Bioinformatics-Guided Scutellaria Flavonoids Ameliorate Memory Impairment Induced by Ovariectomy and D-Galactose in Rats
Chen Chao, Guan Lihua, Chen Yan, Zhai Yujian, Zhao Chunying, Shang YazhenIntroduction:
This study aimed to explore the protective effects of flavonoids extracted from the stems and leaves of Scutellaria baicalensis (SSFs) against memory deficits in rats induced by combined ovariectomy and D-galactose treatment, as well as the underlying regulatory mechanisms linked to apoptosis-related molecules, estrogen receptors, and Paired Helical Filaments (PHFs).
Methods:
Comprehensive bioinformatic analysis was performed to screen Alzheimer’s Disease (AD)- related Differentially Expressed Genes (DEGs) and conduct functional pathway enrichment analysis. An estrogen-deficient menopausal-like rat model-associated memory impairment was established via ovariectomy combined with D-galactose administration, and the Morris Water Maze (MWM) assay was used to verify model establishment. Rats with successful model induction were randomly divided into a model group and three SSF treatment groups with distinct doses. The learning and memory capacities of rats were assessed using the MWM. Immunohistochemistry was used to detect the protein expression of 5- Bromo-2'-deoxyuridine (BrdU). Quantitative real-time Polymerase Chain Reaction (qPCR) was used to quantify the mRNA level of BCLAF1. Western Blotting (WB) was applied to measure the protein levels of Estrogen Receptor α (ERα), Estrogen Receptor β (ERβ), the anti-apoptotic protein Bcl-2, BCLAF1, non-phosphorylated tau, and PHFs in the cerebral cortex and hippocampus.
Results:
Bioinformatic analysis identified 13 AD‑related DEGs along with their enriched functional pathways. Combined ovariectomy and D‑galactose treatment induced severe memory impairment in rats (P < 0.01), accompanied by a prominent decrease in BrdU‑positive cells in the hippocampal dentate gyrus (P < 0.01). In the cerebral cortex and hippocampus of model rats, the mRNA and protein expression of BCLAF1, as well as protein levels of ERα and PHFs, were significantly upregulated (P < 0.05, P < 0.01). By contrast, the expression of ERβ, Bcl‑2 and non- phosphorylated tau was markedly downregulated (P < 0.05, P < 0.01). SSFs dose- dependently ameliorated the above behavioral and molecular abnormalities triggered by ovariectomy plus D- galactose.
Discussion:
Our bioinformatic analysis identified 13 Alzheimer's disease-related differentially expressed genes, mainly enriched in ion-channel- and GABA-receptor-associated pathways, providing potential molecular clues for postmenopausal cognitive impairment. The ovariectomy-combined-Dgalactose rat model partially recapitulates postmenopausal AD‑like neuropathological changes and serves as a practical in vivo tool for evaluating natural phytoestrogen‑like candidates. SSFs exerted multi‑target neuroprotection by modulating neuronal proliferation, estrogen receptor balance, neuronal apoptosis and tau‑related pathology. Nevertheless, this animal model cannot fully recapitulate complete Alzheimer’s‑disease hallmarks such as mature senile plaques. Moreover, the direct molecular targets of SSFs remain uncharacterized, warranting further mechanistic exploration. Collectively, our findings support that SSFs is a promising natural agent against postmenopausal memory decline.
Conclusion:
SSFs effectively ameliorate memory impairment in rats induced by ovariectomy combined with D-galactose. The therapeutic mechanism may involve the regulation of SSFs on BrdU, ERα/ERβ, Bcl-2/BCLAF1, and non-phosphorylated tau levels, and PHFs formation. These results suggested that SSFs ameliorate memory impairment through neuronal proliferation, estrogen signaling, neuronal apoptosis, and tau pathology, supporting its use for postmenopausal cognitive decline.