Abstract
Aloe saudiarabica and Aloe shadensis are a rare species of the genus Aloe found only in Saudi Arabia. The cytotoxic activity of both plants were evaluated in the current study using three different human cancer cell line, lung carcinoma (A-549), breast adenocarcinoma (MCF-7) and liver cancer (HepG2), assessed by WST-1 cell viability assays. The results indicate that the Aloe saudiarabica and Aloe shadensis showed weak cytotoxic effects against all three tested cancer cell lines, with an IC50 value of >300 mu g/ml. In addition, HepG2 cells were more sensitive to Aloe saudiarabica treatment than MCF-7 and A549 cells, while MCF-7 cells were more sensitive to Aloe shadensis treatment than HepG2 and A549 cells. This study also identified the characteristic chemical constituents of the two plants using gas chromatography-mass spectrometry technique and the result indicated that 9-octadecenoic acid (Z)-, methyl ester (32.23%) was the main compound of Aloe saudiarabica while methyl 9-octadecenoate (17.28%) was the main compound of Aloe shadensis. In conclusion, the in vitro evaluation of Aloe saudiarabica and Aloe shadensis methanolic extraction showed low cytotoxicity on the viability of A-549, MCF-7 and HepG2 cell lines.