Aberrant deposition of β-amyloid (Aβ) and hyperphosphorylated tau, along with neuroinflammation, are key drivers of Alzheimer's disease (AD) pathology. Here, we identify ramalin, a natural antioxidant Show more
Aberrant deposition of β-amyloid (Aβ) and hyperphosphorylated tau, along with neuroinflammation, are key drivers of Alzheimer's disease (AD) pathology. Here, we identify ramalin, a natural antioxidant, as a promising therapeutic agent that alleviates AD pathology by modulating β-site APP cleaving enzyme 1 (BACE1), histone deacetylase 6 (HDAC6), and the mitogen-activated protein kinases (MAPK) pathway. Ramalin reduced BACE1 protein levels, independently of its transcription, translation, or enzymatic activity, an effect mediated by inhibition of HDAC6. Consistently, HDAC6 knockout similarly decreased BACE1 levels, highlighting HDAC6 as a key regulator of BACE1. Ramalin further suppressed neuroinflammatory responses by downregulating inducible nitric oxide synthase (iNOS) and the NLR family pyrin domain containing 3 (NLRP3) inflammasome. In AD mouse models, ramalin treatment significantly attenuated neuroinflammation, Aβ plaque burden, and tau hyperphosphorylation, while improving cognitive performance. Notably, ramalin reversed Aβ oligomer-induced synaptic transmission impairment and restored synaptic vesicle recycling in hippocampal neurons. Transcriptomic analysis identified modulation of the MAPK pathway, with reduced phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) implicated in tau pathology. These findings establish ramalin as a disease-modifying intervention that provides neuroprotection through concurrent regulation of BACE1, HDAC6, and MAPK signaling pathway. Collectively, our findings highlight ramalin as a compelling disease-modifying candidate with the potential to drive a breakthrough approach targeting AD pathology. Show less
Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder characterized by cognitive decline, anxiety-like behavior, β-amyloid (Aβ) accumulation, and tau hyperphosphorylation. BACE1, the Show more
Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder characterized by cognitive decline, anxiety-like behavior, β-amyloid (Aβ) accumulation, and tau hyperphosphorylation. BACE1, the enzyme critical for Aβ production, has been a major therapeutic target; however, direct BACE1 inhibition has been associated with adverse side effects. This study investigates the therapeutic potential of RA-PR058, a novel ramalin derivative, as a multi-targeted modulator of AD-related pathologies. The effects of RA-PR058 were evaluated Show less