Ditan Decoction ameliorates vascular dementia-induced cognitive dysfunction through anti-ferroptosis via the HIF1α pathway: Integrating network pharmacology and experimental validation

Ethnopharmacological relevance: Vascular dementia (VaD) represents a frequently seen cognitive dysfunction syndrome and has ranks second among dementia subtypes following Alzheimer's disease. At present, Ditan Decoction (DTD), the traditional Chinese herbal prescription, is clinically applied in treating VaD. However, the material basis of its efficacy and therapeutic mechanism still remain unknown.

Aim of the study: This experiment investigated the protection induced by DTD against VaD and the associated mechanism through network pharmacology, mass spectrometry analysis, and in vivo validation.

Materials and methods: We induced VaD in a rat model using bilateral common carotid artery ligation method (2-VO) and administered DTD at doses of 2.14, 4.28 and 8.55 g/kg, with Memantine (0.9 mg/kg) being the positive control. Following oral administration with DTD or Memantine for 4 weeks, behavioral tests were used for assessing cognitive function. H&E and Nissl staining was used for evaluating hippocampal pathology. TEM was used to visualize the ultrastructure of the hippocampal tissue. ELISA was carried out for measuring inflammatory factor levels in rat serum, and biochemical assays were employed to assess oxidative stress levels. Ferroptosis in the hippocampus was examined through analyzing corresponding biomarkers and protein expression. Additionally, HPLC-Q-Exactive-MS technology was employed for identifying DTD components, whereas network pharmacology was conducted for predicting DTD's targets for treating VaD. HIF1α expression levels were assessed by Western blotting and immunofluorescence. We also further validated whether the protective effects of DTD on VaD were mediated through the HIF1α-regulated Ferroptosis signaling pathway by using an HIF1α inhibitor in rats.

Results: DTD demonstrated protective effects against 2VO-induced hippocampal injury through alleviating oxidative stress, lowering systemic inflammation, while preventing Ferroptosis of hippocampal tissue. As revealed by network pharmacology, DTD probably executes its function in VaD by activating HIF1α pathway. According to immunofluorescence and Western blotting, DTD activated HIF1α within hippocampal tissue. Furthermore, DTD's protection against VaD and Ferroptosis was reversed when an HIF1α inhibitor was applied.

Conclusion: These findings suggested that DTD rescued cognitive dysfunction in VaD by inhibiting Ferroptosis via activating HIF1α pathway.

Ditan Decoction; Ferroptosis; HIF1α pathway; Oxidative stress; Vascular dementia.