Effects of non-contact electric fields on kidney and liver histology in tumour-induced rats

Abstract

Background A novel modality of cancer treatment based on exposure to non-contact electric fields has been developed to reduce cancer incidence. However, the safety of the electric field exposure was not fully investigated. Therefore, This study aimed to observe the safety of electric field exposure on kidney and liver structures. Methods Female Sprague-Dawley rats were divided into one control group and three treatment groups. Animals were treated with 7,12-dimethylbenz[a]anthracene for mammary tumour induction and exposed to non-contact electric fields individually for 10 hours a day for three weeks. Fresh samples of the kidney and liver were collected for observation of structural damage in both organs. Both organs were prepared for histopathological cross-sectioning using the paraffin method and Hematoxylin and Eosin staining followed by histological scoring using the post-examination masking method. Results Damages found in the kidney were as follows: thickening of the Bowman capsule, karyolysis, karyorrhexis, pyknosis, cloudy swelling, epithelial sloughing, inflammation, haemorrhage, and congestion. In addition, the number of inflammation and haemorrhage in the kidney structure of healthy rats that were exposed to electric fields was significantly lower than that in the control group. All damages to the kidneys were also found in the liver, but each showed a different degree of damage. Exposure to this electric field can cause haemorrhagic damage to the livers of healthy rats, but not to rats with breast cancer. Conclusions Exposure to non-contact electric fields can cause haemorrhagic damage to the livers of healthy rats, however, in other liver tissues and the kidneys, exposure to this electric field was safe. It can even decrease the number of inflammations and haemorrhages in the kidneys.