Low-Dose Oxidant Toxicity and Oxidative Stress in Human Papillary Thyroid Carcinoma Cells K1

Medical gas plasmas are of emerging interest in pre-clinical oncological research. Similar to an array of first-line chemotherapeutics and physics-based therapies already approved for clinical application, plasmas target the tumor redox state by generating a variety of highly reactive species eligible for local tumor treatments. Considering internal tumors with limited accessibility, medical gas plasmas help to enrich liquids with stable, low-dose oxidants ideal for intratumoral injection and lavage. Pre-clinical investigation of such liquids in numerous tumor entities and models in vitro and in vivo provided evidence of their clinical relevance, broadening the range of patients that could benefit from medical gas plasma therapy in the future. Likewise, the application of such liquids might be promising for recurrent BRAF(V600E) papillary thyroid carcinomas, resistant to adjuvant administration of radioiodine. From a redox biology point of view, studying redox-based approaches in thyroid carcinomas is particularly interesting, as they evolve in a highly oxidative environment requiring the capability to cope with large amounts of ROS/RNS. Knowledge on their behavior under different redox conditions is scarce. The present study aimed to clarify resistance, proliferative activity, and the oxidative stress response of human papillary thyroid cancer cells K1 after exposure to plasma-oxidized DMEM (oxDMEM). Cellular responses were also evaluated when treated with different dosages of hydrogen peroxide and the RNS donor sodium nitroprusside (SNP). Our findings outline plasma-oxidized liquids as a promising approach targeting BRAF(V600E) papillary thyroid carcinomas and extend current knowledge on the susceptibility of cells to undergo ROS/RNS-induced cell death

ESTRESSE OXIDATIVO EM ERITRÓCITOS SUBMETIDOS A 2,2- AZOBIS AMIDINOPROPANO (AAPH): EFEITO ANTIOXIDANTE E ANTIHEMOLÍTICO DO CHÁ VERDE (Camellia sinensis)

O ch verde (Camellia sinensis) uma bebida, bastante consumida pelos orientais, cuja composio apresenta as catequinas, polifenis que possuem atividade antioxidante, quimioprotetora, antiinflamatria e anti-carcinognica. Vrios estudos tm demonstrado que o ch verde pode prevenir vrias doenas associadas ao estresse oxidativo, tais como o cncer, doenas cardiovasculares e neurodegenerativas. Estes efeitos benficos dependero da quantidade de ch consumida e da biodisponibilidade das catequinas. O objetivo deste estudofoi avaliar a ao do extrato do ch verde (ECV) na inibio da hemlise oxidativa induzida pelo 2,2 azobis amidinopropano (AAPH). Este composto um gerador de radicais livres que, a 37C e ao abrigo da luz, gera radicais do tipo peroxil a uma taxa constante. Hemcias humanas de doadores saudveis foram submetidas AAPH e ao extrato de ch verde em diferentes concentraes. Os resultados indicam que o ch verde, na concentrao de 0,54 mg/Ml, um timo antioxidante e anti-hemoltico, inibindo em 81,6% a hemlise oxidativa dehemcias tratadas com AAPH. A ao antioxidante durou at 5 horas aps a exposio das hemcias aos radicais livres gerados pelo AAPH, sendo que o ch verde, por si s, no levou a nenhuma leso as hemcias. Nossos dados demonstram, pela primeira vez, que o ch verde pode inibir a hemlise oxidativa de eritrcitos humanos. Ensaios clnicos so necessrios para investigar os possveis benefcios do uso do ch verde como adjuvante teraputico em doenas hemolticas que envolvam a ao de radicais livres

Nasal and systemic inflammatory profile after short term smoking cessation

SummaryIntroductionSmoking cessation promotes health benefits and, despite cigarette smoking be an important pro inflammatory stimulus, there are few studies concerning the nasal and systemic inflammation; as well as the mucociliary clearance behavior in smokers after short period of smoking cessation.AimTo evaluate the nasal and systemic inflammatory markers and mucociliary clearance behavior after 30 days of cigarette smoking abstinence.MethodsTwenty-five smokers were included and divided into two groups: abstinent smokers (n = 14) and current smokers (n = 11). Tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-8 and IL-10 were measured on nasal lavage and blood serum samples by ELISA at baseline and after 30 days. The mucociliary clearance, exhaled carbon monoxide (exCO) and carboxyhemoglobin (HbCO) were also measured at the same moments.ResultsThere was a decrease of TNF-α level only in blood serum at 30 days of abstinence compared to current smokers. The mucociliary clearance improved and there was a reduction in exCO and HbCO (p < 0.05 for all) after 30 days of smoking cessation.ConclusionThe short term smoking abstinence decreased systemic inflammation and improved nasal mucociliary clearance, despite not having changed the nasal inflammation

Lung injury-dependent oxidative status and chymotrypsin-like activity of skeletal muscles in hamsters with experimental emphysema

BACKGROUND: Peripheral skeletal muscle is altered in patients suffering from emphysema and chronic obstructive pulmonary disease (COPD). Oxidative stress have been demonstrated to participate on skeletal muscle loss of several states, including disuse atrophy, mechanical ventilation, and chronic diseases. No evidences have demonstrated the occurance in a severity manner. METHODS: We evaluated body weight, muscle loss, oxidative stress, and chymotrypsin-like proteolytic activity in the gastrocnemius muscle of emphysemic hamsters. The experimental animals had 2 different severities of lung damage from experimental emphysema induced by 20 mg/mL (E20) and 40 mg/mL (E40) papain. RESULTS: The severity of emphysema increased significantly in E20 (60.52 ± 2.8, p < 0.05) and E40 (52.27 ± 4.7; crossed the alveolar intercepts) groups. As compared to the control group, there was a reduction on body (171.6 ± 15.9 g) and muscle weight (251.87 ± 24.87 mg) in the E20 group (157.5 ± 10.3 mg and 230.12 ± 23.52 mg, for body and muscle weight, respectively), which was accentuated in the E40 group (137.4 ± 7.2 g and 197.87 ± 10.49 mg, for body and muscle weight, respectively). Additionally, the thiobarbituric acid reactive substances (TBARS), tert-butyl hydroperoxide-initiated chemiluminescence (CL), carbonylated proteins, and chymotrypsin-like proteolytic activity were elevated in the E40 group as compared to the E20 group (p < 0.05 for all comparisons). The severity of emphysema significantly correlated with the progressive increase in CL (r = −0.95), TBARS (r = −0.98), carbonyl proteins (r = −0.99), and chymotrypsin-like proteolytic activity (r = −0.90). Furthermore, augmentation of proteolytic activity correlated significantly with CL (r = 0.97), TBARS (r = 0.96), and carbonyl proteins (r = 0.91). CONCLUSIONS: Taken together, the results of the present study suggest that muscle atrophy observed in this model of emphysema is mediated by increased muscle chymotrypsin-like activity, with possible involvement of oxidative stress in a severity-dependent manner

Atividade hepatoprotetora do extrato alcoólico da Camellia sinensis (L.) Kuntze (chá-verde) em ratos Wistar tratados com dietilnitrosamina

O chá-verde (Camellia sinensis (L.) Kuntze) é utilizado por suas propriedades: antioxidante, quimioprotetora e antiinflamatória em varias situações patológicas, principalmente frente a compostos químicos cancerígenos. Para tanto se avaliou o efeito hepatoprotetor do extrato de chá verde (ECV) sobre a lipoperoxidação e necrose provocada pelo agente cancerígeno Dietilnitrosamina (DEN) no fígado de ratos machos Wistar. Os ratos foram expostos a dose única de 200 mg/kg de DEN via intra peritoneal e tratados por via oral de 120 mg/kg de ECV em diferentes momentos experimentais. Após 24 h em relação a exposição ao DEN, os animais foram sacrificados sendo avaliado: os níveis de AST/ALT no plasma, a lipoperoxidação por quantificação de TBARS e FOX no fígado e a ocorrência de necrose e hemorragia hepática através do estudo histopatológico. A ação quimioprotetora e a diminuição da lipoperoxidação foram verificadas pela diminuição das transaminases, TBARS, FOX e redução da necrose hepática. A avaliação confirmou a importância de se utiliza o chá verde como agente quimioprotetor, principalmente na forma preventiva