The ketogenic diet (KD) has been used as a treatment for epilepsy since the 1920s, and its role in the prevention of many other diseases is now being considered. In recent years, there has been an intensive investigation on using the KD as a therapeutic approach to treat acute pathologies, including ischemic ones. However, contradictory data are observed for the effects of the KD on various organs after ischemic injury. In this review, we provide the first systematic analysis of studies conducted from 1980 to 2022 investigating the effects and main mechanisms of the KD and its mimetics on ischemia–reperfusion injury of the brain, heart, kidneys, liver, gut, and eyes. Our analysis demonstrated a high diversity of both the composition of the used KD and the protocols for the treatment of animals, which could be the reason for contradictory effects in different studies. It can be concluded that a true KD or its mimetics, such as β-hydroxybutyrate, can be considered as positive exposure, protecting the organ from ischemia and its negative consequences, whereas the shift to a rather similar high-calorie or high-fat diet leads to the opposite effect.

Drug-induced nephrotoxicity is a leading cause of acute kidney injury (AKI) and subsequent chronic kidney disease. Nephrotoxicity often develops as a consequence of treatment with commonly prescribed aminoglycoside antibiotics, and remains a significant clinical challenge. One approach to treating AKI and its associated complications is caloric restriction or its pharmacological mimetics. This study aimed to evaluate the effects of caloric restriction mimetic hydroxycitrate (HC) in gentamicin-induced nephrotoxicity, with particular focus on the influence of treatment duration and the underlying molecular mechanisms. In vitro renal tubular epithelial cells models were used to assess HC’s effects on viability, proliferation, and autophagy activation. For in vivo validation, rats with gentamicin-induced AKI received HC treatment via two distinct regimens (3-week and 7-week administration). Experiments on renal tubule cells showed that HC significantly increased cell viability and proliferation and led to the activation of autophagy. In the rat model, only the 7-week administration of HC demonstrated significantly attenuated renal dysfunction in gentamicin-induced AKI. Moreover, it reduced macrophage infiltration, increased renal cell tolerance to apoptosis, activated autophagy, and reduced oxidative stress. Thus, our results indicate that 7-week HC administration could be used as a prophylactic strategy against antibiotic nephrotoxicity, exerting its effects by promoting autophagy, resisting apoptosis, and attenuating oxidative damage.

Caloric restriction (CR) is known to activate a broad spectrum of cytoprotective signaling pathways and enhance tissue tolerance to various stressors, including those associated with the cytotoxic effects of pharmaceutical agents. Nephrotoxic drugs, such as aminoglycoside antibiotics, remain a major clinical concern due to their frequent use and potential to cause acute kidney injury (AKI), for which effective preventive strategies are still limited. In this study, we investigated whether CR applied for 5 weeks (4-week pretreatment + 1-week concurrent with AKI induction) can alleviate AKI triggered by the antibiotic gentamicin, with a focus on evaluating changes in antioxidant-related parameters and autophagy-associated signaling during CR-mediated nephroprotection. CR’s nephroprotective effects were evaluated using diagnostic assays, Western blotting, and histological analysis. Additionally, oxidative stress markers and mitochondrial integrity were assessed to analyze the impact of CR on antioxidant-related pathways. CR significantly improved renal function and structure, with reduced kidney injury markers (KIM-1, NGAL) and alleviated histological damage. Critically, CR mitigated oxidative stress, evidenced by decreased thiobarbituric acid reactive substances (TBARS) and protein carbonylation, as well as increased levels of the reduced form of glutathione and activity of glutathione peroxidase (GPx). A lowered Bcl-X_L/X_S ratio was consistent with reduced apoptotic signaling, while reduced leukocyte infiltration reflected attenuated renal inflammation. Additionally, a reduction in mitochondrial DNA (mtDNA) lesions suggested that CR was associated with modulation of mitochondrial and metabolism-related pathways, with concurrent improvements in mitochondrial stability. Our findings demonstrate that CR attenuated gentamicin-induced AKI and was associated with changes in antioxidant-related parameters, reduced mtDNA damage, a decrease in inflammatory cell infiltration, and modulation of autophagy-related signaling.