Glutathione levels in and total antioxidant capacity of Candida sp. cells exposed to oxidative stress caused by hydrogen peroxide

Abstract

Candida albicans, C. glabrata, C. tropicalis, and C. parapsilosis account for approximately 95% of identifiable Candida infections. Other species, including C. krusei, C. lusitaniae, and C. guilliermondii, account for less than 5% of cases of invasive candidiasis. The most common causative agent is still C. albicans, but its incidence is declining and the frequencies of other species are increasing. Recently, Furlaneto et al. 1 noted that non-albicans Candida was the predominant species in different clinical specimens, with the exception of urine samples, in a Brazilian tertiary-care hospital. Invasive candidiasis has a mortality rate that approaches 40% 2,3 . Although most people are colonized by Candida sp., the majority never develop invasive candidiasis. Alterations in host immunity, physiological features, or normal microflora, rather than the acquisition of novel or hypervirulent factors by Candida, are suggested to degenerate the commensal-host interaction and lead to an opportunistic infection 4 .During the course of a systemic infection, Candida cells are engulfed by host phagocytes, where they are exposed to reactive oxygen species (ROS) 5 . ROS contribute to the killing of C. albicans in both cultured cells and entire organisms [6][7][8][9] . Upon incubation with macrophages, C. albicans deoxyribonucleic acid (DNA) repair genes are transcriptionally induced, suggesting that DNA damage indeed occurs in the phagosome and that genotoxic hypersensitivity stress would be disadvantageous to the pathogen 10 . Recently, it was demonstrated that a large proportion of C. albicans cell surface antigens related to acute candidemia are involved in oxidative stress 4 . In C. albicans, hyphal cells ABSTRACT Introduction: The capacity to overcome the oxidative stress imposed by phagocytes seems to be critical for Candida species to cause invasive candidiasis. Methods: To better characterize the oxidative stress response (OSR) of 8 clinically relevant Candida sp., glutathione, a vital component of the intracellular redox balance, was measured using the 5,5'-dithiobis-(2-nitrobenzoic acid (DTNB)-glutathione disulfide (GSSG) reductase reconversion method; the total antioxidant capacity (TAC) was measured using a modified method based on the decolorization of the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic) acid radical cation (ABTS* + ). Both methods were used with cellular Candida sp. extracts treated or not with hydrogen peroxide (0.5 mM). Results: Oxidative stress induced by hydrogen peroxide clearly reduced intracellular glutathione levels. This depletion was stronger in Candida albicans and the levels of glutathione in untreated cells were also higher in this species. The TAC demonstrated intra-specific variation. Conclusions: Glutathione levels did not correlate with the measured TAC values, despite this being the most important non-enzymatic intracellular antioxidant molecule. The results indicate that the isolated measurement of TAC does not give a clear picture of the ability of a given Candida sp. to resp...

Antioxidant activities of Moringa oleifera L. and Bidens pilosa L. leaf extracts and their effects on oxidative stability of ground raw beef during refrigeration storage

“…This could be attributed to differences in mechanism of action and reaction of DPPH and ABST radical. The ABTS has been reported to be soluble in aqueous and organic solvents, and can therefore determine both hydrophilic and lipophilic antioxidant capacities (Abegg, Alabarse, Schuller, & Benfato, 2012). However, our observations agreed with the finding of Moyo et al (2012) who found that scavenging ability of M. oleifera extract against ABTS was greater than DPPH radicals.…”

<p>Stigmasterol Exerts Neuro-Protective Effect Against Ischemic/Reperfusion Injury Through Reduction Of Oxidative Stress And Inactivation Of Autophagy</p>

“…Total glutathione (GSH) level was measured using the 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB)-GSSG reductase according to the previous study 24. As for quantification of the GSSG level, 2-vinylpyridine solution was firstly supplemented to eliminate the reduced GSH.…”

Antimicrobial activity and acetylcholinestrase inhibition of novel synthesized pyrimidine derivatives versus Candida albicans trafficking to brain and kidney

“…Different studies previously reported that malevolence of C. albicans seems to be multifactorial; however, the ability of this fungus to augment the stress resistance is essential to be more survival within host in different organs. Different studies investigated an association of the oxidative effects (resistance degree and oxidative damage induction) and anti-oxidative effects (ability to adapting and induction of anti-oxidative enzymes) [[25], [26], [27]].…”