Histopathological and Ultrastructural evaluation of the Effect of Electronic Cigarette Smoke on the Submandibular Gland of Albino Rats

Introduction: E-cigarettes (E-cigs) have received a considerable attention within the last years and are among the newest products for reduction of tobacco injury. Recently, it has been postulated that they are not considered a safe substitute for smoking and may have a limited degree of effectiveness in arresting smoking.
Aim: The aim of this study was to detect the histopathological and ultrastructural changes of tissue architecture of the submandibular glands in rats after passive E-cig exposure.
Methods: 12 adult male albino rats were divided into three groups (four rats each). Group I (Control group): Rats were exposed to fresh air. Group II (E-cigarette 4 weeks): Each rat was exposed to passive E-cig smoke for duration of one hour daily. The exposure time was divided into 6 equal intervals of 10 mins /hr, 7 days a week for four successive weeks. Group III (E-cigarette 12 weeks): Rats of this group were exposed to the same dose and manner of treatment of E-cig smoke as in group II for 12 weeks duration. Animals were sacrificed following each treatment period and specimens were prepared for histological examination and transmission electron microscopic
study.
Results: H & E results revealed signs of atrophy and degeneration within the parenchymal elements together with dilatation and congestion of blood vessels with interstitial hemorrhage in 4 weeks E-cig exposed rats. More deleterious changes with marked distortion of the gland’s architecture were detected in 12 weeks E-cig exposed group. These data were supported by the electron microscopic results which reflected degenerative changes in cytoplasmic organelles.
Conclusion: E-cig is not safe and its use to replace cigarette smoking cannot be recommended.