# The role of salvianolic acid B and benzoylpaeoniflorin in enhancing angiogenesis through Nrf2/HO-1/VEGFA signaling axis in ischemic stroke recovery

## TL;DR

This study shows that combining two plant compounds helps brain recovery after stroke by promoting blood vessel growth through a specific signaling pathway.

## Contribution

The novel finding is that SAB-BP enhances angiogenesis in ischemic stroke via the Nrf2/HO-1/VEGFA signaling axis.

## Key findings

- SAB-BP reduced neurological impairment and promoted functional vessel formation in ischemic stroke models.
- SAB-BP upregulated Nrf2, HO-1, HIF-1α, and VEGFA protein expression.
- The pro-angiogenic effect of SAB-BP was inhibited by an Nrf2 inhibitor, confirming the pathway's role.

## Abstract

Angiogenesis is one of the essential protective mechanisms that promote neural repair and regeneration after ischemic stroke (IS). Salvianolic Acid B (SAB) and Benzoyl paeoniflorin (BP) are compounds extracted from the Chinese medicines Salvia miltiorrhiza Bunge and Paeonia suffruticosa Andrews, respectively.

We investigated whether SAB combined with BP alleviated IS by promoting micrangium angiogenesis and determined the potential molecular mechanisms.

The impact of SAB-BP on angiogenesis after IS was investigated in middle cerebral artery occlusion (MCAO) rat model, ponatinib-induced ischemic stroke in zebrafish, and human umbilical vein endothelial cells (HUVECs). The neuroprotective effect of SAB-BP in rats was assessed using behavior tests and histopathological staining. The cerebral thrombosis assessment and angiogenesis assay were performed in the zebrafish model. Cell proliferation and angiogenesis in oxygen-glucose deprivation and reperfusion (OGD/R) HUVECs were assessed through cell viability, tube formation, migration, and invasion assays. Western blot analysis and immunofluorescence staining were used to determine the protein expression levels of Nrf2, HO-1, and VEGFA.

The findings indicated that SAB-BP significantly reduced neurological impairment following IS and promoted the formation of functional vessels in the cerebral ischemic penumbra. Furthermore, SAB-BP up-regulated the protein expression of Nrf2, HO-1, HIF-1α, and VEGFA. Intriguingly, the pro-angiogenic effect of SAB-BP markedly restrained by adding the inhibitor of Nrf2 (ML385).

Our study demonstrates that SAB-BP enhances angiogenesis following IS by modulating the Nrf2/HO-1/VEGFA signaling axis both in vivo and in vitro. SAB-BP could serve as a promising therapeutic agent for IS recovery.