title: Induction of alkaline phosphatase activity by exposure of human cell lines to a low-frequency electric field from apparatuses used in clinical therapies.
abstract: Low-frequency (LF) electric fields (EFs) are currently used in clinical therapies of several bone diseases to increase bone regenerative processes. To identify possible molecular mechanisms involved in these processes, we evaluated the effects on cell cultures of 1 h exposures to the signal generated by an apparatus of current clinical use (frequency 60 kHz, frequency of the modulating signal 12.5 Hz, 50% duty cycle, peak-to-peak voltage 24.5 V). Two different human cell lines, bone SaOS-2 and liver HepG2, were used. Exposures significantly increased alkaline phosphatase (ALP) enzymatic activity in both cell lines. The increase was about 35% in SaOS-2 cells and about 80% in HepG2 cells and occurred in the first 4 h after exposure and decreased to almost no change by 24 h. Since ALP represents a typical marker of bone regeneration, these results represent a first molecular evidence of biological effects from 60 kHz EF exposures. The finding of similar effects in cells derived from two different tissues more likely indicates the effective operation of the mechanism in living organisms.
authors.affiliation: Department of Information and Electrical Engineering, University of Salerno, Fisciano, SA, Italy. bbisceglia@unisa.it
authors.forename: Bruno
authors.initials: B
authors.lastname: Bisceglia
authors.forename: Hylde
authors.initials: H
authors.lastname: Zirpoli
authors.forename: Mariella
authors.initials: M
authors.lastname: Caputo
authors.forename: Francesco
authors.initials: F
authors.lastname: Chiadini
authors.forename: Antonio
authors.initials: A
authors.lastname: Scaglione
authors.forename: Mario Felice
authors.initials: MF
authors.lastname: Tecce
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D002470:Cell Survival; D004599:Electric Stimulation Therapy / Q000295:instrumentation*; D056945:Hep G2 Cells; D006801:Humans; D013997:Time Factors
chemical_list: D000469:Alkaline Phosphatase