The study of therapeutic efficacy and mechanisms of Schisandra chinensis and Evodia rutaecarpa combined treatment in a rat model of Alzheimer's disease

Schisandra chinensis and Evodia rutaecarpa are traditional Chinese herbs used to treat neurodegenerative diseases. This study investigates the combined effects of SC and ER on learning and memory in an Alzheimer's disease rat model and their underlying mechanisms.

Methods

High-performance liquid chromatography was employed to analyze the primary active constituents of Schisandra and Evodia. The effects of the combined treatment of Schisandra and Evodia on learning and memory in an Alzheimer's disease rat model were evaluated through Morris water maze and Hematoxylin-Eosin staining experiments. Immunohistochemical analysis was conducted to investigate the impact of S-E on Aβ1-42 and P-tau proteins. Western blotting and real-time quantitative polymerase chain reaction were utilized to quantify the expression of pivotal proteins and genes within the BDNF/TRKB/CREB and GSK-3β/Tau pathways.

Results

The treatment group exhibited significant neuroprotective effects, ameliorating learning and memory impairments in the Alzheimer's disease rat model. The treatment regimen modulated the activity of the BDNF/TRKB/CREB and GSK-3β/Tau pathways by influencing the expression of relevant genes, thereby reducing the generation of Aβ1-42 and P-Tau proteins and inhibiting the deposition of senile plaques. Furthermore, among the three treatment groups, the combined treatment demonstrated notably superior therapeutic effects on Alzheimer's disease compared to the single-drug treatment groups.

Identification of preclinical Alzheimer's disease by a profile of pathogenic proteins in neurally derived blood exosomes: A case-control study

BACKGROUND

Proteins pathogenic in Alzheimer's disease (AD) were extracted from neurally derived blood exosomes and quantified to develop biomarkers for the staging of sporadic AD.

METHODS

Blood exosomes obtained at one time-point from patients with AD (n = 57) or frontotemporal dementia (FTD) (n = 16), and at two time-points from others (n = 24) when cognitively normal and 1 to 10 years later when diagnosed with AD were enriched for neural sources by immunoabsorption. AD-pathogenic exosomal proteins were extracted and quantified by enzyme-linked immunosorbent assays.

RESULTS

Mean exosomal levels of total tau, P-T181-tau, P-S396-tau, and amyloid β 1-42 (Aβ1-42) for AD and levels of P-T181-tau and Aβ1-42 for FTD were significantly higher than for case-controls. Step-wise discriminant modeling incorporated P-T181-tau, P-S396-tau, and Aβ1-42 in AD, but only P-T181-tau in FTD. Classification of 96.4% of AD patients and 87.5% of FTD patients was correct. In 24 AD patients, exosomal levels of P-S396-tau, P-T181-tau, and Aβ1-42 were significantly higher than for controls both 1 to 10 years before and when diagnosed with AD.

CONCLUSIONS

Levels of P-S396-tau, P-T181-tau, and Aβ1-42 in extracts of neurally derived blood exosomes predict the development of AD up to 10 years before clinical onset.