Cytotoxic effect of esculetin on myeloma and myelogenous leukemic cells.
The cytotoxic effect of Esculetin to mouse myeloma and human acute myelogenous leukemia cells invitro was evaluated. Tumor cells exposed to Esculetin in culture showed an exponential cytotoxic responses. A decreased viabilities of both leukemic cells were noticed with 20, 40 and 80 µg / ml Esculetin. Besides, myeloma cells showed a progressive depletion of viability when exposed continuously for 1,2,3 and 4 days, whereas , pretreatment of myeloma cells with Esculetin for 1,2,4 and 24 h followed by removal of the chemical and culturing the cells for 3 days indicated that the time the cells much effected was 24 h post exposure. At this exposure time , exposure to 10 µg / ml decreased the able cell number to 24.66 × 10-4 cells / ml versus 62.66 × 10-4 cells / ml in the control . t – test = 5.16 , p = 0.007 95 % CI = 17.5 – 58.5. Like wise , a 20 µg / ml concentration of esculetin decreased viable cells number to 23.5 × 10-4 cells / ml versus 62.66 × 10-4 cells / ml of control. T-test 7.39 , P = 0.002. 95 % CI = 24.5 – 53.8. The efficiency of Esculetin in protecting mice implanted with syngeneic myeloma was studied . The results of invivo experiment demonstrated that the chemical could protect mice from lethal dose of the experimentally implanted tumor . The protection value reached 66.7 % in animals treated with 200 or 400 µg Esculetin for 10 consecutive days. For 200µg drug plus myeloma versus myeloma only , chi – square value was 3.086 p=0.08 and 95% CI = 0-2.4. However , at 400 µg drug plus myeloma versus myeloma only , the chi – square analysis showed a value of 4.17 , P=0.04 95% CI = 0.02 – 1.3. Besides , the survival of the animals was increased . The therapeutic relevance and speculated mechanism of Escletin cytotoxic effects are discussed. In conclusion , it seems that esculetin has antiproliferative effects to mouse myeloma and to human myelogenous leukemia cells.