Abstract

PHARMACOLOGICAL STUDIES OF CATHA EDULIS FORSK. ON ISOLATED ANIMALS TISSUES

Nasreddin Osman Sabir*, Amna El Hassan Hamad, Siddig Ibrahim Abdelwahab, Manal Mohamed Elhassan Taha and Bashir Mohamed Ahmed

Abstract

There is growing concern about the health hazard of chronic khat (Catha edulis forsk.) chewing and this research concentrates on the adverse effects of this abused plant including the gastrointestinal tract, reproductive, cardiovascular and muscular system. Extraction of Catha edulis leaves was done and the presence of cathine was confirmed with LC-MS-MS. Hence in this study, we exposed cathine-rich khat extract (KARF) to the vitro models of the three types of muscle tissues (cardiac, smooth and skeletal). This includes rabbit jejunums and aortas, rat fundus strips and uteri, frog rectus abdominal muscles and guinea pig ileum and atria. Acetylcholine (ACh), 5-hydroxytryptamine (5-HT), carbachol, isoprenaline, salbutamol, noradrenaline and histamine were used as positive controls. The current observations recommend that the vasoconstriction of noradrenaline on aorta ring strips was inhibited by the sympatholytic of KARF. KARF alone did not induce any cardio-pharmacological effects. However prior administration of KARF effects the myocardial increasing effects of only non-selective (isoprenaline) but not the selective beta2 adrenoreceptor (salbutamol) agonist on the atrium. Contractile response to carbachol, ACh and 5-HT were dose-dependently antagonized by preadministration of KARF. The spasmogenic effect of histamine on guinea pig ileum were observed to be antagonized by the KARF in a concentration dependent manner. These current findings on isolated animal tissues and organs after KARF administration should be a warning regarding the health hazards of khat chewing.

Keywords: Catha edulis; Animal models; Ach; 5-HT; Alkaloid rich extraction.