Panaxatriol saponins promotes angiogenesis and enhances cerebral perfusion after ischemic stroke in rats.

BACKGROUND: Panaxatriol saponins (PTS), an extract from the traditional Chinese herb Panax notoginseng, which has been used to treat ischemic stroke for many years in China. However, the mechanism underlying the effects of PTS remains unclear. This study aimed to determine whether PTS can protect against ischemic brain injury by promoting angiogenesis and to explore the possible mechanism by which it promotes angiogenesis. METHODS: Middle cerebral artery occlusion (MCAO) was induced in rats, and neurological deficit scores and brain infarct volumes were assessed. Micro-Positron emission tomography (PET) was adopted to assess cerebral perfusion, and real-time PCR and western blotting were used to evaluate vascular growth factor and Sonic hedgehog (Shh) pathway component levels. Immunofluorescence staining was used to determine capillary densities in ischemic penumbrae. RESULTS: We showed that PTS improved neurological function and reduced infarct volumes in MCAO rats. Micro-PET indicated that PTS can significantly increase 18F-fluorodeoxyglucose (18F-PDG) uptake by ischemic brain tissue and enhance cerebral perfusion after MCAO surgery. Moreover, PTS was able to increase capillary densities and enhance angiogenesis in ischemic boundary zones and up-regulate vascular endothelial growth factor (VEGF) and Angiopoietin-1 (Ang-1) expression by activating the Shh signaling pathway. CONCLUSION: These findings indicate that PTS exerts protective effects against cerebral ischemic injury by enhancing angiogenesis and improving microperfusion.

Panaxatriol Saponins Promote M2 Polarization of BV2 Cells to Reduce Inflammation and Apoptosis after Glucose/Oxygen Deprivation by Activating STAT3.

Panaxatriol saponins (PTS) have a long history in the treatment of stroke. In our previous experiments, PTS has been found to alleviate ischemic stroke and play a role through regulating the inflammatory response, but the specific mechanism of its regulation is still unclear. Cell viability was determined by MTT assay. Expressions of polarization-related proteins CD16, CD68, ARG1 and CD206; inflammatory factors interleukin-1ß (IL-1ß); inducible nitric oxide synthase (iNOS); monocyte chemotactic protein 1(MCP-1) and cyclooxygenase-2 (COX-2); apoptosis-related proteins pro-caspase3; bax; caspase3 and bcl-2; and STAT3 and p-STAT3 were detected by western blot. ELISA was used to detect the expression of inflammatory-related factors in cells. The apoptosis rate was detected by flow cytometry. We found that the survival rate of oxygen sugar deprivation/reoxygenation (OGD/R) cells increased obviously after PTS treatment in a dose-dependent manner. PTS can promote M2 polarization of microglial cells (BV2) and inhibit inflammatory response of OGD/R cells, accompanied by decreased expression of inflammatory factors IL-1ß, iNOS, MCP-1, and COX-2. PTS inhibited apoptosis of OGD/R cells and was accompanied by decreased expression of apoptotic proteins Bax and caspase3 and increased expression of Bcl-2. We also found that PTS activated STAT3 levels in BV2 cells. After the addition of STAT3 inhibitor Stattic, it was found that PTS could promote M2 polarization of BV2 cells by activating the STAT3 pathway, thus inhibiting cell inflammation and apoptosis. PTS promoted M2 polarization in microglia cells by activating the STAT3 pathway, thereby reducing cell inflammation and apoptosis after glucose/oxygen deprivation.