@2024 Afarand., IRAN

---

ISSN: 2252-0805    The Horizon of Medical Sciences 2017;23(1):7-12

Background
Today, one of the problems is that whether the magnetic field can affect biological systems [1, 2].
Previous Studies
… [3-14]. Treatment of cancers is very complex. Now, one of the most common treatment is chemotherapy, which has extensive adverse effects [15]. … [16-17].
Aim(s)
The aim of this study was to evaluate the effect of static magnetic field with different intensities (7, 14, and 21 mT) and different duration (24 and 48 hours) on the viability and their proliferation rate.
Research type
This research is applied.
Research society, place and time
Non-declared
Sampling method and number
Non-declared
Used devices&materials
HeLa cell lines and human fibroblasts (HuO2) were purchased from Iran Pasteur Institute. The cell lines were cultivated in DMEM medium containing 10% bovine serum (FBS) in a sterile cell culture flasks and passaged. The flask which is filled to 70% of capacity by the cells, is suitable for freezing the cells. The flask containing the cells was sterile washed and trypsin by phosphate buffered saline (PBS). When cells were isolated, to repeal trypsin, the complete culture medium was added equal to tripled serum-containing medium to the flask. After dilution and centrifugation, the cells were counted and for each 106. 2-1 cells, a milliliter of fluid prepared for freezing was added; cell suspension was poured in the cryotubes and quickly moved to the nitrogen tank. The melting method was in the way that cryotube containing cells was removed from the nitrogen tank and was incubated; so that the cell suspension could be melted. Then the content of cryotube was poured in sterile falcon tube and 3 ml of DMEM medium without phosphate buffer was added and centrifuged. The supernatant was removed and a milliliter of fresh DMEM medium containing FBS was added and it was poured into cell culture flasks. Then, it was incubated to reach the optimum level of cell count after few days. For treatment of the cells with the magnetic field, an incubator was placed in the field to provide the perfect condition for cell growth (temperature 36°C, and 5% CO2). Also, to determine the rate of proliferation and viability, cells were cultured in 96-well plates. To determine the effect of duration and intensity of magnetic field, three intensities of 7, 14, and 21 millitestla and two duration of 24 and 48 hours were chosen. These durations were selected due to the fact that the time for HeLa and fibroblast cells to be doubled is less than 24 hours. The average number of the cells, also, was considered as the cell proliferation rate. Cells without treatment were considered as the control group and the rest of groups were compared with this group. The viability of the cells without treatment and their proliferation rate were considered 100 and 1 respectively. To assess the cytotoxicity, MTT test (tetrazolium color reducing power measurement) was used. MTT is a tetrazolium salt dissolved in water. MTT solution is reduced due to the effect of mitochondrial dehydrogenase enzymes that are only active in the living cells, and it becomes the blue insoluble formazan crystals. Therefore, with using photometry at a wavelength of 540-570 nanometer, the amount of formazan which has become dissolved by using dimethyl sulfoxide or other solvents is measured; from the wavelength of 690 nanometer, referendum is reduced by which the mass of living cells is determined. So that the cells were cultured in 96-well plates and were incubated for 24 hours. Then, 10 microliter of MTT solution and 90 microliter of DMEM medium were added to each well and were incubated for 3-4 hours at a temperature of 37 ° C. At this point, formazan crystals can be observed in living cells by an inverted microscope. Then supernatant was removed and 100 microliter of dimethyl sulfoxide was added to each well. Optical density was read by ELISA reader at a wavelength of 540-690 nanometer. Data was presented in form of mean with at least three independent repeats. The comparison of data was performed using one-way ANOVA. The results of ll50 (Inhibition Intensity of 50% of cells) was calculated by Graphpad Prism 5.
Findings by Text
By increasing the time and intensity of static magnetic field, viability and cell proliferation rate were reduced that this reduction was significant in the HeLa cancer cell, but it was not significant in normal fibroblast cells. The greatest reduction in viability and cell proliferation rate was observed in the intensity of 21 mT for 48 hours (p<0.5, Figures 1 & 2). The ll50 (Inhibition Intensity for 50% of cells) for fibroblast cells and HeLa cells in the presence of a magnetic field for 24 and 48 hours were 75.9, 48.51, 30.9 and 17.57 mT respectively. Therefore, ll50 for fibroblasts was more than the ones for HeLa cells. As a result, HeLa cells were more sensitive to SMF (Static Magnetic Field) compared to fibroblasts.
Main comparison to the similar studies
… [18-26]. In this study, it was observed that static magnetic field was more effective on cancer cells compared to the fibroblasts, and with the increase in duration and intensity of static magnetic field, viability and proliferation rate were reduced in the cells. The findings with respect to the effect of magnetic field in this study is in accordance with the findings of previous studies [27-30].
Suggestions
It is suggested that the effect of static magnetic field on the viability and proliferation rate be studied in the cancer cell lines other than HeLa cancer cells.
Limitations
One of the limitations of this study was the magnetic field generating device that using different intensities was not possible with such device.
Conclusions
The static magnetic field is more effective on HeLa cancer cells than fibroblasts, and the increase of the intensity and duration of static magnetic field reduces the viability and proliferation rate in the cells.
Acknowledgments
The authors of this articles appreciate the cooperation of all authorities in conducting this study.
Conflict of interest
Non-declared
Ethical Permissions
All the issues are ethical.
Funding Sources
This research has been conducted in the project number 92197 and sponsored by Young Researchers Club and Islamic Azad University, Flavarjan branch.

TABLES and CHARTS

Show attach file