Acacetin, apigenin, chrysin, and pinocembrin are flavonoid aglycones found in foods such as parsley, honey, celery, and chamomile tea. Flavonoids can act as substrates and inhibitors of the CYP3A4 enzyme, a heme containing enzyme responsible for the metabolism of one third of drugs on the market. The aim of this study was to investigate the inhibitory effect of selected flavonoids on the CYP3A4 enzyme, the kinetics of inhibition, the possible covalent binding of the inhibitor to the enzyme, and whether flavonoids can act as pseudo-irreversible inhibitors. For the determination of inhibition kinetics, nifedipine oxidation was used as a marker reaction. A hemochromopyridine test was used to assess the possible covalent binding to the heme, and incubation with dialysis was used in order to assess the reversibility of the inhibition. All the tested flavonoids inhibited the CYP3A4 enzyme activity. Chrysin was the most potent inhibitor: IC₅₀ = 2.5 ± 0.6 µM, K_i = 2.4 ± 1.0 µM, k_inact = 0.07 ± 0.01 min⁻¹, k_inact/K_i = 0.03 min⁻¹ µM⁻¹. Chrysin caused the highest reduction of heme (94.5 ± 0.5% residual concentration). None of the tested flavonoids showed pseudo-irreversible inhibition. Although the inactivation of the CYP3A4 enzyme is caused by interaction with heme, inhibitor-heme adducts could not be trapped. These results indicate that flavonoids have the potential to inhibit the CYP3A4 enzyme and interact with other drugs and medications. However, possible food–drug interactions have to be assessed clinically.

Cytochrome P450 (CYP450) enzymes are pivotal in the metabolism of numerous anticancer agents, with CYP3A4 being the predominant isoform involved. Inhibition of CYP450 enzymes is a major mechanism underlying clinically significant drug-drug interactions (DDIs), particularly in oncology, where polypharmacy is frequent. This review aims to provide a comprehensive and critical overview of CYP450 enzyme inhibition, focusing specifically on the impact of kinase inhibitors (KIs) and poly adenosine diphosphate-ribose polymerase (PARP) inhibitors. A systematic review of the current literature was conducted, focusing on the molecular mechanisms of CYP450 inhibition, including reversible, time-dependent, mechanism-based, and pseudo-irreversible inhibition. Specific attention was given to the inhibitory profiles of clinically relevant KIs and PARP inhibitors, with analysis of pharmacokinetic consequences and regulatory considerations. Many KIs, such as abemaciclib and ibrutinib, demonstrate time-dependent or quasi-irreversible inhibition of CYP3A4, while PARP inhibitors like olaparib and rucaparib exhibit moderate reversible and time-dependent CYP3A4 inhibition. These inhibitory activities can significantly alter the pharmacokinetics of co-administered drugs, leading to increased risk of toxicity or therapeutic failure. Regulatory guidelines now recommend early identification of time-dependent and mechanism-based inhibition using physiologically based pharmacokinetic) (PBPK) modeling. CYP450 inhibition by KIs and PARP inhibitors represents a critical but often underappreciated challenge in oncology pharmacotherapy. Understanding the mechanistic basis of these interactions is essential for optimizing treatment regimens, improving patient safety, and supporting personalized oncology care. Greater clinical vigilance and the integration of predictive modeling tools are necessary to mitigate the risks associated with CYP-mediated DDIs.

Steatosis extends beyond the liver to the pancreas, heart, and skeletal muscle, yet prevailing definitions remain narrowly organ-focused. This narrative review introduces the Metabolic Steatotic Axis (MSA) as a framework that captures the dynamic, bidirectional interactions among these organs, driving systemic metabolic dysfunction. We synthesize evidence linking lipotoxicity, inflammatory signaling, and endocrine cross-talk into a self-amplifying network accelerating insulin resistance, β-cell failure, and cardiometabolic risk. The MSA concept provides a rationale for axis-based staging systems and composite biomarker panels to quantify cumulative disease burden better and refine risk stratification. We highlight phenotypic heterogeneity within MSA stages, the possible hierarchy of organ vulnerability, and the implications for prognosis and therapy. Viewing pharmacological and lifestyle interventions through the MSA lens reframes them as systemic modulators rather than organ-specific treatments, underscoring the need for multi-organ endpoints in clinical trials. Finally, we outline priorities for longitudinal imaging, multi-omics integration, and global harmonization to translate the MSA from a conceptual construct to a clinically actionable paradigm. By unifying fragmented observations into a systemic model, the MSA has the potential to reshape disease classification, therapeutic strategies, and precision medicine in metabolic disorders.

Circadian rhythms regulate key biological processes central to cancer biology, including cell cycle control, DNA repair, metabolism, immune function, and drug pharmacokinetics. Experimental models consistently demonstrate marked time-of-day differences in the efficacy and toxicity of chemotherapy, targeted agents, and immunotherapies. Clinical studies of chronomodulated chemotherapy—particularly with fluoropyrimidines, platinum compounds, and anthracyclines—show reproducible reductions in treatment-related toxicity, while effects on survival outcomes remain variable and often sex dependent. Emerging clinical evidence also suggests that timing of immune checkpoint inhibitor administration may influence progression-free and overall survival across several tumor types. However, translation into routine oncology practice has been limited by interindividual variability in circadian phase, tumor-specific disruption of clock function, lack of validated biomarkers, and logistical constraints of time-specific drug delivery. Advances in circadian phenotyping, wearable monitoring, and adaptive dosing technologies now offer feasible pathways toward individualized, biology-driven treatment timing. This narrative review critically evaluates mechanistic, preclinical, and clinical evidence for chronotherapy across oncological treatment modalities and examines challenges and opportunities for its integration into precision cancer care.

Background/Objectives: Various psychological and sociodemographic factors are strongly associated with shopping addiction in different populations. To date, the relationships between these variables have not been fully clarified. European data indicate a rise in shopping addiction among adults over the past two decades, but population-based epidemiological studies in Central and Eastern Europe, including Croatia, remain scarce. This study was conducted to examine the prevalence of shopping addiction and its related factors in Croatian adults. Methods: A cross-sectional online survey was conducted, with data collected via Google Forms from February to April 2024. An anonymous questionnaire covering sociodemographic data, the Bergen Shopping Addiction Scale (BSAS), and the Rosenberg Self-Esteem Scale (RSES) was self-administered by participants recruited using snowball sampling of Croatian adults. Results: The study included 715 participants from all Croatian regions. In the present sample, 14.3% of participants met the BSAS ≥ 12 cutoff, indicating probable and problematic shopping addiction. The BSAS score was significantly higher among females (p = 0.008), high school and university students (p = 0.048), and young adults aged 18–25 years (p = 0.042). Most participants reported average self-esteem (68.0%), while 31.2% and 0.8% had low and high self-esteem, respectively. BSAS scores correlated positively with RSES scores (ρ = 0.225; p < 0.001), while age was negatively correlated with both BSAS (ρ = −0.147; p < 0.001) and RSES (ρ = −0.356; p < 0.001) scores. After controlling for age and sex, the correlation between BSAS and RSES scores remained significant: partial rho = 0.103 and p = 0.006. Conclusions: Shopping addiction was prevalent in the studied population and was associated with specific sociodemographic characteristics and self-esteem levels, highlighting the need for targeted preventive strategies and further research into its underlying mechanisms.