Effects of total saponins of Panax notoginseng on immature neuroblasts in the adult olfactory bulb following global cerebral ischemia/reperfusion

The main active components extracted from Panax notoginseng are total saponins. They have been shown to inhibit platelet aggregation, increase cerebral blood flow, improve neurological behavior, decrease infarct volume and promote proliferation and differentiation of neural stem cells in the hippocampus and lateral ventricles. However, there is a lack of studies on whether total saponins of Panax notoginsertg have potential benefits on immature neuroblasts in the olfactory bulb following ischemia and reperfusion. This study established a rat model of global cerebral ischemia and reperfusion using four-vessel occlusion. Rats were administered total sa- ponins of Panax notoginseng at 75 mg/kg intraperitoneally 30 minutes after ischemia then once a day, for either 7 or 14 days. Total saponins of Panax notoginseng enhanced the number of dou- blecortin （DCX）＋ neural progenitor ceils and increased co-localization of DCX with neuronal nuclei and phosphorylated cAMP response element-binding/DCX＋ neural progenitor cells in the olfactory bulb at 7 and 14 days post ischemia. These findings indicate that following global brain ischemia/reperfusion, total saponins of Panax notoginseng promote differentiation of DCX＋ cells expressing immature neuroblasts in the olfactory bulb and the underlying mechanism is related to the activation of the signaling pathway of cyclic adenosine monophosphate response element binding protein.

Extract of Naotaifang, a compound Chinese herbal medicine, protects neuron ferroptosis induced by acute cerebral ischemia in rats

Objective:Our previous research showed that Naotaifang(a compound traditional Chinese herbal medicine)extract(NTE)has clinically beneficial effects on neurological improvement of patients with acute cerebral ischemia.In this study,we investigated whether NTE protected acute brain injury in rats and whether its effects on ferroptosis could be linked to the dysfunction of glutathione peroxidase 4(GPX4)and iron metabolism.Methods:We established an acute brain injury model of middle cerebral artery occlusion(MCAO)in rats,in which we could observe the accumulation of iron in neurons,as detected by Perl’s staining.Using assay kits,we measured expression levels of ferroptosis biomarkers,such as iron,glutathione(GSH),reactive oxygen species(ROS)and malonaldehyde(MDA);further the expression levels of transferrin receptor1(TFR1),divalent metal transporter 1(DMT1),solute carrier family 7 member 11(SLC7 A11)and GPX4 were determined using immunohistochemical analysis,real-time quantitative polymerase chain reaction and Western blot assays.Results:We found that treatment with NTE reduced the expression levels of TFR1 and DMT1,reduced ROS,MDA and iron accumulation and reduced neurobehavioral scores,relative to untreated MCAO rats.Treatment with NTE increased the expression levels of SLC7 A11,GPX4 and GSH,and the number of Nissl bodies in the MCAO rats.Conclusion:Taken together,our data suggest that acute cerebral ischemia induces neuronal ferroptosis and the effects of treating MCAO rats with NTE involved inhibition of ferroptosis through the TFR1/DMT1 and SCL7 A11/GPX4 pathways.