Acute oral administration of Khat (Catha edulis) aqueous extract elevates blood pressure and prolongs QT and QTC intervals in Wistar albino rats

OBJECTIVE: To investigate the effect of Khat (Catha edulis) acute administration on blood pressure (BP) and electrocardiogram (ECG) in vivo.

METHODS: This study was performed between January and February 2009 at the Physiology Laboratory, Medical College of King Khalid University, Abha, Kingdom of Saudi Arabia. Two groups of Wistar rats (n=10), weighing 190-200 g were divided into control group and Khat treated group. Throughout the study, arterial BP and ECG were recorded for 60 consecutive minutes. The data were collected and analyzed by Power Lab Data Acquisition System every 10 minutes, and were compared within and between the groups.

RESULTS: Oral administration of Khat resulted in significant time dependent increases in both systolic and diastolic BP with a maximum increase at minute 60 after extract administration (systolic BP - 34.1%; and diastolic BP - 46.2%). Heart rate was significantly increased at all minutes of the study with a maximum increase occurring at minute 40 (12.8%). There was a significant decrease in PR interval through the experiment, and the maximum decrease was observed at minute 40 (-15.2%). However, QT and QTc started to widen 20 minutes after extract administration with a maximum prolongation in both intervals to occur at minute 40 (QT - 11.6%; QTc - 9.1%).

CONCLUSION: These newly reported changes in the ECG of rats after Khat administration should be a warning regarding the cardiac hazards of Khat chewing.