Resveratrol mitigates activated astrocytes and microglia preventing Alzheimer’s Disease (AD) progression and facilitates neuronal communication in Amyloid-β25–35 induced rat model for AD: A special emphasis on non-neuronal involvement in AD pathophysiology
Kumar Surya, Anitha Rathinam, Meher Nisha Abubakkar, Kesavan Swaminathan Jayachandran, Mahesh Kandasamy, Muthuswamy Anusuyadevi
Abstract
RATIONALE: Amyloid deposits initiate neuroinflammation by activating astrocytes and microglia in the hippocampus, increasing neuronal vulnerability and loss. Astrocytes, while essential for cerebral function, can contribute to neuronal dysfunction by retracting neuronal synapses, that forms a consequence of neuroinflammation, leading to cognitive deficits in Alzheimer's disease (AD). Upon Amyloid-β (Aβ) deposition, astrocytes become reactive as part of a repair mechanism, however this process can impair neurogenesis resulting in AD progression. OBJECTIVE: The current study hypothesizes that resveratrol (RSV) can address inflammation and promote neural regeneration, mitigating cognitive decline. Our previous research highlights RSV's homeostatic effect through SIRT1 normalization, which is crucial in preventing AD progression. However, its neurogenic potential in AD remains underexplored. METHODS: In this study, Aβ25-35-induced AD rat model was used to study the anti-inflammatory, neurogenic and cellular homeostatic effect of RSV (30 mg/kg) for four weeks. RESULTS: Results showed increased Doublecortin expressing cells, indicating favorable neurogenesis in hippocampus. Immunofluorescence of microglia and astrocytes in the hippocampus revealed that RSV counteracted their activation by reducing the formation of engulfing microglia and elongated astrocytes. Behavioral assessments using the Morris water maze and cued radial arm maze demonstrated significant improvements in spatial and learning memory. These cognitive improvements were supported by increased choline acetyltransferase and SIRT1 levels. CONCLUSION: These findings suggest that RSV effectively reduces neuroinflammation, promotes neurogenesis in the sub granular zone of the hippocampus, and improves learning and memory in both control and AD conditions via SIRT1. This study highlights RSV's potential as a suitable therapeutic agent for AD.