Cellular metabolism is crucial for various physiological processes, with folate-dependent one-carbon (1C) metabolism playing a pivotal role. Folate, a B vitamin, is a key cofactor in this pathway, supporting DNA synthesis, methylation processes, and antioxidant defenses. In dividing cells, folate facilitates nucleotide biosynthesis, ensuring genomic stability and preventing carcinogenesis. Additionally, in neurodevelopment, folate is essential for neural tube closure and central nervous system formation. Thus, dysregulation of folate metabolism can contribute to pathologies such as cancer, severe birth defects, and neurodegenerative diseases. Epidemiological evidence highlights folate’s impact on disease risk and its potential as a therapeutic target. In cancer, antifolate drugs that inhibit key enzymes of folate-dependent 1C metabolism and strategies targeting folate receptors are current therapeutic options. However, folate’s impact on cancer risk is complex, varying among cancer types and dietary contexts. In neurodegenerative conditions, including Alzheimer’s and Parkinson’s diseases, folate deficiency exacerbates cognitive decline through elevated homocysteine levels, contributing to neuronal damage. Clinical trials of folic acid supplementation show mixed outcomes, underscoring the complexities of its neuroprotective effects. This review integrates current knowledge on folate metabolism in cancer and neurodegeneration, exploring molecular mechanisms, clinical implications, and therapeutic strategies, which can provide crucial information for advancing treatments.

The “Warburg effect” consists of a metabolic shift in energy production from oxidative phosphorylation to glycolysis. The continuous activation of glycolysis in cancer cells causes rapid energy production and an increase in lactate, leading to the acidification of the tumour microenvironment, chemo- and radioresistance, as well as poor patient survival. Nevertheless, the mitochondrial metabolism can be also involved in aggressive cancer characteristics. The metabolic differences between cancer and normal tissues can be considered the Achilles heel of cancer, offering a strategy for new therapies. One of the main causes of treatment resistance consists of the increased expression of efflux pumps, and multidrug resistance (MDR) proteins, which are able to export chemotherapeutics out of the cell. Cells expressing MDR proteins require ATP to mediate the efflux of their drug substrates. Thus, inhibition of the main energy-producing pathways in cancer cells, not only induces cancer cell death per se, but also overcomes multidrug resistance. Given that most anticancer drugs do not have the ability to distinguish normal cells from cancer cells, a number of drug delivery systems have been developed. These nanodrug delivery systems provide flexible and effective methods to overcome MDR by facilitating cellular uptake, increasing drug accumulation, reducing drug efflux, improving targeted drug delivery, co-administering synergistic agents, and increasing the half-life of drugs in circulation.

Environmental xenobiotics, including heavy metals, endocrine-disrupting chemicals (EDCs), pesticides, air pollutants, nano- and microplastics, mycotoxins, and phycotoxins, are widespread compounds that pose significant risks to human health. These substances, originating from industrial and agricultural activities, vehicle emissions, and household products, disrupt cellular homeostasis and contribute to a range of diseases, including cancer and neurodegenerative diseases, among others. Emerging evidence indicates that epigenetic alterations, such as abnormal deoxyribonucleic acid (DNA) methylation, aberrant histone modifications, and altered expression of non-coding ribonucleic acids (ncRNAs), may play a central role in mediating the toxic effects of environmental xenobiotics. Furthermore, exposure to these compounds during critical periods, such as embryogenesis and early postnatal stages, can induce long-lasting epigenetic alterations that increase susceptibility to diseases later in life. Moreover, modifications to the gamete epigenome can potentially lead to effects that persist across generations (transgenerational effects). Although these modifications represent significant health risks, many epigenetic alterations may be reversible through the removal of the xenobiotic trigger, offering potential for therapeutic intervention. This review explores the relationship between environmental xenobiotics and alterations in epigenetic signatures, focusing on how these changes impact human health, including their potential for transgenerational inheritance and their potential reversibility.

Antiglycolytic agents inhibit cell metabolism and modify the tumor’s microenvironment, affecting chemotherapy resistance mechanisms. In this work, we studied the effect of the glycolytic inhibitors 3-bromopyruvate (3BP), dichloroacetate (DCA) and 2-deoxyglucose (2DG) on cancer cell properties and on the multidrug resistance phenotype, using lung cancer cells as a model. All compounds led to the loss of cell viability, with different effects on the cell metabolism, migration and proliferation, depending on the drug and cell line assayed. DCA was the most promising compound, presenting the highest inhibitory effect on cell metabolism and proliferation. DCA treatment led to decreased glucose consumption and ATP and lactate production in both A549 and NCI-H460 cell lines. Furthermore, the DCA pretreatment sensitized the cancer cells to Paclitaxel (PTX), a conventional chemotherapeutic drug, with a 2.7-fold and a 10-fold decrease in PTX IC₅₀ values in A549 and NCI-H460 cell lines, respectively. To increase the intracellular concentration of DCA, thereby potentiating its effect, DCA-loaded poly(lactic-co-glycolic acid) nanoparticles were produced. At higher DCA concentrations, encapsulation was found to increase its toxicity. These results may help find a new treatment strategy through combined therapy, which could open doors to new treatment approaches.

Maintaining glucose homeostasis is vital for normal physiological function, and any disturbance in this balance is associated with the development of degenerative and chronic diseases, like Type 2 Diabetes (T2D) and certain types of cancer, where altered glucose metabolism plays a central role. Epidemiological evidence indicates a positive association between diabetes and an increased risk of developing certain types of cancer. Such a correlation may be driven by shared risk factors, namely obesity, inflammation, and insulin resistance. The observed association between diabetes and an increased risk of certain cancers, along with the rising incidence of both diseases, has in recent years raised interest in treatments that may target both conditions. Among them, the biguanide metformin, the first-line drug prescribed for T2D, has attracted significant attention as a repurposed drug due to its potential role in cancer treatment. Metformin is a glucose-lowering drug that reduces hepatic glucose production and improves insulin sensitivity, promoting glucose uptake by the skeletal muscle, contributing to better glycemic control in individuals with T2D and prediabetic syndromes. However, beyond its metabolic effects, metformin also influences key signaling pathways involved in cell growth and survival, such as the AMP-activated protein kinase (AMPK)/mTOR axis, raising interest in its potential application as an anticancer agent. Furthermore, metformin inhibits mitochondrial complex I, disrupting cellular energy production, which is essential for cancer proliferation. This review aims to explore and clarify the multifunctional role of metformin in both T2D and cancer, focusing on the metabolic alterations observed in these diseases. It highlights how glucose metabolism dysregulation contributes to disease progression in both contexts and explores the molecular targets of metformin in each condition and its potential for dual therapeutic benefit. Finally, selected clinical trials concerning metformin use in cancer therapy, alone or in combination, will be presented, highlighting its potential to enhance treatment response, reduce resistance, and improve overall patient outcomes.

Cancer is a complex disease characterized by several alterations, which confer, to the cells, the capacity to proliferate uncontrollably and to resist cellular death. Multiresistance to conventional chemotherapy drugs is often the cause of treatment failure; thus, the search for natural products or their derivatives with therapeutic action is essential. Chiral derivatives of xanthones (CDXs) have shown potential inhibitory activity against the growth of some human tumor cell lines. This work reports the screening of a library of CDXs, through viability assays, in different cancer cell lines: A375-C5, MCF-7, NCI-H460, and HCT-15. CDXs’ effect was analyzed based on several parameters of cancer cells, and it was also verified if these compounds were substrates of glycoprotein-P (Pgp), one of the main mechanisms of resistance in cancer therapy. Pgp expression was evaluated in all cell lines, but no expression was observed, except for HCT-15. Also, when a humanized yeast expressing the human gene MDR1 was used, no conclusions could be drawn about CDXs as Pgp substrates. The selected CDXs did not induce significant differences in the metabolic parameters analyzed. These results show that some CDXs present promising antitumor activity, but other mechanisms should be triggered by these compounds.