in the Arabian Peninsula and East Africa, and has recently spread to Western countries. The association between khat chewing and oral mucosal lesions is well documented in the literature. However, there is no concrete evidence on the association between khat chewing and periodontal disease. The purpose of this systematic review was to analyze the influence of khat chewing on periodontal health.

Material and Methods

A literature search of PubMed, Scopus and Web of Sciences databases was carried out to identify relevant articles published from 1990 to May 2017. The inclusion criteria were all clinical studies that assessed the relationship between khat chewing and periodontal disease.

Results

The search yielded 122 articles, of which 10 were included in this systematic review. Most of the studies exhibited a positive correlation between khat chewing and periodontal disease.

Conclusions

Altogether, the analysis of the current evidence reveals that khat chewing is destructive to the periodontium and enhances the risk of periodontal disease progression. However, due to variability of studies, more longitudinal case-controlled studies are highly warranted to establish a causal relation between khat chewing and periodontal disease.

Key words:Khat chewing, periodontal health, periodontal disease, risk factor.

Khat (Catha edulis) and its oral health effects: An updated review

Khat or qat (Catha edulis) is a plant that grows in East Africa and southern Arabia. The leaves and twigs of this small tree are chewed by several millions of people worldwide for their stimulating amphetamine-like effects. The reported prevalence of khat chewing in Europe and the USA is on the rise, especially with global migration. Long-term khat chewing has several detrimental general and oral health effects. The aim of the present study was to review the current literature regarding khat use and its association with oral and dental diseases, with particular emphasis on its link with oral keratotic white lesions and oral cancer. We searched the literature to identify all relevant articles. Studies showed that khat is associated with several oral and dental conditions, including keratotic white lesions, mucosal pigmentation, periodontal disease, tooth loss, plasma cell stomatitis, and xerostomia. There are limited data on the incidence of dental caries among khat chewers. The evidence that khat chewing is a risk factor for oral cancer is still weak, and is mainly based on anecdotal case reports and uncontrolled studies.

Trend and causes of adult mortality in Kersa health and demographic surveillance system (Kersa HDSS), eastern Ethiopia: verbal autopsy method

Background

The health problems of adults have been neglected in many developing countries, yet many studies in these countries show high rates of premature mortality in adults. Measuring adult mortality and its cause through verbal autopsy (VA) methods is becoming an important process for mortality estimates and is a good indicator of the overall mortality rates in resource-limited settings. The objective of this analysis is to describe the levels, distribution, and trends of adult mortality over time (2008-2013) and causes of adult deaths using VA in Kersa Health and Demographic Surveillance System (Kersa HDSS).

Methods

Kersa HDSS is a demographic and health surveillance and research center established in 2007 in the eastern part of Ethiopia. This is a community-based longitudinal study where VA methods were used to assign probable cause of death. Two or three physicians independently assigned cause of death based on the completed VA forms in accordance with the World Health Organization’s International Classification of Diseases. In this analysis, the VA data considered were of all deaths of adults age 15 years and above, over a period of six years (2008–2013). The mortality fractions were determined and the causes of death analyzed. Analysis was done using STATA and graphs were designed using Microsoft Excel.

Results

A total of 1535 adult deaths occurred in the surveillance site during the study period and VA was completed for all these deaths. In general, the adult mortality rate over the six-year period was 8.5 per 1000 adult population, higher for males (9.6) and rural residents (8.6) than females (7.5) and urban residents (8.2). There is a general decrease in the mortality rates over the study period from 9.4 in 2008–2009 to 8.1 in 2012–2013. Out of the total deaths, about one-third (32.4%) occurred due to infectious and parasitic causes, and the second leading cause of death was diseases of circulatory system (11.4%), followed by gastrointestinal disorders (9.2%). Tuberculosis (TB) showed an increasing trend over the years and has been the leading cause of death in 2012 and 2013 for all adult age categories (15–49, 50–64, and 65 years and over). Chronic liver disease (CLD) was indicated as leading cause of death among adults in the age group 15–49 years.

Conclusion

The increasing TB-related mortality in the study years as well as the relative high mortality due to CLD among adults of age 15–49 years should be further investigated and triangulated with health service data to understand the root cause of death.

Pharmacological and Toxicological Effects of Catha edulis F. (Khat)

Khat chewing is deeply rooted in the culture and tradition of communities in khat belt countries, and its consumption is spread to other countries through the suitcase trade. The aim of this article is to review current knowledge on the chemistry, social, pharmacology and toxicology of khat and its use. Khat produces effect invariably in every system, which is harmful or beneficial in some instances. Harmful effects are observed in heavy users, although firm evidence is lacking. Chewing khat acutely elicits states of euphoria, which is followed by low mood. Khat contains alkaloids with psychostimulant properties, but the effect cannot be totally explained by these alkaloids. It is also not clear whether the effect produced in some organs like liver could be attributed to khat or pesticides sprayed during farming. Although the evidence indicates that khat has adverse effects in most organs, our understanding of the complex interaction between use and effect is incomplete, and causal relationships have not yet been described. Moreover, khat has positioned itself well in the social, economic and political arena. Thus, a multidisciplinary research is required to understand the different dimensions and come up with ways that maximize the benefit while minimizing the risk. Copyright © 2017 John Wiley & Sons, Ltd.

Oral hygiene and periodontal health status among khat chewers. A case-control study

Background

Habitual khat chewing is a widespread male habit in Southern Arabia and East Africa. The aim of this study was to assess the effect of Khat chewing on oral hygiene and periodontal health status among Yemeni male khat chewers.

Material and Methods

This case- control study included 310 khat chewers, aged 20-65 years, and 72 age- and gender- matched non-chewers as controls. Periodontal examination included recording of dental plaque index (PI), gingival index (GI), probing pocket depth (PPD), attachment level (AL) and gingival recession (GR). Demographic data, oral hygiene practices, and duration, frequency and site of khat chewing were obtained using questionnaires. SPSS was used for data analysis. ANOVA and t- tests were used to compare groups.

Results

Khat chewers had significantly higher mean PI, AL, GR scores than non-chewers (P < 0.05). However, no significant differences in the GI and PPD mean scores were observed between both groups (p > 0.05). Interestingly, the results showed that the chewing side had less PI, GI and PPD than non-chewing side. However, gingival recession was significantly higher in the chewing side. The duration of chewing showed a significant effect on PI, PPD, AL, and GR but had no effect on the gingival condition. Likewise, the frequency of chewing showed a significant effect on PPD, AL, and GR, but had no effect on other indices (PI and GI).

Conclusions

The results of this study indicate that khat chewing have a detrimental effect on the periodontium.

Key words:Khat chewing, periodontal health, oral hygiene.

New psychoactive substances of natural origin: A brief review

Plant-based drugs of abuse are as old as recorded human history. Although traditional addictive substances, such as opium, cannabis and coca, have been controlled by the United Nations anti-drug conventions, many, if not most, natural plants with addictive or abuse liability remain elusive. Therefore, the United Nations Office on Drugs and Crime (UNODC) has warned the emerging threat from new psychoactive substances (NPS), which are mostly derived or modified from the constituents of natural origin. For example, synthetic cannabinoids and synthetic cathinones are derived from the cannabis and khat plant, respectively. In this review, we briefly discussed the chemistry, pharmacology and toxicology of five common NPS of natural origin, i.e., khat, kratom, salvia, magic mushroom and mandrake. Through the review, we hope that professionals and general public alike can pay more attention to the potential problems caused by natural NPS, and suitable control measures will be taken.

Prevalence and factors associated with use of khat: a survey of patients entering HIV treatment programs in Ethiopia

Background

Khat, a plant native to East Africa, has psychoactive constituents similar to amphetamine. Chronic khat use can lead to psychological dependence with multiple physical and mental health harms, complicating clinical management of people living with HIV. In two Ethiopian cities where khat is common, we evaluated prevalence and correlates of khat use among patients new to HIV care.

Methods

During 2013–2014, we surveyed 322 patients recently enrolled in HIV clinics in Dire Dawa and Harar about khat use, demographics, smoking and alcohol use, clinical illness, food insecurity, and social support. We analyzed factors associated with khat use in the past year, as well as heaviest use of khat (based on greatest number of hours used in a typical month).

Results

242 (75%) respondents reported lifetime khat use; 209 (65%) reported khat use during the previous year. 54% of khat users started before age 19 years. Although 84% believed that using khat every day is dangerous for health if you have HIV, khat was used in the previous year a median of 5 h/days and 30 days/month; 21% said they felt a need to cut down or control their khat use but had difficulty doing so. Those using khat were more likely to report smoking (46%) and alcohol use (49%) compared to non-khat users (1 and 31% respectively). Those reporting heaviest khat use (≥180 h/typical month) were more likely to rate their health status as poor, have an underweight BMI (≤18.5 kg/m²), report more symptoms of chronic illness, and agree with more statements indicating a negative physical quality of life. In multivariate analysis, heavy users were more likely to be male, Muslim, and non-married.

Conclusions

Khat use was common among HIV patients entering care, and associated with symptoms of poorer physical health. Over half started khat use when they were young. Although most believed khat is harmful for HIV patients, a number of respondents reported some difficulty controlling their drug use. In settings where khat is legal and widely utilized, developing interventions for responsible use represent an important health priority as part of comprehensive care for people living with HIV.

Efficacy and Safety of Cathine (Nor-Pseudoephedrine) in the Treatment of Obesity: A Randomized Dose-Finding Study

OBJECTIVE

To investigate the efficacy and safety of increasing doses of cathine (nor-pseudoephedrine) as a weight-lowering agent in patients with obesity.

METHODS

Overweight and obese patients (n = 241, mean BMI 34.6 ± 3.4 kg/m²) were randomly allocated to one of three doses of cathine (16 mg, 32 mg, 53.3 mg) or placebo in addition to a multimodal lifestyle intervention program in a multicenter, double-blind, controlled, dose-finding study for 24 weeks. Primary outcome was weight loss.

RESULTS

Treatment with the 3 doses of cathine resulted in a significantly greater weight loss compared to placebo over 24 weeks: 6.5 ± 4.2 kg for 16 mg cathine, 6.2 ± 4.7 kg for 32 mg cathine, and 9.1 ± 5.4 kg for 53.3 mg cathine versus 2.4 ± 4.4 kg for placebo (each p < 0.01, ANCOVA). The percentage of patients losing > 5% / >10% of initial body weight was significantly greater for all doses of cathine than for placebo (each p < 0.01, chi-square test). Heart rate increased dose-dependently (by 1.2 bpm under 16 mg, 5.8 bpm under 32 mg, and 6.2 bpm under 53.3 mg cathine), but no suspected unexpected serious adverse reactions were noted. The overall dropout rate was 24.9%, with the highest rate in the placebo group (42.3%).

CONCLUSION

Cathine appears to be an effective weight-lowering agent for adjunct treatment of obesity, but additional clinical studies on its efficacy and safety are required.

Catha edulis Extract Induces H9c2 Cell Apoptosis by Increasing Reactive Oxygen Species Generation and Activation of Mitochondrial Proteins

Background:

Catha edulis (Khat) is an evergreen shrub or small tree, traditionally used by various peoples of the Arabian Peninsula and Africa as an integral component of the socioeconomic traditions. It is believed that the psychostimulant nature and toxic nature of khat is primarily due to the presence of cathinone and cathine respectively. Studies have shown that khat chewing is closely associated with cardiac complications, especially myocardial infarction. Hence in this study, we exposed cathine-rich khat extract in a cardiomyoblast H9c2 (2-1) cell line to check the cell death mechanism.

Materials and Methods:

Extraction of Catha edulis leaves was done and the presence of cathine was confirmed with LC-MS-MS. The anti-proliferative activity was assayed using MTT and apoptosis detection by acridine orange/propidium iodide assay. The expression of Bcl-2 and Bax protein and caspase-3/7 expression were analyzed. The level of reactive oxygen species generation was also evaluated.

Results:

The khat extract showed an IC50 value of 86.5 μg/ml at 48 hours treatment. We have observed significant early apoptosis events by intervened acridine orange within the fragmented DNA with bright green fluorescence upon treatment. The Bcl-2 expression in the treatment with IC50 concentration of khat extract for 24, 48 and 72 hours of incubation significantly decreased with increase in bax level. The increased activation of caspase-3/7 was significantly observed upon treatment together with significant increase of ROS was detected at 24 and 48 hours treatment.

Conclusion:

Collectively, our results provide insight into the mechanisms by which Catha edulis leaves mediate cell death in cardiomyocytes.

SUMMARY

Catha edulis (Khat) is an evergreen psychotropic shrub or small tree

Extraction of khat leaves was done and the presence of cathine was confirmed with liquid chromatography-mass spectrometry-mass spectrometry

The khat extract showed an IC⁵⁰ value of 86.5 μg/ml at 48 h treatment in H9c2 (2–1) cell line

The observed cell death was associated with increased expression of Bcl2 and caspase-3

Significant increase of reactive oxygen species was also detected in the cell with treatment.

Abbreviations used: CNS: central nervous system; AMI: acute myocardial infarction; TLC: thin layer chromatography; ESI: electrospray ionization; FBS: fetal bovine serum; DMSO: dimethylsulfoxide; AO; acridine orange; PI; propidium iodide; HRP: horseradish peroxidase; HBSS: hank's balanced salt solution; DCFH-DA: 2’,7’-dichlorofluorescin diacetate; NAC, 10 mM: NAC: N-acetyl cysteine; ROS: reactive oxygen species.

Conflicting reports on the role of the glycemic effect of Catha edulis (Khat): A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Traditionally, the leaves of Catha edulis Forsskal (Khat) are consumed by the people of Yemen primarily for its recreational effect, and secondarily, for achieving certain tasks. Additionally, Yemeni diabetics chew such leaves in the belief that this can control their elevated blood glucose level.

AIMS

This review focuses on outlining the findings of studies that have been conducted to display the glycemic effect of Catha edulis, while trying to balance it with findings of the association of its chewing with the development of type 2 diabetes mellitus (DM).

MATERIALS AND METHODS

The search strategy adopted was based on a comprehensive research in Medline, PubMed, Web of Science, JSTOR, Scopus and Cochrane for articles, proceeding abstracts and theses to identify complete reports written in the English language about the glycemic effect of Catha edulis in humans and animals from 1976 to 2016. In addition, bibliographies were also reviewed to find additional reports not otherwise published. Thirty seven records were identified of which, 25 eligible studies were included in the meta-analysis using blood glucose as an outcome measurement. Studies were divided into four subgroups according to the experimental model, namely; non-diabetic animals, diabetic animals, non-diabetic humans and diabetic humans. The pooled mean difference (MD) of blood glucose between experimental and control were calculated using random effects model of the weighted mean difference of blood glucose with 95% confidence interval (CI). Heterogeneity between studies was tested using I(2) statistic and a value of P<0.05 was considered to indicate statistical significance.

RESULTS

The scientific reports in the literature prevailed that the glycemic effect of Catha edulis were greatly conflicting with the majority of studies indicating that Catha edulis has a mild hypoglycemic effect. However, the meta-analysis indicted that the overall result showed an insignificant reduction in blood glucose (MD=-9.70, 95% CI: -22.17 to 2.76, P=0.13, with high heterogeneity between subgroups, I(2)=88.2%, P<0.0001). In addition, pooled mean difference of blood glucose of non-diabetic animals, diabetic animals and non-diabetic humans showed an insignificant reduction in blood glucose (MD=-18.55, 95% CI: -39.55 to 2.50, P<0.08, MD=-52.13%, 95% CI: -108.24 to 3.99, P=0.07 and MD=-2.71%, 95% CI: -19.19 to -13.77, P=0.75) respectively. Conversely, a significant elevation in the pooled mean difference of blood glucose in diabetic humans was indicated (MD=67.18, 95% CI: 36.93-97.43, P<0.0001). The conflict shown in the glycemic effect of Catha edulis is thought to be cultivar-related, while demographic and epidemiological reports suggested that chewing Catha edulis might be a predisposing factor contributing to the development of type 2 DM.

CONCLUSION

It was difficult to draw a meaningful conclusion from both the systematic and the meta-analysis with respect to the glycemic effect of Catha edulis since the meta-analysis results were insignificant with high heterogeneity among subgroups and are greatly conflicting. The variation is most likely due to unadjusted experimental factors or is related to Catha edulis itself, such as the differences in the phytochemical composition. Therefore, it is highly recommended that further studies of the glycemic effect of the cultivar of Catha edulis being studied should come with the identification and quantification of phytochemical content so that a meaningful assessment can be made with regard to its hypoglycemic properties. In addition, well-controlled clinical studies should be conducted to confirm whether or not chewing Catha edulis is associated with the development of type 2 DM, since this would be a source of concern seeing that the plant is widely consumed in certain populations.

Subchronic oral administration of crude khat extract (Catha edulis forsk) induces schizophernic-like symptoms in mice

Background

Chewing fresh leaves of the khat plant (Catha edulis forsk) is a deep rooted and widespread habit in East Africa and the Middle East. Although a body of knowledge exists about the adverse effects of khat on health, data are sparse with regard to the consequences of long-term khat chewing in resulting schizophrenic like symptoms.

Methods

A crude extract of khat at different doses (100 mg/kg (K (khat)100), 200 mg/kg (K200) and 400 mg/kg (K400)) were administered for experimental group of mice whereas standard (ketamine (KT) 10 mg/kg- positive controls (KT10)) and vehicle (2 % v/v Tween-80 in distilled water – negative control groups (CON)) were administered for control groups of mice daily for two months to evaluate subchronic oral administration of crude khat extract to induce schizophrenic-like symptoms in mice. Mice were subjected to a battery of behavioural tests and parameters like locomotor activity, total time spent in social interaction and level of cognition among different groups of mice were measured and analyzed.

Results

Khat at all doses significantly increased (p < 0.001) the mean locomotor activity score of mice compared to CON. However, the mean locomotor activity score of mice treated with khat was significantly lower (p < 0.001) compared to the mean locomotor activity score of KT10 mice (p < 0.001).

The mean total time score (in seconds) spent in social interaction, mean total time score (in seconds) spent in sniffing and following the partner was significantly higher (p < 0.001) in CON groups of mice compared to khat and ketamine treated groups. Moreover, in spatial memory task, the mean latency score (in seconds) to find the platform of khat and ketamine treated mice was significantly higher (p < 0.05) when compared to CON.

Conclusions

Subchronic oral administration of khat showed an enhanced locomotor activity, reduced social interaction and impaired cognitive function, which demonstrated that long-term use of khat is associated with schizophernic-like symptoms.

The physiological and perceptual effects of plant extracts (Catha Edulis Forsk) during sustained exercise

Background

Khat (Catha Edulis Forsk) is a natural psychoactive substance that contains addictive substances such as Cathine and Cathinone which have similar structure and action to amphetamine. This substance has been suggested that it can decrease perceived exertion and thus improve performance. There is no study in the literature regarding the effect of khat on exercise performance. Therefore, the aim of this study is to find out whether khat leaves can decrease perceived exertion in humans.

Methods

This study is an experimental crossover study conducted at the Substance Abuse Research Centre in Jazan University, Saudi Arabia. Twenty one healthy volunteers were randomly assigned into two experiment trials. Each volunteer visited the lab three times. The first visit was a familiarization session about the nature of the study and the equipment. On the second visit, 45 min before the experiment volunteers ingested either 33 ml of fruit juice (placebo) or the juice mixed with 45 g of ground khat leaves. Then the participants were instructed to perform a 10 Km cycling on an ergometer and recorded the following physiological variables repeatedly on every 5 min of cycling: heart rate, time to complete 10 km cycling, tympanic temperature, and perceived exertion rate. On the third visit a crossover trial was conducted one week after the second visit; then the same cycling test was performed and the same variables were recorded as the second visit. The experimental protocol was reviewed and approved by Research Ethical Committee of the Medical Research Centre, Jazan University.

Results

According to study results, khat dramatically decreased time taken to complete a 10 km cycling time trail (p < 0.05), and significantly increased heart rate (p < 0.05) and tympanic temperature (p < 0.01). However, khat did not reduce participant's perceived exertion during the physical trial. The Bonferrini simultaneous confidence intervals using multivariate Hotelling’s T² was performed to test the significance of the mean vectors for the placebo group and the Khat group and found that groups are statistically significant.

Conclusions

Khat showed a clear enhancing effect on physical performance. The most parsimonious explanation for this effect is that, like the related amphetamines, cathine/cathinone act as stimulants to increase the capacity to perform exercise. Thus, khat produces the same effects which lead to the banning of amphetamine. These findings conform & endorse the recent prohibition of cathinone by the World Anti-Doping Agency (WADA, 2014).

Khat-induced liver injuries: A report of two cases

Khat is consumed for recreational purposes in many countries, including Yemen, where >50% of adults chew khat leaves regularly. A wide spectrum of khat-induced liver injuries has been reported in the literature. Herein, we report two patients with khat-induced liver injury. Both patients clinically presented with acute hepatitis, one of whom showed radiological evidence of hepatic outflow obstruction. Based on the histological tests, both patients had acute hepatitis, which indicated drug-induced liver injury (DILI) on a background of chronic hepatitis and portal fibrosis; of the two, one presented with symptoms of immune-mediated liver injury.

Memory deficits associated with khat (Catha edulis) use in rodents

Khat products and chewing practices are common in East Africa, Middle East for centuries with concomitant socio-economic and public health repercussions. We assessed memory deficits associated with khat use in rodents. Young male CBA mice, 5-7 weeks old (n = 20), weighing 25-35 g were used. Mice were treated with either 40, 120 or 360 mg/kg body weight (bw) methanolic khat extract, or 0.5 ml saline for 10 days. Spatial acquisition, reversal and reference memory were assessed using modified Morris Water maze (MMWM). Mice treated with 40 mg/kg khat extract had longer (t4 = 4.12 p = 0.015) and t4 = 2.28 p = 0.065) escape latency on first and second day during reversal relative to the baseline. Under 120 mg/kg khat dose, the escape latency was shorter (t4 = -2.49 p = 0.05) vs (t3 = -2.5 p = 0.05) on third and fourth day. Further, treatment with 360 mg/kg khat extract resulted in significantly longer time (49.13, 33.5, 40.2 and 35.75) vs. (23.5 s), compared to baseline. Mice treated with khat or control preferred the target quadrant post acquisition while differential pattern was seen during reversal phase. Mice treated with 40 or 120 mg/kg khat showed significant preference for target quadrant. Substantial time (19.9) was spent in the old target compared to the new (16.9 s) by animals treated with highest dose however, the difference was not significant. There is a biological plausibility that chronic khat use may induce memory deficits and impair cognitive flexibility. The differential patterns of memory deficits may reflect the differences in dose effect as well as time dependent impairment.

Determination of Synthetic Cathinones in Urine Using Gas Chromatography-Mass Spectrometry Techniques

In recent years, the abuse of synthetic cathinones has increased considerably. This study proposes a method, based on gas chromatography/mass spectrometry (GC-MS), to analyze and quantify six synthetic cathinones in urine samples: mephedrone (4-MMC), methylone (bk-MDMA), butylone, ethylone, pentylone and methylenedioxypyrovalerone (MDPV). In our procedure, the urine samples undergo solid-phase extraction (SPE) and derivatization prior to injection into the GC-MS device. Separation is performed using a HP-5MS capillary column. The use of selective ion monitoring (SIM mode) makes it is good sensitivity in this method, and the entire analysis process is within 18 min. In addition, the proposed method maintains linearity in the calibration curve from 50 to 2,000 ng/mL (r(2) > 0.995). The limit of detection of this method is 5 ng/mL, with the exception of MDPV (20 ng/mL); the limit of quantification is 20 ng/mL, with the exception of MDPV (50 ng/mL). In testing, the extraction performance of SPE was between 82.34 and 104.46%. Precision and accuracy results were satisfactory <15%. The proposed method was applied to six real urine samples, one of which was found to contain 4-MMC and bk-MDMA. Our results demonstrate the efficacy of the proposed method in the identification of synthetic cathinones in urine, with regard to the limits of detection and quantification. This method is highly repeatable and accurate.

The Epidemiology of Tobacco Use among Khat Users: A Systematic Review

Khat, an "amphetamine-like green leaf," may influence the consumption of tobacco. This study reviews the epidemiology of tobacco use among khat users. Electronic database searches using appropriate keywords/terms were conducted to identify observational studies of khat use. Assessment of quality and risk of bias of all included studies was conducted, and the results were synthesised descriptively. Nine eligible cross-sectional studies were identified. All assessed self-reported tobacco among khat users and were carried out in Africa and the Middle East. Eight reported cigarettes and one reported waterpipes as the mode of use. Methods of tobacco use prevalence assessment varied. Prevalence of "current" tobacco use among students and university teachers ranged from 29 to 37%; "lifetime" tobacco use in university teachers was 58% and "undefined" tobacco use in nonspecific adults and students ranged from 17 to 78%. Daily tobacco use among adults was reported as 17% whilst simultaneous tobacco and khat use was reported as between 14 and 30% in students. In conclusion, tobacco prevalence among khat users appears significant. Findings should be interpreted cautiously due to self-reported tobacco use, diversity in questions assessing tobacco use, and type of tobacco consumption. Future research should address the methodological shortcomings identified in this review before appropriate policy interventions can be developed.

Before the ban--an exploratory study of a local khat market in East London, U.K

BACKGROUND

Khat is a green leaf with amphetamine-like effects. It is primarily used among people in Africa, the Middle East and in the diaspora communities from these countries. Prior to the prohibition of khat in the UK on 24 June 2014, there was almost no information available on key aspects of the local khat market.

METHODS

A cross-sectional study was conducted in 2012 using snowball sampling, Privileged Access Interviewing and area mapping in order to identify khat sale establishments. Data was collected via face-to-face interviews using mixed methods for data collection. This included information about the establishments selling khat, khat pricing and its use among different ethnic minority groups, in addition to the potential sale of khat to children and risk assessment (e.g., use of pesticides on khat).

RESULTS

Five out of seven sellers identified agreed to participate. Sellers described their khat sale establishments as 'community centres' which included, for example, a restaurant basement. The sellers' history of selling khat ranged between 1-15 years and khat's sale took place between 2pm-10pm. Miraa (e.g., Lara) from Kenya was the most popularly used khat variety, sold in pre-wrapped bundles of approximately 250 g costing £3 each and delivered four days a week. Harari (e.g., Owdi) from Ethiopia was sold in 200 g, 400 g and 1 kg bundles, priced between £5 and £20 and delivered two days a week. The primary benefit of khat use was reported to be social interaction. The customers were predominantly adult males of Somali origin. Most sellers claimed a self-imposed ban on sales to children under 18 years old. Khat bundles had no labelling describing variety or weight and sellers had no knowledge of the use of pesticides on khat and did not advertise the risks associated with khat use.

CONCLUSIONS

Khat selling establishments were businesses that did not adhere to trade standards regulations (e.g., labelling khat bundles). They claimed to provide a community service (facilitating social interaction) to their predominately Somali customers. Without a better understanding of the dynamics of the khat market there is a risk that both health and social needs of the vulnerable populations involved in the market continue to go unaddressed. Future research should track changes in the now illicit khat market in order to evaluate the social and public health implications following the recent changes to the current U.K. regulatory environment regarding khat.

Khat use: history and heart failure

Recent reports suggest that 20 million people worldwide are regularly using khat as a stimulant, even though the habit of chewing khat is known to cause serious health issues. Historical evidence suggests khat use has existed since the 13th century in Ethiopia and the southwestern Arabian regions even before the cultivation and use of coffee. In the past three decades, its availability and use spread all over the world including the United States and Europe. Most of the consumers in the Western world are immigrant groups from Eastern Africa or the Middle East. The global transport and availability of khat has been enhanced by the development of synthetic forms of its active component. The World Health Organization considers khat a drug of abuse since it causes a range of health problems. However, it remains lawful in some countries. Khat use has long been a part of Yemeni culture and is used in virtually every social occasion. The main component of khat is cathinone, which is structurally and functionally similar to amphetamine and cocaine. Several studies have demonstrated that khat chewing has unfavorable cardiovascular effects. The effect on the myocardium could be explained by its effect on the heart rate, blood pressure, its vasomotor effect on the coronary vessels, and its amphetamine-like effects. However, its direct effect on the myocardium needs further elaboration. To date, there are few articles that contribute death among khat chewers to khat-induced heart failure. Further studies are needed to address the risk factors in khat chewers that may explain khat-induced cardiotoxicity, cardiomyopathy, and heart failure.

Ischemic cardiomyopathy and cerebral infarction in a young patient associated with khat chewing

Khat is a stimulating agent used by many people in the Horn of Africa and the Arabian peninsula. Khat chewing is a known cardiovascular risk factor and is thought to cause vasoconstriction, systemic hypertension, and thrombogenicity. A 33-year-old Somalian man initially presented with loss of neurological function of the left arm, hazy vision, and headache. He smokes tobacco and chews two bundles of khat a week for more than 10 years. His ECG on admission showed a Q wave in V1 and V2 and 2 mm ST-elevations in V1, V2, and V3 and a terminal negative T wave in I, aVL, V2, V3, and V4, consistent with a recent, evolving anterior infarction. A noncontrast enhanced CT of the brain showed ischemia in the right middle cerebral artery vascular territory. An MRI showed recent ischemia in the vascular territory of the posterior division of the right middle cerebral artery. Coronary angiography showed a 70% stenosis with haziness of the proximal left anterior descending artery. Diagnostic tests and imaging are consistent with recent myocardial infarction in the LAD vascular territory because of coronary spasm and cerebral infarction in the middle cerebral artery vascular territory probably related to khat chewing.

Prevalence of and factors associated with regular khat chewing among university students in Ethiopia

Purpose

Khat (Catha edulis) is commonly chewed for its psychostimulant and euphorigenic effects in Africa and the Arabian Peninsula. Students use it to help them study for long hours especially during the period of examination. However, how regularly khat is chewed among university students and its associated factors are not well documented. In this article we report on the prevalence of and factors associated with regular khat chewing among university students in Ethiopia.

Methods

We did a cross-sectional study from May 20, 2014 to June 23, 2014 on a sample of 1,255 regular students recruited from all campuses of Hawassa University, southern Ethiopia. The data were collected using self-administered questionnaires. We analyzed the data to identify factors associated with current regular khat chewing using complex sample adjusted logistic regression analysis.

Results

The prevalence of current regular khat chewing was 10.5% (95% confidence interval [CI]: 6.1%–14.9%). After controlling for sex, religion, year of study, having a father who chews khat, cigarette smoking and alcohol drinking in the adjusted logistic regression model, living off-campus in rented houses as compared to living in the university dormitory (adjusted odds ratio [95% CI] =8.09 [1.56–42.01]), and having friends who chew khat (adjusted odds ratio [95% CI] =4.62 [1.98–10.74]) were found to significantly increase the odds of current regular khat use.

Conclusion

Students living outside the university campus in rented houses compared to those living in dormitory and those with khat chewing peers are more likely to use khat. A multipronged prevention approach involving students, the university officials, the surrounding community, and regulatory bodies is required.

Acute liver failure secondary to khat (Catha edulis)-induced necrotic hepatitis requiring liver transplantation: case report

We describe the case of a 26-year-old man with acute liver failure secondary to ingestion of khat (Catha edulis) leaves. In fact, this is the first case of acute liver failure due to khat reported outside the United Kingdom. The combination of specific epidemiologic data (young man of East African origin) and clinical features (central nervous system stimulation, withdrawal reactions, toxic autoimmune-like hepatitis) led to the diagnosis. Mechanisms of action and potential side effects of khat are elaborated on.

Severity of khat dependence among adult khat chewers: the moderating influence of gender and age

ETHNOPHARMACOLOGICAL RELEVANCE

The escalating use of khat (Catha edulis) in East Africa and Arabia is a major concern for public health. Yet little is known about the impact of khat on behavior. There has been no study in the region to assess the extent to which dependence syndrome is associated with khat use in this population.

AIM OF THE STUDY

To examine psychometric properties of the Severity of Dependence Scale-Khat (SDS-khat), gender differences in patterns of khat use and dependence, and the extent to which age moderated the link between gender and khat dependence.

MATERIALS AND METHODS

Two-hundred and seventy khat chewers recruited in two Yemeni cities completed face-to-face interviews asking about demographics and patterns of khat use. Validity of SDS-khat was examined by the principle component analysis and reliability of the scale was tested by Cronbach׳s alpha. A series of chi-square tests and analysis of variances (ANOVAs) were conducted to examine gender differences in khat use variables.

RESULTS

The results indicated that the mean age of khat chewers was 30.52 years (95% CI: 29.34, 31.70) and 52% of them were males. The SDS-khat was found to have two factors with moderate reliability. This pattern was consistent when the analysis was conducted in the entire sample and in each gender. Male khat chewers reported more symptoms related to khat dependence than female chewers. A significant gender by age interaction in SDS-khat levels (p=0.013) revealed a positive association between age and khat dependence in women only.

CONCLUSION

These results provide initial support for the use of SDS-khat in the assessment of khat dependence in Yemen. Gender differences in khat use patterns and dependence observed in this study call the need for more studies carefully examining the role of gender in khat research.

Concurrent tobacco and khat use is associated with blunted cardiovascular stress response and enhanced negative mood: a cross-sectional investigation

OBJECTIVES

Khat (Catha edulis), an amphetamine-like plant, is widely used in East Africa and the Arabian Peninsula and is becoming a growing problem in other parts of the world. The concurrent use of tobacco and khat is highly prevalent and represents a public health challenge. We examined for the first time associations of the concurrent use of tobacco and khat with psychophysiological responses to acute stress in two sites in Yemen.

METHODS

Participants (N = 308; 135 women) included three groups: users of khat and tobacco, users of khat alone, and a control group (nonsmokers/nonusers of khat). These individuals completed a laboratory session in which blood pressures (BP), heart rate, and mood measures were assessed during rest and in response to acute stress.

RESULTS

Concurrent use of khat and tobacco was associated with attenuated systolic BP, diastolic BP, and heart rate responses to laboratory stress (ps < 0.05) and with increased negative affect relative to the control group (ps < 0.05).

CONCLUSIONS

Results demonstrated blunted cardiovascular responses to stress and enhanced negative affect in concurrent khat and tobacco users. These findings extend previous studies with other substances and suggest that adverse effects of khat use may lie in its association with the use of tobacco.

Khat Use, PTSD and Psychotic Symptoms among Somali Refugees in Nairobi - A Pilot Study

In East-African and Arab countries, khat leaves are traditionally chewed in social settings. They contain the amphetamine-like alkaloid cathinone. Especially among Somali refugees, khat use has been associated with psychiatric symptoms. We assessed khat-use patterns and psychiatric symptoms among male Somali refugees living in a disadvantaged urban settlement area in Kenya, a large group that has not yet received scientific attention. We wanted to explore consume patterns and study the associations between khat use, traumatic experiences, and psychotic symptoms. Using privileged access sampling, we recruited 33 healthy male khat chewers and 15 comparable non-chewers. Based on extensive preparatory work, we assessed khat use, khat dependence according to DSM-IV, traumatic experiences, posttraumatic stress disorder (PTSD), and psychotic symptoms using standardized diagnostic instruments that had been adapted to the Somali language and culture. Hazardous use patterns like chewing for more than 24 h without interruption were frequently reported. All khat users fulfilled the DSM-IV-criteria for dependence and 85% reported functional khat use, i.e., that khat helps them to forget painful experiences. We found that the studied group was heavily burdened by traumatic events and posttraumatic symptoms. Khat users had experienced more traumatic events and had more often PTSD than non-users. Most khat users experience khat-related psychotic symptoms and in a quarter of them we found true psychotic symptoms. In contrast, among control group members no psychotic symptoms could be detected. We found first evidence for the existence and high prevalence of severely hazardous use patterns, comorbid psychiatric symptoms, and khat use as a self-medication of trauma-consequences among male Somali refugees in urban Kenyan refugee settlements. There is a high burden by psychopathology and adequate community-based interventions urgently need to be developed.

Adverse drug reactions in some African herbal medicine: literature review and stakeholders' interview

BACKGROUND

In view of the large consumption of herbal medicine in Africa countries, it is likely that many adverse drugs reactions go unrecorded with either patients failing to present to health services, or no pharmacovigilance analysis being made, or the analysis not being reported centrally. This problem is of interest especially for those who are working in the general area of adverse drug reactions or stakeholders in the domain of herbal medicine for considering safety issues.

METHODS

We are particularly interested in the way that the use of very well-known and highly valued plants is linked to the observation of adverse drug reactions in African countries. We investigated, through a literature review and using the Internet (with a semantic search strategy), some well-known or popular medicinal plants used in African herbal medicine (AHM). Other information on the properties related to use, and characteristics of medicinal plants was complemented by some interviews with stakeholders.

RESULTS

Although substantial progress has been made in elucidating the mechanisms of action of many drugs, the pharmacological actions of many medicinal plants are generally not well understood. The results of a literature review suggest that the reported adverse drug reactions of herbal remedies are often due to a lack of understanding of their preparation and appropriate use. The results of stakeholders' interviews suggest that there is a growing need to provide patients with correct information about the herbal medicines they consume.

CONCLUSION

An important aspect of herbal medicine is the correct, timely, and integrated communication of emerging data on risk as an essential part of pharmacovigilance, which could actually improve the health and safety of patients. This calls for improved collaboration between traditional practitioners and modern healthcare professionals, researchers, and drug regulatory authorities. In addition, there is a need for an adverse drug reaction reporting system to facilitate the collection, monitoring, and evaluation of adverse drug events.

Subacute administration of crude khat (Catha edulis F.) extract induces mild to moderate nephrotoxicity in rats

BACKGROUND

Although various studies have been conducted to shed light on the pharmacological actions of khat, little or no data are available regarding khat's effect on the renal redox system. The aim of this study was therefore to investigate the potential of nephrotoxicity associated with khat exposure in rats.

METHODS

Sprague Dawely rats were randomly assigned into eight experimental groups. Animals were treated with Tween80, gentamicin 100 mg/kg and khat at various doses (100, 200 and 400 mg/kg) alone or in combination with gentamicin for ten days. The animals were then sacrificed to obtain blood and renal tissues for subsequent analysis. Renal markers, including creatinine, blood urea nitrogen, antioxidant enzymes as well as markers for lipid peroxidation were determined using established protocols. In addition, histopathological changes were evaluated with hematoxilin and-eosin staining technique.

RESULTS

Lower and moderate doses of khat did not alter the measured parameters compared to controls. By contrast, higher dose (400 mg/kg) of khat not only increased levels of serum creatinine and blood urea nitrogen (p < 0.001) but also levels of malondialdehyde (p < 0.01). Moreover, 400 mg/kg of khat significantly decreased enzymatic activities of superoxide dismutase (p < 0.01) and catalase (p < 0.001). When khat was administered with gentamicin, it was again the higher dose that significantly accentuated gentamicin-induced alterations in the renal system.

CONCLUSIONS

Khat treatment at high dose is demonstrated to induce mild to moderate renal damage. Moreover, it creates synergy when combined with nephrotoxic drugs such as gentamicin.

Bath salts and other emerging toxins

Novel classes of synthetic drugs, including synthetic cathinones ("bath salts") and synthetic cannabinoids ("spice" or "K2"), have recently emerged as popular drugs of abuse. Salvia divinorum, a naturally occurring herb, has gained popularity in the last decade as a hallucinogenic as well. The legal status of these substances has been undergoing rapid changes and has been confusing to lawmakers and medical practitioners alike. We present an up-to-date information about the legality of these substances. We also discuss the historical background, chemical composition, patterns of abuse, clinical presentations, laboratory analysis, and management strategies for these drugs, with an emphasis on synthetic cathinones.

Khat and synthetic cathinones: a review

For centuries, 'khat sessions' have played a key role in the social and cultural traditions among several communities around Saudi Arabia and most East African countries. The identification of cathinone as the main psychoactive compound of khat leaves, exhibiting amphetamine-like pharmacological properties, resulted in the synthesis of several derivatives structurally similar to this so-called natural amphetamine. Synthetic cathinones were primarily developed for therapeutic purposes, but promptly started being misused and extensively abused for their euphoric effects. In the mid-2000's, synthetic cathinones emerged in the recreational drug markets as legal alternatives ('legal highs') to amphetamine, 'ecstasy', or cocaine. Currently, they are sold as 'bath salts' or 'plant food', under ambiguous labels lacking information about their true contents. Cathinone derivatives are conveniently available online or at 'smartshops' and are much more affordable than the traditional illicit drugs. Despite the scarcity of scientific data on these 'legal highs', synthetic cathinones use became an increasingly popular practice worldwide. Additionally, criminalization of these derivatives is often useless since for each specific substance that gets legally controlled, one or more structurally modified analogs are introduced into the legal market. Chemically, these substances are structurally related to amphetamine. For this reason, cathinone derivatives share with this drug both central nervous system stimulating and sympathomimetic features. Reports of intoxication and deaths related to the use of 'bath salts' have been frequently described over the last years, and several attempts to apply a legislative control on synthetic cathinones have been made. However, further research on their pharmacological and toxicological properties is fully required in order to access the actual potential harm of synthetic cathinones to general public health. The present work provides a review on khat and synthetic cathinones, concerning their historical background, prevalence, patterns of use, legal status, chemistry, pharmacokinetics, pharmacodynamics, and their physiological and toxicological effects on animals and humans.

Khat chewing and restrictive dietary behaviors are associated with anemia among pregnant women in high prevalence rural communities in eastern Ethiopia

Background

Anemia affects a high proportion of pregnant women in the developing countries. Factors associated with it vary in context. This study aimed to determine the prevalence and predictors of anemia among pregnant women in the rural eastern Ethiopia.

Methods

A community-based cross-sectional study was done on 1678 pregnant women who were selected by a cluster random sampling technique. A pregnant woman was identified as anemic if her hemoglobin concentration was <11 g/dl. Data were collected in a community-based setting. Multilevel mixed effect logistic regression was used to determine the adjusted odds ratios (AOR) with 95% confidence intervals (CI) for the predictors of anemia.

Results

Anemia was observed among 737(43.9%) of the 1678 pregnant women studied (95% CI 41.5%–46.3%). After controlling for the confounders, the risk of anemia was 29% higher in the women who chewed khat daily than those who sometimes or never did so (AOR, 1.29; 95% CI, 1.02–1.62). The study subjects with restrictive dietary behavior (reduced either meal size or frequency) had a 39% higher risk of anemia compared to those without restrictive dietary behavior (AOR, 1.39; 95% CI, 1.02–1.88). The risk of anemia was increased by 68% (AOR, 1.68; 95% CI, 1.15–2.47), and 60% (AOR, 1.60; 95% CI, 1.08–2.37) in parity levels of 2 births and 3 births, respectively. Compared to the first trimester, the risk of anemia was higher by two-fold (AOR, 2.09; 95% CI, 1.46–3.00) in the second trimester and by four-fold (AOR, 4.23; 95% CI, 2.97–6.02) in the third trimester.

Conclusion

In this study, two out of five women were anemic. Chewing khat and restrictive dietary habits that are associated with anemia in the setting should be addressed through public education programs. Interventions should also focus on the women at higher parity levels and those who are in advanced stages of pregnancy.

Khat (Catha edulis): A systematic review of evidence and literature pertaining to its harms to UK users and society

The use of khat ( Catha edulis) has been associated with a large number of physiological and societal harms, leading to calls for it to be controlled in the UK. The evidence of these harms is often equivocal, limited by confounding factors, or entirely anecdotal: high-powered, quality-controlled studies are lacking. Regardless, the body of relevant literature indicates that the once socially-regulated use of khat has been eroded. Some individuals have developed excessive consumption patterns, either using khat daily or in binge-sessions, though daily consumption is not necessarily problematic per se. The majority of users seem to use khat in moderation, where the associated harms appear low. For excessive users, harms associated with khat are greater, particularly relating to mental health. Social harms also seem to be largely related to excessive khat use rather than khat use itself. Even in cases of excessive khat use, however, causal relationships between chewing and harms have not been described. More research is required to establish the role of khat in liver disease, coronary problems, cancers of the digestive tract and incidents of domestic violence. Studies should consider the likeliness that certain users are more vulnerable to developing patterns of excessive khat use due to an interwoven set of factors such as social health determinants and pre- and post-migration experiences.

Chronic khat (Catha edulis) and alcohol marginally alter complete blood counts, clinical chemistry, and testosterone in male rats

INTRODUCTION

Khat (Catha edulis) is a recreational psychoactive drug with psychostimulant properties. While the use of this drug is widespread in eastern Africa, including the Horn of Africa, surveys and anecdotal data show that its use has become cosmopolitan, with users now living in Europe and North America as well. Recent data in Uganda suggest an increasing pattern of simultaneous khat and ethanol use particularly among young adults. However, the effects of this pattern of use remain largely unknown, even though long-term use of either drug alone is known to be harmful. The aim of this study was to examine the toxic effects of simultaneous chronic administration of khat and ethanol on hematological parameters, clinical chemistry, and testosterone in a rat model.

METHODS

Adult male Sprague-Dawley rats were randomly assigned to one of six dose groups: 2 g/kg khat; 4 g/kg khat; 4 g/kg ethanol; combined khat and ethanol (4 g/kg each); control; and an untreated group. Treatments were given by gavage twice daily for 28 days, followed by determination of hematological parameters, blood clinical chemistry, and testosterone.

RESULTS

Ethanol alone significantly reduced platelet counts compared to control-, untreated and low-dose khat-treated rats; conversely low-dose khat significantly increased both the hemoglobin and hematocrit values, while ethanol alone also significantly increased the hemoglobin value compared to controls. Simultaneous khat and ethanol administration per se did not produce more toxic consequences in chronic use than either drug alone.

CONCLUSION

Chronic short-term khat use and ethanol dependence individually produce note-worthy effects on the blood, but not on clinical chemistry or testosterone. Chronic short-term combined khat and ethanol use does not produce more toxic effects compared to use of either drug alone. This provides an opportunity for appropriate clinical interventions to avert the chronic long-term effects that result from use of these drugs of abuse.

Khat dependence syndrome: a cross sectional preliminary evaluation amongst UK-resident Yemeni khat chewers

ETHNOPHARMACOLOGICAL RELEVANCE

Khat is a natural psychostimulant that has pharmacological effects similar to that of amphetamine. The behaviour of khat chewing is embedded within a cultural context. Meanwhile khat chewing is associated with psychological and physiologically burden, as a 'dependence producing' substance.

AIMS OF THE STUDY

To assess the applicability of the construct of substance dependence syndrome (DSM-IV, 1994) to khat chewing and to examine psychosocial and behavioural correlates of this syndrome including tobacco use.

MATERIALS AND METHODS

A sample of 204 khat chewers was recruited during random visits to khat sale outlets. A face to face interview that assessed socio-demographic, psychosocial dependence, substance dependence syndrome and behavioural characteristics was conducted. Descriptive, exploratory psychometric and multivariate analyses were employed.

RESULTS

Approximately a third (31%) of khat chewers reported symptoms consistent with dependence syndrome including increased khat chewing (13%) and cessation attempts (19%) while 17% reported withdrawal symptoms including depression (61%), increase in appetite (74%) and interrupted sleep (58%). Thirty-eight percent reported continued khat chewing despite impacts on their health. Psychometric assessment of the DSM-IV criteria for khat chewing dependence identified two factors; factor 1 consisted of bio-behavioural items and factor 2 withdrawal items, accounting for 67% of the variance and Cronbach's alpha coefficient at 0.78. In multivariate logistic regression modelling, there was an association between intensity of psychological khat dependence (SDS-Khat) and nicotine dependence with the likelihood of exhibiting khat chewing dependence syndrome (p=0.0005, OR=1.51, 95%CI=1.33-1.71; p=0.043, OR=2.87, 95%CI=1.03-7.98, respectively).

CONCLUSIONS

The substance dependence syndrome criteria are applicable to khat chewing and associated with increased intensity of nicotine and psychological khat dependence. The applicability of khat dependence syndrome and exploration of its dimensions and associated factors should be extended in future research. Concurrent validation of these findings using specific objective measures for self-report khat chewing is also recommended.

Effects of chronic khat use on cardiovascular, adrenocortical, and psychological responses to stress in men and women

BACKGROUND

Khat is a psychostimulant plant widely used in Africa and its use has been growing rapidly in Europe and North America.

OBJECTIVES

We investigated effects of chronic khat (Catha edulis) use on cardiovascular, adrenocortical, and psychological responses to acute stress.

METHODS

Chronic khat users and nonusers were compared on physiological measures and mood reports in a cross-sectional, mixed design. Measurements were conducted during 24-hour ambulatory monitoring and during a laboratory session. A total of 152 participants (58 women) were recruited by flyers posted around Sana'a University campus and the surrounding community in Sana'a, Yemen. Salivary cortisol and self-report measures were collected during a 24-hour ambulatory period prior to a lab testing session. In addition, blood pressures (BP), salivary cortisol, and mood measures were assessed during rest and in response to acute mental stress.

RESULTS

Khat users exhibited enhanced evening and attenuated morning cortisol levels, reflecting a blunted diurnal pattern of adrenocortical activity compared to nonusers. Khat users reported greater negative affect during the ambulatory period and during the laboratory session. In addition, they exhibited attenuated BP responses to stress.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

These novel results demonstrate altered adrenocortical activity and increased dysphoric mood among khat users. The extent to which these associations are due to effects of chronic khat use per se or instead reflect predisposing risk factors for khat use is yet to be determined.

Cardiovascular complications of Khat

This article reviews current knowledge in khat (cathinone) research and its health impacts and toxicity in the cardiac system of khat chewers based on current evidence. The authors describe the process by which khat is postulated to induce multiple cardiac abnormalities by illustrating multiple case reports as described from around the world. The role of free radicals in inducing cardiac disease is also discussed. Future research areas are proposed to enhance our understanding of the mode of action of this toxicological drug.

Cardiovascular toxicity of novel psychoactive drugs: lessons from the past

The long use of ephedrine, amphetamines, cocaine, LSD and more recently 3,4-methylenedioxy-N-methylamphetamine (MDMA; "Ecstasy") allows us to predict with some confidence what cardiovascular risks are likely to be associated with novel psychoactive substances (NPS). Once the probably multiple biological activities of a compound are known it is possible to define the likely risks of cardiovascular toxicity. Agonists of 5-HT(2A) receptors or alpha-adrenoceptors may cause vasoconstriction and tissue ischemia. Drugs which have agonist affinity for 5-HT(2B) receptors will probably promote heart valve fibrosis leading to heart failure. Compounds that interfere with uptake of dopamine or 5-hydroxytryptamine (5-HT) are likely to also have effects on noradrenergic neurotransmission and lead to sympathomimetic effects on the heart and vasculature. Drugs that cause dopamine release, or inhibit uptake are likely to be addictive and lead to chronic use. Other drugs (particularly the so-called empathogens) are associated with weekly usage in social settings; over time such use can lead to cardiovascular harm. Defining which of these effects NPS have is an important element of predicting the harm they may cause and informing those appointed to introduce regulations to control them.

Toxicological Features of Catha edulis (Khat) on Livers and Kidneys of Male and Female Sprague-Dawley Rats: A Subchronic Study

Hepato- and nephrotoxicity of Khat consumption (Catha edulis Forskal) have been evoked. Therefore, this study was conducted to evaluate such possible hepatorenal toxicity in female and male Sprague-Dawley rats (SD rats) focusing primarily on liver and kidney. In addition, female and male rats were investigated separately. Accordingly, forty-eight SD-rats (100–120 g) were distributed randomly into four groups of males and female (n = 12). Normal controls (NCs) received distilled water, whereas test groups received 500 mg/kg (low dose (LD)), 1000 mg/kg (medium dose (MD)), or 2000 mg/kg (high dose (HD)) of crude extract of Catha edulis orally for 4 weeks. Then, physical, biochemical, hematological, and histological parameters were analyzed. Results in Khat-fed rats showed hepatic enlargement, abnormal findings in serum aspartate aminotransferase (AST), and alkaline phosphatase (ALP) of male and female SD-rats and serum albumin (A) and serum creatinine (Cr) of female as compared to controls. In addition, histopathological abnormalities confirmed hepatic and renal toxicities of Khat that were related to heavy Khat consumption. In summary, Khat could be associated with hepatic hypertrophy and hepatotoxicity in male and female SD-rats and nephrotoxicity only in female SD-rats.

Clinical Toxicology and Management of Intoxications With Synthetic Cathinones (“Bath Salts”)

Synthetic cathinones are synthetic derivatives of the natural cathinone, one of the psychoactive compounds present in Catha edulis (khat). There are at least 12 different types of synthetic cathinones, with mephedrone and 3,4-methylendioxypyrovalerone (MDPV) being the most commonly used by the purchasers. The legal control of these substances is especially difficult because when a specific compound is banned, a new slightly modified chemical variant is introduced into the market. It has been described that patients after taking synthetic cathinones may show signs and symptoms of the sympathicomimetic toxidrome, including agitation, psychosis, tachycardia, hypertension, and seizures. Furthermore, some cases of deaths related to their consumption have also been reported. Nowadays, there is no established treatment protocol for the clinical management of these intoxications. Because of this, we have developed some recommendations that may be useful to determine the treatment of these patients.

Mephedrone ('bath salt') elicits conditioned place preference and dopamine-sensitive motor activation

Abuse of a dangerous street drug called mephedrone (4-methylmethcathinone) has become commonplace in the United States. Mephedrone is hypothesized to possess abuse liability, share pharmacological properties with psychostimulants, and display toxicity that has been linked to fatalities and non-fatal overdoses. Knowledge about the pharmacology of mephedrone has been obtained primarily from surveys of drug abusers and emergency room visits rather than experimental studies. The present study used motor activity and conditioned place preference (CPP) assays to investigate behavioral effects of mephedrone. Acute mephedrone (3, 5, 10, 30 mg/kg, ip) administration increased ambulatory activity in rats. Mephedrone (5 mg/kg, ip)-induced ambulation was inhibited by pretreatment with a dopamine D1 receptor antagonist (SCH 23390) (0.5, 1, 2 mg/kg, ip) and enhanced by pretreatment with a dopamine D2 receptor antagonist (sulpiride) (2 mg/kg, ip). Rats injected for 5 days with low dose mephedrone (0.5 mg/kg, ip) and then challenged with mephedrone (0.5 mg/kg, ip) following 10 days of abstinence displayed sensitization of ambulatory activity. In CPP experiments, mephedrone (30 mg/kg, ip) conditioning elicited a preference shift in both rats and mice. The CPP and dopamine-sensitive motor activation produced by mephedrone is suggestive of abuse liability and indicates commonalities between the neuropharmacological profiles of mephedrone and established drugs of abuse.

Khat use among HIV voluntary counselling and testing centre clients in Ethiopia

Khat (Catha edulis, a natural stimulant), has been used in Ethiopia for centuries. Over the past few decades, however, its use has dramatically increased, with recent research linking khat use to HIV status. Using qualitative methods, we explored the individual and micro-environmental characteristics of khat use and the social and physical contexts influencing type, acceptability and consequences of khat use. Among khat chewers attending an HIV voluntary counselling and testing centre in Addis Ababa, Ethiopia, we found that chewing typically starts at an early age (15-18 years). The majority of users are young (aged 18-35) and chew for pleasure, primarily in social settings. Over 25 types of khat, with varying effects were reported. Approximately half of the participants perceived khat to enhance sexual desire, while the rest claimed the effect on sexual desire to be the opposite. Alcohol use among chewers was high. Our findings suggest the need for culturally appropriate interventions that highlight the factors associated with khat use and the potential interplay between khat, alcohol and risky sexual behaviour.

Validation of self-reported khat chewing amongst khat chewers: an exploratory study

ETHNOPHARMACOLOGICAL RELEVANCE

Khat chewing amongst the UK communities originating from Yemen and the East African coast is suggested to create dependency through its main stimulant components (cathinone, norephedrine and norpseudoephedrine) on the central nervous system.

AIMS OF THE STUDY

To validate self-reported khat chewing behaviours by measuring levels of cathinone, norephedrine and norpseudoephedrine in saliva and to explore their associations with self-reported khat chewing dependency.

MATERIALS AND METHODS

Face-to-face interviews were conducted amongst 30 male UK-resident khat chewers. Saliva samples were collected from each participant and high-performance liquid chromatography (HPLC) employed to extract and quantify the levels of the biomarkers.

RESULTS

The mean (SD) for cathinone and the composite norephedrine and norpseudoephedrine levels were 33.93 (±39.20) and 29.28 (±26.32)μg/mL respectively. These biomarkers were significantly associated (p≤0.05) with khat chewing dependency.

CONCLUSIONS

Validation of self-reported khat chewing is possible. Khat chewing dependency correlates significantly with biomarker levels in saliva. Replication is required.