Comparison between inhalational anesthetics in terms of DNA damage and immunological markers

This study compared genetic damage and immunological markers between surgical patients who underwent inhalational anesthesia with isoflurane or sevoflurane. Blood samples were collected from surgical patients (n = 18 in the isoflurane group and n = 17 in the sevoflurane group) at baseline (before the anesthesia procedure) and the day after anesthesia. DNA damage was detected using an alkaline comet assay; proinflammatory interleukin (IL)-6 was detected by flow cytometry, and white blood cells were detected via an automatic hematology analyzer. The characteristics of both groups were similar, and neither of the two anesthetics induced DNA damage. Similarly, mild neutrophilia was observed after anesthesia in both groups. Increased IL-6 levels were observed 1 day after anesthesia regardless of the type of anesthetic, but this increase was greater in the isoflurane group. Our study suggested that isoflurane and sevoflurane administration may contribute to changes in the immune parameters measured, though no genotoxic hazard was identified, in healthy adult patients who undergo low-stress surgery.

Modulation of gene expression and influence of gene polymorphisms related to genotoxicity and redox status on occupational exposure to inhaled anesthetics

The extensive use of inhalational anesthetics contributes to both indoor and outdoor (environmental) pollution. The influence of genetic susceptibility on DNA damage and oxidative stress and the possible modulation of gene expression have not yet been investigated upon occupational exposure to waste anesthetic gases (WAGs). This study assessed 8-oxoguanine DNA glycosylase 1 (OGG1) and superoxide dismutase 2 (SOD2) gene expression, which are related to oxidized DNA repair and antioxidant capacity, respectively, and the influence of their polymorphisms (OGG1 rs1052133 and SOD2 rs4880) in 100 professionals highly exposed to WAGs and 93 unexposed volunteers (control group). Additionally, X-ray repair cross complementing 1 (XRCC1 rs25487 and rs1799782) and ataxia telangiectasia mutated (ATM rs600931) gene polymorphisms as well as genetic instability (micronucleus-MN and nuclear bud-NBUD) and oxidative stress (malondialdehyde-MDA and ferric reducing antioxidant power-FRAP) biomarkers were assessed in the groups (control and exposed) and in the subgroups of the exposed group according to job occupation (anesthesiologists versus surgeons/technicians). Except for the ATM TT controls (associated with increased FRAP), there were no influences of OGG1, XRCC1, ATM, and SOD2 polymorphisms on MN, NBUD, MDA, and FRAP values in exposed or control subjects. No significant difference in the expression of either gene evaluated (OGG1 and SOD2) was found between the exposed and control groups. Increased OGG1 expression was observed among OGG1 -/Cys individuals only in the control group. Among the exposed group, anesthesiologists had a greater duration of WAG exposure (both h/week and years) than surgeons/technicians, which was associated with increased MDA and decreased antioxidant capacity (FRAP) and SOD2 expression (redox status). Higher expression of OGG1 was found in -/Cys surgeons/technicians than in anesthesiologists with the same genotype. Increased antioxidant capacity was noted in the surgeons/technicians carrying the ATM T allele and in those carrying XRCC1 -/Gln. Increased MN was influenced by OGG1 -/Cys in surgeons/technicians. Anesthesiologists with ATM CC exhibited increased MN, and those carrying the C allele (CC/CT genotype) exhibited increased NBUD. SOD2 polymorphism did not seem to be relevant for WAG exposure. These findings contribute to advancing the knowledge on genetic susceptibility/gene expression/genetic instability/oxidative stress, including differences in job occupation considering the workload, in response to occupational exposure to WAGs.

High anesthetic exposure leads to oxidative damage and gene expression changes in physicians during medical residency: a cohort study

Evaluation of the possible toxic effects of occupational exposure to anesthetics is of great importance, and the literature is limited in assessing the possible association between occupational exposure to anesthetics and oxidative stress and genetic damage. To contribute to the gap of knowledge in relation to cause-effect, this cohort study was the first to monitor exposure assessment and to evaluate oxidative stress, DNA damage, and gene expression (OGG1, NRF2, HO-1, and TP53) in young adult physicians occupationally exposed to the most modern halogenated anesthetics (currently the commonly used inhalational anesthetics worldwide) in addition to nitrous oxide gas during the medical residency period. Therefore, the physicians were evaluated before the beginning of the medical residency (before the exposure to anesthetics-baseline), during (1 1/2 year) and at the end (2 1/2 years) of the medical residency. Anesthetic air monitoring was performed in operating rooms without adequate ventilation/scavenging systems, and biological samples were analyzed for lipid peroxidation, protein carbonyl content, primary and oxidative DNA damage, antioxidant enzymes and plasma antioxidant capacity, and expression of some key genes. The results showed induction of lipid peroxidation, DNA damage, glutathione peroxidase activity, and NRF2 and OGG1 expression up to the end of medical residency. Plasma antioxidant capacity progressively increased throughout medical residency; oxidative DNA damage levels started to increase during medical residency and were higher at the end of residency than at baseline. Protein carbonyls increased during but not at the end of medical residency compared to baseline. The antioxidant enzyme superoxide dismutase activity remained lower than baseline during and at the end of medical residency, and HO-1 (related to antioxidant defense) expression was downregulated at the end of medical residency. Additionally, anesthetic concentrations were above international recommendations. In conclusion, high concentrations of anesthetic in the workplace induce oxidative stress, gene expression modulation, and genotoxicity in physicians during their specialization period.

Modulation of gene expression and inflammation but not DNA damage after sevoflurane anesthesia

This study assessed, for the first time, the expression of the genes hOGG1, TP53, and IL-6 in leukocytes by real-time quantitative polymerase chain reaction in surgical patients before (baseline), during (2 h of anesthesia) and 1 day after sevoflurane anesthesia. Additionally, DNA damage was detected by the comet assay, serum interleukin (IL)-6 was detected by flow cytometry, and differential leukocyte counting was also performed. TP53 and hOGG1 expression was downregulated on the day after anesthesia compared to before anesthesia. However, IL-6 expression did not change, and no DNA damage induction was observed during or after anesthesia. At the systemic level, mild neutrophilia and an increase in IL-6 levels occurred after anesthesia. Our findings suggest that sevoflurane anesthesia downregulates gene expression (hOGG1 and TP53) and contributes to an inflammatory status (increased systemic IL-6 and mild neutrophilia) but is not associated with DNA damage in patients without comorbidities who undergo minor elective surgery.

Evaluation of genetic instability, oxidative stress, and metabolism-related gene polymorphisms in workers exposed to waste anesthetic gases

Professionals who work in operating rooms (ORs) may be exposed daily to waste anesthetic gases (WAGs) due to the use of inhalational anesthetics. Considering the controversial findings related to genetic damage and redox status in addition to a lack of knowledge about the effect of polymorphisms in genes related to phase I and II detoxification upon occupational exposure to WAGs, this cross-sectional study is the first to jointly evaluate biomarkers of genetic instability, oxidative stress, and susceptibility genes in professionals occupationally exposed to high trace amounts of halogenated (≥ 7 ppm) and nitrous oxide (165 ppm) anesthetics in ORs and in individuals not exposed to WAGs (control group). Elevated rates of buccal micronucleus (MN) and nuclear bud (NBUD) were observed in the exposure group and in professionals exposed aged more than 30 years. Exposed males showed a higher antioxidant capacity, as determined by the ferric reducing antioxidant power (FRAP), than exposed females; exposed females had higher frequencies of MN and NBUD than nonexposed females. Genetic instability (MN) was observed in professionals with greater weekly WAG exposure, and those exposed for longer durations (years) exhibited oxidative stress (increased lipid peroxidation and decreased FRAP). Polymorphisms in metabolic genes (cytochrome P450 2E1 (CYP2E1) and glutathione S-transferases (GSTs)) did not exert an effect, except for the effects of the GSTP1 (rs1695) AG/GG polymorphism on FRAP (both groups) and GSTP1 AG/GG and GSTT1 null polymorphisms, which were associated with greater FRAP values in exposed males. Minimizing WAG exposure is necessary to reduce impacts on healthcare workers.

High anesthetic (isoflurane) indoor pollution is associated with genetic instability, cytotoxicity, and proliferative alterations in professionals working in a veterinary hospital

This is the first study to monitor anesthetic pollution in veterinary operating rooms (VOR) and assess the toxicological impact of the inhalational anesthetic isoflurane (exposed group) compared to matched volunteers (control group). DNA damage was evaluated in mononuclear cells by the comet assay while genetic instability (including micronucleus-MN), cell proliferation, and cell death markers were assessed by the buccal MN cytome assay. Residual isoflurane concentrations in VOR (air monitoring) lacking the scavenging system were assessed by infrared spectrophotometry; the mean concentration was 11 ppm (≥ 5 times above the international recommended threshold). Comet assay results did not differ between groups; however, both younger exposed professionals (with higher week workload) compared to older individuals exposed for the same period and older professionals with greater time of exposure (years) compared to those in the same age group with fewer years of exposure presented higher DNA damage. The exposed group had a higher frequency of MN, nuclear buds, binucleated cells, karyorrhexis, and karyolysis and a lower frequency of basal cells than the control group. Exposed women were more vulnerable to genetic instability and proliferative index; exposed men presented more cytotoxicity. High WAG exposure has deleterious effects on exposed professionals.

Hepatotoxic and neuroendocrine effects in physicians occupationally exposed to most modern halogenated anesthetics and nitrous oxide

The lack of data on hepatic and hormonal markers for occupational exposure to most modern halogenated anesthetics has stimulated our research, which assessed liver enzymes, high-sensitivity C-reactive protein (hs-CRP) and neuroendocrine response. The study investigated 106 physicians who were categorized in an exposed group (primarily exposed to isoflurane and sevoflurane and less to desflurane and nitrous oxide) as well as as a control group. Anesthetic air monitoring was performed, and biological samples were analyzed for the most important liver enzymes, hs-CRP, adrenocorticotrophic hormone, cortisol and prolactin. No biomarkers were significantly different between the groups. Exposed males showed significant increases in cortisol and prolactin compared to unexposed males. However, values were within the reference ranges, and 22 % of exposed males versus 5 % of unexposed males exhibited higher prolactin values above the reference range. This study suggests that occupational exposure to the most commonly used inhalational anesthetics is not associated with hepatotoxicity or neurohormonal changes.

Genetic instability assessed by telomere length and micronucleus in physicians exposed to anesthetics

This study evaluated both telomere length (TL) and micronucleus (MN) as indicators of genome instability in 40 anesthesiologists occupationally exposed to anesthetics and in 40 physicians without occupational exposure to anesthetics who were matched by age, sex, and lifestyle. Blood and buccal samples were collected from both groups at the same period. Anesthetic exposure assessment was performed. The studied groups were assessed regarding relative TL by quantitative polymerase chain reaction and MN by buccal MN assay. Mean trace concentrations of anesthetics were below two parts per million. No significant differences between groups were found for both biomarkers. However, MN frequency was slightly increased (1.9-fold; p = .094) in the exposed group compared to the control group and in the exposed males (2.4-fold; p = .090) compared to unexposed males. TL and age showed a significant negative correlation. Anesthetic occupational exposure below recommended levels is not associated with changes in TL and MN in anesthesiologists.

Involvement of AOX and UCP pathways in the post-harvest ripening of papaya fruits

Enhanced respiration during ripening in climacteric fruits is sometimes associated with an uncoupling between the ATP synthesis and the mitochondrial electron transport chain. While the participation of two energy-dissipating systems, one of which is mediated by the alternative oxidase (AOX) and the other mediated by the uncoupling protein (UCP), has been linked to fruit ripening, the relation between the activation of both mitochondrial uncoupling systems with the transient increase of ethylene synthesis (ethylene peak) remains unclear. To elucidate this question, ethylene emission and the two uncoupling (AOX and UCP) pathways were monitored in harvested papaya fruit during the ripening, from green to fully yellow skin. The results confirmed the typical climacteric behavior for papaya fruit: an initial increase in endogenous ethylene emission which reaches a maximum (peak) in the intermediate ripening stage, before finally declining to a basal level in ripe fruit. Respiration of intact fruit also increased and achieved higher levels at the end of ripening. On the other hand, in purified mitochondria extracted from fruit pulp the total respiration and respiratory control decrease while an increase in the participation of AOX and UCP pathways was markedly evident during papaya ripening. There was an increase in the AOX capacity during the transition from green fruit to the intermediate stage that accompanied the transient ethylene peak, while the O2 consumption triggered by UCP activation increased by 80% from the beginning to end stage of fruit ripening. Expression analyses of AOX (AOX1 and 2) and UCP (UCP1-5) genes revealed that the increases in the AOX and UCP capacities were linked to a higher expression of AOX1 and UCP (mainly UCP1) genes, respectively. In silico promoter analyses of both genes showed the presence of ethylene-responsive cis-elements in UCP1 and UCP2 genes. Overall, the data suggest a differential activation of AOX and UCP pathways in regulation related to the ethylene peak and induction of specific genes such as AOX1 and UCP1.