Analysis of the Status of the Cutaneous Endogenous and Exogenous Antioxidative System of Smokers and the Short-Term Effect of Defined Smoking Thereon

Abstract

The daily consumption of tobacco products leads to a boost in free radical production in tissues, promoting the risk for malignancies, metabolic alterations and chronic-inflammatory diseases. This study aimed to broaden the knowledge of the status of the antioxidative (AO) system in the skin, compared to the blood, of healthy appearing smokers. Both, the basic status compared to non-smokers and the short-term impact of controlled cigarette consumption in smokers were analyzed. Our study showed that the basic level of the AO system of smokers significantly differed from that of non-smokers. As determined by resonant Raman spectroscopy (RRS), the levels of exogenous AOs were decreased in both, the skin, in vivo (β-carotene and lycopene), and blood plasma (β-carotene only). In contrast, the levels of glutathione (GSH), the prototypical endogenous AO, which were analyzed by fluorimetric assays in cutaneous tape strips and blood plasma, were increased in the skin, although unchanged in the blood of smokers. Elevated cutaneous GSH levels were reflected by an elevated overall radical scavenging activity in the skin, as quantified by non-invasive electron paramagnetic resonance (EPR) spectroscopy. Analysis of the expression of selected stress-associated genes in blood immune cells by quantitative RT-PCR in subgroups of non-smokers and smokers additionally demonstrated the downregulation of AKR1C2 in smokers, and its negative correlation with blood plasma levels of the protective immune mediator interleukin-22, assessed by the ELISA technique. Controlled cigarette consumption did not alter exogenous or endogenous AOs in the skin of smokers, but decreased lycopene levels in blood plasma. Moreover, there was a decline in blood IL-22 levels, while no relevant response of blood cell gene expressions was found after the considered short time. Our data therefore demonstrate a strengthened endogenous AO status in the skin of smokers, which may indicate a long-term adaptation to chronic oxidative stress in this specific organ. While this effect was not clearly visible in the blood, this compartment seems to be useful as an immediate indicator of the body’s AO consumption. Moreover, decreased levels of AKR1C2, which we show for the first time to be expressed in immune cells, may be a candidate marker for long-term smoking. In addition, this study demonstrates that the rate constant of a spin probe decline determined by EPR spectroscopy mainly represents the endogenous AO status of a tissue.

Carotenoids in Human Skin In Vivo: Antioxidant and Photo-Protectant Role against External and Internal Stressors

“…Using non-invasive RRS and diffuse reflectance spectroscopy it was shown in human skin in vivo that the consumption of high doses of alcohol [ 186 ], excessive physical activity [ 187 ], domestic and work stress [ 52 , 188 , 189 ], and other stress factors [ 189 , 190 ] result in a reduction of the carotenoid concentration in the human SC, which depends on the initial concentration of the carotenoids’ and stressor’s intensity. It has been noticed that the concentration of carotenoids in the SC of smokers is significantly lower than in non-smokers ( p < 0.001) [ 135 , 191 , 192 ], which is in agreement with the literature data [ 50 , 193 , 194 ]. The concentration of carotenoids in the SC of women is significantly higher than in men ( p < 0.05) [ 192 ].…”

“…However, recent investigations have shown that smokers may have a lower carotenoid concentration but higher k values in the SC. This was explained by the substantial increase of glutathione concentration in the upper SC of smokers compared to non-smokers and primarily the interaction of the skin probe TEMPO with the endogenous antioxidants [ 135 ]. Thus, in smokers, the skin probe TEMPO was reduced primarily by glutathione, resulting in a higher k value.…”

Influence of Oxidative Stress Generated by Smoking during Pregnancy on Glutathione Status in Mother-Newborn Pairs

“…Increased blood GSH levels have been shown in heavy smokers (>20 cigarettes a day). On the other hand, in people who smoked less than 20 cigarettes a day, the concentrations of glutathione were similar to those observed in the group of non-smokers [29,31,34].…”

Spectroscopic biofeedback on cutaneous carotenoids: A powerful tool for primary prevention in advanced age

“…The skin represents a reservoir for endogenous antioxidants as well as antioxidants obtained from dietary intake. [36]. Prior studies showed that a healthy nutrition rich in fruits and vegetables was associated with an enhanced cutaneous carotenoid content [37, 38] which corresponds to other literature that showed that carotenoids are suited biomarkers for fruit and vegetable intake [21].…”

“…Moreover, the negative effect of smoking on the cutaneous carotenoid concentration was shown by a study of Meinke et al [35]. This effect was later more detailed on a biochemical level studied by Lohan et al and a promoted stress‐level by tobacco consumption was assumed, which consumed antioxidants from the bloodstream [36]. The reduced antioxidant levels in the skin of smokers versus non‐somkers are assumed as a result of a higher radical load by smoking which leads to a higher initial consumption of the antioxidants from the bloodstream.…”