Dengzhan Shengmai capsule ameliorates cognitive impairment via inhibiting ER stress in APP/PS1 mice.

Alzheimer's disease (AD) is a common type of neurodegenerative disease with the β-amyloid plaques (Aβ) deposition. Previously, Dengzhan Shengmai capsule (DZSM) has been shown to reduce the pathology associated with AD, but the underlying mechanism is unclear. This study investigated the potential mechanisms of DZSM against AD. The six-month-old wild-type male mice and APP/PS1 double transgenic male mice were administered 0.9 % saline or DZSM for 8 weeks by gavage. Open field test, new object recognition test, and Morris Water maze test were used to assess spatial learning and memory. Aβ plaques in brains were visualized using ThT staining. Nissl staining, TUNEL staining, and Western blot analyses were used to detect the neuronal function and apoptosis level. The superoxide dismutase (SOD), glutathione peroxidase assay kit (GSH-Px), and malondialdehyde (MDA) kits were performed to assess oxidative stress levels. Then, immunofluorescence and Western blot analysis were applied to evaluate ER stress pathway protein levels. Finally, HT22 cells were treated by Aβ1-42 with or without DZSM medicated serum. Cell viability was assessed using the CCK-8 assay, and Western blot analysis was applied to evaluate ER stress pathway protein levels. Open filed test, new object recognition test and Morris Water maze test showed that DZSM restored cognitive disorders in APP/PS1 mice. Immunohistochemistry and Thioflavin T staining results indicated that DZSM reduced Aβ plaques in the brain. Deeper and denser Nissl bodies were found in APP/PS1 mice after DZSM administration. Besides, APP/PS1 mice treated with DZSM showed a lower level of TUNEL and Bax/Bcl-2 ratio. DZSM improved the acetylcholine (ACh), choline acetyltransferase (ChAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity while reducing acetylcholinesterase (AChE) and malondialdehyde (MDA) activity. In addition, the levels of ER stress pathway containing Phospho-PKR-like ER kinase (P-PERK), phosphorylate eukaryotic initiation factor 2 (P-eIF2α), activating transcription factor 4 (ATF4), glutamine-rich protein 1 (QRICH1), phosphorylate inositol-requiring protein 1α (P-IRE1α), the spliced form of X-box binding protein 1 (XBP1s), activating transcription factor-6 (ATF6) and C/EBP homologous binding protein (CHOP) were decreased by DZSM. CCK-8 results indicated that DZSM medicated serum played cytoprotective effects on Aβ1-42-induced HT22 cells. Western blot results suggested DZSM possibly inhibited ER stress pathways in Aβ1-42-induced HT22 cells. The potential protective mechanism of DZSM on cognitive impairment in AD might be related to ER stress pathways.

Ma HH ，Zheng JY ，Qiu YH ，Su S ，Lu FM ，Wu GL ，Zhang SJ ，Cai YF ... -  《-》

Lancao decoction in the treatment of alzheimer's disease via activating PI3K/AKT signaling to promote ERK involving in enhancing neuronal activities in the hippocampus.

Previous study has demonstrated lancao decoction (LC), a traditional Chinese medicine (TCM) fomula and recorded in "Huangdineijing", has a therapeutic effect on cognitive impairment (early clinical manifestations of alzheimer's disease (AD), which suggests that LC may have potential therapeutic advantages for AD. Whether LC has the therapeutic effect on AD and its potential mechanisms were still further indicated. In this study, we aimed to uncover the potential advantage and neuronal mechanisms of LC in the treatment of AD in APP/PS1 mice in the hippocampus. We chose APP/PS1 mice to combing with behavioral tests including morris water maze (MWM) or y-maze to determine the role of LC in the therapeutic actions of AD. Network pharmacology was used to screen potential targets and pathways involving in LC's treatments of AD. Western blot was used to detect the phosphorylated expressions of proteins in hippocampus in APP/PS1 mice in the hippocampus. Pharmacological interventions were used to elucidate the relationship between the role of LC in the treatment of AD and the pathway, as well as the upstream and downstream interactions with neuronal activities. According to our previous LC effective dose (2.5 g/kg), the dose was also able to significantly reduce the latency to the platform, and significantly increase the number of crossing times and time spend in the target quadrant in APP/PS1 mice in MWM, which was consistent with donepezil (DON) after 14 days chronic treatments. Network pharmacology showed that PI3K/AKT and MAPK pathways were closely associated with LC's treatments of AD, and protein autophosphorylation played a role in this process. The phosphorylated expressions of PI3K and AKT were obviously reduced in APP/PS1 mice in the hippocampus, which were both reversed by LC or DON. The phosphorylated expressions of MAPK including P38, JNK and ERK were also significantly reduced in APP/PS1 mice hippocampus, but only the phosphorylated expression of ERK was reversed by LC or DON. Inhibiting the activities of PI3K/AKT pathway by LY294002 blocked LC's improvement of behavioral deficits in APP/PS1 mice, including reducing latency to platform and increasing the number of crossings time in MWM in APP/PS1 mice, which also blunted LC's up-regulated phosphorylated expressions of PI3K, AKT and ERK in the hippocampus. Moreover, suppressing the activities of ERK by PD98059 also blocked LC's improvement of AD-related behavioral deficits including decreasing latency to new arm and increasing time in new arm in y-maze test, which also inhibited LC's enhancement of synaptic proteins (PSD95 and synapsin1) in the hippocampus and the number of EGR1-positive cells in the hippocampal dentate gyrus (DG). Take together, our study revealed that LC had the therapeutic effects on AD by activating the PI3K/AKT pathway to enhance ERK activity and further strengthened neuronal activities in the hippocampus.

Wu L ，Sun Y ，Yin Y ，Wu Z ，Liu R ，Liu Y ，Zhu Y ，Shao M ，Zhou H ，Lu C ，Zhang H ... -  《-》

Osmundacetone ameliorates Alzheimer's-like pathologies by inhibiting β-amyloid fibrillation, oxidative damage and neuroinflammation in APP/PS1 transgenic mice.

β-Amyloid (Aβ) fibrillation is critical for Aβ deposition and cytotoxicity during the progression of Alzheimer's disease (AD). Consequently, anti-Aβ monoclonal antibody drugs targeting Aβ oligomers and aggregation are considered potential therapeutic strategies for AD treatment. Similar to the working mechanisms of anti-Aβ monoclonal antibody drugs, our study identified osmundacetone (OAC), a small-molecule compound isolated from the traditional Chinese medicine Rhizoma Osmundae, as exerting anti-AD effects by targeting Aβ. This study sought to determine whether OAC influences the Aβ burden in APP/PS1 mice and to identify potential regulatory mechanisms. Five-month-old APP/PS1 mice were injected intraperitoneally with OAC at a dose of 1 mg/kg for 12 weeks. The cognitive functions of the mice were assessed via the Morris water maze test and the open field test. Osmundacetone was analyzed via molecular docking, an isothermal dose‒response fingerprint-cellular context thermal shift assay, a thioflavine T fluorescence assay, and an atomic force microscopy assay to analyze the effects of OAC on Aβ fibrillation. Immunofluorescence, immunoblotting, and immunohistochemistry were used to assess Aβ clearance, AD pathology, oxidative stress, and inflammatory responses. The innovative biochemical and physical data illustrated that the ability of OAC to inhibit Aβ fibrillation was accomplished by binding directly to Aβ, which differed from the majority of previously reported natural polyphenols that modulate the Aβ content and structure in an indirect manner. The inhibition of Aβ fibrosis by OAC subsequently promoted Aβ lysosomal degradation, resulting in a decreased Aβ burden in APP/PS1 mice. Furthermore, OAC treatment inhibited oxidative damage by upregulating glutathione peroxidase expression and attenuated the production of inflammatory factors by downregulating nuclear factor-kB phosphorylation in APP/PS1 mice. These findings demonstrate, for the first time, that OAC could reduce the brain Aβ burden in APP/PS1 mice by inhibiting Aβ fibrillation through direct binding to Aβ and improve cognitive dysfunction by attenuating oxidative damage and neuroinflammation. These findings indicate that OAC may be a promising candidate for the treatment of AD.

Zhao LX ，Ren H ，Su JY ，Zhang Q ，He DL ，Wu TY ，Zhang YH ，Wang ZY ，Fan YG ... -  《-》

Kaixinsan regulates neuronal mitochondrial homeostasis to improve the cognitive function of Alzheimer's disease by activating CaMKKβ-AMPK-PGC-1α signaling axis.

Alzheimer's disease (AD) is a neurodegenerative disease primarily characterized by cognitive impairments. With the intensification of population aging, AD has become a major health concern affecting the elderly. Kaixinsan, a classical traditional Chinese formula, consists of Ginseng Panax et Rhizoma, Polygalae Radix, Poria and Acori Tatarinowii Rhizoma, and is commonly used in clinical for treating memory decline. However, its mechanism remains unclear, which hinders its popularization and application. Morris water maze (MWM) was performed to evaluate the effect of Kaixinsan on improving learning and memory ability in SAMP8 (senescence-accelerated mouse prone 8, an AD model mice) mice. Nissl staining, TdT-mediated dUTP Nick End Labeling (TUNEL) and western blotting (Bax and Bcl-2) were used to confirm the effect of Kaixinsan on the neuronal structure and apoptosis of SAMP8 mice. Ultra performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UPLC-Q-TOF/MS) was performed to identify the distribution components in brain tissue after administration of Kaixinsan extraction. Based on the identified brain distribution components, the mechanism of Kaixinsan improving the cognitive function was predicted by network pharmacology. Then, using HSP60 as a mitochondrial marker and RBFOX3 as a neuronal marker, immunofluorescence co-localization was used to confirm the effect of Kaixinsan on neuronal mitochondria quantity in SAMP8 mice. Western blotting was employed to access the expression of predicted proteins (AMPK, CaMKKβ, PGC-1α and HSP90) implicated in mitochondrial homeostasis. To further confirm the mechanism of Kaixinsan, SH-SY5Y cell injury model induced by amyloid β - protein fragment 25-35 (Aβ25-35) was replicated and the effect of Kaixinsan - containing serum on apoptosis in injured SH-SY5Y cells was investigated by flow cytometer. The expression level of apoptosis-associated proteins (Bax and Bcl-2) and mitochondrial homeostasis related proteins (AMPK, CaMKKβ, PGC-1α and HSP90) in the presence or absence of CaMKKβ inhibitor (STO-609) were compared. The results indicate that Kaixinsan can improve the cognitive function of SAMP8 mice, alleviate the hippocampal tissue lesions and inhibit neuron apoptosis. Seventeen brain distribution components of Kaixinsan were identified. Based on the brain distribution components of Kaixinsan, the results of network pharmacology suggest that Kaixinsan may regulate mitochondrial homeostasis through the CaMKKβ-AMPK-PGC-1α signaling axis. In vivo experiments indicated that Kaixinsan could reverse neuronal mitochondrial loss in SAMP8 mice by upregulating CaMKKβ, AMPK, HSP90 and PGC-1α to promote mitochondrial biogenesis and increase the number of neuronal mitochondria. Additionally, the in vitro experiments demonstrated that Kaixinsan can inhibit apoptosis of Aβ25-35 injured SH-SY5Y cells and upregulate mitochondrial homeostasis-related proteins CaMKKβ, AMPK and PGC-1α. However, in addition to CaMKKβ inhibitors, the neuroprotective effect disappeared. The results indicate that Kaixinsan can improve the cognitive function of SAMP8 mice by regulating CaMKKβ-AMPK-PGC-1α signaling axis to maintain mitochondrial homeostasis and inhibit neuronal apoptosis.

Ren J ，Xiang B ，Song L ，René DJ ，Luo Y ，Wen G ，Gu H ，Yang Z ，Zhang Y ... -  《-》

The volatile oil of Acorus tatarinowii Schott ameliorates Alzheimer's disease through improving insulin resistance via activating the PI3K/AKT pathway.

Alzheimer's disease (AD) presently stands as the most prevalent neurodegenerative disease. Existing research underscores the pivotal role of insulin signaling in the progression of AD. Acorus tatarinowii Schott (SCP), a traditional Chinese herbal, is employed for AD treatment in China. The volatile oil of Acorus tatarinowii Schott (SCP-oil) is the active component. However, its impact on AD-associated insulin resistance (AD-IR) remains inadequately investigated. This study used network pharmacology and experimental to investigate the effects and mechanisms of SCP-oil on cognitive improvement in AD by inhibiting IR. GC-Q/TOF-MS was employed to analyze the chemical composition of SCP-oil, while network pharmacology predicted the targets associated with SCP-oil in treating AD-IR to identify its regulatory mechanism. IR in the brain was simulated by intracerebroventricular streptozotocin administration (ICV-STZ). The neuroprotective and cognitive improvement effects of SCP-oil were assessed using the Morris water maze and hematoxylin and eosin, as well as Nissl staining. The expression levels of Neun and proteins related to p-tau, tau, amyloid-beta (Aβ), apoptosis, and the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway were measured using immunohistochemistry and Western blotting, respectively. Dexamethasone (DXM)-induced HT22 cells were used for IR modeling. Chemical analysis determined the glucose consumption rate, and periodic acid Schiff staining was employed to detect glycogen deposition. Western Blots were utilized to investigate the expression of characteristic AD proteins, apoptosis-related proteins, and PI3K/AKT pathway-related proteins. The apoptosis rate was detected by flow cytometry. Reverse validation was further performed using LY294002 to evaluate the pharmacodynamic effects of SCP-oil after PI3K/AKT pathway inhibition. A total of 25 chemical constituents were identified in SCP-oil. The network pharmacology findings indicated that SCP-oil holds the potential to ameliorate IR in the brain by activating the PI3K/AKT pathway, thereby improving AD. SCP-oil significantly improved ICV-STZ-induced cognitive dysfunction and pathological damage, reduced neuronal loss, Aβ deposition, and tau protein hyperphosphorylation, inhibited cell apoptosis, and activated the PI3K/AKT signaling pathway. Neuron loss, Aβ deposition, and tau protein hyperphosphorylation and cell apoptosis were further enhanced following treatment with LY294002, while the PI3K/AKT signaling pathway was further inhibited, and the protective effect of SCP-oil was weakened. SCP-oil exhibited the potential to ameliorate brain IR, inhibiting cell apoptosis by activating the PI3K/AKT signaling pathway, thereby improving learning and memory ability.

Huang J ，Xu Z ，Yu C ，Liu L ，Ji L ，Qiu P ，Li C ，Zhou X ... -  《-》