Serum LDH and ALP isozyme activities in mice bearing solid Ehrlich carcinoma and/or treated with the maximum tolerated dose (MTD) of aloin.

Determination of total LDH and ALP activities and their isozyme patterns in the sera of normal and tumour-bearing animals treated with aloin, a natural anthraquinone with potential antitumour activity, was carried out at 3, 6 and 9 weeks of treatment. Treatment of normal mice with the MTD of aloin (50 mg/Kg b.w.) showed non-significant changes in serum total LDH and ALP activities along with their isozymes throughout the experimental periods. In untreated tumour-bearing animals, serum LDH activity and its isozymes: LDH1-LDH5 showed highly significant increases (192, 32.4, 25.2, 24.7, 29.2 and 30.6%, respectively) after 3 weeks. Highly significant inhibition was recorded in serum total ALP activity and its intestinal and bone isozymes (64, 100 and 56%, respectively), while liver ALP isozyme was increased by 82.3%. Treatment of tumour-bearing mice with the MTD of aloin manifested a significant gradual improvement in both enzyme activities and their isozymes, which were normalized at the end of the experiment (9 weeks), with the exception of intestinal ALP isozyme. All results were reported in comparison to the normal control group.