The widespread production and poor management of plastic waste have led to the pervasive presence of microplastics (MPs) in environmental and biological systems. Among various polymers, polyethylene (PE) is the most widely produced plastic globally, primarily due to its use in single-use packaging. Its persistence in ecosystems and resistance to degradation processes result in the continuous formation of PE-derived MPs. These particles have been detected in human biological matrices, including blood, lungs, placenta, and even the brain, raising increasing concerns about their bioavailability and potential health effects. Once internalized, PE MPs can interact with cellular membranes, induce oxidative stress, inflammation, and apoptosis, and interfere with epigenetic regulatory pathways. In vitro studies on epithelial, immune, and neuronal cells reveal concentration-dependent cytotoxicity, mitochondrial dysfunction, membrane disruption, and activation of pro-inflammatory cytokines. Moreover, recent findings suggest that PE MPs can induce epithelial-to-mesenchymal transition (EMT), senescence, and epigenetic dysregulation, including altered expression of miRNAs and DNA methyltransferases. These cellular changes highlight the potential role of MPs in disease development, especially in cardiovascular, metabolic, and possibly cancer-related conditions. Despite growing evidence, no standardized method currently exists for quantifying MPs in human samples, complicating comparisons across studies. Further, MPs can carry harmful additives and environmental contaminants such as bisphenols, phthalates, dioxins, and heavy metals, which enhance their toxicity. Global estimates indicate that humans ingest and inhale tens of thousands of MPs particles each year, yet long-term human research remains limited. Given these findings, it is crucial to expand research on PE MP toxicodynamics and to establish regulatory policies to reduce their release. Promoting alternative biodegradable materials and improved waste management practices will be vital in decreasing human exposure to MPs and minimizing potential health risks.

Piperine, the principal alkaloid of Piper nigrum, has gained attention as a multifunctional dietary compound with broad effects on epigenetic and transcriptional regulation in cancer and chronic diseases. Evidence shows that piperine modulates DNA methylation (↓ DNMT3B), histone acetylation (↓ HDAC activity), and microRNA networks (↑ miR-29c, ↓ miR-383), thereby reshaping key oncogenic and tumor-suppressive pathways. Beyond canonical epigenetic control, it can also stabilize G-quadruplex structures in promoters such as c-MYC, adding an architecture-based mechanism of transcriptional repression. Its dual redox behavior—antioxidant at low doses and pro-oxidant at higher doses—confers context-dependent selectivity, enabling oxidative stress–mediated apoptosis in tumor cells. Compared with other nutriepigenetic agents (curcumin, resveratrol, EGCG), piperine stands out for its multi-target profile and preliminary evidence of activity against cancer stem cell–like phenotypes. Nonetheless, limited solubility, rapid metabolism, and scarce in vivo validation constrain clinical translation. Future efforts should focus on advanced formulations, multi-omics approaches, and cancer stem cell models to better define its therapeutic potential and safety.

Gastric cancer (GC) is among the most common and deadliest types of cancer, with a poor prognosis primarily due to late-stage detection and the presence of cancer stem cells (CSCs). This study investigates the mechanisms regulating extracellular adenosine levels in gastric cancer stem-like cells (GCSCs) derived from the MKN-74 cell line. Our results show that GCSCs release more ATP into the extracellular medium and exhibit higher levels of CD39 expression, which enables them to hydrolyze a greater amount of ATP. Furthermore, we also found that GCSCs possess a greater capacity to hydrolyze AMP, primarily due to the activity of the CD73 protein, with no significant changes in CD73 transcripts and protein levels between GCSCs and differentiated cells. Additionally, adenosine transport is primarily mediated by members of the equilibrative nucleoside transporter (ENT) family in GCSCs, where a significant increase in the expression level of the ENT2 protein is observed compared to non-GCSCs MKN-74 cells. These findings suggest that targeting the adenosine metabolism pathway in GCSCs could be a potential therapeutic strategy for gastric cancer.

Classical Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the MECP2 gene, resulting in a devastating phenotype associated with a lack of gene expression control. Mouse models lacking Mecp2 expression with an RTT-like phenotype have been developed to advance therapeutic alternatives. Environmental enrichment (EE) attenuates RTT symptoms in patients and mouse models. However, the mechanisms underlying the effects of EE on RTT have not been fully elucidated. We housed male hemizygous Mecp2-null (Mecp2^-/y) and wild-type mice in specially conditioned cages to enhance sensory, cognitive, social, and motor stimulation. EE attenuated the progression of the RTT phenotype by preserving neuronal cytoarchitecture and neural plasticity markers. Furthermore, EE ameliorated defects in neuromuscular junction organization and restored the motor deficit of Mecp2^-/y mice. Treatment with plasma from young WT mice was used to assess whether the increased activity could modify plasma components, mimicking the benefits of EE in Mecp2^-/y. Plasma treatment attenuated the RTT phenotype by improving neurological markers, suggesting that peripheral signals of mice with normal motor function have the potential to reactivate dormant neurodevelopment in RTT mice. These findings demonstrate how EE and treatment with young plasma ameliorate RTT-like phenotype in mice, opening new therapeutical approaches for RTT patients.

Cancer stem cells (CSCs) drive therapeutic resistance and tumor relapse by exploiting redundant regulatory networks that integrate Wnt/β-catenin, Notch, and Hedgehog signaling with metabolic reprogramming, epigenetic plasticity, and tumor microenvironment crosstalk, a network architecture that renders single-pathway inhibition strategies insufficient. This review systematically examines evidence that natural compounds (curcumin, sulforaphane, resveratrol, EGCG, berberine, and quercetin) act as multitarget modulators of CSC plasticity, analyzing their molecular mechanisms of action in specific cancer models. Each compound engages distinct regulatory nodes: curcumin suppresses β-catenin nuclear translocation and STAT3 phosphorylation in lung cancer CSC models; sulforaphane represses ΔNp63α-driven stemness transcription in colorectal cancer and reduces CSC self-renewal in prostate and head and neck models; resveratrol dissociates the β-catenin–GLI-1 interaction in oral and lung CSC populations and induces Wnt/β-catenin-dependent autophagy in breast CSCs; EGCG inhibits DNMT and HDAC activity in glioblastoma and colorectal models; berberine activates AMPK-mediated suppression of mTORC1 in colorectal cancer; and quercetin suppresses PI3K/AKT/mTOR signaling while downregulating EMT transcription factors in breast and colorectal systems. We critically assess persistent methodological limitations, including bulk cell-line models, supraphysiological concentrations, and the absence of functional tumor-initiating validation, that currently prevent stronger translational conclusions. Natural compounds from Latin American biodiversity are identified as an underexplored source of CSC-active molecules. We conclude by defining the experimental standards required to reposition natural compounds as clinically relevant network-level modulators of CSC plasticity.