Oxidative stress, a pivotal driver of neurodegenerative diseases, results from an imbalance between the generation of reactive oxygen species (ROS) and cellular antioxidant defenses. This review provides a comprehensive analysis of key oxidative stress sources, focusing on NADPH oxidase (NOX) hyperactivity and mitochondrial Uncoupling Protein (UCP) downregulation. Critically, we examine the therapeutic potential of phytochemicals in mitigating NOX-mediated ROS generation through direct enzyme inhibition, including impacts on NOX subunit assembly and gene expression. Furthermore, we explore the ability of phytochemicals to bolster cellular antioxidant defenses by activating the Kelch-like ECH-associated protein 1 (KEAP1)/nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway, elucidating the upregulation of antioxidant genes, such as GPx, SOD, CAT, and HO-1. This review expands beyond confined overviews; emphasizes specific molecular interactions between phytochemicals and target proteins, including NOX isoforms; and provides an in-depth analysis of the specific antioxidant genes upregulated via Nrf2. This approach aims to pave the way for targeted and translatable therapeutic strategies in neurodegenerative diseases. Ultimately, this review illuminates the intricate molecular dynamics of oxidative stress in neurodegenerative diseases; underscores the potential of phytochemicals to restore redox homeostasis and reverse pathological conditions through precise modulation of key signaling pathways.

Introduction: SARS-CoV-2 belongs to the coronavirus family, a large family of viruses infecting avian and mammalian hosts. Accumulated mutations over time in the genome of SARS-CoV-2 have given rise to different variants differing in type and sequence. Variants that did not affect transmissibility, infectivity, and severity have gone unnoticed, and mutations that made the virus unfit for survival were deleted eventually from the gene pool. An emerging variant in the host population needs to be monitored closely for its infection consequences. In addition, the variants of concern (VOC) need to be focused on developing effective disease-fighting regimes. As viral epidemics are better fought using effective vaccines, several vaccines have been developed and used since December 2020. The central point of the present study is the continuous variation in the genome of SARS-CoV-2, instigating the researchers to refine their modus operandi to fight against COVID-19. Methods: Prominent medical and literature databases were searched using relevant keywords to gather study results, reports, and other data helpful in writing this traditional, narrative review. Results: This article successfully collates information about the structure and life cycle of SARS-CoV-2, followed by types and nomenclature of mutations in SARS-CoV-2. Variants B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.617.2 (Delta), and B.1.1.529 (Omicron) are current VOCs due to their widespread transmission capability and probable immune evasion. Furthermore, this review article presents information about the major vaccines available and those under development. Based on the original and new strains of SARS-CoV-2, 19 vaccines have been granted emergency use or conditional marketing approvals, 141 are under clinical development, and 194 in preclinical development stages worldwide. Conclusion: Continuous variation in the genome of SARS-CoV-2, presenting new VOCs frequently, has posed a compelling need to amend and evolve current and future vaccine development strategies to overpower the ever-evolving virus.

Viruses use the host cell’s biochemical machinery for replication and survival; and also undergo mutations to evade the immune response and achieve better transmission. These features make it challenging to develop selective drugs to kill viruses only and not the host cells. New and effective pharmaceutical agents are required to overcome this challenge. Tetrazole moiety, as a bio-isostere of carboxylic acid/amide group, has been extensively used as a potent pharmacophore in several bioactivities. Intrigued by the necessity of finding new antiviral compounds and tendency of tetrazole scaffolds to render various bioactivity profiles, this review article comprising literature reports of tetrazole-based synthetic compounds with promising antiviral activity is presented. This review comprises significant literature reports from the scientific databases published during the past four decades. It is found that tetrazole based molecules are promising endeavor for the development of potential agents against influenza virus, HIV, HCV and other viruses.