Activity of Aloe arborescens leaf extracts: in vitro effects on Human Adenocarcinoma HT-29 cell line and free-radical species.

Aloe arborescens Mill. (syn. Candelabra Aloe; Xanthorrhoeaceae) is native to South Africa; in Italy it is grown for ornamental, therapeutic and cosmetic uses. Various Aloe spp. have been used since ancient times and have a well-documented history of use as medicines. Nowadays, it is widely studied as potential anticancer, antidiabetic, antimicrobial and for several other uses. The presence of aloin, aloe-emodin, polysaccharides, mannose and acemannan was reported in whole-leaf preparations. The aim of the present research was to study Aloe arborescens leaf extracts, also to improve the uses of Aloe since many products are marketed also in Western countries. For this purpose, methanolic and ethanolic extracts were obtained from freeze-dried leaves, and then studied using: a) HPLC-DAD analysis to determine aloins and aloe-emodin contents, b) two radical-scavenging assays to assess the radical scavenger activity, and 3) MTT assay on colorectal adenocarcinoma cell line (HT29 cells) to evaluate cell viability.