Calycosin ameliorates advanced glycation end product-induced neurodegenerative changes in cellular and rat models of diabetes-related Alzheimer's disease.

Growing pieces of evidence suggest that Alzheimer's disease (AD) is interlinked with Type 2 diabetes mellitus (DM), which has been described as "type 3 DM". In this study, we investigate the neuronal insult attributable to advanced glycation end products (AGEs) as the models of DM-related AD to understand the effects exerted by calycosin on neurodegenerative changes both in vivo and in vitro studies and also studied the associated molecular mechanisms. The results reported herein revealed that the viability of the PC12 cells induced by AGEs increased when treated with calycosin. It was also observed that the learning and memory abilities of AGE-induced DM-related AD rats improved under these conditions. Analysis of the reported results indicates that calycosin can effectively down-regulate the activity of GSK-3ß to result in the reversal of the process of tau hyperphosphorylation, inhibit the expression of RAGE and BACE-1 proteins, resulting in a decrease in the production of ß-amyloid and regulate the PGC-1α/TFAM signaling pathway to repair mitochondrial dysfunction. It can be inferred that calycosin can potentially exhibit important therapeutic properties that can be exploited during the treatment of AD, especially DM-related AD.

Anti-Inflammatory Activity of 4-(4-(Heptyloxy)phenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one via Repression of MAPK/NF-κB Signaling Pathways in ß-Amyloid-Induced Alzheimer's Disease Models.

Alzheimer's disease (AD) is a major neurodegenerative disease, but so far, it can only be treated symptomatically rather than changing the process of the disease. Recently, triazoles and their derivatives have been shown to have potential for the treatment of AD. In this study, the neuroprotective effects of 4-(4-(heptyloxy)phenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (W112) against ß-amyloid (Aß)-induced AD pathology and its possible mechanism were explored both in vitro and in vivo. The results showed that W112 exhibits a neuroprotective role against Aß-induced cytotoxicity in PC12 cells and improves the learning and memory abilities of Aß-induced AD-like rats. In addition, the assays of the protein expression revealed that W112 reversed tau hyperphosphorylation and reduced the production of proinflammatory cytokines, tumor necrosis factor-α and interleukin-6, both in vitro and in vivo studies. Further study indicated that the regulation of mitogen-activated protein kinase/nuclear factor-κB pathways played a key role in mediating the neuroprotective effects of W112 against AD-like pathology. W112 may become a potential drug for AD intervention.

1,8-Cineole Ameliorates Advanced Glycation End Products-Induced Alzheimer's Disease-like Pathology In Vitro and In Vivo.

Advanced glycation end products (AGEs) are stable products produced by the reaction of macromolecules such as proteins, lipids or nucleic acids with glucose or other reducing monosaccharides, which can be identified by immunohistochemistry in the senile plaques and neurofibrillary tangles of Alzheimer's disease (AD) patients. Growing evidence suggests that AGEs are important risk factors for the development and progression of AD. 1,8-cineole (CIN) is a monoterpenoid compound which exists in many plant essential oils and has been proven to have neuroprotective activity, but its specific effect and molecular mechanisms are not clear. In this study, AGEs-induced neuronal injury and intracerebroventricular-AGE animals as the possible models for AD were employed to investigate the effects of CIN on AD pathology as well as the molecular mechanisms involved both in vivo and in vitro. Our study demonstrated that CIN could ameliorate tau phosphorylation by down-regulating the activity of GSK-3ß and reducing Aß production by inhibiting the activity of BACE-1 both in vivo and in vitro. It is suggested that CIN has certain therapeutic value in the treatment of AD.

Sanweidoukou decoction, a Chinese herbal formula, ameliorates ß-amyloid protein-induced neuronal insult via modulating MAPK/NF-κB signaling pathways: Studies in vivo and in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: The traditional Chinese medicine Sanweidoukou decoction (DK-3) was a classical formula for the treatment of nervous system diseases, recorded in the Chinese medical classic Sibu Yidian. AIM OF THE STUDY: The present study is aim to investigate the neuroprotective effects of DK-3 on ß-amyloid (Aß) protein -induced AD-like pathologies and underlying molecular mechanisms both in vitro and in vivo studies. MATERIALS AND METHODS: Hydrolysates of DK-3 were analyzed by LC-ESI-MS/MS. In vitro, MTT was utilized to examine effects of DK-3 on Aß25-35-induced cytotoxicity in PC12 cells. In vivo, male Sprague-Dawley rats were administered with Aß25-35 to induce AD-like pathologies and behavioral evaluations were conducted via Morris water maze (MWM) test. Histopathological changes were observed by Hematoxylin-eosin (HE) straining. Immunohistochemistry (IHC) was used to detect the tau hyperphosphorylation at Thr181 site. The expression levels of tau hyperphosphorylation, inflammation-related cytokines such as COX-2, iNOS, TNF-α, IL-1ß, IL-6, the phosphorylated state of various mitogen-activated protein kinase (MAPK) signaling molecules (p38 MAPK, ERK, and JNK) and activation of nuclear factor κB (NF-κB) in vitro and in vivo were assessed via Western blot. RESULTS: In vitro, DK-3 dose-dependently increased cell viability of PC12 cells induced by Aß25-35. In vivo, DK-3 improved learning and memory abilities of Aß25-35-induced AD-like rats. Moreover, DK-3 reversed hyperphosphorylation of tau and reduced the production of inflammation-related cytokines through significantly inhibited MAPK and NF-κB signaling pathways both in vitro and in vivo studies. CONCLUSION: The present study suggested that the traditional Chinese medicine DK-3 may play a role in preventing and treating AD by reducing the hyperphosphorylation of tau protein and the expressions of inflammation-related cytokines via modulating the MAPK/NF-κB signaling pathways.