Inhibition of salivary enzymes by cigarette smoke and the protective role of glutathione

Abstract

<jats:p> Tobacco smoke is involved in the pathogenesis of several diseases regarding different body systems, mainly cardiovascular and respiratory in addition to its local toxic effect in the oral cavity. The noxious effects of smoke compounds justify the high incidence of periodontal diseases, caries, and neoplastic diseases of oral tissues in smokers. Some toxic components of tobacco smoke, unsaturated and saturated aldehydes, could interact with thiol rich compounds, leading to structural and functional modification of these molecules. Previous papers have demonstrated an in vitro significant decrease of some enzymatic activities, both in plasma and in saliva, following external addition of aldehydes or exposure to cigarette smoke (CS). Furthermore, the same studies underlined the protective effect exerted by the addition of glutathione (GSH) against the damaging role of smoke aldehydes. In this study some salivary enzymes (lactic dehydrogenase [LDH], aspartate aminotransferase [AST] and amylase), and total GSH were measured in 20 volunteers smokers, before and just after smoking a single cigarette. All enzymatic activities showed a significant inhibition following a single cigarette, probably due to the interaction between smoke aldehydes and–SH groups of the enzyme molecules. Moreover, the percentage of the enzymatic inhibition showed a negative correlation with the basal level of salivary GSH. Our results emphasize that not only one cigarette is sufficient to impair the salivary enzymatic activities but also strengthen the proposed protective role of GSH against the noxious biochemical effects of CS. </jats:p>

Effect of non surgical periodontal therapy on salivary and RBC lysate superoxide dismutase levels in periodontitis: A clinico biochemical study

“…The purpose of using Modified Prasad's classification is that it takes into consideration only the per capita monthly income as a variable and can be applied to both rural and urban populations. Smokers were excluded from the study keeping in view their negative impact over AO profile (47).…”

Tobacco: Incessant Human Health Menace (A Review)

“…Interaction between cigarette smoke and saliva may be deleterious; destruction of biological macromolecules (enzymes and proteins) [57][58][59][60].…”

Influência do fumo na atividade da amilase salivar e na curva glicêmica

“…Os resultados obtidos no gráfico acima mostram que a atividade da enzima antes e após alimentação apresentou-se 87,3% e 87,5% menor nos indivíduos fumantes. Além disso, Zappacosta et al 19,20 verificaram também que um cigarro é suficiente para diminuir a atividade enzimática em 40%. Segundo Moldeus et al 21 e Joshi et al 22 , os aldeídos do tabaco inibem diretamente a amilase salivar, e que esta atividade, na presença da glutationa, um antioxidante natural presente na saliva, é preservada.…”

“…Os estudos demonstraram que um cigarro é suficiente para diminuir a atividade enzimática, assim como ficou evidente o efeito protetor exercido pela glutationa salivar cuja concentração ficou significantemente reduzida 19,20 . A glutationa reage com a acroleína e o crotonaldeído, os mais importantes aldeídos insaturados 23 .…”

“…Contudo, outros estudos têm demonstrado um aumento real no peso após a parada de fumar [11][12][13][14] . Alguns mecanismos são propostos para este aumento de peso, como o aumento da atividade da lipase lipoproteíca do tecido adiposo, fazendo um maior depósito de ácidos graxos neste tecido 19 , o aumento do aporte calórico, diminuição da taxa metabólica e diminuição da atividade física 20 . Estes trabalhos vão de encontro com os resultados aqui demonstrados, onde se sugere que o cigarro diminuiu a absorção de carboidratos.…”