Spectroscopic Study of Methylene Blue Interaction with Coenzymes and its Effect on Tumor Metabolism.

UNLABELLED

is to study the interaction of methylene blue (MB) with NADH, FADH coenzymes and lactate, and to evaluate a long-term effect of its intravenous or oral introduction on tumor metabolism .

MATERIALS AND METHODS

The MB interaction with NADH, FADH coenzymes and lactate was studied using absorption spectrophotometry. A long-term effect of MB on tumor metabolism was investigated on a mice model of Ehrlich carcinoma. The effect of MB on tumor metabolism was assessed using time-resolved fluorescence microscopy based on the NADH fluorescence lifetime.

RESULTS

NADH has been established to be the main coenzyme with which MB interacts. The reduction of the lactate quantity is mediated by the shift of tumor metabolism as a result of MB interaction with the NADH. In the experiments , no noticeable tumor growth rate reduction was observed in the groups with intravenous MB introduction in comparison with the control. In the group receiving MB with drinking water, a decrease of the tumor growth rate, reduction of oxygenation level, and a1/a2 metabolic index were observed, which confirms the shift from glycolysis to oxidative phosphorylation.

CONCLUSION

The possibility of using MB for the tumor metabolism correction and growth rate reduction has been demonstrated, however, the time of therapy and MB concentration should be optimized to obtain more pronounced therapeutic effect.