Despite decades of research, Alzheimer’s disease (AD) remains without a curative therapy. While amyloid- and tau-centered approaches have dominated the field, failures of monotherapeutic strategies underscore the need for a broader system-level understanding. Here, this review critically revisits the principal hypotheses of AD pathogenesis, including the amyloid cascade, tauopathy, neuroinflammation, cholinergic dysfunction, oxidative and mitochondrial stress, metal dyshomeostasis, autophagy–lysosomal failure, genetic susceptibility, and infectious triggers. This review synthesizes molecular and cellular evidence from human genetics, neuropathology, and experimental models, correcting common misconceptions and emphasizing interactions between pathways. Neuroinflammation is increasingly recognized as a central hub linking amyloid, tau, and vascular factors, while mitochondrial and lysosomal dysfunctions emerge as amplifiers of proteotoxic stress. Genetic studies highlight apolipoprotein-E ε4 (APOE ε4) as the strongest common risk allele, but also implicate genes involved in endosomal trafficking, lipid metabolism, and immune regulation. Taken together, AD is best understood as a multi-hit disorder in which converging processes, rather than a single driver, dictate disease initiation and progression. This narrative review proposes a systems neurobiology framework that integrates these mechanisms and identifies key points of convergence amenable to therapeutic targeting and biomarker development. Finally, this reappraisal aims to inform future research directions and guide the rational design of multi-target interventions.

Centella asiatica (C. asiatica) has attracted significant scientific interest due to its extensive medicinal properties and long-established use in traditional medicine. This review synthesizes recent advances in the technological exploitation of C. asiatica, covering the extraction of bioactive constituents to product development. Modern extraction techniques such as supercritical fluid extraction (SFE) and microwave-assisted extraction (MAE) have substantially improved the yield, selectivity, and preservation of key phytochemicals, particularly triterpenoids, saponins, and flavonoids. These compounds are now routinely characterized using advanced analytical platforms, ensuring product quality, consistency, and standardization. Moreover, the use of innovative formulation technologies and advanced delivery systems has facilitated the development of C. asiatica-based products tailored for various therapeutic areas, including pharmaceuticals, nutraceuticals, and cosmeceuticals targeting neuroprotection, wound healing, skin aging, and stress modulation. Alongside these developments, stringent quality control protocols, toxicological evaluations, and adherence to evolving regulatory standards enhance the safety and efficacy of C. asiatica-derived interventions. This review highlights the integration of traditional knowledge with modern science across the domains of extraction, analysis, formulation, and regulation. It serves as a comprehensive resource for researchers, formulators, and regulatory stakeholders aiming to develop high-quality, evidence-based C. asiatica products with improved bioavailability and therapeutic value.

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder marked by neuronal loss, cognitive decline, and pathological hallmarks such as amyloid-beta (Aβ) plaques and tau neurofibrillary tangles. Recent evidence highlights autophagy as a pivotal mechanism in cellular homeostasis, mediating the clearance of misfolded proteins and damaged organelles. However, impaired autophagy contributes significantly to AD pathogenesis by disrupting proteostasis, exacerbating neuroinflammation, and promoting synaptic dysfunction. This review aims to scrutinize the intricate relationship between autophagy dysfunction and AD progression, explaining key pathways including macroautophagy, chaperone-mediated autophagy (CMA), and selective autophagy processes such as mitophagy and aggrephagy. This further extends the discussion beyond the central nervous system, evaluating the role of hepatic autophagy in Aβ clearance and systemic metabolic regulation. An understanding of autophagy’s involvement in AD pathology via various mechanisms could give rise to a novel therapeutic strategy targeting autophagic modulation to mitigate disease progression in the future.

Neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease, multiple sclerosis, and amyotrophic lateral sclerosis share converging mechanisms of neuronal dysfunction, including protein aggregation, oxidative stress, and chronic neuroinflammation. Glial cells, once considered passive supporters, are now recognized as central drivers of these processes, offering both pathogenic triggers and therapeutic opportunities. Yet, despite compelling preclinical evidence, the translation of glial-targeted therapies into clinical success has been limited. This review provides a critical synthesis of current knowledge by examining therapeutic strategies through the lens of their translational challenges and failures. This narrative review highlights how interspecies variability of glial phenotypes, shifting neuroprotective versus neurotoxic states, limited biomarker stratification, and delivery barriers have constrained trials, such as anti-triggering receptor expressed on myeloid cells 2 (anti-TREM2) antibodies in AD and glial cell line-derived neurotrophic factor (GDNF) in PD. By analyzing these obstacles across major neurodegenerative disorders, this review argue that the next stage of glial medicine requires precision approaches that integrate stage-specific phenotyping, biomarker-guided patient selection, and innovative delivery platforms. Understanding not only what has been tried but why translation has stalled is essential to chart a roadmap for effective, disease-modifying glial therapies in the aging brain.

Alzheimer’s disease (AD) is increasingly recognized as a disorder of dysregulated neuroimmune connectivity rather than isolated proteinopathy. The immuno-glial connectome, the dynamic interplay between microglia, astrocytes, and peripheral immune systems, constitutes a central driver of disease initiation and progression. Emerging single-cell and spatial transcriptomic studies reveal heterogeneous glial subpopulations with context-dependent transcriptional programs governed by TREM2–APOE, NF-κB, JAK/STAT, and NLRP3 inflammasome signaling. These networks converge to sustain chronic inflammation, impair amyloid-β clearance, and accelerate tau pathology. Complement dysregulation (C1q–C3 axis) further promotes aberrant synaptic pruning, while cytokine feedback loops involving IL-1β, TNF-α, and IFN-γ amplify neurotoxicity. Beyond the brain, peripheral immune cells, monocytes, macrophages, T and B lymphocytes, and neutrophils breach the compromised blood–brain barrier (BBB), perpetuating inflammatory cascades. Parallelly, gut dysbiosis and microbial metabolites modulate microglial reactivity via the gut–brain axis (GBA), linking systemic inflammation to central immune activation. Recent advances in plasma and cerebrospinal biomarkers (GFAP, sTREM2, YKL-40, and neurofilament light chain) enable in vivo tracking of neuroinflammatory dynamics, bridging mechanistic research with clinical translation. Therapeutic strategies targeting the immuno-glial interface, including selective NLRP3 inhibitors, TREM2 agonists, anti-cytokine biologics, and microbiome modulation, are reshaping the therapeutic landscape. Framed through the concept of an immune–glial connectome, this review synthesizes how coordinated interactions among microglia, astrocytes, and peripheral immune cells converge to drive synaptic dysfunction, circuit-level disintegration, and cognitive decline in neurodegenerative disease, particularly in AD. Graphical Abstract An immuno-glial network in AD, where central glia, peripheral immune cells, and the gut–brain axis interact through cytokines, oxidative stress, and barrier dysfunction. These interrelated pathways amplify inflammation via NF-κB, JAK/STAT, and NLRP3 signaling, linking immune dysregulation to neurodegeneration.

The amygdala is a complex cellular structure situated centrally in the brain, adjacent to the hippocampus. It is an integral part of the limbic system and is essential for the processing of emotional reactions. The amygdala possesses extensive connections to multiple brain regions, enabling it to acquire sensory information and affect responses. The amygdaloid complex has over ten nuclei located in the mid-temporal lobe. It is quite likely that the primary root of certain anxiety disorders in humans, such as posttraumatic stress disorder, is a dysfunction in the processing of information associated with fear. This article analyzes the anatomical and physiological foundations suggested to support amygdala function.