Oxidant and antioxidant balance in the airways and airway diseases

Free Radicals: Properties, Sources, Targets, and Their Implication in Various Diseases

“…Increased generation of oxidants have been reported in asthma patients than in healthy individuals [204] which provoked airway inflammation by inducing diverse proinflammatory mediators including macrophages, neutrophils and eosinophils [205]. Numerous studies have suggested that oxidative stress is caused by overproduction of various free radicals or by an insufficient antioxidant defense system in asthma and thus it contributes to the tissue damage which is induced by inflammatory cells [206].…”

“…Numerous studies have suggested that oxidative stress is caused by overproduction of various free radicals or by an insufficient antioxidant defense system in asthma and thus it contributes to the tissue damage which is induced by inflammatory cells [206]. Elevated levels of oxidative stress markers such as H 2 O 2 , 8-isoprostane, nitric oxide, and carbon monoxide were reported in exhaled air of asthmatic patients [204]. Increased MDA levels, and Protein carbonyls; decreased protein sulfhydryl and antioxidant activity were observed in plasma, bronchoalveolar lavage (BAL) fluid and exhaled air of asthamatic patients [207][208][209].…”

Fontes vegetais naturais de antioxidantes

“…1 Estresse redox é comumente definido como o desequilíbrio entre a produção de espécies reativas de oxigênio, nitrogênio e enxofre, entre outras, e a remoção destas pelos sistemas químicos e enzimáticos de defesa antioxidante e, também, pelo reparo enzimático das biomoléculas lesadas. 2,3 As espécies reativas mais estudadas nos sistemas biológicos incluem as espécies reativas de oxigênio, as espécies reativas de nitrogênio, os radicais derivados de tióis (RS • ), as espécies reativas de cloro, as espécies reativas de carbono e complexos de metais de transição, principalmente Fe, Cu, Mn e Cr. 1,3,4 Outros íons metálicos, sem atividade redox direta, também podem afetar o balanço oxidativo, como os íons de metais pesados (Pb, Cd) e trivalentes (Bi, Al), que são capazes de se ligar fortemente aos grupos fosfatos dos fosfolipídios de membranas celulares, diminuindo sua fluidez e, consequentemente, aumentando sua peroxibilidade.…”

Thioredoxin suppresses airway inflammation independently of systemic Th1/Th2 immune modulation

“…Several different pathways have evolved to protect the host from oxidative stress associated with inflammation including small antioxidant molecules such as ascorbate, a-tocopherol and glutathione (GSH), as well as antioxidant enzymes such as superoxide dismutase, catalase, GSH reductase, thioredoxin (TRX) and TRX reductase [15]. TRX is a 12 kDa protein with a highly conserved redox-active dithiol/disulfide active site sequence, Cys 32 -Gly-Pro-Cys 35 , which, together with GSH constitutes the major redox-regulating molecules that maintain cellular redox balance [16,17].…”