Estimating Toxicity Putative Mechanisms from Smoking Residual Substances Using a Whole-Cell Bioreporter System

Cigarette smoking is known to be an unhealthy activity that can cause a number of human diseases, including chronic obstructive pulmonary disease (COPD) and lung cancer. It was further reported that even being exposed to secondhand cigarette smoke can affect human health. To assess the toxicity of the smoke from different cigarette brands, an artificial smoking device was developed, and three fractions designated, Filter Fraction, Smoke Fraction and Tar Fraction, were prepared from the smoke of each brand. Then, to elucidate possible effects of some of the toxins found in cigarette smoke, we investigated their effects in vitro using a bioluminescent bacterial array that comprises three bacterial strains. Using this array, we compare smoke from three cigarette brands, each with different tar and nicotine contents. GC-MS analysis showed that the cigarette smoke extracts (fractions) from different brands differed in their compositions and chemical concentrations. The results further showed that, in general, cigarette smoke triggered mainly an oxidative stress reaction in our bacterial models. The Smoke Fraction was tested for sequential smoking rounds and found to produce cumulative effects following each subsequent smoking cycle for all three cigarette brands. Finally, it was found that cigarette smoke and its specific components are toxic at various degrees with the Smoke Fraction, acting as oxidative stressors, and that this can be effectively analyzed using bioreporter panel arrays.