Molecular mechanisms and therapeutic potential of icariin in the treatment of Alzheimer's disease.

BACKGROUND: Icariin (ICA) is the main active component of Epimedium, a traditional Chinese medicine (TCM), known to enhance cognitive function in Alzheimer's disease (AD). This study aims to investigate and summarize the mechanisms through which ICA treats AD. METHODS: The PubMed and CNKI databases were utilized to review the advancements in ICA's role in AD prevention and treatment by analyzing literature published between January 2005 and April 2023. To further illustrate ICA's impact on AD development, tables, and images are included to summarize the relationships between various mechanisms. RESULTS: The study reveals that ICA ameliorates cognitive deficits in AD model mice by modulating Aß via multiple pathways, including BACE-1, NO/cGMP, Wnt/Ca2+, and PI3K/Akt signaling. ICA exhibits neuroprotective properties by inhibiting neuronal apoptosis through the suppression of ER stress in AD mice, potentially linked to NF-κB, MAPK, ERK, and PERK/Eif2α signaling pathways. Moreover, ICA may safeguard neurons by attenuating mitochondrial oxidative stress injury. ICA can also enhance learning, memory, and cognition by improving synaptic structure via regulation of the PSD-95 protein. Furthermore, ICA can mitigate neuroinflammation by inactivating microglial activity through the upregulation of PPARγ, TAK1/IKK/NF-κB, and JNK/p38 MAPK signaling pathways. CONCLUSION: This study indicates that ICA possesses multiple beneficial effects in AD treatment. Through the integration of pharmacological and molecular biological research, ICA may emerge as a promising candidate to expedite the advancement of TCM in the clinical management of AD.

Shen Qi Wan attenuates renal interstitial fibrosis through upregulating AQP1.

Renal interstitial fibrosis (RIF) is the crucial pathway in chronic kidney disease (CKD) leading to the end-stage renal failure. However, the underlying mechanism of Shen Qi Wan (SQW) on RIF is not fully understood. In the current study, we investigated the role of Aquaporin 1 (AQP1) in SQW on tubular epithelial-to-mesenchymal transition (EMT). A RIF mouse model induced by adenine and a TGF-ß1-stimulated HK-2 cell model were etablished to explore the involvement of AQP 1 in the protective effect of SQW on EMT in vitro and in vivo. Subsequently, the molecular mechanism of SQW on EMT was explored in HK-2 cells with AQP1 knockdown. The results indicated that SQW alleviated kidney injury and renal collagen deposition in the kidneys of mice induced by adenine, increased the protein expression of E-cadherin and AQP1 expression, and decreased the expression of vimentin and α-smooth muscle actin (α-SMA). Similarly, treatmement with SQW-containing serum significantly halted EMT process in TGF-ß1 stimulated HK-2 cells. The expression of snail and slug was significantly upregulated in HK-2 cells after knockdown of AQP1. AQP1 knockdown also increased the mRNA expression of vimentin and α-SMA, and decreased the expression of E-cadherin. The protein expression of vimentin increased, while the expression of E-cadherin and CK-18 significantly decreased after AQP1 knockdown in HK-2 cells. These results revealed that AQP1 knockdown promoted EMT. Furthermore, AQP1 knockdown abolished the protective effect of SQW-containing serum on EMT in HK-2 cells. In sum, SQW attentuates EMT process in RIF through upregulation of the expression of AQP1.

Essential oil of Acorus tatarinowii Schott inhibits neuroinflammation by suppressing NLRP3 inflammasome activation in 3 × Tg-AD transgenic mice.

BACKGROUND: Shi chang pu (Acorus tatarinowii Schott) is a herbal used in the treatment of Alzheimer's disease (AD) in China. The essential oil of Shi chang pu (SCP-oil) is the main active component. However, its effects on the neuroinflammation of AD have not been well studied. PURPOSE: Neuroinflammation mediated by the NLRP3 inflammasome plays a crucial role in AD. This study was designed to evaluate the effect of SCP-oil on cognitive impairment of AppSwe/PSEN1M146V/MAPTP301L triple transgenic (3 × Tg-AD) mice model and investigate the mechanism underlying its anti-inflammation effects. METHODS: Thirty-two 3 × Tg-AD mice at 12 months and 8 wild-type B6 mice were used for this experiment. The 3 × Tg-AD mice were administered with SCP-oil or donepezil hydrochloride for 8 weeks. Morris water maze test and step-down test were used to evaluate the cognitive ability of mice. The pathological changes, neuroinflammation, and the NLRP3 inflammasome related-protein of AD mice were detected by histomorphological examination, TUNEL staining, immunofluorescence, immunohistochemistry, qRT-PCR, Elisa, and western blot assays. RESULTS: SCP-oil treatment attenuated cognitive dysfunction of 3 × Tg-AD mice. Moreover, SCP-oil also ameliorated characteristics pathological of AD, such as pathological changes damage, deposition of Aß, phosphorylation of Tau, and neuronal loss. Additionally, SCP-oil treatment alleviated the neuroinflammation and inhibited phosphorylation of IKKß, NF-κB, and NLRP3 inflammasome related-protein NLRP3, ASC, Caspase-1, cleaved-Caspase-1, and GSDMD-N in the hippocampus of 3 × Tg-AD mice. CONCLUSION: Overall, SCP-oil contributed to neuroprotection in 3 × Tg-AD mice by reduced activation of NLRP3 inflammasome by inhibiting the NF-κB signaling pathway.

Curcumin Regulates Gut Microbiota and Exerts a Neuroprotective Effect in the MPTP Model of Parkinson's Disease.

Objectives: The experiment aimed to explore the effects of curcumin on motor impairment, dopamine neurons, and gut microbiota in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mice model. Methods: Mice were randomly assigned to six groups: normal control group, solvent control group, MPTP group, curcumin-low-dose group (40 mg/kg), curcumin-medium-dose group (80 mg/kg), and curcumin-high-dose group (160 mg/kg). After 14 days, each group of mice was subjected to the pole text, the hanging test, and the open-field test. Tyrosine hydroxylase (TH) immunohistochemistry was used to observe the survival of nigrostriatal dopamine neurons. Moreover, ultrastructural changes were observed with a transmission electron microscope in mice striatal tissue cells. Then, 16S rRNA was used to assess changes in the gut microbiota. Results: (1) Each dose of curcumin reduced pole climbing time and increased suspension score and total distance moved dose-dependently. (2) All curcumin groups improved cell wrinkling and vacuolar degeneration, increased the number of TH positives, improved cell survival, and the higher the dose of curcumin, the better the effect. (3) There were differences in microbiota composition and a relative abundance among the groups. The relative abundance of Patescibacteria, Proteobacteria, and Verrucomicrobia was higher in the MPTP group. The relative abundance of Patescibacteria, Enterobacteriaceae, Enterococcaceae all decreased in all curcumin groups. In addition, the Kyoto Encyclopedia of Genes and Genomes pathways showed a reduction in the superpathway of N-acetylneuraminate degradation after medium- and high-dose curcumin administration. Conclusions: Curcumin regulates gut microbiota and exerts a neuroprotective effect in the MPTP mice model. This preliminary study demonstrates the therapeutic potential of curcumin for Parkinson's disease, providing clues for microbially targeted therapies for Parkinson's disease.

Guifu Dihuang Pills Ameliorated Mucus Hypersecretion by Suppressing Muc5ac Expression and Inactivating the ERK-SP1 Pathway in Lipopolysaccharide/Cigarette Smoke-Induced Mice.

Mucus hypersecretion is a hallmark of chronic obstructive pulmonary disease (COPD) and is associated with increasing sputum production and declining pulmonary function. Therefore, reducing mucus secretion can be a new therapeutic opportunity for preventing COPD. The Guifu Dihuang pill (GFDHP) is a classical Chinese medicine and has been used as an immunoregulator for treatment of kidney yang deficiency syndrome, including hypothyroidism, adrenocortical hypofunction, chronic bronchitis, and COPD, for more than 2000 years. However, the protective effects and mechanisms of GFDHP against mucus hypersecretion in COPD remain obscure. The aim of the present study was to explore the inhibitory effects of GFDHP on lipopolysaccharide/cigarette smoke- (LPS/CS-) induced Mucin5ac (Muc5ac) overproduction and airway goblet cell hyperplasia in mice. The mice were randomly assigned into 6 groups: control, model, GFDHP-L, GFDHP-M, GFDHP-H, and dexamethasone. The mice were given LPS twice through intranasal inhalation and then exposed to CS daily for 6 weeks. Three doses of GFDHP were orally administered daily during the last 3 weeks of the experiment. Pulmonary function was examined with an EMKA pulmonary system, and pulmonary hyperpermeability and lung damage were evaluated with an in vivo imaging system. Inflammatory cells and cytokines in bronchoalveolar lavage fluid (BALF) were detected with a cell count analyzer and though ELISA analysis, respectively. Lung pathological changes and airway goblet cell hyperplasia were analyzed with hematoxylin and eosin and Alcian blue periodic acid Schiff staining. The protein expression levels of Muc5ac and extracellular signal-regulated kinase (ERK)-specificity protein1 (SP1) signaling pathway were measured with Western blot and immunohistochemistry. The results demonstrated that GFDHP improved pulmonary function and suppressed mouse pulmonary hyperpermeability and edema. GFDHP suppressed inflammatory cell infiltration and cytokine release in BALF, thereby elevating pulmonary function. It ameliorated lung pathological changes and airway goblet cell hyperplasia, and suppressed expression levels of Muc5ac mRNA and protein and phospho-ERK and SP1 levels in the lung tissues of the COPD mice. In conclusion, GFDHP inhibited mucus hypersecretion induced by LPS/CS by suppressing the activation of the ERK-SP1 pathway.

The Protective Effect of Shen Qi Wan on Adenine-Induced Podocyte Injury.

Podocytes are a special type of differentiated epithelial cells that maintain the glomerular filtration barrier in the kidney. Injury or damages in podocytes can cause kidney-related disorders, like CKD. The injury or dysfunction of podocytes can occur by different metabolic disorders. Due to the severity and complexity of podocyte injuries, this state is considered as a serious health issue worldwide. Here, we examined and addressed the efficacy of an alternative Chinese medicine, Shen Qi Wan (SQW), on podocyte-related kidney injury. We evaluated the role and mechanism of action of SQW in podocyte injury. We observed that SQW significantly reduced 24-hour urinary protein and blood urea nitrogen levels and alleviated the pathological damage caused by adenine. Moreover, SQW significantly decreased the expression of nephrin and increased the expression of WT1 and AQP1 in the kidney of mice treated with adenine. We observed that SQW did not effectively reduce the high level of proteinuria in AQP1-/- mice indicating the prominent role of AQP1 in the SQW-ameliorating pathway. Transmission electron microscopy (TEM) images indicated the food processes effacement in AQP1-/- mice were not lessened by SQW. In conclusion, podocyte injury could alter the pathological nature of the kidney, and SQW administration relieves the nature of pathogenesis by activating AQP1.

Acori tatarinowii rhizoma extract ameliorates Alzheimer's pathological syndromes by repairing myelin injury and lowering Tau phosphorylation in mice.

It has been shown that Acori tatarinowii rhizoma (ATR) extract can improve cognitive functions in Alzheimer Diseas (AD) patients or animal models. In this study, we have examined the activity of ATR in 3×Tg-AD model mice with different comprehensive behavioral tests like the Morris water maze and Y-maze test assay for behavior. Moreover, we performed LFB staining for myelin determination in the AD model mouse. By analyzing different pathways, we determined key proteins that are beneficial for ameliorating AD syndrome in the mouse. Periluminally, ATR treatment improved the learning and memory ability that was determined by comprehensive behavioral tests. Moreover, treatment reduces the p-Tau accumulation in the 3×Tg-AD mouse and the level of p-Tau accumulation was at per with the wildtype control mouse and improves the myelin lining in 3×Tg-AD mouse. In conclusion, our results indicate that ATR-treatment can improve the learning ability of AD model mice and the hyperphosphorylation of Tau protein was decreased. ATR can protect myelin lining from damage in AD syndrome.

Anti-Alzheimer's Disease Molecular Mechanism of Acori Tatarinowii Rhizoma Based on Network Pharmacology.

BACKGROUND Acori Tatarinowii Rhizoma (ATR), a traditional Chinese herbal medicine, is used to treat Alzheimer's disease (AD), which is a worldwide degenerative brain disease. The aim of this study was to identify the potential mechanism and molecular targets of ATR in AD by using network pharmacology. MATERIAL AND METHODS The potential targets of the active ingredients of ATR were predicted by PharmMapper, and the targets of Alzheimer's disease were searched by DisGeNET. All screened genes were intersected to obtain potential targets for the active ingredients of ATR. The protein-protein interaction network of possible targets was established by STRING, GO Enrichment, and KEGG pathway enrichment analyses using the Annotation of DAVID database. Next, Cytoscape was used to build the "components-targets-pathways" networks. Additionally, a "disease-component-gene-pathways" network was constructed and verified by molecular docking methods. In addition, the active constituents ß-asarone and ß-caryophyllene were used to detect Aß1₋42-mediated SH-SY5Y cells, and mRNA expression levels of APP, Tau, and core target genes were estimated by qRT-PCR. RESULTS The results showed that the active components of ATR participate in related biological processes such as cancer, inflammation, cellular metabolism, and metabolic pathways and are closely related to the 13 predictive targets: ESR1, PPARG, AR, CASP3, JAK2, MAPK14, MAP2K1, ABL1, PTPN1, NR3C1, MET, INSR, and PRKACA. The ATR active components of ß-caryophyllene significantly reduced the mRNA expression levels of APP, TAU, ESR1, PTPN1, and JAK2. CONCLUSIONS The targets and mechanism corresponding to the active ingredients of ATR were investigated systematically, and novel ideas and directions were provided to further study the mechanism of ATR in AD.

[Protective effect of ß-asarone on AD rat model induced by intracerebroventricular injection of Aß1₋42 combined 2-VO and its mechanism].

This study was aimed to investigate the protective effect and mechanism of ß-asarone on the animal model of Alzheimer's disease(AD) which was induced by intracerebroventricular injection of Aß1₋42 combined cerebral ischemia. One hundred and five rats were randomly divided into seven groups including sham-operated group, AD model group, ß-asarone 10 mg•kg⁻¹ group, ß-asarone 20 mg•kg⁻¹ group, ß-asarone 30 mg•kg⁻¹ group, donepezil group(0.75 mg•kg⁻¹) and Ginkgo biloba extract group(24 mg•kg⁻¹). Rats' learning and memory abilities, cerebric regional blood flow, pathological changes in hippocampal CA1 region, the expression level of HIF-1α and serum CAT, SOD and MDA level were detected 4 weeks later. The results showed that the application of intracerebroventricular injection of Aß1₋42 joint 2-VO could lead to rats' dysfunction of learning and memory, decrease in regional cerebral blood flow. Neurons in CA1 region were arranged in disorder, and amyloid deposition was increased. The number of cerebral cortical cells expressing HIF-1α was increased as well. The level of serum CAT and SOD decreased, while level of serum MDA increased. However these symptoms were improved by 20 mg•kg⁻¹ and 30 mg•kg⁻¹ ß-asarone. The results indicated that ß-asarone could effectively relieve the symptoms of the AD model induced by intracerebroventricular injection of Aß1₋42 combined cerebral ischemia, and the potential mechanism might be that it could attenuate damage of MDA to the body by improving the level of CAT and SOD, meanwhile the level of HIF-1α decreased as the decline of hyperoxide which might attenuate its damage to neuron, so it finally achieved alleviating Alzheimer's disease.

Neuroprotective Effects and Mechanism of ß-Asarone against Aß1-42-Induced Injury in Astrocytes.

Emerging evidence suggests that activated astrocytes play important roles in AD, and ß-asarone, a major component of Acorus tatarinowii Schott, was shown to be a potential therapeutic candidate for AD. While our previous study found that ß-asarone could improve the cognitive function of rats hippocampally injected with Aß, the effects of ß-asarone on astrocytes remain unclear, and this study aimed to investigate these effects. A rat model of Aß1-42 (10 µg) was established, and the rats were intragastrically treated with ß-asarone at doses of 10, 20, and 30 mg/kg or donepezil at a dose of 0.75 mg/kg. The sham and model groups were intragastrically injected with an equal volume of saline. Animals were sacrificed on the 28th day after administration of the drugs. In addition, a cellular model of Aß1-42 (1.1 µM, 6 h) was established, and cells were treated with ß-asarone at doses of 0, 2.06, 6.17, 18.5, 55.6, and 166.7 µg/mL. ß-Asarone improved cognitive impairment, alleviated Aß deposition and hippocampal damage, and inhibited GFAP, AQP4, IL-1ß, and TNF-α expression. These results suggested that ß-asarone could alleviate the symptoms of AD by protecting astrocytes, possibly by inhibiting TNF-α and IL-1ß secretion and then downregulating AQP4 expression.