Targeting PKM2 signaling cascade with salvianic acid A normalizes tumor blood vessels to facilitate chemotherapeutic drug delivery

Aberrant tumor blood vessels are prone to propel the malignant progression of tumors,and targeting abnormal metabolism of tumor endothelial cells emerges as a promising option to achieve vascular normalization and antagonize tumor progression.Herein,we demonstrated that salvianic acid A(SAA)played a pivotal role in contributing to vascular normalization in the tumor-bearing mice,thereby improving delivery and effectiveness of the chemotherapeutic agent.SAA was capable of inhibiting glycolysis and strengthening endothelial junctions in the human umbilical vein endothelial cells(HUVECs)exposed to hypoxia.Mechanistically,SAA was inclined to directly bind to the glycolytic enzyme PKM2,leading to a dramatic decrease in endothelial glycolysis.More importantly,SAA improved the endothelial integrity via activating theβ-Catenin/Claudin-5 signaling axis in a PKM2-dependent manner.Our findings suggest that SAA may serve as a potent agent for inducing tumor vascular normalization.

The enhanced protective effects of salvianic acid A: A functionalized nanoparticles against ischemic stroke through increasing the permeability of the blood-brain barrier

Ischemic stroke is the leading cause of disability and death worldwide. Currently, the only proven treatment for ischemic stroke is restoring the cerebral blood supply. In addition, some of the tissue is damaged during the subsequent reperfusion because of the overproduction of reactive oxygen species (ROS). Furthermore, antioxidant therapies have shown promise in preclinical studies for the treatment of ischemia-reperfusion injury. However, their therapeutic efficacy has been limited because of their low bioavailability in brain. To resolve this issue, we synthesized ROS-responsive, fan-shaped dendrimer nanoparticles (NPs) and conjugated them with a blood-brain barrier (BBB)-targeting peptide, COG1410, and salvianic acid A (SA), which is an effective antioxidant in ischemic stroke. The BBB targeting peptide acts as a ligand of the nanocarrier system and penetrates the BBB through the endocytosis of the ligand receptor. The results showed that T-SA-NPs not only target and accumulate in the infarct area, they also reduce over 2 times of the infarct area and reverse the behavioral deficits in MCAO mice, which illustrates that these NPs have an effective therapeutic effect on the ischemic stroke. In addition, these NPs had no toxicity in any organs of the body. Importantly, the present study provides an alternative strategy for delivering antioxidants to the brain and achieving targeted therapy of ischemic stroke.

Anti-oxidant effect of picroside II in a rat model of cerebral ischemia/reperfusion injury

Picroside II,the major active component of picroside,has been shown to induce PC12 cell axonal growth and relieve free radical damage.In vivo experiments have demonstrated that picroside II can improve neurological function in rats with cerebral ischemia/reperfusion injuries.In the present in vivo study,enzyme-linked immunosorbent assay and immunohistochemistry revealed that picroside II increased superoxide dismutase content and reduced inducible nitric oxide synthase content in the ischemic hemisphere.The effects of picroside II were similar to those of salvianic acid A sodium,an active control drug.These results indicate that picroside II exerts a neuroprotective effect,possibly by downregulating inducible nitric oxide synthase expression,increasing superoxide dismutase activity,and inhibiting neuronal apoptosis.