CYTOTOXICITY OF A LOW-MOLECULAR-WEIGHT FRACTION FROM ALOE-VERA (ALOE-BARBADENSIS MILLER) GEL

The cytotoxicity of a low mel. wt fraction (LMWF) obtained from Aloe v ela gel was determined by two different assays. Firstly, exposure of m onolayers of chicken fibroblasts to LMWF induced disruption of interce llular junctions and detachment of individual cells from the bottom of the flask, with formation of cell-free gaps in the monolayer. Secondl y, LMWF inhibited the production of reactive oxygen species by human p olymorphonuclear leukocytes stimulated by zymosan, as followed by lumi nol-dependent chemiluminescence. The toxic activity of LMWF was compar ed to that of sodium dodecyl sulfate (a well-known toxic substance), a loe-emodin and aloin (an anthraquinone and its precursor present in Al oe vera cortex) using the chemiluminescence assay, and was found to be of similar potency to these toxic substances on a weight-to-weight ba sis. These results confirm that Aloe vel a gel contains toxic low mel. wt compounds, and every effort must be made to limit the amount of th ese toxins in the commercially prepared Aloe vera gel products. (C) 19 97 Elsevier Science Ltd.