INHIBITION OF MOLONEY-VIRUS-INDUCED LEUKEMOGENESIS IN MICE BY DIETARYRESTRICTION AND SUPPLEMENTARY SOYBEAN

Background - Dietary manipulation for control of malignant disorders f orms an important area of current research on cancer, The present stud y attempts to explore the influence of reduced intake in total calorie s from the daily diet as well as the effect of soyabean, known to be r ich in many anticancer components, during dietary restriction on a vir ally;induced leukaemia in mice. Methods - The effect of restricted die t in presence or absence of soyabean was assessed on tumour incidence and host survival, Serum protein and lipid profiles were determined us ing biochemical analysis. Serum retinol and tocopherol were quantified by HPLC. Circulating immunoglobulins, IgG and IgM were determined by single radial immunodiffusion and the response of peripheral blood lym phocytes was assayed by radiolabelled thymidine uptake following mitog enic stimulation. Results and Conclusion - The incidence of leukaemia was reduced from 63% of the control group to 26.6% and 30% in the diet restricted groups with or without soyabean respectively, The reduced incidence of leukaemia and concomitant increase in host survival indic ated the potential value of restricted diet and soyabean feeding in vi ral leukaemogenesis. The experimental diets were also found to enhance host immunity, as revealed by the improved response Of T cells to mit ogenic stimulation and changes in antibody titres, The haematological picture, showing a lower number of abnormal and/or malignant cells in the circulation, reflects the controlling effect of the diet on the pr ogression of the disease, Serum vitamin, protein and lipid profiles sh ow a shift towards normal values in the leukaemic mice, suggesting a b eneficial influence of restricted diet and soyabean supplementation in viral leukaemogenesis.