Changes in ATPase activity, antioxidant enzymes and proline biosynthesis in yeast Candida guilliermondii NP-4 under X-irradiation.

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.

Hypericum alpestre extract exhibits in vitro and in vivo anticancer properties by regulating the cellular antioxidant system and metabolic pathway of L-arginine.

Conventional treatment methods are not effective enough to fight the rapid increase in cancer cases. The interest is increasing in the investigation of herbal sources for the development of new anticancer therapeutics. This study aims to investigate the antitumor capacity of Hypericum alpestre (H. alpestre) extract in vitro and in vivo, either alone or in combination with the inhibitors of the  l-arginine/polyamine/nitric oxide (NO) pathway, and to characterize its active phytochemicals using advanced chromatographic techniques. Our previous reports suggest beneficial effects of the arginase inhibitor NG-hydroxy-nor- l-arginine and NO inhibitor NG-nitro-Larginine methyl ester in the treatment of breast cancer via downregulation of polyamine and NO synthesis. Here, the antitumor properties of H. alpestre and its combinations were explored in vivo, in a rat model of mammary gland carcinogenesis induced by subcutaneous injection of 7,12-dimethylbenz[a]anthracene. The study revealed strong antiradical activity of H. alpestre aerial part extract in chemical (DPPH/ABTS) tests. In the in vitro antioxidant activity test, the H. alpestre extract demonstrated pro-oxidant characteristics in human colorectal (HT29) cells, which were contingent upon the hemostatic condition of the cells. The H. alpestre extract expressed a cytotoxic effect on HT29 and breast cancer (MCF-7) cells measured by the MTT test. According to comet assay results, H. alpestre extract did not exhibit genotoxic activity nor possessed antigenotoxic properties in HT29 cells. Overall, 233 substances have been identified and annotated in H. alpestre extract using the LC-Q-Orbitrap HRMS system. In vivo experiments using rat breast cancer models revealed that the H. alpestre extract activated the antioxidant enzymes in the liver, brain, and tumors. H. alpestre combined with chemotherapeutic agents attenuated cancer-like histological alterations and showed significant reductions in tumor blood vessel area. Thus, either alone or in combination with Nω -OH-nor- l-arginine and Nω -nitro- l-arginine methyl ester, H. alpestre extract exhibits pro- and antioxidant, antiangiogenic, and cytotoxic effects.

The antimicrobial effects of silver nanoparticles obtained through the royal jelly on the yeasts Candida guilliermondii NP-4.

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.