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BACKGROUND: Khat (Catha edulis Forsk) is a natural psychoactive substance which contains two main addictive substances; Cathine and Cathinone. Khat is widely used in east Africa and southern Arabian Peninsula. Khat chewers believe that it improves work capacity and increases energy level and alertness. That is why we aimed in this study to investigate the physiological and ergogenic effects of khat extract. METHODS: This study is an experimental study conducted at the Substance Abuse Research Centre in Jazan University, Saudi Arabia. Thirty healthy young volunteers were randomly assigned into two experimental groups. The first group ingested 45 g of grounded khat leaves extract mixed with juice in the first session then placebo (juice only) in the second session. While the second group ingested the placebo in the first session and the grounded khat leaves with juice in the second session. Experiments were done between December 2012 and March 2013. We recorded the blood pressure, heart rate, grip strength, and reaction time every 15 min for 75 min after each ingestion. The study proposal was reviewed and approved by Research Ethics Committee (REC) of the Medical Research Centre in Jazan University. RESULTS: The results showed the consumption of 45 g of grounded khat leaves contributed to the increase in blood pressure (SBP & DBP) and reaction time (p < 0.05); but had no significant effect on heart rate and grip strength (p > 0.05). CONCLUSIONS: The findings of this study showed that Khat has an acute effect on some physiological parameters. These findings support the prohibition of cathinone and cathine by the World Anti-Doping Agency (WADA, 2016).

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BACKGROUND: Angiogenesis is involved in many cardiovascular and cancerous diseases, including atherosclerosis and is controlled by a fine balance between angiogenic and angiostatic mediators. Endostatin is one of the main angiostatic mediators, and inhibits angiogenesis and prevents progression of atherosclerosis. The available literature shows a broad range of concentrations in relatively small samples of healthy controls and is calculated by using different techniques. This study was aimed to determine the basal endostatin concentration in plasma of healthy volunteers, to fully understand its physiological role. METHODS: Fifty healthy adult volunteers were recruited to the study. Participants were advised not to participate in any physical activity on the day before the blood sampling. The volunteers' physical activity, height, weight, heart rate and blood pressure were recorded. The samples were analysed for plasma endostatin concentration, using ELISA. The participants were divided by gender and ethnic groups to calculate any difference. RESULTS: Endostatin and other variables were normally distributed. Most of the participants had a moderate level of physical activity with no gender related difference (p=0.370). The mean value for plasma endostatin in all samples was 105±12 ng/ml with range of 81-132 ng/ml. For males, it was 107±13 ng/ml, while for females; 102±12 ng/ml. There were no significant gender or ethnicity related differences in endostatin concentration. Moreover, endostatin was not significantly related with any anthropometric and physical variable. CONCLUSIONS: This study gives endostatin levels in normal healthy people and show no gender and ethnicity related differences in endostatin levels. Endostatin was not related with any anthropometric and physical variable.

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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 T(2) 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).

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