Royal jelly induces coordinated redox and energy metabolic responses in Candida guilliermondii NP-4

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.