Recent Developments on the Mechanism of Anti- Cancer Activity of Complexes of Molecular Iodine with α-Dextrins and Polypeptides and Lithium Halogenides

Some anti-infective drugs exhibit also anti-tumor activity. The anti-tumor activity of anti-infective drug
(AID) containing a complex of molecular iodine with polypeptides, α-dextrins and lithium halogenides,
was studied in human and murine tumor cell lines in vitro.
The experiments were performed with human (HeLa and K562) and murine (L5178Y) tumor cell lines.
As a control was used dog kidney epithelial cell line MDCK. The anti-tumor activity of AID was
assessed by measuring of IC50. The drug was used at the concentrations of 500 μg/ml; 250 μg/ml;
125 μg/ ml; 63 μg/ml; 32 μg/ml; 16 μg/ml; 8
μg/ml; 4 μg/ml; 2 μg/ml; 1 μg/ml; and 0.5 μg/ml. It was found that the IC50’s were 112 μg/ml, 11.8
μg/ml, 10.3 μg/ml and 40.6 μg/ml for Hela, K562, L5178Y and MDCK cells, respectively.
The probable mechanism of the drug’s cytotoxic activity is explained by the results of molecular
modeling process and DFT calculations.
AID interacts with the onco-DNA, and the following inhibiting complexes are formed: lithium (Li)
halogenide included in the AID, forms a complex with the phosphate group while the molecular iodine
is coordinated by the adenosine or guanosine nitrogenous bases and Li halogenide.
These inhibitory centers disturb the interaction of topo I active site with phosphate group, and two new
nucleoprotein complexes are formed. In one the Arg amino acid residue is bounded by the Li
halogenide complex with the phosphate group, in the second one Tyr is bounded by the adenosine
complex with molecular iodine and Li halogenide. Experimental research have shown the possibility
to use the AID as antitumor drugs against certain cancer cells, namely against leukemia. Calculations
have shown that the action of AID on onco-DNA results in the formation of the following inhibitory
complexes: the halogenide lithium-phosphate group complex (Ia,b structure), and complexes in which
molecular iodine coordinates nitrogen bases of adenosine or guanosine and lithium halogenide
(IIa, b-IIIa, b structure).