ABSTRACT
The chemical constituents from 95% ethanol extract of Dendropanax proteus rhizomes and their anti-inflammatory activities were investigated. These compounds in 95% ethanol extract of D. proteus rhizomes were isolated and purified by silica gel column chromatography, medium-pressure liquid chromatography, preparative liquid chromatography, etc. Their structures were elucidated based on the spectral data and physicochemical properties. All the compounds were tested for their ability to inhibit lipopolysaccharide (LPS) induced nitric oxide production in the murine microglia BV2 cell line. Nine compounds were isolated from the ethyl acetate fraction of 95% ethanol extract of D. proteus rhizomes, and identified as (-)-syringaresinol (1), (+)-(7S,8S)-1',4-dihydroxy-3,3',5'-trimethoxy-7',8,9'-trinor-8,4'-oxyneoligna-7,9-diol (2), erythro-guaiacylglycerol-β-O-4'-coniferyl ether (3), threo-guaiacylglycerol-β-O-4'-coniferyl ether (4), coniferyl alcohol (5), 7-O-ethylguaiacylglycerol (6), vanillin (7), syringaldehyde (8), and excoecanol B (9). Compounds 2 and 4 showed neuritis inhibitory activity against microglial inflammation factor, their half inhibitory concentrations (IC50) were 5.85, 7.29 μmol ·L-1, respectively. Compounds 1-6,8-9 are isolated from this plant for the first time, compounds 2 and 4 exhibit the potent inhibitory activity.
ABSTRACT
Aim To study the effect of circulating mi-crovesicles containing miR-27 a on blood brain barrier tight junction injury of ischemia stroke mice and its mechanism. Methods The middle cerebral artery occlusion mouse model was established, and the mi-crovesicles in the supernatant of 2 h of ischemic stroke brain tissues were separated by centrifugal ultrafiltra-tion method. The transmission electron microscopy was used to observe microvesicle morphology, and the di-ameter of microvesicles was detected. Based on the 2 h ischemia stroke mouse model, mice were injected via femoral vein with microvesicles at 5 mg · kg-1 . TTC staining was applied to detect infarction volume of is-chemia brain, while HE staining was applied to detect the expression change of tight junction protein occludin and claudin-5 . Western blot was subjected to detect occludin, claudin-5, TLR4, NF-κB and p38 protein expression. ELISA method was used to measure the contents of cytokines IL-1β and TNF-α. Results The microvesicle shape was approximately circular bi-lateral membrane structure, with an average diameter of 160 nm, which conformed to the morphological char-acteristics of microvesicles. Compared with the ische-mic stroke group, injection of microvesicles could ag-gravate the damage of brain tissues in ischemic mice, further increase the infarct volume and reduce the posi-tive staining areas of occludin and claudin-5 in ische-mia brain tissues. Meanwhile, the protein expressions of occludin and claudin-5 further decreased, and fur-ther up-regulated TLR4 and phosphorylation of NF-κB and p38 compared with the ischemia stroke group. Al-so, more content of IL-1βand TNF-αwere detected in ischemia stroke group injected with microvesicles com-pared with those in ischemia stroke group with signifi-cant difference, while the injection of antagomir-27a could alleviate brain damage and reduce the activation of TLR4, NF-κB and p38 in ischemia stroke mice. Conclusions Microvesicles containing miR-27 a could significantly attenuate brain injury in ischemia stroke mice, while aggravate the tight junction damage of ischemia brain. The mechanism might be correlated with the up-regulation of the expression of TLR4 , the phosphorylation of NF-κB, p38, and the release of cy-tokines IL-1β and TNF-α.