Effects of Catha Edulis Forsk on spatial learning, memory and correlation with serum electrolytes in wild-type male white albino rats.

BACKGROUND: The burdens of psychostimulant use disorders are becoming a worldwide problem. One of the psychostimulants widely consumed in Ethiopia and East African countries is Catha edulis Forsk (khat). However, no studies have been conducted on the cognitive effects of khat and its correlation with serum electrolytes. The present study was aimed to evaluate the effects of khat on spatial learning and memory and their correlation with serum electrolytes. MATERIALS AND METHODS: Diethyl ether and chloroform (3:1v/v ratio) were solvents used to obtain the crude khat extract in this study. T80W was used to prepare the khat juice, fresh khat leave extract. The rats were received crude khat extract subchronically (KESC) (100 mg/kg, 200 mg/kg and 300 mg/kg b.w), khat juice (KHJ 2.5 mL/kg), 2% tween 80 in distilled water (T80W- v/v, vehicle) and khat extract subacutely (KESA) (300 mg/kg). For subchronic treatment, each rat was administered for twelve weeks before Morris water maze experiment has been started, while it was administered for a week for acute treatment. Spatial learning and memory were measured using the Morris water maze model and serum sodium, calcium, potassium, and chloride were evaluated using Cobas 6000. RESULTS: Spatial learning was improved with trials across the groups, while average escape latency (s) of rats received KESC 200 mg/kg (p<0.001), KESC 300 mg/kg (p<0.01) and KHJ 2.5 mL/kg (p<0.05) was significantly greater than rats that received vehicle. There was no significant difference in the latency between rats that received KESA 300mg/kg and vehicle (p>0.05). Thigmotaxis was significantly higher in rats that received all doses of khat extract (p<0.001). The time spent in the target quadrant in rats that received KESC 300 mg/kg was significantly reduced (p<0.05). Serum calcium level was inversely correlated with the escape latency (R = -0.417, p<0.05) in rats that received khat. CONCLUSIONS: Khat extract and juice administered subchronically, but not subacutely, impaired learning and memory and was associated with serum calcium reduction. The neuronal basis for such alteration should be investigated.

Khat chewing leads to increase in glycaemic parameters in patients with type 2 diabetes mellitus in Jazan region, Saudi Arabia and Yemen.

BACKGROUND: Khat is known to have a stimulating effect on the sympathetic nervous system by producing a temporary sensation of activeness and happiness, along with mood disturbance and anxiety. Despite growing evidence of the association between khat chewing and glycaemic control in patients with diabetes, the position of khat chewing in DM is not fully recognised. AIM: To evaluate the association of khat chewing with the risk of elevated blood glucose levels among patients with type 2 diabetes mellitus. METHOD: A web-based literature search was performed using the electronic databases PubMed, EMBASE and Google Scholar. Databases were searched for studies published about khat chewing and diabetes mellitus in the Jazan region, Saudi Arabia and Yemen. RESULT: Twenty-five published articles studying the relation between khat chewing and diabetes mellitus were identified, but only 10 studies reported an association between khat chewing and blood glucose levels and were included. CONCLUSION: Khat chewing increases fasting blood glucose, post-prandial blood glucose and HbA1c levels in patients with diabetes in the Jazan region, Saudi Arabia and Yemen.

In vitro effects of 95% khat ethanol extract (KEE) on human recombinant cytochrome P450 (CYP)1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2 and CYP3A5.

OBJECTIVES: Khat, a natural amphetamine-like psychostimulant plant, are widely consumed globally. Concurrent intake of khat and xenobiotics may lead to herb-drug interactions and adverse drug reactions (ADRs). This study is a continuation of our previous study, targeted to evaluate the in vitro inhibitory effects of khat ethanol extract (KEE) on human cytochrome (CYP) 1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2, and CYP3A5, major human drug metabolizing enzymes. METHODS: In vitro fluorescence enzyme assays were employed to assess CYPs inhibition with the presence and absence of various KEE concentrations. RESULTS: KEE reversibly inhibited CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2 and CYP3A5 but not CYP1A2 with IC50 values of 25.5, 99, 4.5, 21, 27, 17, and 10 µg/mL respectively. No irreversible inhibition of KEE on all the eight CYPs were identified. The Ki values of CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2 and CYP3A5 were 20.9, 85, 4.8, 18.3, 59.3, 3, and 21.7 µg/mL, respectively. KEE inhibited CYP2B6 via competitive or mixed inhibition; CYP2E1 via un-competitive or mixed inhibition; while CYP2A6, CYP2C8, CYP2C19, CYP2J2 and CYP3A5 via non-competitive or mixed inhibition. CONCLUSIONS: Caution should be taken by khat users who are on medications metabolized by CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2, and CYP3A5.

Khat Chewing Habits in the Population of the Jazan Region, Saudi Arabia: Prevalence and Associated Factors.

The use of khat (Catha edulis) is a major public health and social problem that is believed to be growing globally. The khat chewing habit is prevalent in all areas of the Jazan region, Kingdom of Saudi Arabia (KSA). However, few studies have been conducted at the community level to investigate the khat chewing habits in this area. This study was conducted with the aim of assessing the prevalence and predictors of khat chewing among the Jazan community population. A cross-sectional study was conducted with a sample (n = 4,500) of the Jizani population who attended primary heath care centers in Jazan region. The participants were selected using a two-stage cluster random sampling. A structured questionnaire was used for data collection. The overall lifetime prevalence of khat chewing was 33.2% (95% CI 31.8-34.7) and was significantly higher for males 42.2% (95% CI 40.4-43.9) than for females 11.3% (95% CI 9.6-13.1) (P < 0.001). Current khat chewers accounted for 28.7% (95% CI 27.4-30.1) of the population sampled; 36.9% (95% CI 35.2-38.6) of whom were males, which is a significantly higher percentage than the 8.7% (95% CI 7.3-10.4) of current khat chewers who were females (P < 0.001). The multivariate logistic regression analysis suggests that the most important independent predictors of khat chewing were having a friend who chewed khat (OR = 20.1, P < 0.001), participant's smoking status (OR) = 3.9, P < 0.001), friend's smoking status (OR = 2.2, P < 0.001), gender (OR = 2.2, P < 0.001) and educational level (OR = 1.5, P < 0.05). A large proportion of the Jizani populations chew khat. Government and non-governmental organizations NGOs should design and strengthen community prevention programs to curb the high prevalence of khat use.

Transcriptome profiling of khat (Catha edulis) and Ephedra sinica reveals gene candidates potentially involved in amphetamine-type alkaloid biosynthesis.

Amphetamine analogues are produced by plants in the genus Ephedra and by khat (Catha edulis), and include the widely used decongestants and appetite suppressants (1S,2S)-pseudoephedrine and (1R,2S)-ephedrine. The production of these metabolites, which derive from L-phenylalanine, involves a multi-step pathway partially mapped out at the biochemical level using knowledge of benzoic acid metabolism established in other plants, and direct evidence using khat and Ephedra species as model systems. Despite the commercial importance of amphetamine-type alkaloids, only a single step in their biosynthesis has been elucidated at the molecular level. We have employed Illumina next-generation sequencing technology, paired with Trinity and Velvet-Oases assembly platforms, to establish data-mining frameworks for Ephedra sinica and khat plants. Sequence libraries representing a combined 200,000 unigenes were subjected to an annotation pipeline involving direct searches against public databases. Annotations included the assignment of Gene Ontology (GO) terms used to allocate unigenes to functional categories. As part of our functional genomics program aimed at novel gene discovery, the databases were mined for enzyme candidates putatively involved in alkaloid biosynthesis. Queries used for mining included enzymes with established roles in benzoic acid metabolism, as well as enzymes catalyzing reactions similar to those predicted for amphetamine alkaloid metabolism. Gene candidates were evaluated based on phylogenetic relationships, FPKM-based expression data, and mechanistic considerations. Establishment of expansive sequence resources is a critical step toward pathway characterization, a goal with both academic and industrial implications.

Khat a drug of abuse: roles of free radicals and antioxidants.

Many articles have reviewed the health impact of Khat consumption; however the role of free radicals in the pathogenesis associated with short- and long-term consumption of Khat is absent in the literature. As free radicals and antioxidants converge across various mechanisms in normal physiological function and in disease, this review attempts to uncover the role of endogenous free radicals and the mechanism of cellular injury associated with Khat consumption.

Camptothecin and khat (Catha edulis Forsk.) induced distinct cell death phenotypes involving modulation of c-FLIPL, Mcl-1, procaspase-8 and mitochondrial function in acute myeloid leukemia cell lines.

BACKGROUND: An organic extract of the recreational herb khat (Catha edulis Forsk.) triggers cell death in various leukemia cell lines in vitro. The chemotherapeutics camptothecin, a plant alkaloid topoisomerase I inhibitor, was tested side-by-side with khat in a panel of acute myeloid leukemia cell lines to elucidate mechanisms of toxicity. RESULTS: Khat had a profound effect on MOLM-13 cells inducing mitochondrial damage, chromatin margination and morphological features of autophagy. The effects of khat on mitochondrial ultrastructure in MOLM-13 correlated with strongly impaired routine respiration, an effect neither found in the khat-resistant MV-4-11 cells nor in camptothecin treated cells. Enforced expression of anti-apoptotic Bcl-2 protein provided protection against camptothecin-induced cell death and partly against khat toxicity. Khat-induced cell death in MOLM-13 cells included reduced levels of anti-apoptotic Mcl-1 protein, while both khat and camptothecin induced c-FLIPL cleavage and procaspase-8 activation. CONCLUSION: Khat activated a distinct cell death pathway in sensitive leukemic cells as compared to camptothecin, involving mitochondrial damage and morphological features of autophagy. This suggests that khat should be further explored in the search for novel experimental therapeutics.

Developmental patterns of phenylpropylamino alkaloids accumulation in khat (Catha edulis, Forsk.).

Khat (Catha edulis Forsk., Celastraceae) is a perennial shrub that was introduced to Israel by Yemenite immigrants. Khat young leaves are chewed as a stimulant. The main stimulating active principles in this plant are the phenylpropylamino alkaloids (-)-cathinone [(S)-alpha-aminopropiophenone], (+)-cathine [(+)-norpseudoephedrine] and (-)-norephedrine. A novel GC-MS analysis method for the quantitative determination of phenylpropylamino alkaloids and their putative precursor 1-phenyl-1,2-propanedione in khat leaves was developed. We found a marked diversity in the phenylpropylamino alkaloids content and composition in 9 different accessions originated in seedlings and in the commercial cultivar "Mahanaim". The highest 1-phenyl-1,2-propanedione and (-)-cathinone levels occur in young leaves, the part traditionally chewed for its psycho-stimulating properties. Older leaves lack (-)-cathinone but contain the less active (+)-cathine and (-)-norephedrine. Young stems and flowers also contain 1-phenyl-1,2-propanedione, (-)-cathinone, (+)-cathine and (-)-norephedrine. We report the presence of a (-)-cathinone reductase in khat leaves capable of reducing (-)-cathinone to (+)-cathine in the presence of NADPH. We propose that (-)-cathinone is a biosynthetic precursor of (+)-cathine and (-)-norephedrine in khat leaves.