Carbon Sources for Yeast Growth as a Precondition of Hydrogen Peroxide Induced Hormetic Phenotype

Abstract

Hormesis is a phenomenon of particular interest in biology, medicine, pharmacology, and toxicology. In this study, we investigated the relationship between H2O2-induced hormetic response in S. cerevisiae and carbon sources in yeast growth medium. In general, our data indicate that (i) hydrogen peroxide induces hormesis in a concentration-dependent manner; (ii) the effect of hydrogen peroxide on yeast reproductive ability depends on the type of carbon substrate in growth medium; and (iii) metabolic and growth rates as well as catalase activity play an important role in H2O2-induced hormetic response in yeast.

Growth on Alpha-Ketoglutarate Increases Oxidative Stress Resistance in the YeastSaccharomyces cerevisiae

“…The yeast pellets were resuspended in 1 mL of 50 mM potassium phosphate buffer (pH 7.0) and mixed with 0.35 mL of 0.5% 2,3,5-triphenyl tetrazolium chloride (TTC). Metabolically active cells are capable of reducing the dye to a water-insoluble red formazan that was extracted from the cells with ethanol/acetone mixture (2 : 1), and the absorbance of this solution was measured at 485 nm [25, 26]. Metabolic activity was expressed in units of optical density at 485 nm per 10 8 cells.…”

Effects of pH on antioxidant and prooxidant properties of common medicinal herbs

“…Stimulation of proliferation was found to be beneficial for normal cells or tissues which require rejuvenation and regeneration and it is undesirable for cancer cells due to promoting cancer malignization [48,50]. In yeast, stimulation of the reproductive potential seems to be an effective approach to increase biomass and to improve yeast survival under different stresses [38].…”

“…Mild prooxidant activity can be beneficial as a pre-adaptation mechanism, since it can stimulate endogenous defense system leading to overall cytoprotection and cross-adaptation to followed stresses [3,14,20,38]. Prooxidant activity of plant extracts is also considered as one of the mechanisms of anticancer effects of many phytochemicals [12].…”

“…cerevisiae cells are able to grow at relatively broad range of external pH values, but proliferate better at acidic than at neutral or alkaline pH, and in fact, their growth is stopped in a medium with pH 8.2 [42]. Furthermore, it was shown that H 2 O 2 at very low concentrations could stimulate reproduction of yeast cells [20,38] and other fungi [46]. Taking into consideration these facts and the showed above H 2 O 2 producing ability of the plant extracts at alkaline pH, we addressed the question if plant extracts were able to affect yeast growth in the culture medium with different pHs.…”

Dietary alpha-ketoglutarate increases cold tolerance in Drosophila melanogaster and enhances protein pool and antioxidant defense in sex-specific manner

“…The total antioxidant capacity (TAC) of supernatants was measured by ABTS assay (Erel, 2004;Vasylkovska et al, 2015). Rate at which absorbance of ABTS þ cation radical dropped in the presence of the supernatant was monitored at wavelength 414 nm using microplate reader Multiskan MCC/340 (Labsystems, Helsinki, Finland).…”