4-Chloro-orthophenylenediamine alters DNA integrity and affects cell survival: inferences from a computational, biophysical/biochemical, microscopic and cell-based study

Abstract

The deleterious impact of toxic constituents of hair dyes over the human health has gained immense attention in the recent past. Their oncogenicity, mutagenicity, role in protein modification, impact on cellular metabolism has been documented. There is little information on the mechanism of reactivity of hair dye components with the nucleic acids and its implications. This work, therefore, uses computational, biophysical/biochemical, microscopic and cell-based study to analyze the interaction of monocyclic aromatic amine and a hair dye component, 4-chloro-orthophenylenediamine (4-Cl-OPD) with the DNA, its impact on DNA structure and cell survival. The results suggest that 4-Cl-OPD binds with the DNA in minor groove of the duplex involving three base pairs preferentially the G-C residues, induces strand breaks and makes DNA thermally labile through loss of hydrogen bonding/base unstacking. 4-Cl-OPD causes fragmentation of DNA, reduction in size of the molecule, alters B-DNA conformation and disrupts its secondary structure. The modified DNA gives fragmented appearance, shows broken strands and aggregation in ultra-structural analysis. 4-Cl-OPD induces ROS generation in lymphocytes, increases the comet’s average tail length and reduces the viability of lymphocytes. This study forms a base for establishing the direct toxicity of 4-Cl-OPD at the molecular and cellular level through direct production of superoxide radical

Communicated by Ramaswamy H. Sarma

Keywords:

• 4-Chloro-orthophenylenediamine
• cytotoxicity
• DNA damage
• hair dyes
• minor groove binders
• reactive oxygen species

Acknowledgements

The authors acknowledge Indian Council of Medical Research (ICMR), New Delhi for providing financial support in the form of ICMR-SRF (45/27/2019-BIO/BMS) to Miss Shifa Khan. The support of the University Sophisticated Instrumentation Facility (USIF) is duly acknowledged. Thanks to Prof. Mohd Shakir, Chairman of the Department of Chemistry, Aligarh Muslim University, India for providing instrumentation facility for melting temperature curve analysis.

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethical clearance statement

The study was duly approved by the Institutional Ethics Committee of Jawaharlal Nehru Medical College, Aligarh Muslim University, India vide number: 401/GO/Re/S/2001/CPCSEA.