1999 Volume 22 Issue 12 Pages 1271-1274
Hypericin is a unique photosensitizing plant pigment and has been separately reported to induce differentiation and apotosis in neoplastic cells. In this study, we examined the relationship between activities to induce differentiation and apoptosis in human promyelocytic leukemia HL-60 cells, at a concentration range of 0.15 to 0.2μM. When treated with hypericin, the cell ratio reducible of nitroblue tetrazolium was significantly increased and the cell size was enlarged by flow cytometry analysis. Hypericin also significantly increased the ratio of the cells, which were of positive α-naphthyl acetate esterase activity and phagocytic activity, whereas it hardly influenced the naphthol AS-D chloroacetate esterase activity in the cells, as well as 1α, 25(OH)2D3 (10nM). In addition, hypericin increased hypodiploid nuclei and caused a nucleosomal ladder. These results indicate that hypericin induced both differentiation toward monocyte/macrophage lineage and apoptosis in HL-60 cells.
