Full Length Research Paper

DNA damage by the cobalt (II) and zinc (II) complexes of tetraazamacrocyclic in Tetrahymena thermophila

Zhong-Dong Xu¹*, Rong-Hua Shi², Wei Wang¹, Rui-Song Tao¹, Jian-Hong Bi³ and Zhao-Jun Wei⁴*

¹Department of Biology, Hefei Teachers College, Hefei, 230061, China.

²School of Life Science, University of Science and Technology of China, Hefei, 230027, China.

³Department of Chemistry, Hefei Teachers College, Hefei, 230061, China.

⁴Department of Biotechnology, Hefei University of Technology, Hefei 230009, China.

*Corresponding author. E-mail: zjwei@hfut.edu.cn. Tel: 86-551-2821000. Fax: 86-551-2821000.

Abbreviations: L, Tetraazamacrocycle  (5,7,12,14-tetraethyl-5,12-dimethyl-1,4,8,11-tetraazabutadecacyclo -7,14- diene); Zn(II)-L, tetraazamacrocycle Zn(II) complex; and Co(II)-L, tetraazamacrocycle Co(II) complex.

Accepted 17 June, 2008

Using the single cell gel electrophoresis method, the tetraazamacrocycle Zn(II) complex (Zn(II)-L) and the tetraazamacrocycle Co(II) complex (Co(II)-L) were investigated focusing on their DNA damage to Tetrahymena thermophila. When the cells were treated with the 0.05, 0.25 and 0.50 mg/ml Zn(II)-L, the tail length increased significantly, with 10.83, 11.56 and 11.87 μm, respectively. With the dose of 0.5 mg/ml Zn(II)-L treatment, 45.5% cells distributed in grade 3. After treatment with the 0.05, 0.25 and 0.50 mg/ml Co(II)-L, the tail length of the cells also increased significantly, with the length of 15.64, 17.75 and 19.21 μm, respectively. When treated with 0.5 mg/ml Co(II)-L, 98.1% cells showed tail and 75.6% cells distributed in grade 3. The results indicated that Co(II)-L induced a relatively high level of DNA damage in comparison with the level of damage induced by Zn(II)-L.

Key words: Tetraazamacrocycle Zn(II) complex, tetraazamacrocycle Co(II) complex, Tetrahymena thermophila, DNA damage, the comet assay.