Epstein-Barr virus (EBV), human papillomavirus (HPV), and hepatitis C virus (HCV) are significant human pathogens associated with various diseases, employing complex molecular mechanisms for cellular entry and immune evasion. Peptide-based research, using more than 700 synthetic peptides, has deciphered some of the molecular interactions between viral proteins and host cell receptors, offering promising diagnostics and therapeutic strategies. In EBV, binding peptides have been identified: 11382, 11389, and 11416 derived from gp350/220; 11435, 11436, and 11438 from gp85 [glycoprotein H (gH)]; and 11521 from BNRF1/p140. Most of these peptide sequences are surface-exposed and are part of the contact regions with human cell receptors, making them promising candidates for strategies aimed at inhibiting EBV invasion of human cells. Peptide 11382 is the target of the neutralizing antibody 72A1; peptides 11382 and 11416 induce interleukin-6 production; peptide 11435 binds to integrin αvβ6, and peptide 11438 triggers a cytokine storm. In the HPV L1 protein, a major component of the viral capsid, peptides 18283 and 18294 have been identified as epithelial cell-binding peptides located on the virus surface. Parts of the sequences are recognized by anti-HPV neutralizing antibodies. These two peptides, along with peptide 18301, have been identified as potential biomarkers for HPV infection because they are recognized by antibodies elicited during natural HPV infection, making them suitable targets for serological detection. In the envelope proteins E1 and E2 from HCV, five hepatocyte- and CD81-positive cell-binding peptides have been identified. The sequences of these peptides contain linear B-cell epitopes recognized by neutralizing antibodies, and some of them have been used to develop serological tests for determining HCV infection. Peptide-based approaches can lead to innovative strategies for the prevention, diagnosis, and treatment of these viral diseases. Additionally, these peptides and their sequences can be used to modulate the immune response and generate tools for cancer theragnostic.

Proteins from the neurotrophin family perform trophic and regulatory functions in the nervous and other body systems. Understanding the mechanisms of neurotrophin action is crucial not only for the evolution of fundamental scientific knowledge but also for developing new treatment strategies targeting neurotrophin signaling regulation. At our center, dimeric dipeptide mimetics of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) have been obtained based on the structure of neurotrophins’ individual loops β-turns. These mimetics activated tyrosine kinase (Trk) receptors TrkA, TrkB, or TrkC specific to their respective neurotrophins, but exhibited varied activation patterns in the main post-receptor signaling cascades. Thus, some dipeptides activated all three main phosphoinositide 3-kinase (PI3K)/threonine-protein kinase (Akt), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) and phospholipase C-gamma (PLC-γ) pathways, while others triggered only PI3K/Akt and PLC-γ or MAPK/ERK and PLC-γ. Herewith, dipeptides exhibited a specific set of effects (neuroprotective, differentiating, antidepressant-like, anxiolytic, memory-enhancing, analgesic, antidiabetic) within the spectrum of biological activities of their corresponding native neurotrophin. It was revealed that these effects are influenced by both the patterns of post-receptor signaling activation and the nature of progenitor neurotrophin, uncovering significant correlations. This article is dedicated to reviewing the data that has been collected.

4-Aminobenzoic acid (PABA, para-aminobenzoic acid) exhibits multifaceted therapeutic potential in neuropsychiatric disorders through its roles in neurotransmitter modulation, anti-inflammatory action, and antioxidant defense. Experimental and clinical evidence demonstrates that PABA enhances serotonin and dopamine synthesis by activating key enzymes (e.g., tryptophan hydroxylase and tyrosine hydroxylase), thereby stabilizing mood and improving cognitive function. Mechanistically, PABA suppresses neuroinflammation by inhibiting NF-κB signaling and cytokine production (e.g., IL-1β, TNF-α) while scavenging reactive oxygen species (ROS) to mitigate oxidative stress and protect neuronal integrity. Clinical studies indicate that PABA may synergize with traditional antidepressants by targeting serotonin reuptake transporters (SERT) and monoamine oxidase (MAO), offering improved outcomes in major depressive disorder. Despite promising results, further research is needed to optimize dosing regimens, validate long-term safety, and explore pharmacogenomic interactions. Crucially, experimental validation through cellular and animal models is required to substantiate PABA’s proposed mechanisms, particularly its regulation of NF-κB signaling and enzyme activity in neurotransmitter synthesis. This review underscores PABA’s potential as a neuroprotective agent and calls for integrated strategies to translate mechanistic insights into clinical applications for complex neurological conditions.

Metabolic syndrome is a complex, multifactorial disorder, with emerging research emphasizing the significant role of gut health in its prevention and management. Recent studies suggest that dietary strategies promoting a healthy gut microbiome, including the incorporation of fiber, fermented foods, and healthy fats, are crucial for regulating metabolism. Additionally, the use of postbiotics and supplements, such as probiotics, omega-3 fatty acids, and polyphenols, provides promising avenues for enhancing metabolic health. This holistic approach to managing metabolic syndrome not only supports gut health but also offers the potential for improving long-term health outcomes. This review examines the influence of the gut microbiome on metabolism, highlighting the increasing significance of dietary strategies and supplements in managing metabolic syndrome.

Cancer remains the second leading cause of death globally, posing an ongoing threat to public health. A hallmark of cancer cells is their capacity to invade adjacent tissues and evolve into malignant forms, often resulting in aggressive tumors resistant to conventional treatments. At the heart of this therapeutic challenge are cancer stem cells (CSCs), which possess distinctive capabilities for self-renewal, differentiation, and generation of diverse tumor cell populations. These CSCs have been identified across multiple tissue types, including lung, colon, breast, pancreas, and ovary. Research has demonstrated that CSC subpopulations contribute significantly to therapeutic resistance, tumor recurrence, and metastasis by regulating multiple signaling pathways, making them compelling targets for cancer therapy. Notably, emerging evidence suggests that natural products may offer protective benefits against cancer development while potentially targeting CSCs. This review synthesizes current knowledge of CSCs, examining their identifying markers, isolation techniques, study methods, and associated signaling pathways. Additionally, we explore various natural products that specifically target CSCs across different cancer types, presenting potential strategies to address the persistent challenges of drug resistance and cancer relapse.