[Oxidative Stress and DNA Damage Induced by DEP Exposure in Earthworms].

Diethyl phthalate (DEP) is a plastic additive that entered the soil environment due to the extensive use of plastic products. However, its toxicity to soil animals and the associated toxicity mechanism were not completely understood. Eisenia foetida was selected as the research object and exposed to simulated contaminated soil with different concentrations of DEP. Antioxidant enzyme activity, reactive oxygen species (ROS) content, Glutathione-S-Transferase (GST) activity, Malondialdehyde (MDA) content and amount of DNA damage in the earthworms were used as evaluation parameters for the study. The results showed that under DEP stress, the activities of antioxidant enzymes, GST and ROS in earthworms changed and resulted in gene damage. Under the stress of 0.1-50 mg·kg-1 DEP exposure during the 28 d experiment, the level of ROS increased and there was a "dose-effect" relationship. Excessive ROS gave rise to an increase of MDA content in the body from lipid peroxidation. Under the combined action of ROS and MDA, DNA in the body cavity of earthworm was damaged and there was also a "dose-effect" relationship between the degree of damage and the concentration of DEP. In summary, DEP may cause a certain degree of damage to organisms, with damage to the DNA of earthworms representing fairly strong eco-toxicological effects. Therefore, adequate attention should be paid to DEP disposal.

Isoflurane enhances malignancy of head and neck squamous cell carcinoma cell lines: a preliminary study in vitro.

The objective of this study was to explore the influence of isoflurane on the cell proliferation, apoptosis, and invasion of Tca8113 and HSC2 cell lines in vitro. MTT test was used to detect the cell proliferation. It was performed 72h after exposure to isoflurane to make sure that a time for normal cell cycle progression was allowed. The cell apoptosis of Tca8113 and HSC2 cell lines were detected by flow cytometry. We used transwell chamber to detect the cell invasion of Tca8113 and HSC2 cell lines. There was a statistically significant increase of cell proliferation in Tca8113 and HSC2 cell lines after exposure to 2% isoflurane for 3 and 6h. The difference between 3 and 6h group is statistically significant in Tca8113 and HSC2 cell lines. Flow cytometry showed that there was a decrease of cell apoptosis in Tca8113 and HSC2 cell lines after exposure to 2% isoflurane for 3 and 6h. Transwell test showed there was a statistically significant increase of cell invasion in Tca8113 and HSC2 cell lines after exposure to 2% isoflurane for 3 and 6h, and it showed a significant difference between 3h group and 6h group of Tca8113 cell line. Our results demonstrated that isoflurane increased malignancy of head and neck squamous cell carcinoma cell lines in vitro. Isoflurane might enhance tumor development and promote metastasis of tumor cells in HNSCC patients. It is suggested that it might be more suitable to choose total intravenous anesthesia for HNSCC patients.