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Updated: Aug 13, 2026

Methods to Evaluate Cytotoxicity and Immunosuppression of Combustible Tobacco Product Preparations
Published on: January 10, 2015
Smoke treatment triggers the release of a novel DNA damaging factor by lymphocytes
Raghavendra Pralhada Rao1, S S Thammanna Gowda, Srinivas Leela
1Indian Institute of Science, Bangalore, 12, Karnataka, India.
Abstract:
Organic fuel smoke is a hazardous agent, which pushes the cells towards"prooxidant state'', leading to 4,46,400 strand breaks/cell/day as against 47,000 strand breaks/cell/day produced by constitutive oxygen radicals. This prooxidants scenario switches on a plethora of intercellular events. Here we report a novel DNA damaging factor released by lymphocytes, upon treatment with smoke condensate. Human lymphocytes, when exposed to cow dung cake smoke condensate, were found to release a low molecular weight factor into the media at 20 min of exposure. The conditioned media, displayed a propensity of inducing DNA damage in fresh, normal lymphocytes, which were not exposed to any damaging agent. The above DNA damaging effect of the conditioned media was not due to any residual presence of Polycyclic Aromatic Hydrocarbons, which were present in the smoke. The release of this factor was in correlation with the DNA damaging event, taking place in the cells. This secondary DNA damaging factor had a molecular weight less than 5 kd. The factor had the cell death inducing propensity when allowed to act on lymphocytes.
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