ObjectiveThis study aims to investigate the effectiveness and mechanisms of Polygonati Rhizoma polysaccharides （PRP） on improving cognitive and emotional functions in the ovariectomy （OVX）-Alzheimer's disease （AD） model rats. MethodsAfter being randomly divided into blank group， model group， estradiol group （0.18 mg·kg^-1·d^-1）， low-PRP group （200 mg·kg^-1）， medium-PRP group （400 mg·kg^-1）， and high-PRP group （800 mg·kg^-1）， 60 SPF female Sprague-Dawley （SD） rats were subjected to OVX. One week later， vaginal smear examination as well as D-galactose intraperitoneal injection （150 mg·kg^-1·d^-1， once daily， for eight weeks） were adopted to establish the OVX-AD model， and drug intervention was initiated nine weeks after surgery. Upon completion of the treatment course， cognitive and emotional functions， as well as hippocampal CA3 region damage were assessed in all rats by open-field test， new object recognition test， Morris water maze test， and transmission electron microscopy. Indicators of inflammation ［interleukin-6 （IL-6）， tumor-necrosis-factor-α （TNF-α）， interleukin-1β （IL-1β））， oxidative-stress （superoxide-dismutase （SOD）， glutathione-peroxidase （GSH-Px）］ were measured by enzyme-linked immunosorbent assay （ELISA） and biochemical methods. The mRNA and protein expression levels of estrogen-receptor α （ERα）/phosphoinositide 3kinase （PI3K）/protein-kinase-B （Akt） signaling pathway， apoptosis ［Bcl-2 associated X protein （Bax）， B-cell lymphoma/leukemia-2 （Bcl-2）］ and the indicators of pathological sedimentary proteins ［amyloid β-protein_1-42 （Aβ_1-42）， microtubule-associated protein Tau， phosphorylated site 404 of microtubule-associated protein Tau ［p-Tau （Ser404）］ were detected by using real-time polymerase chain reaction （Real-time PCR） and western blot analysis. ResultsCompared with those in blank group， the rats in model group exhibited marked ultra-structural damage to hippocampal CA3 neurons， along with the reduction of activity time and shuttle frequency in central area， the index and exploration frequency of new object recognition， and the platform crossings and time spent in target quadrant， as well as the prolonged latency （P<0.05， P<0.01）. Furthermore， the contents and expression levels of IL-6， TNF-α， IL-1β， Bax， Aβ_1-42， Tau， and p-Tau （Ser404） were significantly increased， and the activity and expression of SOD， GSH-Px， ERα， PI3K， Akt， and Bcl-2 were significantly decreased （P<0.05， P<0.01）. Compared to those in model group， the rats in estradiol group and groups with different doses of PRP noticeably presented with amelioration of neuronal damage， along with increased activity time and shuttle frequency in the central zone， elevated new object recognition index and exploration frequency， shortened latency， prolonged activity time， and increased platform crossings in the target quadrant （P<0.05， P<0.01）. What is more， the contents and expression levels of IL-6， TNF-α， IL-1β， Bax， Aβ_1-42， Tau， and p-Tau （Ser404） were significantly reduced， whereas the activity and expression levels of SOD， GSH-Px， ERα， PI3K， Akt， and Bcl-2 were markedly elevated （P<0.05， P<0.01）. ConclusionPRP can improve the cognitive and emotional functions of AD model rats， and its mechanisms are probably related to modulating the ERα/PI3K/Akt pathway as well as inhibiting Aβ， Tau， neuro-inflammation， oxidative stress， and apoptosis， resulting in alleviation of neuronal damage.

ObjectiveTo investigate the effects of jujuboside A （JuA） on the learning and memory abilities and histopathological changes in the rat model of vascular cognitive impairment （VCI） and explore the potential mechanisms by which JuA treats VCI. MethodsA total of 50 male SPF-grade SD rats were randomized into a sham operation group （n=10）， a blank control group （n=10）， and a modeling group （n=30）. The rats in the modeling group underwent bilateral carotid artery ligation （2-VO） for the modeling of VCI. After stabilization， the VCI rats were randomized into model， JuA （20 mg·kg^-¹）， and donepezil （0.45 mg·kg^-¹） groups. After 4 weeks of gavage， the novel object recognition and Morris water maze tests were conducted to evaluate the learning and memory abilities of rats. Nissl staining was employed to evaluate the morphology and number of hippocampal neurons. Real-time PCR was employed to measure the mRNA levels of glycogen synthase kinase-3β （GSK-3β）， cAMP response element-binding protein （CREB）， B cell lymphoma-2 （Bcl-2）， phosphatidylinositol 3-kinase （PI3K）， and protein kinase B （Akt） in the hippocampal tissue. Western blot was employed to quantify the protein levels of GSK-3β， p-GSK-3β， p-CREB， Bcl-2， PI3K， p-PI3K， Akt， and p-Akt in the hippocampal tissue. ResultCompared with the sham operation group， the model group exhibited declines in the learning and memory abilities （P<0.01）， neuronal damage and decreased neurons in the hippocampal CA1 region （P<0.01）， up-regulation in the mRNA level of GSK-3β （P<0.01）， and down-regulation in the mRNA levels of PI3K， Akt， CREB， and Bcl-2， as well as the protein levels of p-PI3K， p-Akt， p-GSK-3β， p-CREB， and Bcl-2 （P<0.01）. In comparison to the model group， both the JuA and donepezil groups demonstrated improvements in the learning and memory abilities （P<0.05， P<0.01）， with reduced neuronal damage and increased neurons （P<0.05， P<0.01）. In addition， the two groups showed down-regulation in the mRNA level of GSK-3β （P<0.01） and up-regulation in the mRNA levels of PI3K， Akt， CREB， and Bcl-2 and the protein levels of p-PI3K， p-Akt， p-GSK-3β， p-CREB， and Bcl-2 （P<0.05， P<0.01）. There were no statistically significant differences between the blank control and sham operation groups in terms of the learning and memory abilities， neuron count， and mRNA and protein levels of PI3K/Akt/GSK-3β pathway-related factors. ConclusionJuA can ameliorate the cognitive impairment in the rat model of VCI by activating the PI3K/Akt signaling pathway， reducing the apoptosis of hippocampal neurons， and alleviating the hippocampal neuronal damage.

Objective:To examine the correlation between serum Klotho levels and frailty in elderly people.Methods:In this cross-sectional study, 150 community-dwelling elderly people aged 65 years and over were enrolled.Subjects were divided into a frail(n=50, 33.3%), a pre-frail(n=47, 31.3%)and a non-frail(n=53, 35.3%)group based on the Fried phenotype.General participant data, routine laboratory test results, short physical performance battery(SPPB)results and human body composition data were collected.Serum Klotho protein levels were measured by an enzyme-linked immunosorbent assay.The relationship between serum Klotho protein levels and frailty was analyzed by using Spearmen's correlation analysis and Logistic regression analysis.Results:Klotho protein levels were lower in the frail group than in the non-frail group( P=0.001), whereas differences between the frail group and the pre-frail group and between the pre-frail group and the non-frail group were not statistically significant(all P>0.05).When Klotho protein levels were classified into four quartiles, i.e., Q 1, Q 2, Q 3, and Q 4, using three cut-off vales(2.28, 3.52, and 5.09 mg/L), the prevalences of frailty were 51.4%(19/37), 39.5%(15/38), 24.3%(9/37)and 18.4%(7/38), respectively.The prevalence of frailty decreased with increasing Klotho protein levels( χ2=11.204, P=0.011).Spearman correlation analysis showed that the Klotho protein level was negatively correlated with frailty( r=-0.310, P<0.001).Multivariate Logistic regression analysis results showed that age( OR=1.109, 95% CI: 1.011-1.217, P=0.028)and sarcopenia( OR=6.511, 95% CI: 1.279-33.147, P=0.024)were risk factors for frailty, while walking( OR=0.104, 95% CI: 0.033-0.326, P<0.001), a high SPPB score( OR=0.780, 95% CI: 0.627-0.970, P=0.026), and a high Klotho protein level( OR=0.752, 95% CI: 0.581-0.974, P=0.031)were protective factors against frailty. Conclusions:The serum Klotho protein level may be used as a parameter for the assessment of frailty.It is negatively correlated with frailty, suggesting that elderly people with low serum Klotho protein levels are at high risk of developing frailty.