Inhalation toxicity of volatile components from hair straightener: biological alterations in air-liquid interface of pulmonary cells
Author: Samara Eberlin
Published at: October 28, 2019
XXI Brazilian Congress of Toxicology, Águas de Lindóia, Brazil 28-31 October, 2019.
Silva, Michelle S.; Facchini, Gustavo; Silva, Gustavo H.; Picon, Francini C.; Pinheiro, Ana L. T. A.; Pinheiro, Adriano S.; Eberlin, Samara.
Cell cultures are essential tools for the development of alternative methods to the use of animals to evaluate the safety of products intended for human use. Many toxic xenobiotics to the respiratory tract not only cause cell death, but also induce pro-inflammatory responses that may potentiate airway injury. Thus, to assess the inhalation toxicity of a product, it is important to have an integrated view of its role in inflammation and apoptosis using a test system that mimics respiratory tract conditions. In this study, we developed an experimental model in an air-liquid lung cell interface culture to evaluate the inhalation toxicity potential of the volatile components from the hair straightening procedure. Pulmonary fibroblasts cultured in an air-liquid interface were exposed in a controlled atmosphere during the application of hair straighteners and formaldehyde (15%) on hair tresses. After the procedure, the cells were maintained in an incubator for further cellular viability evaluation (MTT) and assessment of mediators Caspase 3/7 and SERCA2. The results showed that the exposure of the cultures to the straightening treatment promoted cell death - activation of Caspase 3/7 (21.17%, P<0.05) and MTT (11.44%, P<0.01) and reduction of SERCA2 (20.95%, P<0.01) after 1 hour of incubation, but after 24 hours these values were reestablished. On the other hand, the exposure of cell cultures to 15% formalin vapor significantly and irreversibly increased cell death and inflammatory response compared to the baseline group. We observed a decrease in viability by 74.11% and 76.82% (P<0.001) by MTT technique, an increase of 3.14 and 4.18-fold in Caspase 3/7 activation, and a reduction of SERCA2 by 20.95% and 18.20% (P<0.01), after 1 and 24 hours, respectively. The experimental methodology presented shows an important advance in the evaluation of cosmetic toxicology, allowing the development of tools to reduce, replace, and/or refine the use of experimental animals. Moreover, unlike animal inhalation toxicity models, where the observed parameter is often just death, the air-liquid interface model proposed in the present study allows a broader view of the effects of hair straightening on the respiratory tract, considering even the impacts of the inflammatory response.