Changes in the Honeybee Antioxidant System after 12 h of Exposure to Electromagnetic Field Frequency of 50 Hz and Variable Intensity

Abstract

In recent years, on a global scale, more and more reports of a phenomenon called CCD (Colony Collapse Disorder) have been reported. In addition to pesticides, diseases, and other environmental stressors, electromagnetic fields are also mentioned as one of the possible causes of CCD. One of the body's first lines of defense against harmful factors is the antioxidant system. We hypothesized that electromagnetic field upregulate the activity of SOD (superoxide dismutase), CAT (catalases), and changed FRAP (total antioxidant potential) in honeybee hemolymph. In our research, 12 h bee's exposure to E-field was analyzed to determine changes in the antioxidant system. The frequency of 50 Hz and various intensities were used: 5.0 kV/m, 11.5 kV/m, 23.0 kV/m, and 34.5 kV/m. Superoxide dismutase was characterized by four times higher activity in the study groups as compared to the control group. Catalase activity in all groups was characterized by statistically significantly different activity between the groups. The highest activity was recorded in the 34.5 kV/m group. The lowest activity was recorded in the 11.5 kV/m group. A relationship was found between different E-field intensities and changes in the antioxidant system.

Keywords: 50 Hz; E-field; antioxidant system; catalase (CAT); honeybee; superoxide dismutase (SOD); total antioxidant potential (FRAP).

Figure 1

Superoxide dismutase (SOD) activity in honeybee hemolymph after exposure to the E-field (50 Hz and different intensities). The group name is the f E-field intensity. The control group was marked with the letter C. The control groups were not treated to the artificial electromagnetic field, they were under the influence of an electromagnetic field lower than 2.00 kV/m. Statistical differences between the mean values for groups are marked with different letters. Different letters mean the difference is at the p-value ≤ 0.05 significance level.

Figure 2

Catalase (CAT) activities in honeybee hemolymph after exposure to the E-field (50 Hz and different intensities). Details as in Figure 1. Statistical differences between the mean values for groups are marked with different letters. Different letters mean the difference is at the p-value ≤ 0.05 significance level.

Figure 3

Ferric reducing antioxidant power (FRAP) in honeybee hemolymph after exposure to the E-field (50 Hz and different intensities). Details as in Figure 1. Statistical differences between the mean values for groups are marked with different letters. Different letters mean the difference is at the p-value ≤ 0.05 significance level.