•Berberine activates AMPK in neuroblastoma cells and neurons.•Berberine reduces Aβ generation in neuroblastoma cells and neurons.•Berberine decreases the expression of BACE1 via activating AMPK.Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by memory deficits and cognitive decline. Excessive amyloid-β (Aβ) peptide aggregates and forms soluble oligomers and insoluble cerebral amyloid plaques, which is widely thought to be the underlying pathogenic mechanism of AD. Therefore, effective regulation of Aβ metabolism is an important aspect of preventing and improving AD. Berberine, which is the main active component of the traditional medicinal herb Coptidis rhizoma, has a positive effect on reducing Aβ levels. However, the exact mechanism involved is unclear and requires more investigation. In the present study, we examined the role of berberine in the activation of AMP-activated protein kinase (AMPK) in neuroblastoma cells and primary cultured neurons and sought to characterize the role of AMPK in the metabolism of Aβ. The results indicate that berberine reduces Aβ generation and decreases the expression of β-site APP cleaving enzyme-1 (BACE1) via activating AMPK in N2a mouse neuroblastoma cells stably expressing human Swedish mutant APP695 (N2a/APP695sw), N2a cells, and primary cultured cortical neurons. Therefore, berberine reduced the accumulation of Aβ, which likely contributes to its memory enhancing effect in patients with AD.

Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases. Although many researchers have attempted to explain the origins of AD, developing an effective strategy in AD clinical therapy is difficult. Recent studies have revealed a potential link between AD and circRNA-associated-ceRNA networks. However, few genome-wide studies have identified the potential circRNA-associated-ceRNA pairs involved in AD. In this study, we systematically explored the circRNA-associated-ceRNA mechanism in a 7-month-old senescence-accelerated mouse prone 8 (SAMP8) model brain through deep RNA sequencing. We obtained 235 significantly dysregulated circRNA transcripts, 30 significantly dysregulated miRNAs, and 1,202 significantly dysregulated mRNAs. We then constructed the most comprehensive circRNA-associated-ceRNA networks in SAMP8 brain. GO analysis revealed that these networks were involved in regulating the development of AD from various angles, for instance, axon terminus (GO: 0043679) and synapse (GO: 0045202). Following rigorous selection, we discovered that the circRNA-associated-ceRNA networks in this AD mouse model were mainly involved in the regulation of Aβ clearance (Hmgb2) and myelin function (Dio2). This research is the first to provide a systematic dissection of circRNA-associated-ceRNA profiling in SAMP8 mouse brain. The selected circRNA-associated-ceRNA networks can profoundly affect the diagnosis and therapy of AD in the future.

•This is the first comprehensive review of Coreopsis tinctoria (C. tinctoria).•Dominant flavonoids in C. tinctoria are thoroughly reviewed for the first time.•Updated study results of the biological properties of C. tinctoria are summarized.•This review will be an important reference for future research on C. tinctoria.A Chrysanthemum family member, Coreopsis tinctoria has been grown in high plateau regions, particularly in Xinjiang, China, for many decades. It has been reported that Coreopsis tinctoria (C. tinctoria) possesses many biological activities, including hypoglycaemic activity, hypolipidaemia activity, blood pressure reduction activity, and antioxidant activity. Previous reviews of C. tinctoria have mostly focused on one of its characteristics, such as analytical or separation chemistry of its major components, or biological properties of its extract, or phytotaxonomy, among others. The aims of the present review are to introduce the analysis and isolation of identified phytochemicals in C. tinctoria and the biological properties of C. tinctoria extracts with targeted indication of nutraceutical properties, and to endeavour to develop a relationship between the chemical identity and pharmacological effects of C. tinctoria.

•Geniposide ameliorates memory impairment in middle-aged APP/PS1 mice.•Geniposide rescues cholinergic defect in hippocampus and neurons.•Geniposide suppresses Aβ-induced activation of the RAGE-MAPK signaling pathway.•Geniposide reduces Aβ accumulation in the cerebrum of APP/PS1 mice.Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by memory deficits and cognitive decline. Amyloid-β (Aβ) deposition and cholinergic defect are widely thought to be the underlying mechanism of learning and memory impairment. Geniposide, which is the main active component of the traditional Chinese herbal Gardenia jasminoides Ellis, elicits neuroprotective effects by alleviating inflammation responses and oxidative damages. In this study, we investigated the protective effect of geniposide on levels of cholinergic markers, RAGE, RAGE-dependent signalling pathways and amyloid accumulation in the APPswe/PS1dE9 AD model mouse. Geniposide suppressed MAPK signaling over-activation mediated by Aβ-RAGE interaction, resulting in reduced Aβ accumulation and amelioration of cholinergic deficits in the cerebral hippocampus. Furthermore, geniposide inhibited the toxic effect of oligomeric Aβ1-42 induced cholinergic deficit by increasing ChAT levels and activity but decreasing AChE activity in cultured primary hippocampal neurons. These results indicated that geniposide enhanced cholinergic neurotransmission, which likely contributes to its memory enhancing effect.

Long noncoding RNAs (lncRNAs) may play an important role in Alzheimer's disease (AD) pathogenesis. However, despite considerable research in this area, the comprehensive and systematic understanding of lncRNAs in AD is still limited. The emergence of RNA sequencing provides a predictor and has incomparable advantage compared with other methods, including microarray. In this study, we identified lncRNAs in a 7-month-old mouse brain through deep RNA sequencing using the senescence-accelerated mouse prone 8 (SAMP8) and senescence-accelerated mouse resistant 1 (SAMR1) models. A total of 599,985,802 clean reads and 23,334 lncRNA transcripts were obtained. Then, we identified 97 significantly upregulated and 114 significantly downregulated lncRNA transcripts from all cases in SAMP8 mice relative to SAMR1 mice. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analyses revealed that these significantly dysregulated lncRNAs were involved in regulating the development of AD from various angles, such as nerve growth factor term (GO: 1990089), mitogen-activated protein kinase signaling pathway, and AD pathway. Furthermore, the most probable AD-associated lncRNAs were predicted and listed in detail. Our study provided the systematic dissection of lncRNA profiling in SAMP8 mouse brain and accelerated the development of lncRNA biomarkers in AD. These attracting biomarkers could provide significant insights into AD therapy in the future.