ß-Caryophyllene Liposomes Attenuate Neurovascular Unit Damage After Subarachnoid Hemorrhage in Rats.

This study was conducted to prepare ß-caryophyllene loaded liposomes (BCP-LP) and investigated their effects on neurovascular unit (NVU) damage after subarachnoid hemorrhage (SAH) in rats. A blood injection into the pre-chiasmatic cistern was used to achieve SAH. BCP-LP were prepared, characterized and administrated to rats with SAH. The prepared BCP-LP were spherical with a size distribution of approximately 189.3 nm and Zeta potential of - 13.9 mV. Neurological scoring, the balance beam test, cerebral blood flow monitoring, brain edema and biochemical analyses were applied to evaluate the effects of BCP-LP on rat NVU damage after SAH. The results demonstrated that BCP-LP treatment improved neurological function disorder, balance ability and cerebral blood perfusion in rats. Brain edema detection and blood-brain barrier permeability detection revealed that BCP-LP could reduce brain edema and promote repairment of blood-brain barrier after SAH. Using the western blot experiments, we demonstrated that BCP-LP attenuated the loss of tight junction proteins Occludin and Zonula occludens-1, inhibit the high expression of VEGFR-2 and GFAP, and promote the repair of laminin. These results demonstrate the protective effect BCP-LP exert in the NVU after SAH in rats, and supports the use of BCP-LP for future study and therapy of SAH.

Dendrobium Alkaloids Promote Neural Function After Cerebral Ischemia-Reperfusion Injury Through Inhibiting Pyroptosis Induced Neuronal Death in both In Vivo and In Vitro Models.

Pyroptosis is a newly identified lytic form of programmed cell death which is characterized by plasma membrane blebbing and rupture. Pyroptosis occurs in cerebral ischemia injury, and contributes to the activation and secretion of the inflammatory cytokines interleukin (IL)-1ß, IL-18, and IL-6. Previous reports have found that Dendrobium alkaloids (DNLA) can exert neuroprotective effects against oxygen-glucose deprivation/reperfusion (OGD/R) damage in vitro, but the mechanisms underlying these effects remain elusive. In this study, we investigated whether DNLA exerted therapeutic benefits against cerebral ischemia-reperfusion (CIR) damage via ameliorating pyroptosis and inflammation. OGD/R damage was induced in HT22 cells pretreated with DNLA (0.03, 0.3, or 3 mg/ml, 24 h prior to OGD/R), MCC950 (10 ng/ml, 1 h prior), and VX765 (10 ng/ml, 1 h prior). Neuronal apoptosis, necrosis, pyroptosis, and pathological changes were analyzed 24 h following OGD/R. Further to this, male C57/BL mice pretreated with different concentrations of DNLA (0.5 or 5 mg/kg, ip.) for 24 h and VX765 (50 mg/kg, ip., 1 h before CIR) underwent transient middle cerebral artery occlusion and reperfusion. We found that DNLA pretreatment resulted in a lower neurologic deficit score, a reduced infarct volume, fewer pyroptotic cells, and reduced levels of inflammatory factors 24 h after CIR. Furthermore, DNLA administration also reduced the levels of the pyroptosis-associated proteins Caspase-1 and gasdermin-D, particularly in the hippocampal CA1 region. Similar decreases were observed in the levels of the inflammatory factors IL-1ß, IL-6, and IL-18. OGD/R-associated ultrastructural damage was seen to improve following DNLA administration, likely due to the regulation of the tight junction protein Pannexin-1 by DNLA. Overall, these findings demonstrate that DNLA can protect against CIR damage through inhibiting pyroptosis-induced neuronal death, providing new therapeutic insights for CIR injury.

[ß-caryophyllene alleviates cerebral ischemia/ reperfusion injury in mice by activating autophagy].

Cerebral ischemia-reperfusion(I/R) injury is an important cause of acute ischemic stroke. Timely elimination of damaged proteins and organelles by regulating autophagy during cerebral ischemia-reperfusion plays an important role in relieving brain damage. In order to investigate whether ß-caryophyllene(BCP) could protect neurons from cerebral I/R injury by regulating auto-phagy, C57 BL/6 J male mice were randomly divided into sham operation group, model group, and drug-administered group. After intra-gastric administration was given for 5 days, the middle cerebral artery occlusion(MCAO) model was established by suture method. Twenty four hours after surgery, the infarct volume and neurological function were assessed; the pathological changes of cortical tissue were observed by HE staining; Western blot was used to detect the expression of autophagy-related proteins beclin1, p62, LC3 B and apoptosis-related protein Bcl-2; immunofluorescence was used to observe the expression of LC3 B in the ischemic cortex. The autophagy of cortical tissue in the ischemic area was observed by transmission electron microscopy. The experimental results showed that as compared with the model group, the BCP pretreatment significantly reduced the neurological deficit, decreased the percentage of cerebral infarction volume, reduced the death of brain tissue cells in the ischemic area, up-regulated the expression of beclin1, LC3 B and Bcl-2 protein, down-regulated p62 protein expression, and significantly increased the number of autophagosomes in the cortical tissue of the ischemic area. It was finally determined that BCP could protect neurons from cerebral ischemia-reperfusion injury by activating autophagy.