Abstract
Chronic myeloid leukemia (CML) is a clonal disorder characterized by proliferation of hematopoietic cells that possess the
BCR–ABL fusion gene resulting in the production of a 210
kDa chimeric tyrosine kinase protein. CML, when left untreated, progresses to a blast phase during which the disease turns aggressive and shows poor response to known treatment regimens. We have studied a Siddha herbal agent,
Semecarpus anacardium Linn. nut milk extract (SA) for its antileukemic activity and its effect on the changes in energy metabolism in leukemic mice. Leukemia was induced in BALB/c mice by tail vein injection of
BCR–ABL
+
12B1 murine leukemia cell line. This resulted in an aggressive leukemia, similar to CML in blast crisis, myeloid subtype, confirmed by histopathological study and RT-PCR for the p210 mRNA in the peripheral blood, spleen and liver. Leukemia-bearing mice showed a significant increase in lipid peroxides, glycolytic enzymes, a decrease in gluconeogenic enzymes and significant decrease in the activities of TCA cycle and respiratory chain enzymes as compared to control animals. SA treatment was compared with standard drug imatinib mesylate. SA administration to leukemic animals resulted in clearance of the leukemic cells from the bone marrow and internal organs on histopathological examination and this was confirmed by RT-PCR for the p210 mRNA. Treatment with SA significantly reversed the changes seen in the levels of the lipid peroxides, the glycolytic enzymes, the gluconeogenic enzymes and the mitochondrial enzymes. These effects are probably due to the flavonoids, polyphenols and other compounds present in SA which result in total regression of leukemia and correction of the alterations in energy metabolism. Study of animals treated with SA alone did not reveal any adverse effects. On the basis of the observed results, SA can be considered as a readily accessible, promising and novel antileukemic chemotherapeutic agent.