In a pre-experiment, the optimal concentration of zinc sulfate (ZnSO4) to enhance cell growth was found to be 0.14 µg/ml. Therefore, the following groups were examined: 1) sham exposure, 2) magnetic field exposure, 3) sham exposure + 0.14 µg/ml ZnSO4, and 4) magnetic field exposure + 0.14 mg/ml ZnSO4.
Exposure duration: 30 minutes per day for 21 consecutive days
|Exposure duration||30 minutes per day for 21 consecutive days|
|Setup||MF was generated by a parallel set of Helmholtz coils (diameter 27 cm, respectively) with 500 turns of 0.70 mm coated copper wire; coils were placed in a cell incubator; 6-well plates were placed in the middle between the coils to receive a uniform field|
|Sham exposure||A sham exposure was conducted.|
|Additional info||sham exposed plates were kept under the same conditions (CO2 concentration, temperature and humidity) in another incubator without MF|
|magnetic flux density||20 mT||-||measured||-||-|
The mRNA level of TERT was significantly reduced after exposure (group 2) compared to sham exposure (group 1) while the number of beta-galactosidase positive cells was significantly increased. A combination of zinc sulfate and magnetic field exposure (group 4) significantly lowered the expression level compared to zinc sulfate alone (group 3) but remained significantly increased compared to sham exposure (group 1). Similarly, but vice versa, a combination of zinc sulfate and magnetic field exposure (group 4) significantly increased the number of beta-galactosidase positive cells compared to zinc sulfate alone (group 3), but the number remained significantly lowered compared to sham exposure (group 1).
The authors conclude that exposure of rat adipose-derived mesenchymal stem cells to 50 Hz magnetic fields could affect cellular aging and that an addition of zinc sulfate could attenuate these alterations.