Khat consumption: a pharmacological review

Epidemiology of Khat (Catha edulis) Chewing in Ethiopia: A Systematic Review and meta-analysis

In several countries, including Ethiopia, the shrub Catha edulis (khat) leaves are chewed for their stimulant properties. The present review summarizes evidence on the prevalence of khat use in Ethiopia and forwards recommendations for future action. PubMed, Embase, and Scopus were searched for studies examining the prevalence of Khat chewing among adolescent and/or adult populations in Ethiopia. A random-effects model was employed to estimate the pooled prevalence of khat chewing. Of the 568 articles identified, 26 were included in the review. The pooled prevalence of current and lifetime khat use was 19.55% (95% CI 14.62-25.64) and 26.14% (CI 17.66-36.87), respectively. The current prevalence of khat use was higher in men, 23.72% (CI 13.42-38.41), than in women 8.45% (CI 4.94-14.08). Lifetime prevalence of khat use was higher in men, 29.8% (CI: 22.80-37.99) than in women 13.02% (CI 8.96-18.56). The results of the meta-analysis demonstrated a higher odds of current (OR = 4.00, CI 2.80-5.73) and lifetime (OR = 2.84, CI 2.50-3.23) khat use in men than in women. Our review found a high prevalence of current (19.55%) and lifetime (26.14%) khat chewing in Ethiopia and demonstrated higher odds of current and lifetime khat use in men than in women. Awareness creation and integrated management of khat use problems at the primary health-care level is highly recommended.

Fatalities Involving Khat in Jazan, Saudi Arabia, 2018 to 2021

Interpreting fatalities involving khat is challenging due to a lack of data on cathinone and cathine reference concentrations in postmortem tissues. This study investigated the autopsy findings and toxicological results of fatalities involving khat in Saudi Arabia's Jazan region from 1 January 2018 to 31 December 2021. All confirmed cathine and cathinone results in postmortem blood, urine, brain, liver, kidney, and stomach samples were recorded and analyzed. Autopsy findings and the manner and cause of death of the deceased were assessed. Saudi Arabia's Forensic Medicine Center investigated 651 fatality cases over four years. Thirty postmortem samples were positive for khat's active constituents, cathinone and cathine. The percentage of fatalities involving khat was 3% in 2018 and 2019 and increased from 4% in 2020 to 9% in 2021, when compared with all fatal cases. They were all males ranging in age from 23 to 45. Firearm injuries (10 cases), hanging (7 cases), road traffic accident (2 cases), head injury (2 cases), stab wounds (2 cases), poisoning (2 cases), unknown (2 cases), ischemic heart disease (1 case), brain tumor (1 case), and choking (1 case) were responsible for the deaths. In total, 57% of the postmortem samples tested positive for khat only, while 43% tested positive for khat with other drugs. Amphetamine is the drug most frequently involved. The average cathinone and cathine concentrations were 85 and 486 ng/mL in the blood, 69 and 682 ng/mL in the brain, 64 and 635 ng/mL in the liver, and 43 and 758 ng/mL in the kidneys, respectively. The 10th-90th percentiles of blood concentrations of cathinone and cathine were 18-218 ng/mL and 222-843 ng/mL, respectively. These findings show that 90% of fatalities involving khat had cathinone concentrations greater than 18 ng/mL and cathine concentrations greater than 222 ng/mL. According to the cause of death, homicide was the most common fatality involving khat alone (77%). More research is required, especially toxicological and autopsy findings, to determine the involvement of khat in crimes and fatalities. This study may help forensic scientists and toxicologists investigate fatalities involving khat.

Cathine and cathinone disposition kinetics and neurotransmitter profile in several organs of rats exposed to a single dose of Catha edulis (Vahl) Forssk. ex Endl. extract

OBJECTIVES

Catha edulis (Vahl) Forssk. ex Endl. (Khat) is a stimulant plant that contains cathine and cathinone, which its abuses induce euphoria, alertness, and motor activity. Since the toxicokinetics of these substances remain unclear, this study was carried out to investigate the disposition kinetics of cathine and cathinone, the neurotransmitter profile, following a single dose of C. edulis extract in rats.

METHODS

Twenty-four adult male Wistar albino rats (250-300 g) were randomly selected and divided into six groups of four rats each. All groups received a single oral dose of 2,000 mg/kg body weight, and blood and tissue samples from the brain, lung, heart, liver, and kidney were obtained at intervals of 0.5, 1, 2.5, 5, 12, and 24 h. The cathine and cathinone concentrations were identified and quantified using ion trap ultra-high performance liquid chromatography (HPLC-IT/MS). The neurotransmitter profile was detected using the quadrupole time of flight UPLC-QTOF/MS method.

RESULTS

The lung, liver, and heart tissues attained the highest levels of cathine, while the highest level of cathinone was determined in the heart. Cathine and cathinone concentrations in the blood and heart peaked at 0.5 h. The concentrations peaked in the brain 2.5 h later, indicating that the heart had an immediate effect, whereas the brain had a longer-lasting one. They have longer half-lives (2.68 and 5.07 h, respectively) and may remain in the brain for longer durations (3.31 and 2.31 h, respectively). The neurotransmitters epinephrine, dopamine, norepinephrine, and serotonin were detected in a delayed, prolonged and organ-specific manner.

CONCLUSIONS

Cathine and cathinone were deposited in considerable concentrations in all tissues analyzed, with the highest C_max in the lung and T_max in the heart tissues but not in the brain. In addition, neurotransmitters such as adrenaline, dopamine, norepinephrine, and serotonin were differentially detected in all tested samples in a organ-specific fashion. More study is needed to identify cathine and cathinone's effects on neurotransmitter profiles. Nevertheless, these findings provided a further basis for experimental, clinical, and forensic investigations.

Khat and neurobehavioral functions: A systematic review

Background

Khat is a plant that is used for its amphetamine-like stimulant properties. However, although khat is very popular in Eastern Africa, Arabian Peninsula, and the Middle East, there is still a lack of studies researching the possible neurobehavioral impairment derived from khat use.

Methods

A systematic review was conducted to identify studies that assessed the effects of khat use on neurobehavioral functions. MedLine, Scopus, Cochrane, Web of Science and Open Grey literature were searched for relevant publications from inception to December 2020. Search terms included (a) khat and (b) several cognitive domains. References from relevant publications and grey literature were also reviewed to identify additional citations for inclusion.

Results

A total of 142 articles were reviewed, 14 of which met the inclusion criteria (nine human and five rodent studies). Available human studies suggest that long term khat use is associated with significant deficits in several cognitive domains, including learning, motor speed/coordination, set-shifting/response inhibition functions, cognitive flexibility, short term/working memory, and conflict resolution. In addition, rodent studies indicated daily administration of khat extract resulted in dose-related impairments in behavior such as motor hyperactivity and decreased cognition, mainly learning and memory.

Conclusions

The findings presented in this review indicates that long-term khat use may be contributing to an impairment of neurobehavioral functions. However, gaps in literature were detected that future studies could potentially address to better understand the health consequences of khat use.

Epidemiology of khat (Catha edulis) consumption among university students: a meta-analysis

BACKGROUND

Khat is amphetamine-like substance commonly consumed by students when they wish to study for long hours especially during examination periods. Khat consumption is associated with increased rates of cardiovascular problems, stroke, myocardial infarction, cardiomyopathy, periodontal disease, gastritis, poor oral hygiene, psychosis, decreased quality of life, and poor academic performance.

METHODS

PubMed, EMBASE, and SCOPUS were systematically searched without restriction by publication status. Publications were screened according to predefined inclusion criteria. Twenty-five articles were included. Random effect model was used to calculate weighted prevalence, odds ratio (OR) and corresponding 95% confidence interval (CI). We assessed the risk of publication bias by using funnel plot and Eggers's regression tests.

RESULTS

The pooled prevalence of current khat use among university students was 14.16% (95% CI; 11.87-16.81). The pooled prevalence of current khat use was highest in Saudi Arabia 18.85% and it was 13.59% in Ethiopia and 13.04% in Yemen. In addition, the current pooled prevalence of khat use was higher in men at 19.26% than in women 6.41%. Regarding lifetime khat use, in this study, the pooled prevalence of lifetime khat use was 27.31%. The lifetime prevalence was higher in men at 31.47% than in women 11.79%. Moreover, the lifetime prevalence of khat use was 43.27% in Yemen, 37.32% in Saudi Arabia, and 24.82% in Ethiopia. We found significantly increased odds of current (OR 3.59; 95%CI 2.01-6.41) as well as lifetime (OR 3.48; 95%CI 2.09-5.78) khat chewing in men as compared to women.

CONCLUSION

The pooled prevalence of current and lifetime khat consumption was 14.16 and 27.31%, respectively. Both the current and lifetime prevalence of khat use was higher in men than in women. In addition, both the current and lifetime prevalence estimates of khat consumption were low in Ethiopia than in Saudi Arabia. Moreover, the odds of both current and lifetime khat consumption were higher in male students than in female students. Programmes that specifically aim at increasing awareness and that most motivate reduced khat consumption among university students were recommended.

Impact of chronic khat (Catha edulis Forsk) chewing on pulmonary function test and oxygen saturation in humans: A comparative study

Background:

Chronic consumption of khat affects many organ systems and leads to various health disturbances in the chewers. Few studies examined the acute effects of khat ingestion on lung function parameters. However, studies which assessed the long-term effects of khat chewing on pulmonary function parameters and oxygen saturation are lacking.

Objective:

The aim of this study was to assess the impact of chronic Khat chewing on pulmonary function parameters and oxygen saturation among chronic Khat chewers in Wolkite, Ethiopia.

Methods:

A community-based comparative cross-sectional study was conducted in Wolkite, Ethiopia from 1 June 2018 to 15 August 2018. A total of 324 participants, 162 khat chewers and 162 non-chewers were included in the study. The data were collected through face-to-face interview by trained data collectors. British Medical Research Council respiratory questionnaire was used to assess respiratory symptoms. A spirometer was used to assess various lung function parameters. Moreover, oxygen saturation of hemoglobin was measured using pulse oximeter. Data were entered into CSPro version 6.2 and analyzed using SPSS version 23.

Results:

This study showed statistically significant (p < 0.05) reduction in the mean values of forced vital capacity, forced expiratory volume in first second and maximum ventilation volume among khat chewers as compared to non-chewers. There was no significant difference in the mean values of other lung function parameters between the two groups. Similarly, there was no significant difference (p = 0.642) in mean oxygen saturation of hemoglobin (SaO₂) across the two groups.

Conclusion:

It is evident from this study that long-term khat consumption is associated with decreased mean forced vital capacity, forced expiratory volume in first second and maximum ventilation volume. Hence, there is a need for further study to strengthen the current findings and to explore the mechanisms of khat chewing effect on lung function parameters.

Wastewater-based epidemiology in low Human Development Index states: bias in consumption monitoring of illicit drugs

Wastewater-based epidemiology is a promising approach worldwide, and its application is currently being developed in non-advanced economies. This technology, based on known toxicokinetic data initially used to detect illicit drugs in well-managed and maintained local sewer networks, has been extended to assess other products such as pesticides, alcohol, flame retardants, nicotine, and other substances. This technology is also used in countries with non-advanced economies. The present review aims to support future wastewater-based epidemiology in such countries by providing toxicokinetic data for locally used narcotic drugs that are expected or known to be emerging in developed countries, outlining the excretion differences due to human polymorphism, and summarising the practical obstacles due to the coverage, maintenance efficiency, or type of local sewage network.Case study feedback from Martinique is presented as an example; the Martinique field study complies with the Organisation for Economic Co-operation and Development standards for health issues, but not with regard to population and urban dynamics.

Stopping khat use: Predictors of success in an unaided quit attempt

INTRODUCTION AND AIMS

Despite the adverse effects of khat use and chewers interest in cessation, there are few studies that have reported on the outcome of khat cessation attempts, and limited resources available for potential quitters. We used electronic diaries to monitor the outcomes of an unassisted quit attempt among daily and near daily khat consumers, and examine predictors of success.

DESIGN AND METHODS

Sixty participants between the ages of 18 and 35 years who regularly chewed khat and who were attempting to quit were purposively recruited from an Ethiopian University campus. Real-time prospective daily recording of khat use was obtained for an average of 10 days prior to quit day (range 6-13) and 28 post-quit days (range 9-31), using an electronic diary.

RESULTS

Almost all (95%) achieved initial abstinence. Of these, 80% reached at least seven continuous days of abstinence; 7% maintained continuous abstinence for 28 days post-quit. While 93% lapsed (average 11 days post-quit, SD = 7), only a smaller proportion relapsed (41%: chewed for at least three consecutive days after at least 5 days of abstinence). No demographic factors were predictive of successful abstinence.

DISCUSSION AND CONCLUSIONS

Regular khat chewers have difficulties in maintaining abstinence despite having motivation and desire to quit. This implies that treatment aids may be needed to assist chewers' in their quit attempts. Controlled experimental trial through the use of available low cost quit aids and behavioural resources is crucial in order to increase success rates for those seeking to desist from khat use.

Catha edulis Forsk. (Khat): Evaluation of its Antidepressant-like Activity

BACKGROUND

Catha edulis Forsk. (Khat) is traditionally used for treating various disorders. Nevertheless there are no reports of any scientific assessment of its psychopharmacological properties.

OBJECTIVE

Therefore, the current study was designed to evaluate the antidepressant-like activity of Khat ethanolic extract using established animal models of depression and stress.

MATERIALS AND METHODS

Ninety healthy male albino mice were used in this study. Forced swim, tail suspension and head poking tests were utilized to evaluate the antidepressant-like activity of the ethanolic extract of Khat (100, 200 and 400 mg/kg, i.p.) and escitalopram (standard drug) which were administered 30 min prior to the tests. Phytochemical analysis of the standardized extract was conducted using liquid chromatography-mass spectroscopy (LC-MS).

RESULTS

A significant decrease in the head-dipping behavior was noticed after administration of 100, 200 and 400 mg/kg of Khat extract. Moreover, the extract significantly decreased the immobility time in tail suspension and forced swim tests. The presence of cathinone and cathine were detected in the extract using LC-MS.

CONCLUSION

The current results suggest that the extract of Khat leaves has acute antidepressant properties and may have sedative effects.

SUMMARY

Antidepressant-like activity of Khat established in vivoThe extract decreased the immobility time in tail suspension and forced swim testsLiquid chromatography-mass spectroscopy data revealed the presence of cathinone and cathine in Khat extract. Abbreviations used: LC-MS: Liquid chromatography-mass spectroscopy; NIST: National institute of standard technology; SSRI: Serotonin reuptake inhibitors; FST: Forced swim test; TST: Tail suspension test.

Khat chewing habit produces a significant adverse effect on periodontal, oral health: A systematic review and meta-analysis

Although there is a general agreement that a khat chewing habit produces clinicopathological changes in the oral mucosa. However there is no reliable evidence of the effects of a khat chewing habit on the periodontal tissues. Thus, authors aimed to investigate the influence of khat chewing habits on periodontal, oral health, by comparing khat chewers to non-chewers in respect of gingival recession, periodontal pocketing depth and loss of attachment. A systematic review and meta-analysis were conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched PubMed, the Cochrane Library, Web of Science, Scopus and grey literature. The inclusion criteria were all studies with aims of comparing khat chewers and/or sides to non-chewers and/or sides in respect of gingival recession, periodontal pocketing depth and loss of attachment. For continuous data, we computed weighted mean difference or standard mean difference analyses. An odds ratio using a random effect model was used if heterogeneity was detected; otherwise, a fixed effects model with a 95% confidence interval was used for continuous data. Two subgroups were analysed: khat chewers vs non-chewers and khat chewer sides vs non-chewer sides of the chewer's individuals. A total of 6373 participants were enrolled in 12 studies (khat chewers=3812, non-chewers=2561). There were statistically significant differences between khat and non-chewers in both subgroup analyses regarding gingival recession, periodontal pocketing depth and loss of attachment (P<.05). The odds ratios for khat chewers compared to non-chewers, in respect of depth of periodontal pocket and gingival recession were 4.797 and 6.853 respectively. The results of this meta-analysis have shown that the khat chewing habit produces a destructive and adverse effect on periodontal, oral health.

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.

What constitutes problematic khat use? An exploratory mixed methods study in Ethiopia

Background

Khat is a psycho-stimulant herb, which has been in use in traditional societies in East Africa and the Middle East over many centuries. Although khat is reported to cause various health problems, what constitutes problematic khat use has never been systematically investigated. This study explored the acceptable and problematic uses of khat from the perspective of users.

Methods

The study used a mixed methods design (exploratory sequential) in which qualitative (emic) data were collected to develop a framework to define problematic khat use. The qualitative data were gathered through in-depth interviews (N = 13) and focus group discussions (N = 34). By supplementing the emic experiences considered to constitute problematic khat use with an etic definition, DSM-5 criteria for stimulant related disorders, a structured questionnaire was developed. Subsequently a cross-sectional evaluation of 102 respondents was carried out. Respondents both for qualitative and quantitative study were selected through purposive sampling and snowballing methods. Qualitative data were transcribed and subjected to thematic analysis whereas quantitative data were analyzed using descriptive and nonparametric statistics.

Results

Khat use was acceptable socio-culturally and for functional purposes. However, even in these acceptable contexts there was a restriction to the amount, frequency and type of khat used, and in relation to the experience of the individual using khat and other personal characteristics. More specifically, khat use was considered problematic if there was: 1) Impairment (in social and occupational functioning); 2) loss of control in the use of khat; and 3) withdrawal symptoms when not using khat. Among the participants who use khat (n = 102), 45.1% (n = 46) used khat on a daily basis. The commonest indicators of problematic khat use endorsed by the khat users were loss of control over chewing (73.5%), continuing use of khat despite harm (72.5%) and efforts to avoid withdrawal from khat (61.8%).

Conclusion

Despite reported religious, sociocultural and functional benefits to the use of khat, those with defined problematic khat use have impaired mental health, and social and occupational performance. Comparison of these respondent defined indicators of problem behavior matched almost completely to the DSM-5 (etic-defined) understanding of problematic stimulant use. Although the findings have relevant clinical, research and policy implications, the study focused on users purposively identified. Future larger scale definitive studies are required to make concrete policy recommendations.

Herbal Highs: Review on Psychoactive Effects and Neuropharmacology

BACKGROUND

A new trend among users of new psychoactive substances' the consumption of "herbal highs": plant parts containing psychoactive substances. Most of the substances extracted from herbs, in old centuries were at the centre of religious ceremonies of ancient civilizations. Currently, these herbal products are mainly sold by internet web sites and easily obtained since some of them have no legal restriction.

OBJECTIVE

We reviewed psychoactive effects and neuropharmacology of the most used "herbal highs" with characterized active principles, with studies reporting mechanisms of action, pharmacological and subjective effects, eventual secondary effects including intoxications and/or fatalities Method: The PubMed database was searched using the following key.words: herbal highs, Argyreia nervosa, Ipomoea violacea and Rivea corymbosa; Catha edulis; Datura stramonium; Piper methysticum; Mitragyna speciosa.

RESULTS

Psychoactive plants here reviewed have been known and used from ancient times, even if for some of them limited information still exist regarding subjective and neuropharmacological effects and consequent eventual toxicity when plants are used alone or in combination with "classical" drugs of abuse.

CONCLUSION

Some "herbal highs" should be classified as harmful drugs since chronic administration has been linked with addiction and cognitive impairment; for some others taking into consideration only the recent trends of abuse, studies investigating these aspects are lacking.

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.

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).

Hepatotoxicity Induced by "the 3Ks": Kava, Kratom and Khat

The 3Ks (kava, kratom and khat) are herbals that can potentially induce liver injuries. On the one hand, growing controversial data have been reported about the hepatotoxicity of kratom, while, on the other hand, even though kava and khat hepatotoxicity has been investigated, the hepatotoxic effects are still not clear. Chronic recreational use of kratom has been associated with rare instances of acute liver injury. Several studies and case reports have suggested that khat is hepatotoxic, leading to deranged liver enzymes and also histopathological evidence of acute hepatocellular degeneration. Numerous reports of severe hepatotoxicity potentially induced by kava have also been highlighted, both in the USA and Europe. The aim of this review is to focus on the different patterns and the mechanisms of hepatotoxicity induced by “the 3Ks”, while trying to clarify the numerous aspects that still need to be addressed.

Khat Dependency and Psychophysical Symptoms among Chewers in Jazan Region, Kingdom of Saudi Arabia

BACKGROUND

Khat chewing is highly prevalent in Africa, Yemen and Jazan region, southwest of Saudi Arabia. Most of Jazani Khat chewers consider khat session as a social activity and do not consider khat dependency. The aim of this study was to explore khat dependency and its relationship with the psychophysical symptoms among chewers.

METHODS

Cross-sectional study on seventy Saudi male khat chewers living in Jazan area. Psychological dependence to khat chewing was evaluated using the Severity of Dependency Scale (SDS). The participants filled in a self-administrated assisted structured questionnaire designed to collect data about their medical history, neurological symptoms, and their chewing behavior.

RESULTS

Half (52.2%) of khat chewers showed psychological dependency. Those having longer khat sessions (≥6 hours) were more liable for dependency. Physical and psychological symptoms were more prevalent among khat dependent chewers.

CONCLUSIONS

khat has a psychological dependence effect that can be measured by the SDS, even in low doses and with irregular use. SDS scale is a useful tool to expect the burden of either physical or psychological symptoms on khat chewers.

Acute Methylenedioxypyrovalerone Toxicity

The objective of this study was to characterize the acute clinical effects, laboratory findings, complications, and disposition of patients presenting to the hospital after abusing synthetic cathinone. We conducted a retrospective multicenter case series of patients with synthetic cathinone abuse by searching for the terms bath salts, MDPV, methylenedioxypyrovalerone, mephedrone, methcathinone, methylone, methedrone, and cathinone within the "agent" field of a national clinical toxicology database (ToxIC). The medical records of these patients were obtained and abstracted by investigators at each study site. Patients with confirmatory testing that identified a synthetic cathinone in either blood or urine were included in the series. Patients who had either an undetectable synthetic cathinone test or no confirmatory testing were excluded. A data abstraction sheet was used to obtain information on each patient. We entered data into an Excel spreadsheet and calculated descriptive statistics. We identified 23 patients with confirmed synthetic cathinone exposure--all were positive for methylenedioxyprovalerone (MDPV). Eighty-three percent were male and 74 % had recreational intent. The most common reported clinical effects were tachycardia (74 %), agitation (65 %), and sympathomimetic syndrome (65 %). Acidosis was the most common laboratory abnormality (43 %). Seventy-eight percent of patients were treated with benzodiazepines and 30 % were intubated. Ninety-six percent of patients were hospitalized and 87 % were admitted to the ICU. The majority (61 %) of patients was discharged home but 30 % required inpatient psychiatric care. There was one death in our series. The majority of patients presenting to the hospital after abusing MDPV have severe sympathomimetic findings requiring hospitalization. A number of these patients require inpatient psychiatric care after their acute presentation.

Khat use and appetite: an overview and comparison of amphetamine, khat and cathinone

ETHNOPHARMACOLOGICAL RELEVANCE

To understand the role of khat (Catha edulis) use on the aberrations in appetite and weight which are common comorbidities for khat and other amphetamine users.

MATERIALS AND METHODS

We provide a comprehensive overview and conceptual summary of the historical cultural use of khat as a natural stimulant and describe the similarities and differences between cathinone (the main psychoactive constituent of khat) and amphetamine highlighting the limited literature on the neurophysiology of appetite and subsequent weight effects of khat.

RESULTS

Animal and some human studies indicate that khat produces appetite suppression, although little is known about mechanisms of this effect. Both direct and indirect effects of khat stem from multiple factors including behavioral, chemical and neurophysiological effects on appetite and metabolism. Classic and newly identified appetite hormones have not been explored sufficiently in the study of appetite and khat use. Unique methodological challenges and opportunities are encountered when examining effects of khat and cathinone including khat-specific medical comorbidities, unique route of administration, differential patterns of behavioral effects relative to amphetamines and the nascent state of our understanding of the neurobiology of this drug.

CONCLUSION

A considerable amount of work remains in the study of the appetite effects of khat chewing and outline a program of research that could inform our understanding of this natural amphetamine׳s appetite effects and help prepare health care workers for the unique health effects of this drug.

Sensitive hydrophilic interaction liquid chromatography/tandem mass spectrometry method for rapid detection, quantification and confirmation of cathinone-derived designer drugs for doping control in equine plasma

RATIONALE

Cathinone derivatives are new amphetamine-like stimulants that can evade detection when presently available methods are used for doping control. To prevent misuse of these banned substances in racehorses, development of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method became the impetus for undertaking this study.

METHODS

Analytes were recovered via liquid-liquid extraction using methyl tert-butyl ether. Analyte separation was achieved on a hydrophilic interaction column using liquid chromatography and mass analysis was performed on a QTRAP mass spectrometer in positive electrospray ionization (ESI) mode with multiple reaction monitoring (MRM). Analyte identification was carried out by screening for a specified MRM transition. Quantification was conducted using an internal standard. Confirmation was performed by establishing a match in retention time and ion intensity ratios comparison.

RESULTS

The method was linear over the range 0.2-50 ng/mL. The specificity was evaluated by analysis of six different batches of blank plasma and those spiked with each analyte (0.2 ng/mL). The recovery of analytes from plasma at three different concentrations was >70%. The limits of detection, quantification and confirmation were 0.02-0.05, 0.2-1.0 and 0.2-10 ng/mL, respectively. The matrix effect was insignificant. The intra-day and inter-day precision were 1.94-12.08 and 2.58-13.32%, respectively.

CONCLUSIONS

The method is routinely employed in screening for the eleven analytes in post-competition samples collected from racehorses in Pennsylvania to enforce the ban on the use of these performance-enhancing agents in racehorses. The method is sensitive, fast, effective and reliably reproducible.

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.

Epicardial coronary arteries in khat chewers presenting with myocardial infarction

Background. Khat chewing is a common habit in Yemen despite increased evidence of its negative impact on the cardiovascular system. Aims. We aimed to study the epicardial coronary arteries in khat chewers presenting with myocardial infarction (AMI). Materials and Methods. A descriptive, cross-sectional study was conducted between November 2008 and May 2009 in Yemen. AMI patients who underwent coronary angiogram were enrolled and divided into groups (gp): gp1 (diabetic and khat chewers), gp2 (khat chewers and nondiabetic), and gp3 (diabetic and non-khat users). Results. Of 347 AMI patients 63%, 21%, and 16% were in gp 2, 3, and 1, respectively. Khat chewers were younger in comparison to non-khat users. Group 3 patients were more likely to have multivessel disease, severe left anterior descending (LAD), right coronary artery (RCA) stenosis and total RCA, and left circumflex (Lcx) occlusion compared to other groups. Group 1 patients were more likely to have total LAD occlusion and severe Lcx lesions. In multivariate analysis, age, diabetes mellitus, and smoking were significant independent predictors for significant coronary artery lesions; however, khat chewing did not show such association. Conclusions. Coronary spasm is the main mechanism of AMI in khat chewers. The impact of our finding for risk stratification and management warrants further studies.

Leaf of paradise?: the intricate effects of khat in Madagascar

Purpose

–Khat is a bushy plant whose leaves are chewed for a mild amphetamine effect. The purpose of this paper is to investigate khat's multiple effects, broadly defined to include impacts on producers, traders, and consumers, as well as on the biophysical environment, in northern Madagascar.

Design/methodology/approach

– This primarily ethnographic study (conducted from 2004 to 2010), includes observation, semi-structured interviews, and orally administered questionnaires.

Findings

– Khat's effects include strain on the household budgets of consumers, but increased earnings to producers and traders. In addition, there is some evidence of consumers’ strained primary social relationships, yet khat chewing is also positively linked with new forms of urban multiethnic identity.

Research limitations/implications

– To evaluate a drug's overall effects, it is critical to understand it within wide-ranging political, economic, biological, and cultural contexts. Many studies of drugs focus on only one component. While this makes for more manageable research designs, it obscures the complex interplay of numerous factors. This impedes general understanding and furthermore makes it difficult to design broadly effective, multisector intervention strategies.

Originality/value

– This analysis reveals the intricacy of khat's effects in Madagascar while programmatically proposing a model for doing research with policy implications on other psychotropic substances.

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.

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.

Khat (Catha edulis) and ethanol co-dependence modulate seizure expression in a pentylenetetrazol seizure model

ETHNOPHARMACOLOGICAL RELEVANCE

Khat is a plant with psychostimulant properties whose parts, mainly leaves and twigs, are chewed for its euphoriant effects. Khat use and ethanol abuse are increasingly becoming global health concerns especially among many disadvantaged social groups. The present studies were undertaken to investigate seizure susceptibility and responses following chronic co-administration of khat and ethanol.

MATERIALS AND METHODS

Juvenile male Sprague-Dawley (SD) rats were administered khat, ethanol or combined khat and ethanol twice daily for 28 days by gavage. Khat-treated animals received 2 g/kg or 4 g/kg body weight continuously for the study period. Ethanol-treated animals received 20% ethanol at a dose of 4 g/kg body weight. The convulsant, pentylenetetrazol (PTZ), was administered intraperitoneally at a dose of 40 mg/kg body weight. Seizure responses were recorded.

RESULTS

Twice-daily dosing of khat did not produce inhibition of weight gain. Khat alone, combined khat and 20% ethanol, but not 20% ethanol alone, significantly reduced the latency to seize. Khat treatment at 2 g/kg but not 4 g/kg body weight also significantly increased the duration of seizures. Conversely, combined khat and ethanol reduced the duration of seizures compared to controls. Ethanol alone reduced the seizure severity while khat alone, and combined khat and ethanol, produced close to the maximum seizure severity.

CONCLUSIONS

These data suggest that combined moderate to high dose khat and ethanol co-dependence produce a greater deleterious CNS effect than either drug alone. Future studies will address neurochemical effects, in addition to neuroadaptations, resulting from coabuse of these drugs.

Validity and reliability of a Severity of Dependence Scale for khat (SDS-khat)

AIMS OF THE STUDY

(1) To assess psychological khat dependence and (2) to assess the validity and reliability of the Severity Dependence Scale (Gossop et al., 1995) amended for khat use (SDS-khat), in a sample of UK-resident male adult Yemeni khat chewers.

MATERIALS AND METHODS

A cross-sectional study using a face to face structured interview schedule was conducted amongst purposively sampled UK-resident adult Yemeni male khat chewers, aged 18 years and above, selected during random visits to places of khat sale. A factor analysis with principal components extraction was conducted to explore the construct validity of the proposed SDS-khat. Reliability of the proposed scale was assessed using test-retest and internal reliability tests. The concurrent validity of the proposed SDS-khat was assessed in relation to individual measures and a composite index of khat chewing behaviours using univariate analyses.

RESULTS

Two hundred and four Yemeni male adult khat chewers were interviewed. The mean score of the proposed SDS-khat was 5.52 (SD ±4.03). Forty nine percent of respondents (95% CI=43-55%) with ≤5 scores were more likely not psychologically dependent. A single factor, uni-dimensional solution identifying the five items making up the scale accounted for 52.33% of variance. The internal reliability was good (Cronbach's alpha coefficient=0.76) and the test retest intraclass correlation coefficient (ICC) was 0.93 (95% CI=0.80-0.97). Many individual aspects of the khat chewing were significantly related to the scale. Assessment of the proposed SDS-khat's concurrent validity with individual items of khat chewing identified several significant relationships (p≤0.05) whilst the composite index of khat behaviour also identified a significant relationship (OR=14.40, 95% CI=6.71-30.89). The proposed SDS-khat also correlated with self-reported reasons for khat chewing (p≤0.001, OR=3.54; 95% CI=1.80-6.96).

CONCLUSIONS

In this sample of Yemeni khat chewers the SDS-khat is recommended as a valid and reliable research tool for measuring psychological dependence upon khat. Further validation in other samples is indicated.

Motives for khat use and abstinence in Yemen--a gender perspective

Background

Khat consumption is widespread in Yemeni society and causes problems both in economic development and public health. Preventive measures have been largely unsuccessful and the cultivation continues to proliferate. The gender-specific motives for khat use and abstinence were studied to create a toe-hold for more specific interventions.

Methods

In a quota sample with equal numbers of males, females, abstainers and consumers, 320 subjects were interviewed on their specific opinions about khat and its impact on subjective and public health, and on social and community functioning. Strata were compared in their acceptance and denial of opinions. Notions that could predict abstinence status or gender were identified with multivariate logistic regression analysis.

Results

Male khat users had a strong identification with khat use, while females were more ambivalent. The notion that khat consumption is a bad habit (odds ratio (OR) 3.4; p < 0.001) and consumers are malnuorished (OR 2.2; p = 0.046) were associated with female gender among khat users. Among the females worries about health impact (OR 3.2; p = 0.040) and loss of esteem in the family (OR 3.1; p = 0.048) when using khat predicted abstinence. Male abstainers opposed khat users in the belief that khat is the cause of social problems (OR 5.1, p < 0.001). Logistic regression reached an accuracy of 75 and 73% for the prediction of abstinence and 71% for gender among consumers. (All models p < 0.001.)

Conclusions

Distinct beliefs allow a differentiation between males, females, khat users and abstainers when targeting preventive measures. In accordance to their specific values female khat users are most ambivalent towards their habit. Positive opinions scored lower than expected in the consumers. This finding creates a strong toe-hold for gender-specific public health interventions.

Recreational use of mephedrone (4-methylmethcathinone, 4-MMC) with associated sympathomimetic toxicity

INTRODUCTION

Cathinone is a pharmacologically active alkaloid that can be extracted from the leaves of the khat plant (Catha edulis). There are synthetic derivatives of cathinone entering the recreational drug market, including mephedrone (4-methylmethcathinone, 4-MMC). There are discrepancies in the legal status of both the khat plant and its extracted alkaloids between the UK and the USA.

CASE REPORT

A 22-year-old man purchased 4 g of mephedrone powder over the Internet from a chemical supplier based in China. He initially ingested 200 mg of the mephedrone orally, with no perceived clinical effects, and thereafter injected the remaining 3.8 g intramuscularly into his thighs. Shortly after the injection, he developed palpitations, "blurred tunnel vision," chest pressure, and sweating and felt generally unwell; he presented to hospital with continuing features of sympathomimetic toxicity. His symptoms settled over the next 4 h after a single dose of oral lorazepam. Qualitative analysis of the urine and serum sample was undertaken using gas chromatography with mass spectrometric (GC/MS) detection, both positive for the presence of 4-methylmethcathinone. Quantitative analysis of the serum sample was undertaken by liquid chromatography with tandem mass spectrometric detection; the estimated mephedrone concentration was 0.15 mg/l. Routine toxicological analysis of the serum and urine specimens using a broad GC/MS toxicology screen did not detect any other drugs or alcohol.

DISCUSSION

This is the first case of isolated 4-MMC toxicity, with confirmatory analytical findings. It is important that clinical toxicologists and emergency physicians work together to ensure a better understanding of the toxicity of novel/emerging drugs such as 4-MMC.

Khat - a controversial plant

Khat (Catha edulis) is a shrub or tree whose leaves have been chewed for centuries by people who live in the Eastern part of Africa and the Arabian Peninsula. It has recently turned up in North America and Europe, particularly among emigrants and refugees from countries such as Somalia, Ethiopia and Yemen. Khat contains a number of chemicals, among which are two controlled substances, cathinone (Schedule I) and cathine (Schedule IV). Both chemicals are stimulant drugs with effects similar to amphetamine. Chewing the leaves makes people feel more alert and talkative, and suppresses appetite. Chewing khat leaves releases cathinone, a stimulant that produces the feeling of euphoria. When cathinone is broken down in the body, it produces chemicals including cathine and norephedrine, which have a similar structure to amphetamine and adrenaline (epinephrine). Regular khat use is associated with a rise in arterial blood pressure and pulse rate, corresponding with levels of cathinone in the plasma. Moreover, regular khat chewers have gingivitis and loose teeth, but there appears to be no convincing unusual incidence of oral cancer. Among khat users in Yemen there is, however, a higher incidence of esophageal cancer compared with gastric cancer. Long term use or abuse can cause insomnia, anorexia, gastric disorders, depression, liver damage and cardiac complications, including myocardial infarction. Manic and delusional behavior, violence, suicidal depression, hallucinations, paranoia and khat-induced psychosis have also been reported. On the basis of the scientific data it seems clear that khat use has negative consequences on the economic development of a country and on the health of the society.

Risk assessment of khat use in the Netherlands: a review based on adverse health effects, prevalence, criminal involvement and public order

In preparing a decision about the legal status of khat in the Netherlands, the Dutch Minister of Health requested CAM (Coordination point Assessment and Monitoring new drugs) to assess the overall risk of khat in the Netherlands. The present paper is a redraft of a report which formed the scientific basis of the risk evaluation procedure (October 2007). This report reviews the scientific data about khat available in the international literature. In addition, the report contains some information specific for the Netherlands (prevalence, availability of khat and public order aspects). The main psychoactive compounds in khat leaves are cathine and cathinone, which are some 2- to 10-fold less active than amphetamine. Acute health problems are rarely seen, and are usually related with malnutrition, social and financial problems. Khat has a low addictive potential. Chronic toxicity of khat is modest when used in low amounts, whereas at high levels, khat use is associated with adverse effects, like hypertension, heart rhythm disorders, insomnia and loss of appetite. In addition, khat users show a higher prevalence of cancers in the digestive tract. At population level, khat does not lead to specific health risks in the Netherlands, as its use is confined to East-African immigrants. A relationship between khat use and psychiatric disorders has been suggested, but the reports are contradictory, and such studies are presumably heavily confounded by posttraumatic and social stress. In the Netherlands (and other countries), khat use occasionally leads to minor disturbance of civil order in the public domain (loud talking, spitting), but is not related to criminal activities. Following the assessment, CAM estimated the overall risk potential of khat use in the Netherlands as very low. A similar conclusion may be drawn for countries with a comparable prevalence of khat use and khat related public order disturbance.

A review of the neuropharmacological properties of khat

BACKGROUND

The psychostimulant khat (Catha edulis Forsk), is a herbal drug cultivated and chewed as a recreational and socializing drug in East Africa and the Arabian Peninsula for centuries. Due to increasing air transportation and the loosening of customs restrictions, it is now readily available in the Western Countries mainly used by immigrants from khat growing areas causing a concern to policy-makers.

OBJECTIVE

We conducted this review to further gain an insight to the neuropharmacological effects of khat.

METHODOLOGY

PubMed search engine with key terms 'khat' or 'qat' or 'mirra' or'qaad/jaad' or 'cathinone' was used to obtain articles relevant to khat chewing. In total 284 English written articles published from 1959 to 2007 were screened.

RESULTS

Most of the studies focused on cathinone, the postulated active psychostimulant alkaloid in khat. There were few studies which investigated the entire plant extract in either in vitro or animal studies. In the majority of the studies it was reported that both cathinone and cathine, another psychoactive constituent, have actions that are similar to those of amphetamine.

CONCLUSIONS

It seems that the well investigated khat alkaloids have many features similar to amphetamines; however there is a need for a more thorough examination of khat itself in well designed in vitro, animal and human studies with a range of comparator drugs before confirming the claim that khat is a "natural amphetamine".

Khat in East Africa: taking women into or out of sex work?

Women's drug use is often associated with sex work as a means of raising money for consumption. Similarly, in Kenya and Uganda, journalists, the general public and aid agencies associate female consumption of the stimulant drug, khat (Catha edulis), as pulling women into prostitution. In contrast to Yemen and Ethiopia, these views are expressed by people living in areas where there are no rituals or traditions of female khat consumption. This paper presents data from a study carried out in Kenya and Uganda in 2004 and 2005 that documents that the majority of women engaging in khat chewing are not sex workers. Frequently, however, women who retail khat are often assumed by men to be sexually immoral. The role of women in the retail and wholesale khat trade is examined. The stigma attached to selling khat is linked to the overall situation of independent women in East Africa and the place of commercial sex in urban life.

Genotoxic effect of Catha edulis (khat) crude extract after sub-chronic administration in rats

The aim of this study was to evaluate the genotoxic effects of a crude extract of khat (Catha edulis, Forsk) leaves in rats. Two groups were fed khat crude extract, 1000 and 2000mg/kg body weight, for 90 days and were compared with a control group. The alkaline (pH>13) version of comet assay was used in this study. However, no previous published work has been undertaken and showed the effect of khat on DNA migration in the comet assay. To compare the comet assay results with another genetic endpoint, blood samples were analyzed for chromosomal aberrations. These results showed no DNA damage detected using comet assay in both the khat treated groups, while the results of chromosomal aberrations assay showed a significant increase (P<0.05) in the 2000mg/kg body weight treated group compared to the control group.

Khat chewing from the pharmacological point of view: an update

Khat chewing is deeply rooted in the every day life of people living in the Horn of Africa and in South Arabia, where Catha edulis is endemic. Considered little more than an exotic habit producing just mild pharmacological effects, systematic investigations on its active principles have instead lead to the isolation and chemical characterization of cathinone, a compound structurally related to amphetamine. Three decades of intense experimental and clinical research on khat have depicted a consistently clear picture of its pharmacological and toxicological effects.

The consumption of khat and other drugs in Somali combatants: a cross-sectional study

BACKGROUND

For more than a decade, most parts of Somalia have not been under the control of any type of government. This "failure of state" is complete in the central and southern regions and most apparent in Mogadishu, which had been for a long period in the hands of warlords deploying their private militias in a battle for resources. In contrast, the northern part of Somalia has had relatively stable control under regional administrations, which are, however, not internationally recognized. The present study provides information about drug abuse among active security personnel and militia with an emphasis on regional differences in relation to the lack of central governmental control-to our knowledge the first account on this topic.

METHODS AND FINDINGS

Trained local interviewers conducted a total of 8,723 interviews of armed personnel in seven convenience samples in different regions of Somalia; 587 (6.3%) respondents discontinued the interview and 12 (0.001%) were excluded for other reasons. We assessed basic sociodemographic information, self-reported khat use, and how respondents perceived the use of khat, cannabis (which includes both hashish and marijuana), psychoactive tablets (e.g., benzodiazepines), alcohol, solvents, and hemp seeds in their units. The cautious interpretation of our data suggest that sociodemographic characteristics and drug use among military personnel differ substantially between northern and southern/central Somalia. In total, 36.4% (99% confidence interval [CI] 19.3%-57.7%) of respondents reported khat use in the week before the interview, whereas in some regions of southern/central Somalia khat use, especially excessive use, was reported more frequently. Self-reported khat use differed substantially from the perceived use in units. According to the perception of respondents, the most frequent form of drug use is khat chewing (on average, 70.1% in previous week, 99% CI 63.6%-76.5%), followed by smoking cannabis (10.7%, 99% CI 0%-30.4%), ingesting psychoactive tablets (8.5%, 99% CI 0%-24.4%), drinking alcohol (5.3%, 99% CI 0%-13.8%), inhaling solvents (1.8%, 99% CI 0%-5.1%), and eating hemp seeds (0.6%, 99% CI 0%-2.0%). Perceived use of khat differs little between northern and southern Somalia, but perceived use of other drugs reaches alarmingly high levels in some regions of the south, especially related to smoking cannabis and using psychoactive tablets.

CONCLUSIONS

Our data suggest that drug use has quantitatively and qualitatively changed over the course of conflicts in southern Somalia, as current patterns are in contrast to traditional use. Although future studies using random sampling methods need to confirm our results, we hypothesize that drug-related problems of armed staff and other vulnerable groups in southern Somalia has reached proportions formerly unknown to the country, especially as we believe that any biases in our data would lead to an underestimation of actual drug use. We recommend that future disarmament, demobilization, and reintegration (DDR) programs need to be prepared to deal with significant drug-related problems in Somalia.

The dihydro-β-agarofuran sesquiterpenoids

Dihydro-Beta-agarofuran sesquiterpenoids are a structurally diverse class of natural products based on tricyclic 5,11-epoxy-5Beta,10alpha-eudesman-4-(14)-ene skeleton. Between January 1990 and June 2006, 462 new dihydro-Beta-agarofuran sesquiterpenoids of 74 structural types have been isolated from about 64 species of Celastraceae, 3 species of Hippocrateaceae and one species of Lamiaceae. The present review covers the chemical and biological activity research of dihydro-Beta-agarofuran sesquiterpenoids in the past 16 years. The chemical research includes structural classification into sesquiterpene polyesters and macrolide sesquiterpene pyridine alkaloids, synthesis of dihydro-Beta-agarofuran as well as extraction, isolation and purification methods. The biological activity research includes activities such as multidrug resistance (MDR) reversal activity, HIV inhibition, cytotoxicity, antitumor activity, antifeedant activity and insecticidal activity with some insights to their modes of actions.

The potential adverse effects of habitual use of Catha edulis (khat)

The habit of Catha edulis Forsk (khat) chewing has prevailed for centuries among populations in the horn of Africa and the Arabian peninsula. Fresh leaves of Catha edulis are customarily chewed to attain a state of stimulation. The fact that cathinone has a closer structural similarity with amphetamine, and both share common pharmacodynamic features, led to the conclusion that cathinone is the most important active ingredient of Catha edulis, which causes the major pharmacological effects. Problems associated with repeated consumption of Catha edulis leaves are becoming evident. Literature surveys and clinical diagnostic studies revealed an association with prevalence of psychiatric morbidity. Repeated intermittent oral administration of Catha edulis to laboratory animals lead to development and expression of locomotor sensitisation. Catha edulis also leads to several peripheral effects that include increases in blood pressure and has been associated with the increased incidence of acute coronary vasospasm and myocardial infarction. Catha edulis also accounts for a number of gastrointestinal tract problems, oesophagitis, gastritis and delay intestinal absorption, as well as the development of oral keratotic white lesions at the site of chewing. Administration of Catha edulis extracts showed a deranged systemic capacity to handle oxidative radicals and induces cytotoxic effects in cells of liver and kidney, as well as induction of cell death in various human leukaemia cell lines and in peripheral human blood leukocytes.

Khat use as risk factor for psychotic disorders: a cross-sectional and case-control study in Somalia

BACKGROUND

Little is known about the prevalence of khat-induced psychotic disorders in East African countries, where the chewing of khat leaves is common. Its main psycho-active component cathinone produces effects similar to those of amphetamine. We aimed to explore the prevalence of psychotic disorders among the general population and the association between khat use and psychotic symptoms.

METHODS

In an epidemiological household assessment in the city of Hargeisa, North-West Somalia, trained local interviewers screened 4,854 randomly selected persons from among the general population for disability due to severe mental problems. The identified cases were interviewed based on a structured interview and compared to healthy matched controls. Psychotic symptoms were assessed using the items of the WHO Composite International Diagnostic Interview and quantified with the Positive and Negative Symptoms Scale. Statistical testing included Student's t-test and ANOVA.

RESULTS

Local interviewers found that rates of severe disability due to mental disorders were 8.4% among males (above the age of 12) and differed according to war experiences (no war experience: 3.2%; civilian war survivors: 8.0%; ex-combatants: 15.9%). The clinical interview verified that in 83% of positive screening cases psychotic symptoms were the most prominent manifestations of psychiatric illness. On average, cases with psychotic symptoms had started to use khat earlier in life than matched controls and had been using khat 8.6 years before positive symptoms emerged. In most cases with psychotic symptoms, a pattern of binge use (> two 'bundles' per day) preceded the onset of psychotic symptoms, in contrast to controls of the same age. We found significant correlations between variables of khat consumption and clinical scales (0.35 to 0.50; p < 0.05), and between the age of onset of khat chewing and symptom onset (0.70; p <0.001).

CONCLUSION

Evidence indicates a relationship between the consumption of khat and the onset of psychotic symptoms among the male population, whereby not the khat intake per se but rather early onset and excessive khat chewing seemed to be related to psychotic symptoms. The khat problem must be addressed by means other than prohibition, given the widespread use and its role in Somali culture.