Vol 59, No 4 (2021)
Original paper
Published online: 2021-12-09
Effect of e-cigarette flavoring agents on the neural retina of chick embryo: histological and gene expression study
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Abstract
Background: An electronic cigarette (e-cigarette) is initially marketed as an assistant product to quit smoking or limit its use. However, recent studies suggest the opposite, describing it as a product that lacks adequate quality and user safety. The present study aimed to investigate the effect of e-cigarette flavoring agent (cinnamon flavor) on the neural retina development of chick embryos and apoptosis induction after the early and late apoptosis stages by quantitative detection of gene expression CASP-3 at both embryonic days E9 and E17.
Methods: Fertilized chicken eggs were divided into two groups: control and treatment, and each group included two embryonic days; E9 and E17. For each treatment stage, two dosages of the treatment were applied, 2% and 5%. The neural retinas were dissected from the sclera and retinal pigment epithelium for subsequent RNA extraction and histological examination.
Results: This study indicated that aerosol of the subtle cinnamon flavor e-liquid causes downregulated expression of CASP3 in neural retina development. In addition, the hematoxylin and eosin (H&E)-stained sections showed multiple structural changes in the retinal layers and evidence of apoptotic cell death.
Conclusion: Cell death was visible and abundant in E9, and E17 concludes that flavor vapor condensate treatment caused neuronal cell death. CASP-3 was downregulated, which indicates that cell death occurred independently of CASP-3.
Keywords: chick embryocaspase-3 (CASP-3)electronic cigarettehistologyretinal development
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