Aqueous extract of tobacco induces mitochondrial potential dependent cell death and epithelial-mesenchymal transition in gingival epithelial cells

Smokeless tobacco habits are detrimental to oral health. A correlation between tobacco use and local epithelial tissue damage exists. Yet, the underlying cellular mechanism is not precisely characterized. This study assessed the dose-dependent action of Smokeless tobacco extract on gingival epithelial cells. Gingival tissue was taken from 5 healthy donors. Gingival epithelial cells were isolated by an enzymatic method and cultured up to passage 2. The cultured cells were treated with smokeless tobacco extract at 10%, 25%, 50%, and 75% volume concentration. After 48 h of incubation, MTT assay, Annexin V/PI assay, and DiIC1(5) assay were used to evaluate viability, apoptosis, and mitochondrial potential of the cells. RT-qPCR was used to determine the expression of BAX, BCL2, ECAD, NCAD, and TWIST. The Smokeless tobacco extract reduced cell viability by disrupting the mitochondrial potential and inducing apoptosis. Further, the Smokeless tobacco extract induced a dose-dependent epithelial-mesenchymal-transition in gingival epithelial cells. Apoptotic cellular death caused by tobacco extract on the gingival epithelial sys-tem was dependant on the mitochondrial potential of the cell. The results demonstrate that smokeless tobacco causes detrimental metabolic alterations of the periodontium. Featured application: This study elucidates the mechanism by which Smokeless tobacco products cause cellular damage to the gingival epithelium. The use of Smokeless tobacco products can lead to major cel-lular and surface changes in the gingiva and its appearance. The consequences of these changes are not limited to oral cancer but also increases a person's risk for dental and periodontal disease. (c) 2021 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Smokeless tobacco extract can reduce cell viability, disrupt mitochondrial potential, induce apoptosis, and lead to epithelial-mesenchymal transition in gingival epithelial cells, ultimately causing detrimental metabolic alterations to the periodontium.