OBJECTIVES: To exple the mechanism of Qixiong Zuogui Granules (QXZG) for enhancing synaptic plasticity in aging rats. METHODS: Forty SD rats were randomized into control group, aging model group, donepezil treatment group, and QXZG treatment group (n=10). Except for the control rats, all the rats were subjected to daily intraperitoneal injection of D-galactose for 8 consecutive weeks to induce brain aging, and donepezil hydrochloride and QXZG suspension were administered by gavage during modeling. After the interventions, the rats were evaluated for general conditions, behavioral changes, oxidative stress indicators, hippocampal pathologies, and expressions of the brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) pathway, p16, and synaptic plasticity-associated proteins. RESULTS: The rats in the model group exhibited obvious aging phenotypes such as yellowing of the teeth and hair, body weight loss, and impaired learning and memory abilities, with decreased serum SOD and GSH-Px activities and increased serum MDA level. The rat models also showed obvious pathological changes, reduced Nissl bodies, and elevated p16 protein expression in the hippocampal CA1 region, with significantly decreased expression levels of BDNF, TrkB, CREB and synaptic plasticity proteins SYN, GAP43, and PSD95. Treatment with QXZG alleviated the aging phenotypes in the rat models, improved their learning and memory abilities and pathological changes in the hippocampal CA1 region, reduced oxidative stress and p16 protein expression, and promoted the expressions of the BDNF/TrkB pathway proteins and synaptic plasticity proteins. CONCLUSIONS QXZG enhances synaptic plasticity and reduces oxidative stress in aging rats possibly by upregulating the BDNF/TrkB signaling pathway proteins, thereby delaying brain aging and improving learning and memory abilities of the rats.
Animals ; Brain-Derived Neurotrophic Factor/metabolism* ; Neuronal Plasticity/drug effects* ; Signal Transduction/drug effects* ; Rats, Sprague-Dawley ; Receptor, trkB/metabolism* ; Rats ; Aging ; Drugs, Chinese Herbal/pharmacology* ; Male ; Oxidative Stress ; Hippocampus/metabolism*

Objective To investigate the role and mechanism of ginsenoside Rk3 in alleviating the senescence of retinal pigment epithelial(RPE)cells and in treating neovascular age-related macular degeneration(nAMD).Methods An ARPE-19 cell senescence model induced by hydrogen peroxide and an nAMD mouse model were subjected to validate the pharmacological activity of ginsenoside Rk3 in reducing RPE cell senescence and shrinking choroidal neovascularization(CNV)area.Transcriptome sequencing was performed to analyze the changes in differential gene expression profiles.Western blotting was used to detect the expression levels of mTOR,S6K1,p-S6K1,4EBP1,p-4EBP1,p62,and LC3A/B.Molecular docking and dynamics simulations were conducted to analyze the binding affinity of ginsenoside Rk3 with mTOR protein.Results ① Cell experiments showed that ginsenoside Rk3 significantly alleviated the senescence in ARPE-19 cells(P<0.05).② Animal experiments confirmed that ginsenoside Rk3 significantly reduced the retinal CNV area in nAMD mice(P<0.01),and its efficacy was comparable to the first-line clinical drug aflibercept(P>0.05).③ Transcriptome sequencing suggested that ginsenoside Rk3 led to enrichment of the PI3K-Akt signaling pathway.Western blotting showed that ginsenoside Rk3 inhibited the overactivation of mTORC1 signaling(P<0.05)and simultaneously enhanced cellular autophagy(P<0.05).④ Molecular docking and dynamics simulations further validated that ginsenoside Rk3 probably targets mTOR to alleviate RPE cell senescence.Conclusion Ginsenoside Rk3 alleviates RPE cell senescence and reduces retinal CNV area in nAMD mice by enhancing autophagy through inhibition of mTOR.

Background and purpose:Tumor microenvironment plays an important role in the introduction of foreign factors that mediate tumor acquired resistance. The antitumor effects of many chemotherapeutic agents depend on the level of oxygen pressure (pO2) in tumor microenvironment. This study aimed to evaluate electron paramagnetic reso-nance (EPR)-based monitoring on an oxygen-enriched tumor microenvironment to increase chemotherapeutic sensitivity. Methods:MCF-7 cells were used to establish human breast cancer in nude mice. EPR was used to directly measure pO2 levelin vivo. Tumor tissues were collected, and mitochondrial activity was assayed on the basis of the kinetics of enzyme-catalyzed reactions. A laser Doppler monitor was used to detect regional blood flow. Tumor apoptotic rate was analyzed by flow cytometry.Results:The tumor volume decreased more evidently in the chemotherapy group with oxy-gen-enriched environment than that in the conventional chemotherapy group after the treatment was administered (P<0.01). After chemotherapy was completed, the apoptotic rate of tumor cells was significantly higher in the chemotherapy group with oxygen-enriched environment than that in the conventional chemotherapy group (P<0.001). This study examined the mechanism ofpO2 changes in tumor microenvironment: This was related to the change of the balance between the oxygen consumption and the regional blood flow in the tumor tissues after chemotherapy.Conclusion:Based on the characteristics ofpO2 changes in the tumor microenvironment after chemotherapy was completed, the selection of chemotherapy mode forthe treatment inpO2 peak time window improves the sensitivity of chemotherapy, which provides a new idea for individual-ized chemotherapy in clinical applications.

Objective To analyze transthoracic echocardiographic characteristics of cardiac amloidosis (CA).Methods Fifteen cases of biopsy-proven CA were retrospectively reviewed.Results Interventricular septal thickening(＞1.3 cm)of varing degrees were found in all cases.In 11 cases,the posterior of left ventricular wall were thickened.Myocardial echoes of interventricular septum and free wall of left ventricular were enhanced evidently and distributed unevenly.The echoes presented as ground glass-like images,with some spotty hyper echoes.Both atria were enlarged,and LVEF decreased,with diastolic function impaired,and mild-moderate hydropericardium found in the CA.Conclusions Transthoracic echocardiography is a relatively sensitive and highly specific non-invasive mothod tO diagnose CA.