Efthymios Paronis

Background Oleuropein (OP), the predominant secoiridoid glycoside of Olea europaea L., is a pleiotropic natural compound with well-documented anticancer properties. Despite preclinical evidence that spans proliferation inhibition, apoptosis induction, angiogenesis suppression, and immune modulation, systematic integration of OP’s effects within a comprehensive oncological framework is lacking. Objective This review employs Hanahan's 2022 cancer hallmark paradigm – encompassing 14 hallmarks – to map mechanistic evidence, identify knowledge gaps, and establish translational priorities. Key findings A comprehensive literature analysis on OP reveals solid mechanistic evidence for its implication in seven hallmarks which characterise cancer cells: sustaining proliferative signaling (via PI3K/Akt/mTOR and MAPK/ERK inhibition; cyclin-CDK modulation), evading growth suppressors (p53/Rb pathway restoration), resisting cell death (intrinsic mitochondrial apoptosis induction), enabling angiogenesis (VEGF/HIF-1α suppression; endothelial dysfunction), activating invasion and metastasis (EMT reversal; MMP inhibition), deregulating cellular energetics (glycolysis inhibition; AMPK activation; mTOR suppression), and tumor-promoting inflammation (NF-κB/COX-2/iNOS inhibition). Emerging evidence further suggests that OP may reverse immune evasion, restrict cancer stemness and phenotypic plasticity, modulate cell senescence, and reshape the gut microbiota. By contrast, direct evidence for OP’s effects on DNA repair and mutation accumulation, telomere maintenance and telomerase activity, and stable epigenetic reprogramming remains limited. Conclusion OP acts hierarchically across intracellular, tissue, organ, and systemic levels rather than through a single molecular target. Clinical translation is constrained by OP’s limited bioavailability, uncertain active species and exposure-response relationships, incomplete mechanistic validation, and the absence of biomarkers predicting its therapeutic efficacy. Priorities should focus on pharmacokinetic-pharmacodynamic studies, optimized formulations or derivatives, biomarker-guided patient selection, and rational combination strategies, particularly with immunotherapy.

Standard laboratory housing often restricts the expression of natural behaviors in rodents, raising concerns regarding animal welfare and the translational value of experimental data. The current study investigated whether increasing cage bedding volume functions as an effective, low-impact environmental enrichment strategy that enhances welfare without confounding physiological parameters. An in-depth analysis was conducted comparing the effect of Deep Bedding (DB; 1600 mL) versus Normal Bedding (NB; 400 mL) on the microenvironment, physiology, and behavior of wild-type (129SV) and desmin-knockout (Des−/−) mice. Results demonstrated that deep bedding acts as a significant environmental buffer, effectively decoupling intra-cage temperature and humidity from ambient room fluctuations. While physiological parameters, including body surface temperature, body weight, and food intake, remained stable across bedding conditions, behavioral analysis revealed a robust upregulation of species-specific fossorial activities, such as digging and burrowing, in the DB group. This suggests a beneficial “bioenergetic reallocation” where energy is directed toward natural behaviors rather than thermal stress responses. Furthermore, deep bedding significantly improved cage hygiene through the mechanical sequestration of waste. These findings indicate that deep bedding serves as a multifactorial refinement strategy that supports animal welfare and hygiene without increasing experimental variability, proving safe even for physiologically sensitive models like Des−/− mice.

Objective: Several strategies have been described for stroke prevention, and the most commonly used medication is aspirin. Cilostazol, which is a substance with a pleiotropic effect, is still not well investigated. In this study, we aimed to delineate the effects of mono- and combinatorial pre-treatment upon neurological status and biomarkers, namely protein S100b, GFAP, procalcitonin, and galectin-3, following stroke. Methods: Twelve-week-old Sprague–Dawley rats were randomly assigned to four groups, each containing six rats: control group (normal saline), cilostazol group (30 mg/kg/daily), aspirin group (10 mg/kg/daily), and aspirin/cilostazol group. Each substance was administered by gavage for four weeks. All animals were subjected to cerebral ischemia for 2 h using intraluminal middle cerebral artery occlusion. A neurological examination was performed, serum concentrations of biomarkers were determined, and the animals were then sacrificed. Results: All treatment groups exhibited variations in the severity of immediate neurological presentation. Unlike the control group, where all rats presented with severe focal neurology or mortality, most rats in the treatment groups displayed no to moderate focal neurology. Moreover, the aspirin/cilostazol group consistently exhibited significantly lower levels in the studied biomarkers compared to other groups. Conclusions: Co-administration of cilostazol and aspirin significantly ameliorates the immediate expression of the studied biomarkers. Further large-scale studies are needed to investigate the effect of combined therapy for primary and secondary prevention of stroke, using not only serum biomarkers but other specific clinical and laboratory endpoints.

Inflammation is a key process in the pathophysiology of various diseases, with macrophages playing a central role in the inflammatory response. This study investigates the anti-inflammatory potential of a newly synthesized analog of oleuropein (OP), the major olive tree (Olea europaea) metabolite. This derivative of OP, named Ole-Oxy, was designed by introducing an oxygen atom between the aromatic ring and the aliphatic chain of OP, to enhance interaction with proteins and improve bioactivity. Ole-Oxy demonstrated notable anti-inflammatory effects in vitro, particularly in phorbol 12-myristate 13-acetate-differentiated THP-1 macrophages, where it markedly reduced interleukin-6, tumor necrosis factor-α, and reactive oxygen species (ROS) levels, surpassing the effects of OP. In vivo, Ole-Oxy was evaluated in mouse models of acute skin and colon inflammation, showing significant efficacy in C57BL/6J mice, likely due to their Th1-biased immune response. Our results suggest that Ole-Oxy modulates inflammation through ROS scavenging and differential macrophage activation, underscoring the need for further research to fully elucidate its mechanism of action and optimize its pharmacokinetic properties for future therapeutic applications.

The clarification of donor variation effects upon red blood cell (RBC) storage lesion and transfusion efficacy may open new ways for donor–recipient matching optimization. We hereby propose a “triangular” strategy for studying the links comprising the transfusion chain—donor, blood product, recipient—as exemplified in two cohorts of control and beta-thalassemia minor (βThal⁺) donors (n = 18 each). It was unraveled that RBC osmotic fragility and caspase-like proteasomal activity can link both donor cohorts to post-storage states. In the case of heterozygotes, the geometry, size and intrinsic low RBC fragility might be lying behind their higher post-storage resistance to lysis and recovery in mice. Moreover, energy-related molecules (e.g., phosphocreatine) and purine metabolism factors (IMP, hypoxanthine) were specifically linked to lower post-storage hemolysis and phosphatidylserine exposure. The latter was also ameliorated by antioxidants, such as urate. Finally, higher proteasomal conservation across the transfusion chain was observed in heterozygotes compared to control donors. The proposed “triangularity model” can be (a) expanded to additional donor/recipient backgrounds, (b) enriched by big data, especially in the post-transfusion state and (c) fuel targeted experiments in order to discover new quality biomarkers and design more personalized transfusion medicine schemes.

Blood donors with beta-thalassemia traits (βThal⁺) have proven to be good “storers”, since their stored RBCs are resistant to lysis and resilient against oxidative/proteotoxic stress. To examine the performance of these RBCs post-storage, stored βThal⁺ and control RBCs were reconstituted in plasma donated from transfusion-dependent beta-thalassemic patients and healthy controls, and incubated for 24 h at body temperature. Several physiological parameters, including hemolysis, were evaluated. Moreover, labeled fresh/stored RBCs from the two groups were transfused in mice to assess 24 h recovery. All hemolysis metrics were better in the group of heterozygotes and distinguished them against controls in the plasma environment. The reconstituted βThal⁺ samples also presented higher proteasome activity and fewer procoagulant extracellular vesicles. Transfusion to mice demonstrated that βThal⁺ RBCs present a marginal trend for higher recovery, regardless of the recipient’s immune background and the RBC storage age. According to correlation analysis, several of these advantageous post-storage characteristics are related to storage phenotypes, like the cytoskeleton composition, low cellular fragility, and enhanced membrane proteostasis that characterize stored βThal⁺ RBCs. Overall, it seems that the intrinsic physiology of βThal⁺ RBCs benefits them in conditions mimicking a recipient environment, and in the circulation of animal models; findings that warrant validation in clinical trials.

Background: Cilostazol is a drug of choice for the treatment of intermittent claudication that also affects innate and adaptive immune cells. The purpose of our study was the evaluation of cilostazol’s impact on the immune and angiogenic response in murine models of hind limb ischemia. Methods: We used 108 immunodeficient NOD.CB17-Prkdcscid/J mice and 108 wild-type CB17 mice. At day 0 (D0), all animals underwent hind limb ischemia. Half of them in both groups received daily cilostazol starting at D0 and for the next 7 postoperative days, while the rest of them served as controls, receiving vehicle. Interleukin (IL) 2, IL-4, IL-6, IL-10, IL-17A, tumor necrosis factor α (TNF-α), and interferon γ (IFN-γ) serum concentrations were measured by flow cytometry on postsurgery days D1, D3, D5, and D7. On D7, both groups underwent positron emission tomography scan with ⁶⁸Ga-RGD. Mice were euthanatized and gastrocnemius muscles were obtained for histological evaluation. Results: There was a statistically significant augmentation ( P < .05) in IL-4, IL-10, IL-6, and IFN-γ concentrations in treated CB17 animals, while IL-2 was significantly suppressed. Significant difference was detected between the CiBisch and Bisch groups on D1 and D7 ( P < .05) in CD31 staining. In treated NOD.CB17 animals, TNF-α, IL-6, and IFN-γ presented significant augmentation, while ⁶⁸Ga-NODAGA-RGDfK uptake and CD31 expression were found significantly lower for both legs in comparison to the control. Conclusion: Cilostazol seems to significantly increase angiogenesis in wild-type animals during the first postoperational week. It also influences immune cells, altering the type of immune response by promoting anti-inflammatory cytokine production in wild-type animals, while it helps toward inflammation regression in immunodeficient animals.

Urinary bladder cancer is one of the most fatal and expensive diseases of industrialized world. Despite the strenuous efforts, no seminal advances have been achieved for its clinical management. Given the importance of metabolic reprogramming in cancer cell survival and growth, we have herein employed 3-BrPA, a halogenated derivative of pyruvate and historically considered inhibitor of glycolysis, to eliminate bladder cancer cells with highly oncogenic molecular signatures. Bladder cancer cells were exposed to 3-BrPA in the absence or presence of several specific inhibitors. Cell viability was determined by MTT and flow-cytometry assays; cell death, signaling activity and metabolic integrity by Western blotting and immunofluorescence; mutant-gene profiling by DNA sequencing; and gene expression by RT-sqPCR. 3-BrPA could activate dose-dependent apoptosis (type 1 PCD) and regulated necrosis (type 3 PCD) of T24 (grade III; H-RasG12V; p53ΔY126), but not RT4 (grade I), cells, with PARP, MLKL, Drp1 and Nec-7-targeted components critically orchestrating necrotic death. However, similarly to RIPK1 and CypD, p53 presented with non-essential contribution to 3-BrPA-induced cellular collapse, while reactivation of mutant p53 with PRIMA-1 resulted in strong synergism of the two agents. Given the reduced expression of MPC components (likely imposing mitochondrial dysfunction) in T24 cells, the suppression of constitutive autophagy (required by cells carrying oncogenic Ras; also, type 2 PCD) and derangement of glucose-homeostasis determinants by 3-BrPA critically contribute to drug-directed depletion of ATP cellular stores. This bioenergetic crisis is translated to severe dysregulation of Akt/FoxO/GSK-3, mTOR/S6, AMPK and MAPK (p44/42, p38 and SAPK/JNK) signaling pathways in 3-BrPA-treated T24 cells. Sensitivity to 3-BrPA (and tolerance to glucose deprivation) does not rely on B-RafV600E or K-RasG13D mutant oncogenic proteins, but partly depends on aberrant signaling activities of Akt, MAPK and AMPK kinases. Interestingly, MCT1- and macropinocytosis-mediated influx of 3-BrPA in T24 represents the principal mechanism that regulates cellular responsiveness to the drug. Besides its capacity to affect transcription in gene-dependent manner, 3-BrPA can also induce GLUT4-specific splicing silencing in both sensitive and resistant cells, thus dictating alternative routes of drug trafficking. Altogether, it seems that 3-BrPA represents a promising agent for bladder cancer targeted therapy.

One of the commonly used animal models in fertility, developmental and neurobiological studies is the laboratory rat. The early recognition of rat pregnancy and confirmation of the exact embryonic day are vital. The aim of this study was to investigate the correlation of maternal weight at the time of conception to its increase throughout gestation, aiming to develop a mathematical model, which can be used for the determination of the exact day of pregnancy, set the threshold, and monitor pregnancy from the onset. We studied a total of 173 Wistar rats with a mean body weight of 238.22 ± 34.9 g. After 72 h at the male’s cages, we considered as Day 0 (D0) the day in which a copulatory plug or sperm was found during the vaginal smear examination. After that period the female animals were transferred into their cages, and weight monitoring started 14 days (D14) after D0, until parturition. Based on the statistical analysis, there is a correlation between maternal body weight at D0 and maternal body weight from D14 to D19. Moreover, the average weight gain from D14 to D19 is positively correlated to initial female body weight, while there is no correlation between each pregnant animal’s weight from D14 to D19 and litter size. A mathematical model was developed as a tool for the verification of the day of pregnancy. In conclusion, continuous monitoring of maternal weight after D14 can be a reliable method for the recognition of pregnancy and determination of the exact gestational day.