Mutagenic and genotoxic potential of direct electric current in Escherichia coli and Salmonella thyphimurium strains

Abstract

Direct electric current has several therapeutic uses such as antibacterial and antiprotozoal action, tissues scarring and regeneration, as well as tumor treatment. This method has shown promising results in vivo and in vitro, with significant efficacy and almost no side effects. Considering lack of studies regarding direct electric current mutagenic and/or genotoxic effects, the present work evaluated both aspects by using five different bacterial experimental assays: survival of repair-deficient mutants, Salmonella-histidine reversion mutagenesis (Ames test), forward mutations to rifampicin resistance, phage reactivation, and lysogenic induction. In these experimental conditions, cells were submitted to an approach that allows evaluation of anodic, cathodic, and electro-ionic effects generated by 2 mA of direct electric current, with doses ranging from 0.36 to 3.60 Coulombs. Our results showed these doses did not induce mutagenic or genotoxic effects.

Dose‐response study for the highly aggressive and metastatic primary F3II mammary carcinoma under direct current

“…Additionally, the metastasis can be favored because the cathode (electrode with negative polarity) repels negatively charged tumor cells [Haltiwanger, ]. These two aspects should not be underestimated during EChT application, although some authors report that DC does not induce metastasis [Zhou et al, ] or mutagenic and genotoxic effects [Gomes et al, ]. On the other hand, the treatment of metastatic lesions may be effective when DC is combined with nanoparticles [Campos et al, ].…”

Direct electric current modifies important cellular aspects and ultrastructure features of Candida albicans yeasts: Influence of doses and polarities

“…Previous studies developed with direct electric current indicated the importance of pH variation in tumoral [Veiga et al, ; Cury et al, ; Holandino et al, ] and non‐tumoral damage [Gomes et al, , ]. For that reason, pH variation was registered with the same values of electric charge previously evaluated in cell viability experiments.…”

“…In the present work, DC effects on C. albicans were evaluated using platinum electrodes since it is an inert material and consequently does not induce ion release in the electrolytic medium, facilitating DC mechanism comprehension, as previously registered in bacteria [Holandino et al, ; Gomes et al, ] and protozoa [Gomes et al, ] samples. The viability assays were performed by two methods: plating to quantify CFUs and propidium iodide (PI) incorporation.…”

“…Veiga et al [] evaluated the electrolytic medium composition and attributed tumoral damage to electrolysis products generated in phosphate‐saline, phosphate, and HEPES buffers. In their experiments, cathodic stimulation‐induced cell lysis in a time‐dependent manner with a progressive pH increase from 7.4 to 10.5 [Veiga et al, ; Gomes et al, ]. In counterpart, the anodic flow promoted H + ion generation, with simultaneous electrolytic medium acidification (7.4–6.0), leading to cell death.…”

“…DC cytotoxicity is attributed to electrolytic reactions and their consequent pH variation. Veiga Gomes et al, 2016]. In counterpart, the anodic flow promoted H þ ion generation, with simultaneous electrolytic medium acidification (7.4-6.0), leading to cell death.…”