Tetrahydroxyquinone (100-500 μM; 24 hours; HL60 cells) treatment shows cytotoxic for HL60 leukaemia cells by total protein content (IC ₅₀ of 20 μM), phosphatase activity (IC ₅₀ of 40 μM), or by MTT assay (IC ₅₀ of 45 μM). Tetrahydroxyquinone is an efficient inducer of ROS production in HL60 leukaemia cells.
Tetrahydroxyquinone efficiently activates caspase 3 in concentration in excess of 25 μM, stimulates DNA fragmentation at the same concentration and provoke phosphatidylserine exposure.
Tetrahydroxyquinone induces the release of cytochrome c from the mitochondria at concentration as low as 25 μM. Tetrahydroxyquinone treatment also causes increase of phosphorylation of Ser473 in protein kinase B (the Bad kinase for Ser112).