Reactive oxygen species (ROS) are well-known for playing a dual role as destructive and constructive species. Indeed, ROS are engaged in many redox-governing activities of the cells for the preservation of cellular homeostasis. However, its overproduction has been reported to result in oxidative stress, which is considered as a deleterious process, and is involved in the damage of cell structures that causes various diseased states. This review provides a concise view on some of the current research published in this topic for an improved understanding of the key roles of ROS in diverse conditions of health and disease. Previous research demonstrated that ROS perform as potential signaling molecules to control several normal physiological functions at the cellular level. Additionally, there is a growing body of evidence supporting the role of ROS in various pathological states. The binary nature of ROS with their profitable and injurious characteristics indicates the complexities of their specific roles at a biological compartment and the difficulties in establishing convenient intervention procedures to treat ROS-related diseases. Cite this article as: Bardaweel SK, Gul M, Alzweiri M, Ishaqat A, AlSalamat HA, Bashatwah RM. Reactive Oxygen Species: the Dual Role in Physiological and Pathological Conditions of the Human Body. Eurasian J Med 2018; 50(3): 193-201.

Nanomaterials have been the focus of intensive development and research in the medical and industrial sectors over the past several decades. Some studies have found that these compounds can have a detrimental impact on living organisms, including their cellular components. Despite the obvious advantages of using nanomaterials in a wide range of applications, there is sometimes skepticism caused by the lack of substantial proof that evaluates potential toxicities. The interactions of nanoparticles (NPs) with cells of the immune system and their biomolecule pathways are an area of interest for researchers. It is possible to modify NPs so that they are not recognized by the immune system or so that they suppress or stimulate the immune system in a targeted manner. In this review, we look at the literature on nanomaterials for immunostimulation and immunosuppression and their impact on how changing the physicochemical features of the particles could alter their interactions with immune cells for the better or for the worse (immunotoxicity). We also look into whether the NPs have a unique or unexpected (but desired) effect on the immune system, and whether the surface grafting of polymers or surface coatings makes stealth nanomaterials that the immune system cannot find and get rid of.

The essential oil of the Jordanian Chrysanthemum coronarium L. (garland) was isolated by hydrodistillation from dried flowerheads material. The oil was essayed for its in vitro scavenging activity using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. The results demonstrate that the oil exhibits moderate radical scavenging activity relative to the strong antioxidant ascorbic acid. In addition, cholinesterase inhibitory activity of C. coronarium essential oil was evaluated for the first time. Applying Ellmans colorimetric method, interesting cholinesterase inhibitory activity, which is not dose dependent, was evident for the oil. Furthermore, antimicrobial activities of the oil against both Gram-negative and Gram-positive bacteria were evaluated. While it fails to inhibit Gram-negative bacteria growth, the antibacterial effects demonstrated by the oil were more pronounced against the Gram-positive strains. Moreover, the examined oil was assessed for its in vitro antiproliferative properties where it demonstrated variable activities towards different human cancer cell lines, of which the colon cancer was the most sensitive to the oil treatment. The essential oil of the Jordanian Chrysanthemum coronarium L. (garland) was isolated by hydrodistillation from dried flowerheads material. The oil was essayed for its in vitro scavenging activity using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. The results demonstrate that the oil exhibits moderate radical scavenging activity relative to the strong antioxidant ascorbic acid. In addition, cholinesterase inhibitory activity of C. coronarium essential oil was evaluated for the first time. Applying Ellmans colorimetric method, interesting cholinesterase inhibitory activity, which is not dose dependent, was evident for the oil. Furthermore, antimicrobial activities of the oil against both Gram-negative and Gram-positive bacteria were evaluated. While it fails to inhibit Gram-negative bacteria growth, the antibacterial effects demonstrated by the oil were more pronounced against the Gram-positive strains. Moreover, the examined oil was assessed for its in vitro antiproliferative properties where it demonstrated variable activities towards different human cancer cell lines, of which the colon cancer was the most sensitive to the oil treatment.

Oncolytic virotherapy (OVT) employs genetically engineered or naturally occurring viruses to selectively replicate within tumor cells, leading to direct lysis and induction of systemic anti-tumor immune responses. This dual mechanism distinguishes OVT from conventional therapies and positions it as a promising candidate in precision oncology. This review synthesizes recent advancements in understanding the molecular mechanisms underlying OVT efficacy, including viral entry, replication kinetics, immunogenic cell death, and modulation of the tumor microenvironment. We highlight innovations in viral engineering, such as promoter targeting, microRNA control, and immune-modulatory gene insertions that enhance tumor specificity and therapeutic safety. Clinically, OVT has shown measurable benefits in various solid tumors, with several viruses, such as talimogene laherparepvec, entering regulatory approval and others progressing through late-phase clinical trials. When combined with immune checkpoint inhibitors, OVT has demonstrated synergistic effects by improving antigen presentation and reversing immunosuppressive signaling. Integration with targeted therapies and nanotechnology-based delivery systems has further refined viral biodistribution and pharmacodynamics. However, therapeutic resistance, immune clearance, stromal barriers, and heterogeneous tumor responses remain key limitations. Overcoming these challenges requires optimized delivery routes, predictive biomarkers, and combination strategies tailored to immune and genetic tumor profiles. As OVT evolves from proof-of-concept to a platform-based therapeutic strategy, its integration into multimodal cancer treatment protocols will depend on refined bridge oncolytic activity with durable immunotherapy effects.

Depression is characterized by a feeling of sadness and a lack of pleasure, with impaired daily functioning and poor quality of life. The neurobiology and the pathogenesis of depression are not fully understood yet. Several hypotheses have been discussed including, monoamine theory, neurotransmission, oxidation, inflammation, glutamatergic transmission, neurotrophic factors, and others. Reviewing three decades of randomized controlled trials of antidepressants revealed that the antidepressants response rate is about 54% compared to a placebo response rate of 37%. Treatment-resistant depression (TRD) could be defined as an inadequate response to two different of antidepressants. In TRD, a combination strategy of using two FDA-approved antidepressants is used, which may predispose patients to adverse effects. Therefore, there is a compelling need to explore the potential “out of the box” adjuvants to antidepressants to provide higher and consistent response rates with high tolerability. These adjuvants could be medications available for other indications, food supplements, or even experimental drugs. This review will highlight potentially beneficial adjuvants to antidepressants such as nitric oxide modulators, NMDA antagonists, anti-inflammatory, antioxidants, mitochondrial modulators, insulin sensitizers, opioids, probiotics, and GABA agonists.

Viral zoonoses represent a critical intersection of global health, ecology, and ethical issues. Pathogens that pass from animals to humans. This review examines the complex landscape of viral zoonoses, including their mechanisms, impact, and mitigation strategies. We begin with insights into the historical context and significance of these diseases and then explore spillover mechanisms influenced by genetic, ecological, and anthropogenic factors. This review covers the host range, transmission dynamics, and immunological barriers, including viral detection, adaptation, and immune evasion. Genomic insights have revealed the genetic determinants of host switching and adaptation, illuminating the dynamics of viral spillover events. We emphasize the anticipation and prevention of zoonotic events, highlighting surveillance, early warning systems, and the “One Health” approach. Using case studies of outbreaks such as Ebola, avian influenza, and COVID-19, this review examines the real-world consequences of zoonotic diseases. We then discuss interventions, including mitigation strategies and vaccination, and their ethical and social implications. Drawing on past outbreaks, we provide recommendations for the future, aiming to balance human health, conservation, and animal welfare. This review aims to inform professionals, academics, and policymakers by offering a multidisciplinary perspective on the complex world of viral zoonoses and strategies to protect global health.