Effect of Extremely Low-Frequency (ELF) Magnetic Fields on the Potency of Drugs in Bacterial Cells

Our previous paper showed that magnetic fields (60 Hz, 50 mT) enhance the potency of the drugs mitomycin C and cisplatin in bacterial cells and suggested that magnetic fields change the permeability of the cell membrane and increase drug uptake. The present paper demonstrates the effect of magnetic fields (60 Hz, 50 mT) on the potency of five different drugs in Escherichia coli cells and additionally assessed the effects of different frequencies of ac magnetic fields. The drugs such as mitoxantrone, daunorubicin, actinomycin D, bleomycin, and zinostatin differ from one another in certain characteristics such as molecular weight and cellular action mechanism. The results showed that the potency of mitoxantrone, daunorubicin, actinomycin D, and bleomycin enhanced approximately 1.3-fold as drug concentration on exposure to the magnetic fields for 6 h. However, in the case of zinostatin, the enhancement was only 1.03-fold. Zinostatin differs from other drugs in that it is a polymeric compound and has an average molecular weight of 15000, which is ten or more times greater than that of the other drugs. These results indicate that magnetic fields (60 Hz, 50 mT) have the ability to enhance the potency of a number of different drugs, although it was difficult to influence the potency of zinostatin. The results of different frequencies of the ac magnetic fields indicated that approximately 60 Hz is the most effective frequency for enhancing the potency of mitomycin C.