Induction of ROS generation by fluconazole in Candida glabrata: activation of antioxidant enzymes and oxidative DNA damage.

In this study, we assessed the generation of reactive oxygen species (ROS) induced by subinhibitory concentration of fluconazole in susceptible and resistant Candida glabrata strains at stationary growth phase and measured their oxidative responses parameters: glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione-S-transferase (GST), consumption of hydrogen peroxide, and total glutathione, as well as oxidative damage in lipids, proteins, and DNA. Data showed that fluconazole increased generation of ROS and GPx and SOD enzymatic activity in treated cells; however, these enzymatic activities did not differ between resistant and susceptible strains. Susceptible strains exhibited higher GST activity than resistant, and when susceptible cells were treated with fluconazole, GST activity decreased. Fluconazole treatment cause oxidative damage only in DNA. There are a possible participation of ROS, as organic peroxides and O2(•-), in antifungal mechanism of fluconazole, which results in higher GPx and SOD enzymatic activities and oxidative DNA damage in C. glabrata.

Oxidative stress in the kidney of reproductive female rats during aging.

Reproduction is a costly life process, and the reproductive investment by females appears to be greater than males in many species. We have analyzed the effects of reproductive investment during aging with respect to oxidative stress parameters in female Wistar rats. We measured the activity glutathione peroxidase, glutathione S-transferase, superoxide dismutase, consumption of hydrogen peroxide, protein carbonylation, lipid peroxidation, nitrite and nitrate levels, and Vitamin C (Vit. C) and E levels. We traced oxidative profiles at ages 3, 6, 12, and 24 months. Animals were grouped according to reproductive experience: experienced or naive with respect to reproductive activity. We measured aconitase activity and sex hormone levels. The naive animals exhibited an increase with respect to experienced in most parameters studied at 6 and 24 months, whereas experienced animals exhibited a similar increase at 3 and 12 months. At 6 months of age, during the period that would represent peak reproductive activity, naive animals showed higher levels of MDA, Vit. C, consumption of hydrogen peroxide and GPx, aconitase, and SOD activities. In naive elderly rats, we observed an increase in oxidative damage markers and an increase in enzymatic and non-enzymatic antioxidants, with the exception of consumption of hydrogen peroxide and Vit. C. In the long term, the reproductive investment was not sufficient to interfere with antioxidant capacity, and did not contribute to oxidative damage in kidneys of female Wistar rats.