Seda Victor Marutyan

Maintenance of redox homeostasis under stress conditions requires tight coordination between antioxidant defenses and cellular energy metabolism. In yeast cells, such adaptive responses are closely linked to mitochondrial function and ATP-dependent processes. Royal jelly (RJ), a natural product rich in biologically active compounds, has been reported to exhibit antioxidant properties; however, its effects on the integration of redox responses and energy metabolism in yeast remain insufficiently characterized. In this study, we investigated the impact of RJ on redox balance and ATPase-associated energy metabolism in Candida guilliermondii NP-4. RJ was added to the cultivation medium at concentrations of 25–150 µg mL⁻¹. RJ supplementation resulted in a concentration-dependent modulation of cellular responses, with the most pronounced effects observed at 50–75 µg mL⁻¹. Biomass accumulation increased by up to ~ 60% compared to control cultures. TBARS levels decreased significantly compared to control cultures. Concurrently, the activities of key antioxidant enzymes, including superoxide dismutase, catalase, and peroxidase, were enhanced. Importantly, RJ treatment led to a marked increase in total and H⁺-ATPase activities in both yeast homogenates and isolated mitochondria, suggesting increased ATP-dependent metabolic activity. In addition, increased proline formation under the assay conditions, reflecting metabolic adaptation to stress conditions. Taken together, these findings suggest that RJ supplementation is associated with coordinated changes in antioxidant defense mechanisms and ATPase-associated metabolic processes. The observed coordinated changes in antioxidant enzyme activities and ATPase-associated metabolic processes suggest a potential role of RJ in yeast stress adaptation.

This study aimed to evaluate the effect of D. scoparium moss extract on biomass accumulation, colony formation ability, and growth kinetics of yeasts Candida guilliermondii NP-4, as well as its effect on the activity of ATPases, antioxidant enzymes catalase, and superoxid dismutase. The antiradical activity of the moss extract was determined using the free radical method. The total content of phenolic substances and total content of flavonoids of moss was determined. D. scoparium moss extracts contained 17.53 μg GAE g-1 of total phenolic compounds and 7.88 μg QE mL-1 of total flavonoids, with an IC50 value of 51.487 μg mL-1. Treatment with the moss extract inhibited yeast colony formation and mitotic activity. The moss extract led to a 64% reduction in malondialdehyde levels and enhanced superoxide dismutase activity by 43%. There was a significant increase in total and H+-ATPase activity in the cell homogenates and mitochondria. The data obtained prove the potential application of D. scoparium extract as a natural antifungal agent with additional antioxidative properties.

Modern telecommunication technologies use the high frequency microwave radiation, the application of which continues to expand rapidly. Exposure to non-ionizing radiation can induce oxidative stress in cells. The biochemical processes involved in overcoming this stress are highly energy-consuming and require additional energy expenditure which consequently enhances the ATP hydrolysis. The indicator of oxidative stress is the intensification of lipid peroxidation, with malondialdehyde (MDA) serving as a key biomarker. In eukaryotic cells, various bioactive dietary supplements, including royal jelly (RJ), may exert beneficial effects on mitigating oxidative stress due to their antioxidant and other biologically active components. Yeasts represent a convenient model for studying the development of oxidative stress and the mechanisms of its overcoming in eukaryotic cells, because they are similar to higher eukaryotes by their structural, reproductive, and functional peculiarities. This study aimed to investigate the effect of 51.8 GHz microwave radiation on ATPase activity, lipid peroxidation, and antioxidant enzyme activity in homogenates and mitochondria of Candida guilliermondii NP-4, as well as to assess the potential role of RJ in migtigating of oxidative stress in yeast cells. The results demonstrated that the exposure to millimeter waves of 51.8 GHz and the following repair period led to intensification of lipid peroxidation, evidenced by an increase in MDA level by 75%. In repaired cells, the MDA content was reduced by ≈27%. Microwave radiation also stimulated catalase and superoxide dismutase (SOD) activity by 65% and 30%, respectively, in repaired cells the SOD activity increased by 13%, while catalase activity - by 25%.

Currently, the development of means of protection against of ionizing radiation is extremely relevant.The aim of the work was to clarify the changes in antioxidant enzymes, polyphosphate nucleotide deamination and ATPase activity in yeasts Candida guilliermondii NP-4 exposed to X-irradiation and the effect of royal Jelly (RJ) on these processes as a possible radioprotective agent. The obtained data indicate that during X-irradiation and subsequent repair in yeast cell homogenates, H+-ATPase activity increases by 3 and 2 times, respectively, and in mitochondria by 1.4 and 1.7 times, which is more pronounced in the presence of RJ due to the increased energy demand in the repairing cells. At the same time, the catabolism of purine and pyrimidine nucleotides decreases, which begin to be used as an additional source of energy. X-irradiation induces oxidative stress in yeast cells, as a result of which the activity of antioxidant enzymes SOD and catalase is stimulated as a protective mechanism, which is facilitated by the presence of RJ. Thus, in the presencein the yeast growth medium of RJ, the SOD activity is stimulated by 35%, catalase activity by 46%, and peroxidase activity is almost unchanged. It is likely that the biologically active compounds of RJ contribute to the increase in the activity of antioxidant enzymes during the repair process and the attenuation of oxidative stress. The results obtained can be used to create protective measures against the effects of X-ray irradiation in living organisms.

The effect of silver nanoparticles (Ag NPs) obtained in the presence of royal jelly (RJ) on the growth of yeast Candida guilliermondii NP-4, on the total and H⁺-ATPase activity, as well as lipid peroxidation process and antioxidant enzymes (superoxide dismutase (SOD), catalase) activity was studied. It has been shown that RJ-mediated Ag NPs have a fungicide and fungistatic effects at the concentrations of 5.4 µg mL⁻¹ and 27 µg mL⁻¹, respectively. Under the influence of RJ-mediated Ag NPs, a decrease in total and H⁺-ATPase activity in yeast homogenates by ~ 90% and ~ 80% was observed, respectively. In yeast mitochondria total and H⁺-ATPase activity depression was detected by ~ 80% and ~ 90%, respectively. The amount of malondialdehyde in the Ag NPs exposed yeast homogenate increased ~ 60%, the catalase activity increased ~ 70%, and the SOD activity—~ 30%. The obtained data indicate that the use of RJ-mediated Ag NPs have a diverse range of influence on yeast cells. This approach may be important in the field of biomedical research aimed at evaluating the development of oxidative stress in cells. It may also contribute to a more comprehensive understanding of antimicrobial properties of RJ-mediated Ag NPs and help control the proliferation of pathogenic fungi.

Cancer treatment is an ongoing struggle around the world, and research into its treatment and prevention is constantly deepening. Unrestricted cell proliferation is a hallmark of cancer. In cell reproduction, the exchange of purine nucleotides is of great importance, because they are involved in the synthesis of DNA, which is necessary for the uninterrupted process of cell division. The activities of deamination enzymes of purine nucleotides, nucleosides, and nitrogenous bases are altered during cancer development both in tumor tissue and in other tissues and organs of diseased animals. From this point of view, it is of great interest to study the changes in the activity of purine metabolism, the first stage of which is deamination. The aim of this work was the study the deamination alterations of AMP, ADP, ATP, as well as adenine and adenosine in the liver and breast tissue homogenates in rats with 7,12-DMBA-induced breast cancer. In the experimental model of rats, mammary cancer was induced by 7,12-DMBA, and further treatment was carried out with the Hypericum alpestre. In addition, we also observed the combined effect of H. alpestre extract and chemical inhibitors on the deamination of purine compounds. Data show a significant elevation of the adenine compounds' deamination level in the breast cancer group treated with H. alpestre extract compared with rats with DMBA-induced breast cancer. During the development of breast cancer in rats, a significant reduction in deamination levels was observed in the liver homogenate. This reduction was compared with the group treated with H. alpestre, where deamination levels showed a notable increase. The levels of deamination of adenine compounds after the treatment with H. alpestre herb become very close to the values typical of the samples of healthy animals. Thus, in conclusion, the mentioned herb's anticancer activity can be expressed by the elevation of the deamination levels of adenine compounds, and one of the molecular mechanisms of the anticancer effect can be the dysregulation of deamination of adenine compounds under the influence of the selected plant․

This study investigates the effects of X-radiation on ATPase activity and antioxidant enzyme activity, particularly enzymes involved in proline biosynthesis, in yeast C. guilliermondii NP-4. Moreover, the study examined the post-irradiation repair processes in these cells. Results showed that X-irradiation at a dose of 300 Gy led to an increase in catalase (CAT) and superoxide dismutase (SOD) activity, as well as, an increase in the CAT/SOD ratio in C. guilliermondii NP-4. The repair of radiation-induced damage requires a substantial amount of energy, resulting in an increased demand for ATP in the irradiated and repaired yeasts. Consequently, the total and FoF1-ATPase activity in yeast homogenates and mitochondria increased after X-irradiation and post-irradiation repair. It was showed an increase in the activity of proline biosynthesis enzymes (ornithine transaminase and proline-5-carboxylate reductase) in X-irradiated C. guilliermondii NP-4, which remained elevated even after post-irradiation repair. As a result, the proline levels in X-irradiated and repaired yeasts were higher than those in non-irradiated cells. These findings suggest that proline may have a radioprotective effect on X-irradiated C. guilliermondii NP-4 yeasts. Taken together this study provides insights into the effects of X-radiation on ATPase activity, antioxidant enzyme activity, and proline biosynthesis in C. guilliermondii NP-4 yeast cells, highlighting the potential radioprotective properties of proline in X-irradiated yeasts.

This study aimed to investigate the effect of X-radiation on the ATPase activity and the activity of antioxidant enzymes, including enzymes of proline biosynthesis, in C. guilliermondii NP-4 yeast cells after X-irradiation and the post-irradiation repair of cells. It has been shown that the X-irradiation of yeasts C. guilliermondii NP-4 at a dose of 300 Gy causes the increase of activity of the enzymes catalase and SOD and the ratio of catalase/SOD. The repair of radiation-induced damages requires a lot of energy, so the demand for ATP increases in irradiated and repaired yeasts. The total and FoF ₁ -ATPase activity in yeast homogenates and mitochondria increases after X-irradiation and post-irradiation repair. Amino acid proline is an antioxidative defense molecule and plays a significant role in the adaptation of cells to stress. So higher proline levels in yeasts can protect them from oxidative damage. There are still no systematic studies of the antioxidant properties of proline. In this study, it has been shown that the activity of enzymes of proline biosynthesis (ornithine transaminase and proline-5-carboxylate reductase) in yeasts C.guilliermondii NP-4 increases after X-irradiation and remains higher after post-irradiation repair. Connected with it, the proline amount in X-irradiated and repaired yeasts also is higher than in non-irradiated cells. We suppose that proline has a radioprotective effect on X-irradiated yeasts C. guilliermondii NP-4.

Investigation of fluorescence, electrophoretic and melting parameters of DNA of yeasts Candida guilliermondii NP-4 after X-radiation and posradiation repair was carried out. It was shown that under influence of X-radiation the rate of saturation of DNA by ethidium bromide and the melting temperature of yeast DNA was increased, and the melting interval was decreased. After repair period the rate of saturation of DNA by ethidium bromide and the melting temperature of yeast DNA were the highest, and the melting interval was the lowest, and in the electrophoregramms or repaired DNA there were additional low molecular fractions which testify about possible changes in DNA primary and secondary structures under influence of X-radiation and postradiation repair.