Tobacco Smoke Carcinogens Induce DNA Repair Machinery Function Loss: Protection by Carbon Nanotubes

Document Type : Research Articles


1 Himalayan School of Biosciences, Swami Rama Himalayan University, Dehradun (Uttarakhand), India.

2 University of Texas Rio Grande Valley, McAllen, United States of America.

3 Dean, Faculty of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia.

4 Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia.

5 Emergency Medical Services Department, Faculty of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia.

6 Department of Preventative Dental Sciences, College of Dentistry, Hail University, Hail, Saudi Arabia.

7 Research and Scientific Studies Unit, Faculty of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia.

8 Medical Research centre, Faculty of Applied Medical Sciences, Jazan University, Jazan, KSA.


Purpose: DNA damage is a continuous process occurring within the cells caused by intrinsic and extrinsic factors, but it gets repaired regularly. If the DNA repair process is faulty, the incidences of damages/mutations can accumulate in cells resulting in cell transformation. It is hypothesized that the negative variations in DNA repair pathways in even at one point viz. genetic, translational or posttranslational stage may fairly be crucial for the beginning and development of carcinogenesis. Therefore, we investigated the potential of tobacco specific nitrosamines (TSNs) related carcinogens to interact with the enzymes involved in DNA repair mechanisms in the current study. Methods: The derivatives of cigarettes’ smoke like NNK and NNAL are very well known and recognized carcinogens. Therefore, almost 120 enzymes playing crucial role in the DNA repair process have been analysed for their reactivity with NNK and NNAL. Results: The molecular docking study helped to screen out,  07 possible DNA repair enzyme targets for NNK, and 12for NNAL. Present study revealed the loss of activity of DNA repair enzymes in the presence of NNK and NNAL, and this accumulation may induce the tendency of DNA damage which can lead the transformation of exposed normal cells in to cancerous cells. This study also demonstrated the protective potential of nanoparticles like SWCNTs/MWCNTs against TSN’s induced toxicity; here SWCNT against NNK (-17.16 Kcal/Mol) and MWCNT against NNK -17.01 Kcal/Mol were showing maximum binding affinities than the known biomolecular target of NNK 1UGH (Uracil-DNA glycosylase,-7.82Kcal/Mol). Conclusion: CNTs can be applied as chemo-preventive agents against environmental and tobacco induced carcinogens owing to their scavenging potential and warrants for in vivo and in vitro experimental validation of the results obtained from the present study.


Main Subjects

Volume 21, Issue 10
October 2020
Pages 3099-3108
  • Receive Date: 25 June 2020
  • Revise Date: 08 September 2020
  • Accept Date: 22 October 2020
  • First Publish Date: 22 October 2020