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.

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.