Antitumor Activity of New Quinoxaline Analogues and Its Complexes

This study shows synthesis of a new quinoxaline derivatives (LH) and preparation of copper (Cu-LH) and cobalt (Co-LH) complexes and studying the effect of these compounds on the activity of lactate dehydrogenase (LDH) a primary enzyme to the process of anaerobic glycolysis which is the source of energy in tumor cell. This study included of 40 women with recently diagnosed of malignancies Breast cancer; (20) subject women in stage I&(20)subject women in stage II who were admitted to Medical City Hospital with age ranged (37-45) years and 30 apparently healthy woman matched for age served as controls. Serum LDH activity was assayed on the time of the diagnosis in all cases and after addition of different concentrations (10 -1 , 10 -2 , 10 -3 ) of quinoxalin derivatives and transition metals complexes in vitro. The results revealed an inhibitory effect of LH and its complexes with Cu and Co in all concentrations used in this study on LDH activity. The inhibition percent’s increased with increase concentration for LH and its complexes. Also the results reveal that the inhibitory effect of LH in all concentrations used were more than inhibitory effect of its complexes. Moreover the inhibitory effect of LH-Co complex was more than inhibitory effect of LH-Cu complex in all concentrations used. The inhibition ability of quinoxaline derivative and its complexes on the enzyme lactate dehydrogenase leads to the fact that these compounds can be characterized as an active anti –cancer substances for one of the metabolic enzymes necessary to feed the cancer cells. Keyword: breast cancer, quinoxaline derivatives, copper and cobalt complexes, lactate dehydrogenase