Biomolecules

Hepatocellular carcinoma (HCC) ranks among the leading causes of cancer death, underscoring the pressing need for therapeutic agents with better efficacy and lower toxicity. Theaflavin (TF) is a polyphenol abundant in black tea that possesses broad-spectrum anti-tumor activity. However, the direct targets and molecular mechanisms of TF in HCC have not been completely defined. Here, reverse virtual screening was employed to predict candidate targets of TF, which were then validated by molecular docking, molecular dynamics (MD) simulation, drug affinity responsive target stability (DARTS), thermal shift assay (TSA) and endogenous fluorescence spectroscopy. The fluorescence titration results showed that TF could directly bind to CDK2, JNK1 and JNK2, with binding free energies of −37.08, −38.77 and −37.27 kJ/mol, and binding constants K_a of 3.16 × 10⁶, 6.25 × 10⁶ and 3.42 × 10⁶ L⋅mol⁻¹, respectively. TF inhibited the viability of HepG2, SK-Hep-1 and Huh-7 cells in a dose-dependent manner, enhanced reactive oxygen species (ROS) accumulation, reduced mitochondrial membrane potential, elevated the Bax/Bcl-2 ratio and activated caspase-9/3, thereby inducing apoptosis through the mitochondrial pathway. Moreover, TF induced G₀/G₁-phase arrest and curtailed cell migration and invasion, although the latter effects may be partly attributable to reduced cell viability. In nude mice bearing subcutaneous xenografts, TF markedly restrained tumor growth and promoted apoptosis. In summary, TF, a multi-target compound potentially interacting with CDK2 and JNK1/2, was associated with alterations in cell cycle- and MAPK-related signaling and may serve as a potential lead compound for HCC treatment.

Manganese (Mn) is an essential trace element, but both insufficient cellular availability and excessive accumulation can disrupt neurological function. This narrative review integrates evidence from inherited Mn transporter disorders, common genetic variation, environmental epidemiology, and experimental models to examine potential links at the gene-environment interface. Biallelic pathogenic variants in SLC39A8, SLC30A10, and SLC39A14 provide direct human evidence that impaired Mn uptake, utilization, or clearance can cause distinct neurological and neurodevelopmental phenotypes. Environmental Mn studies in children mainly report associations with cognitive, motor, attentional, and behavioral outcomes, but findings vary according to exposure timing, biomarker, sex, nutritional status, co-exposure, and outcome definition. Evidence linking environmental Mn specifically to attention deficit hyperactivity disorder or autism spectrum disorder remains heterogeneous and observational. Experimental data suggest that Mn deficiency and excess involve partly distinct mechanisms, including altered glycosylation, mitochondrial and cellular dysfunction, iron-redox imbalance, ferroptosis-related responses, glial activation, and epigenetic or transcriptional changes. However, a causal Mn-epigenetic-neurodevelopmental pathway and a generalizable gene–environment interaction have not been established in humans. Advancing this field will require studies that integrate time-resolved exposure assessment, genetic and nutritional stratification, multi-omics, neuroimaging, and functional models.

Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), is a chronic, immune-mediated condition characterized by considerable clinical and biological heterogeneity. Despite major advances in biologic therapies and small molecules, a considerable proportion of patients fail to achieve sustained clinical and endoscopic remission, highlighting the therapeutic ceiling of current treatment strategies. Increasing evidence suggests that treatment failure may result from the activation of multiple, partially overlapping inflammatory pathways that are not adequately controlled by single-agent therapy. Advanced combination therapy (ACT), defined as the concomitant use of two separate advanced targeted agents, either two biologics or a biologic and a small molecule, with complementary mechanisms of action, has emerged as a potential strategy to overcome these limitations, particularly in patients with refractory disease, extraintestinal manifestations, or concomitant immune-mediated inflammatory diseases. This narrative review, based on a PubMed literature search, summarizes the biological rationale, current clinical evidence, safety considerations, and practical applications of ACT in IBD. Available evidence, largely derived from heterogeneous observational studies and phase 2 randomized trials, suggests potential improvements in clinical and endoscopic outcomes in selected patients. However, the incremental benefit over individual targeted therapies has not been consistently demonstrated. Although available studies have not identified a clear increase in short-term serious adverse events, the evidence remains insufficient to establish long-term safety. Important uncertainties persist regarding optimal patient selection, treatment sequencing, duration, de-escalation strategies, and cost-effectiveness. While ACT represents a potentially valuable therapeutic option for selected patients with IBD, its use for active IBD remains largely off-label, and current evidence does not support routine implementation. Larger randomized trials and long-term studies are needed to better define its efficacy, safety, and clinical positioning.