Figure 1: Inhibition of cancer cell growth by Catha edulis Forsk (CEF) extract. A colorimetric assay was used to determine proliferation of tumour cells (5000 cells/well in a 96 well plate) exposed to different concentrations of CEF extract (3–333 μg/mL) using a 33 mg/mL stock solution. WST-1 was added to each well plate and incubated for 4 hrs at 37°C. As a control, DMSO was added instead of the plant extract (zero value). The absorbance was measured at a wavelength of 450/620 nm by an ELISA reader. The reduction in cell number was calculated from the absorbance given in percent. Statistical significance was calculated using unpaired -test, at 95% CI (*).