Alzheimer’s disease (AD) is the most common form of dementia, characterized by chronic neuron loss and cognitive problems. Aggregated amyloid beta (Aβ) peptides, a product of cleaved amyloid precursor protein (APP) by beta-secretase 1 (BACE-1), have been indicated for the progressive pathogenesis of AD. Currently, screening for anti-AD compounds in foodstuffs is increasing, with promising results. Hence, the purpose of this study was to investigate the extraction conditions, phytochemical contents, and anti-AD properties, targeting Aβ peptides of Morus cf. nigra ‘Chiang Mai’ (MNCM) both in vitro and in vivo. Data showed that the aqueous extract of MNCM contained high amounts of cyanidin, keracyanin, and kuromanin as anthocyanidin and anthocyanins. The extract also strongly inhibited cholinesterases and BACE-1 in vitro. Moreover, MNCM extract prevented Aβ-induced neurotoxicity and promoted neurite outgrowth in neuronal cells. Interestingly, MNCM extract reduced Aβ1–42 peptides and improved locomotory coordination of Drosophila co-expressing human APP and BACE-1, specifically in the brain. These findings suggest that MNCM may be useful as an AD preventive agent by targeting Aβ formation.

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder. To fight the disease, natural products, including mulberry, with antioxidant activities and inhibitory activities against key enzymes (acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and beta-secretase 1 (BACE-1)) are of interest. However, even in the same cultivars, mulberry trees grown in different populated locations might possess disparate amounts of phytochemical profiles, leading to dissimilar health properties, which cause problems when comparing different cultivars of mulberry. Therefore, this study aimed to comparatively investigate the phytochemicals, antioxidant activities, and inhibitory activities against AChE, BChE, and BACE-1, of twenty-seven Morus spp. cultivated in the same planting area in Thailand. The results suggested that Morus fruit samples were rich in phenolics, especially cyanidin, kuromanin, and keracyanin. Besides, the aqueous Morus fruit extracts exhibited antioxidant activities, both in single electron transfer (SET) and hydrogen atom transfer (HAT) mechanisms, while strong inhibitory activities against AD key enzymes were observed. Interestingly, among the twenty-seven Morus spp., Morus sp. code SKSM 810191 with high phytochemicals, antioxidant activities and in vitro anti-AD properties is a promising cultivar for further developed as a potential mulberry resource with health benefits against AD.