The effect of Khat (Catha edulis) as an appetite suppressant is independent of ghrelin and PYY secretion

Clavulanic Acid Improves Memory Dysfunction and Anxiety Behaviors through Upregulating Glutamatergic Transporters in the Nucleus Accumbens of Mice Repeatedly Exposed to Khat Extract

Khat (Catha edulis) is an evergreen shrub whose buds and leaves give a state of delight and euphoria when chewed. Cathinone, an amphetamine-like stimulant that is among the active ingredients in khat, is able to downregulate glutamate transporter subtype I (GLT-1). Neurobehavioral dysfunctions such as altered locomotor activity, anorexia, and nociception have been observed in animals exposed to cathinone. Interestingly, treatment with a β-lactam antibiotic such as ceftriaxone, which upregulates GLT-1, normalizes cathinone-induced conditioned place preference, and alters repetitive movements in rats. However, little is known about the role of the glutamatergic system in memory dysfunction and anxiety-like behaviors in mice exposed to khat. We found here that clavulanic acid, a β-lactam-containing compound and GLT-1 upregulator, would modulate the neurobehavioral changes, including memory impairment and anxiety-like behaviors, associated with repeated exposure of mice to khat. Our data supported that clavulanic acid could improve memory impairment and anxiety-like behaviors through upregulating GLT-1 in the nucleus accumbens (NAc), an effect abolished with a selective GLT-1 blocker. This upregulation was associated with restored glutamate/cystine antiporter expression in the NAc using a Western blotting assay. Cathine and cathinone were identified in khat extract using the gas chromatography technique. Our work provides preclinical insight into the efficacy of β-lactam-containing compounds for the attenuation of neurobehavioral changes induced by khat exposure.

Relationship between Undernutrition and Periodontal Diseases among a Sample of Yemeni Population: A Cross-Sectional Study

Undernutrition is an inadequate supply of energy and nutrients. Periodontal diseases (PDs) are defined as a broad form of chronic inflammatory disease of the gingiva, bone, and ligaments supporting the teeth. This study aimed to reveal the relationship between undernutrition, using body mass index (BMI) and serum albumin level (Alb), and PDs in a sample of Yemeni population. A cross-sectional study was conducted at dental teaching clinics at the Faculty of Dentistry, Sana’a University. Of 1920 patients who attended clinics, only 229 matched the study criteria. Oral examination was performed to assess the periodontal clinical parameter measurements. BMI and Alb were measured. Participants of both genders were involved, with a slight increase in males (n = 134, 58.5%), and most of the study sample was in the age group of 18–35 years (n = 209, 91.3%). Regarding habits, only 18.2% (n = 43) of patients were smokers and about half of the participants (n = 136, 59.4%) were khat chewers. Most cases had mild undernutrition according to BMI (n = 139, 60.7%) and normal Alb level (n = 213, 93%). Regarding the periodontal diagnosis, most of the participants were diagnosed with gingivitis (n = 186, 81.2%). BMI and albumin level were nonsignificantly associated with PDs. PDs were statistically significant with the participant’s age, gender, level of education, and smoking ( $P>0.05$ ). However, BMI, khat chewing, and albumin level were nonsignificant factors of periodontal diseases among Yemeni participants ( $P>0.05$ ). In both genders, variables such as age of the patients, smoking, khat chewing, and PDs were nonsignificantly associated with BMI. This study showed that the majority of the participants had been diagnosed with gingivitis, but there was not an association between PDs and undernutrition. This paper is presented on research square URL // https://www.researchsquare.com/article/rs-429796/v1 with DOI 10.21203/rs.3.rs-429796/v1.

Tea in the Morning and Khat Afternoon: Health Threats Due to Khat Chewing

Khat or qat (Catha edulis) is a flowering plant with an Arabic name قات, regularly named as qāt, also is known by various descriptive names, such as Abyssinian tea, Somali tea, Arabian tea, Miraa, Jima, and Kafta in its endemic regions of the Horn of Africa and the Arabian Peninsula. Fresh leaves and tops of khat are chewed or dried and consumed as a tea to attain a state of euphoria and excitement; it also has appetite-reducing effects. Traditionally, khat is used as a socializing habit in Yemen and is also widely cultivated because of its high income. However, in recent years the plant has been reported in England, Wales, Rome, Amsterdam, Canada, Israel, Australia, New Zealand, and the United States. Although it is believed that khat is a relatively low-risk drug, it's associated with an increased risk for various medical complications, including dental and oropharyngeal disease, gastrointestinal, cardiovascular, neuropsychiatric, obstetric, and even can be the cause of cancer. Our goal in this review article is to revise and determine the relationship between chewing khat and its health issues. Additionally, we tried to determine the mechanism involved in health hazards due to consuming the khat.

Khat (Catha edulis) upregulates lipolytic genes in white adipose tissue of male obese mice (C57BL/6J)

ETHNOPHARMACOLOGICAL RELEVANCE

Khat (Catha edulis (Vahl) Forssk.) is a herb from the Celastraceae family (also known as qat, gaad, or mirra) that is widely-consumed in East Africa and in the Arabian peninsula. The green leaves and small stems are consumed primarily at recreational and social gatherings, and medicinally for their antidiabetic and appetite-suppression effects.

AIMS

The objectives of this study were to determine the effects of khat and its active alkaloid, cathinone, on food intake and body weight in mice maintained on a high-fat diet, and to investigate its mechanism of action in white adipose tissue and in the hypothalamus.

MATERIALS & METHOD

Adult male mice (C57BL/6J) were fed a high fat diet (HFD) for 8 weeks (n = 30), then divided into 5 groups and treated daily for a further 8 weeks with HFD + vehicle [control (HFD)], HFD + 15 mg/kg orlistat (HFDO), HFD + 200 mg/kg khat extract (HFDK200), HFD + 400 mg/kg khat extract (HFDK400) and HFD + 3.2 mg/kg cathinone (HFDCAT). Treatments were carried out once daily by gastric gavage. Blood and tissue samples were collected for biochemical, hormonal and gene expression analyses.

RESULTS

Khat extracts and orlistat treatment significantly reduced weight gain as compared to control mice on HFD, and cathinone administration completely prevented weight gain in mice fed on HFD. Khat treatment caused a marked reduction in body fat and in serum triglycerides. A dose-dependent effect of khat was observed in reducing serum leptin concentrations. Analysis of gene expression in adipose tissue revealed a significant upregulation of two lipolysis pathway genes:(adipose triglyceride lipase (PNPLA-2) and hormone-sensitive lipase (LIPE). In the hypothalamic there was a significant (P < 0.05) upregulation of agouti-related peptide (AgRP) and cocaine-amphetamine regulated transcript (CART) genes in the HFDK400 and HFDCAT groups.

CONCLUSION

Cathinone treatment blocked body weight gain, while high dose khat extract significantly reduced the weight gain of mice on an obesogenic diet through stimulation of lipolysis in white adipose tissue.

Comparison Among Garlic, Berberine, Resveratrol,Hibiscus sabdariffa, GenusZizyphus, Hesperidin, Red Beetroot,Catha edulis,Portulaca oleracea, and Mulberry Leaves in the Treatment of Hypertension and Type 2 DM: A Comprehensive Review

Diabetes mellitus (DM) and hypertension are 2 of the most prevalent diseases with poor impact on health status worldwide. In most cases, they coexist with other metabolic disorders as well as cardiac, micro- and macrovascular complications. Many plants are known for their hypotensive, cardioprotective, and/or antidiabetic activities. Their active ingredients either identified and isolated or still utilized as herbal preparations of certain plant parts. The use of medicinal plants comprises the main basis for most of the traditional medicine (TM) systems and procedures. As conventional medicines seem insufficient to control such progressive diseases, herbal agents from TM could be used as adjuvant with good impact on disease control and progression as well as other concomitant health conditions. The aim of this study is to compare the efficacy of 10 different herbal medicines of botanical origin or herbal preparations in the management of hypertension and its cardiovascular complications and type 2 DM along with various coexisting health disorders. These herbal medicines are garlic, berberine, resveratrol, Hibiscus sabdariffa, Zizyphus ( oxyphylla, mucronate, jujube, rugosa), hesperidin, red beetroot, Catha edulis, mulberry leaves, and Portulaca oleracea.

Rewarding Effect of Catha edulis (Khat) and the Sex Differences to the Responses in Swiss Albino Mice

Background

Burden of substance abuse is becoming a worldwide problem. One of the psychostimulant plants widely consumed in Ethiopia and other East African countries is Catha edulis Forsk (khat). Most of the users claim that its stimulatory effect is the determinant factor that makes them use. However, its rewarding and reinforcing potential and variation between sexes have not been investigated. This study was, therefore, designed to measure the rewarding effect of khat extract (ke) in the addiction mice model of both sexes.

Materials and Methods

Forty-eight Swiss albino mice of both sexes (age 6–7 weeks) weighing 21–33 gm were used. The mice were conditioned to ke (100 mg/kg, 200 mg/kg and 300 mg/kg b.w). The control group was conditioned to tween 80 (2%, v/v) in distilled water. The reinforcing effect of khat was evaluated using the conditioned place preference paradigm. The classical pairing to the extract was made using the place conditioning box. Post-conditioning tests have been conducted four times and the average values were taken for analysis using SPSS version 21.0.

Results

Time spent in the khat-paired compartment was significantly higher for mice conditioned to ke 200 mg/kg (p<0.05) and ke 300 mg/kg (p<0.001). The rewarding effect of khat was strong in females at a higher dose when compared to the same sex of mice conditioned to the vehicle (p<0.001) or male mice conditioned to the same dose of khat extract (p<0.05). Repeated administration increased khat rewarding sensitization at all doses. Though the crude khat extract did not affect the food consumption and total body weight, water consumption was significantly less in mice received ke 100 mg/kg (p<0.01), where it was significantly higher in mice received ke 300 mg/kg (p<0.01). Sniffing (p<0.05) and climbing (p<0.05) psychomotor activities of mice were also affected by the crude khat extract.

Conclusion

Mice showed place conditioning to khat extract, and the response was significantly higher in female mice. The crude khat extract did not affect food consumption and total body weight. The mechanisms behind the rewarding response of khat extract and sexual differences should be investigated.

Natural Phytochemicals and Their Therapeutic Role in Management of Several Diseases: A Review

Introduction:

These days, a lot of people face some health-related problems in day to day life. The conventional synthetic medicine is not effective enough to cure them alone. The conventional therapy for the management of these health-related issues involves the use of hazardous synthetic chemicals and surgical diagnosis, which have lots of serious side effects. It is necessary to conduct research on herbal medicines, this is an alternative approach to avoid the side effects of synthetic medicines to achieve high effectiveness, low cost and improve patient compliance.

Methods:

The present survey is an analysis of some of the available data on the use of plants with their biological source, active phytochemicals constituents and a probable activity/ mechanism of action of several classes of drugs. This work also focused on highlighting the advantages of natural medicines for maximum utilization.

Results:

This article aims to increase awareness about natural medicine and help people find a suitable herbal medicine for the treatment of specific diseases.

Conclusion:

This article also exhibits the scope for further process in the development of new natural substance for the management of several diseases.

Anti-obesity effects of dichloromethane leaf extract of Gnidia glauca in high fat diet-induced obese rats

BACKGROUND

Obesity is a chronic metabolic disorder characterized by increased adipose tissue mass due to positive energy balance. Prescription of anti-obesity drugs can be useful adjuncts to diet and exercise for obese patients who have failed to achieve weight loss. However, these drugs are ineffective and are associated with adverse effects. In recent times, medicinal plants have drawn a sharp focus owing to their biocompatibility and effectiveness. Attempts to determine the therapeutic effects and identification of bio-active principles from herbal prescriptions have become the prime focus in the validation of their folkloric usage and in drug discovery programs. Therefore, the present study aimed to determine the anti-obesity effects of Dichloromethane leaf extract of Gnidia glauca in high-fat-diet-induced obese rats.

METHODS

Obesity was induced experimentally in white albino Wistar rats by feeding them with prepared high-fat-diet and water ad libitum for a period of 12 weeks. The in-vivo anti-obesity effects were determined by oral administration of Gnidia glauca at dosage levels of 200, 250 and 300 mg/kg body weight from the 6th to 12th week of study. Phytochemical analysis of Gnidia glauca was conducted using gas chromatography linked to mass spectrophotometer.

RESULTS

The results indicated that Gnidia glauca exhibited potent anti-obesity effects. It significantly reduced the body weight, organ weights, organo-somatic indices, anthropometric indices, the total fat content, adiposity index, atherogenic index as well as various lipid profiles. It also decreased the total feed intake. However, it significantly increased levels of high-density lipoproteins and rectal body temperature of rats. Quantitative phytochemical analysis also revealed the presence of various phytocompounds that have shown to be associated with anti-obesity effects.

CONCLUSION

The anti-obesity effects of Gnidia glauca maybe attributed to the phytochemicals present. The present study, therefore, scientifically validates the traditional use of Gnidia glauca as a potential candidate for the synthesis of new effective anti-obesity supplement.

Natural anti-obesity agents and their therapeutic role in management of obesity: A future trend perspective

In the present scenario, obesity is a challenging health problem and its prevalence along with comorbidities are on the rise around the world. According to world health organization and organisation for economic co-operation and development epidemiology reports, overweight and obesity are the fifth foremost causes of deaths globally. The increasing rate of obesity is becoming a mammoth problem which enormously affects an individual's quality of life. The conventional therapy of obesity mainly involves synthetic moieties and surgical procedures, which has many harmful side effects and chances of recurrence with severity. Hence, the Present review is a metanalysis of all the available data on the use of the plants with their biological source, active phytochemical constituents and a probable mechanism of action as natural anti-obesity agents. The metanalysis of data during the period of 2000-2018 was performed with the help of scientific data search engine National Center for Biotechnology Information (NCBI/PubMed). This data reveals the need and scope of further research in the development of new natural phytoconstituents for the management of obesity.

Natural Products with Anti-obesity Effects and Different Mechanisms of Action

Obesity, a primary influence on health condition, causes numerous comorbidities and complications and, therefore, pharmacotherapy is considered a strategy for its treatment. However, the adverse effects of most chemical drugs targeting weight loss complicate their approval by regulatory authorities. Recently, interest has increased in the development of ingredients from natural sources with fewer adverse effects for preventing and ameliorating obesity. This review provides an overview of current anti-obesity drugs and natural products with anti-obesity properties as well as their mechanisms of action, which include interfering with nutrient absorption, decreasing adipogenesis, increasing energy expenditure (thermogenesis), appetite suppression, modifying intestinal microbiota composition, and increasing fecal fat excretion.

Projection neurons in the cortex and hippocampus: differential effects of chronic khat and ethanol exposure in adult male rats

BACKGROUND

Recent evidence suggests that many individuals who chew khat recreationally also drink ethanol to offset the stimulating effect of khat. The objective of this study was to describe the separate and interactive effects of chronic ethanol and khat exposure on key projection neurons in the cortex and hippocampus of young adult male rats.

METHODS

Young adult male Sprague Dawley rats were divided into six treatment groups: 2 g/kg khat, 4 g/kg khat, 4 g/kg ethanol, combined khat and ethanol (4 g/kg each), a normal saline control, and an untreated group. Treatments were administered orally for 28 continuous days; brains were then harvested, sectioned, and routine hematoxylin-eosin staining was done. Following photomicrography, ImageJ® software captured data regarding neuron number and size.

RESULTS

No differences occurred in counts of both granular and pyramidal projection neurons in the motor cortex and all four subfields of the hippocampal formation. Khat dose-dependently increased pyramidal neuron size in the motor cortex and the CA3 region, but had different effects on granular neuron size in the dentate gyrus and the motor cortex. Mean pyramidal neuron size for the ethanol-only treatment was larger than that for the 2 g/kg khat group, and the saline control group, in CA3 and in the motor cortex. Concomitant khat and ethanol increased granular neuron size in the motor cortex, compared to the 2 g/kg khat group, the 4 g/kg khat group, and the 4 g/kg ethanol group. In the CA3 region, the 4 g/kg ethanol group showed a larger mean pyramidal neuron size than the combined khat and ethanol group.

CONCLUSION

These results suggest that concomitant khat and ethanol exposure changes granular and pyramidal projection neuron sizes differentially in the motor cortex and hippocampus, compared to the effects of chronic exposure to these two drugs separately.

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.

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.

Effect of Habitual Khat Chewing on Glycemic Control, Body Mass Index, and Age at Diagnosis of Diabetes in Patients with Type 2 Diabetes Mellitus in Yemen

Khat chewing is common in Yemen. We conducted this study to see if it affected diabetes control in patients with type 2 diabetes mellitus (DM). We studied 1540 patients with type 2 DM attending an endocrinology clinic in Sana’a, Yemen, of which 997 were khat chewers (KC) and 543 were non-khat chewers (NKC). The patients answered a questionnaire regarding khat chewing. Hemoglobin A1c (HbA1c) and body mass index (BMI) were measured. KC had a higher mean HbA1c of 9.8 (95% confidence interval (95% CI) 9.6–10) than the NKC, with a mean of 9.1 (95% CI 8.9–9.4) (adjusted odds ratios (AOR) 1.74, P < 0.001) after multivariate regression analysis. KC also had a lower mean BMI, 26.9 (95% CI 26.6–27.2), than the NKC, mean BMI 27.6 (95% CI 27.1–28) (P < 0.01). The mean age at diagnosis of DM among the KC group was 43.3 (10.1) and among the NKC group was 45.9 (11.8) (AOR 1.4 P < 0.008) after multivariate regression analysis. KC patients had a higher mean HbA1c, a lower BMI, and a younger age at diagnosis of type 2 DM when compared with NKC.

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.

Acute and sub-chronic effects of purified cathinone from khat (Catha edulis) on behavioural profiles in vervet monkeys (Chlorocebus aethiops)

We investigated the cumulative effects of cathinone on behavioural alterations in single-caged vervet monkeys. Fourteen adult vervets were divided into tests (12 animals) and controls (2 animals), and exposed to escalating doses of cathinone at alternate days of each week for 4 months in presence and absence of cage enrichment. One month of pre-treatment phase served to establish baseline values. Composite behavioural scores of aggression, anxiety, abnormal responses, withdrawal and appetite loss were done. A series of repeated measures analysis of variances were conducted to examine the extent to which cathinone administration was associated with patterns of changes in behavioural data. Results indicate a dose-dependent effect of cathinone on increases of aggression, anxiety, abnormal responses, withdrawal, and appetite loss. The findings demonstrate that at high doses and long-term exposure, cathinone causes behavioural alterations probably via changes in presynaptic striatal dopamine system.

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.

Herbal delivery system for treatment of obesity administration of encapsulated khat-extracts on body weight of rats

SUMMARY

Obesity is one of the most important problems worldwide. Khat (Catha edulis), an evergreen shrub, is thought to reduce body-weight. Its effect is more prominent when khat leaves are chewed. Thus, anti-obesity effects of khat and its associated side effects may depend on the release rate of its active constituents. The present study aimed to investigate the effect of a selected low dose of dried-khat, extracted, formulated as controlled release delivery systems on the body weight (BW), food intake (FI), cholesterol (CS) and triglyceride (TG) levels in rats. Khat extract (KE) was microencapsulated (KE235) and formulated into a parenteral implant (InjKE235). The effects of KE, KE235 and InjKE235 on BW, FI, CS and TG in rats were investigated. The results showed that microcapsules sustained the khat alkaloid release with T50% 1.58 h for KE235 and 14.41 days for InjKE235. KE and KE235 caused maximum reduction in BW, FI, CS and TG during the first to third weeks but rebound gradually thereafter. On the contrary, InjKE235 exhibited a sustained reduction in BW, FI, CS and TG levels for 2 months. The T50% of KE, KE235 and InjKE235 correlated with the reduction in BW, CS and TG but not with FI. In conclusion, the subcutaneous injection and sustained release rate of khat extract play an important role in enhancing the anti-obesity effect in SD rats.:

Khat chewing and cardiovascular risk profile in a cohort of Yemeni patients with angiographically documented coronary artery disease

OBJECTIVE

We sought to explore the prevalence of khat chewing and cardiovascular risk profile in a cohort of Yemeni patients with angiographically documented coronary artery disease (CAD).

METHODS

We enrolled 100 consecutive Yemeni patients who underwent elective coronary catheterisation. Patients were considered eligible for enrolment if they had angiographically documented significant CAD (>50% obstruction). History of khat chewing was obtained and recorded at the time of presentation. Coronary angiography was performed using the standard technique. Reference vessel diameter and the per cent diameter stenosis were measured using quantitative coronary analysis. Patients were classified according to the number of sizable coronary arteries affected by significant stenosis into three groups: single-vessel disease, two-vessel disease and multi-vessel disease groups.

RESULTS

The mean age was 54.7±11.8 years (16% females); 86% were khat users, 46% had single-vessel disease, 36% had two-vessel disease and 18% had multi-vessel disease. Fifty-four per cent were smokers, 11% were diabetic and 15% were hypertensive. The mean body mass index was 24.7±3.6, the mean serum low-density lipoprotein cholesterol was 129±41 mg/dl, whereas the mean serum triglyceride level was 187±90 mg/dl; the mean serum high-density lipoprotein cholesterol was 38±11 mg/dl. No correlation was found between the extent of CAD and any of the clinical, echocardiographic or laboratory data.

CONCLUSIONS

In Yemeni patients undergoing elective coronary angiography, khat use was highly prevalent, whereas several classic risk factors were relatively infrequent. None of the risk factors or khat use differed substantially with the extent of CAD.

Plants' metabolites as potential antiobesity agents

Obesity and obesity-related complications are on the increase both in the developed and developing world. Since existing pharmaceuticals fail to come up with long-term solutions to address this issue, there is an ever-pressing need to find and develop new drugs and alternatives. Natural products, particularly medicinal plants, are believed to harbor potential antiobesity agents that can act through various mechanisms either by preventing weight gain or promoting weight loss amongst others. The inhibition of key lipid and carbohydrate hydrolyzing and metabolizing enzymes, disruption of adipogenesis, and modulation of its factors or appetite suppression are some of the plethora of targeted approaches to probe the antiobesity potential of medicinal plants. A new technology such as metabolomics, which deals with the study of the whole metabolome, has been identified to be a promising technique to probe the progression of diseases, elucidate their pathologies, and assess the effects of natural health products on certain pathological conditions. This has been applied to drug research, bone health, and to a limited extent to obesity research. This paper thus endeavors to give an overview of those plants, which have been reported to have antiobesity effects and highlight the potential and relevance of metabolomics in obesity research.

Comprehensive review on herbal medicine for energy intake suppression

The obesity drug development is present not a bright and successful story. So far, drugs reported to be effective, either from synthetic or natural sources, mostly stimulated controversy because of serious adverse effects, which ended with stopping clinical trials or even withdrawal from the market. However, obesity and its comorbidities have become rapidly a major problem in both developed and developing countries. This has encouraged pharmaceutical companies and academia to keep on struggling on developing novel effective but safe obesity drugs, and on characterizing novel obesity drug targets. From existing scientific work on obesity drug discovery and commercial slimming preparations, compounds originating from nature, especially from plants, seem to be the first choice. Traditional belief that herbal medicine is safer than synthetic ones is one of the classical arguments, although scientifically this is not always true (e.g. ban on Ephedra). But in general, it has been widely acknowledged that a plant compound, with its unique scaffolds and rich diversity is an unlimited source of novel lead compounds. This paper aims to summarize all works focused on screening plant materials by targeting important pathways related to energy intake regulation, either by in vivo or in vitro experiments.

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

The leaves of khat (Catha edulis Forsk.) are chewed as a social habit for the central stimulant action of their cathinone content. This review summarizes the prevalence of the habit worldwide, the actions, uses, constituents and adverse health effects of khat chewing. There is growing concern about the health hazards of chronic khat chewing and this review concentrates on the adverse effects on health in the peripheral systems of the body, including the cardiovascular system and gastrointestinal tract. Comparisons are made with amphetamine and ecstasy in particular on the detrimental effects on the cardiovascular system. The underlying mechanisms of action of khat and its main constituent, cathinone, on the cardiovascular system are discussed. Links have been proposed between khat chewing and the incidence of myocardial infarction, dilated cardiomyopathy, vascular disease such as hypertension, cerebrovascular ischaemia and thromboembolism, diabetes, sexual dysfunction, duodenal ulcer and hepatitis. The evidence, however, is often based on limited numbers of case reports and only few prospective controlled studies have been undertaken. There is therefore an urgent need for more thorough case-control studies to be performed. This review outlines the current knowledge on the adverse health effects of khat chewing on the cardiovascular system and other internal medical problems, it assesses the evidence and the limitations of the studies and identifies the questions that future studies should address.

Phytochemicals in the Control of Human Appetite and Body Weight

Since obesity has grown to epidemic proportions, its effective management is a very important clinical issue. Despite the great amount of scientific effort that has been put into understanding the mechanisms that lead to overconsumption and overweight, at the moment very few approaches to weight management are effective in the long term. On the other hand, modern society is also affected by the growing incidence of eating disorders on the other side of the spectrum such as anorexia and bulimia nervosa which are equally difficult to treat. This review will try to summarise the main findings available in the literature regarding the effect of plants or plant extracts (phytochemicals) on human appetite and body weight. The majority of plant extracts are not single compounds but rather a mixture of different molecules, therefore their mechanism of action usually targets several systems. In addition, since some cellular receptors tend to be widely distributed, sometimes a single molecule can have a widespread effect. This review will attempt to describe the main phytochemicals that have been suggested to affect the homeostatic mechanisms that influence intake and body weight. Clinical data will be summarised and scientific evidence will be reviewed.