Propolis and propolis-derived constituents in experimental models relevant to alzheimer’s disease: A narrative review of mechanisms and translational gaps

Background: Alzheimer’s disease (AD) involves progressive cognitive decline associated with amyloid-β (Aβ) and tau pathology, oxidative stress, mitochondrial dysfunction, neuroinflammation, synaptic failure, and neuronal loss. Propolis contains geographically variable phenolic acids, flavonoids, and other potentially neuroprotective constituents. 
Aim: This structured narrative review critically evaluates propolis extracts and derived constituents in AD-related and indirect neurodegeneration models, emphasizing mechanistic confidence and translational relevance. 
Method: The review was developed from google scholar and semantic scholar database. Thirty-seven citation records in the source manuscript were audited; one conference record was confirmed as overlapping a later full article. 
Result: Direct evidence was limited to APP-knock-in mice, Aβ-induced cellular and mouse models, and an Aβ-expressing Caenorhabditis elegans model. Selected Brazilian green propolis preparations and pinocembrin were associated with synaptic, cognitive, antioxidant, mitochondrial, inflammatory, and apoptotic outcomes in these systems. Most supporting studies, however, used indirect oxidative, ischemic, hypoxic, excitotoxic, or chemically induced impairment models. The evidence is predominantly preclinical, chemically heterogeneous, and incompletely reported, and no formal risk-of-bias assessment was performed. 
Conclusion: Propolis-derived interventions provide mechanistic plausibility but cannot yet establish clinical efficacy or interchangeability among products. Standardized chemistry, brain-exposure data, rigorous age-appropriate AD models, safety studies, and controlled clinical trials are required.