ABSTRACT
Engeletin is a natural derivative of Smilax glabra rhizomilax that exhibits anti-inflammatory activity and suppresses lipid peroxidation. In the present study, we sought to elucidate the mechanistic basis for the neuroprotective and pro-angiogenic activity of engeltin in a human umbilical vein endothelial cells (HUVECs) oxygen-glucose deprivation and reoxygenation (OGD/R) model system and a middle cerebral artery occlusion (MCAO) rat model of cerebral ischemia and reperfusion injury. These analyses revealed that engeletin (10, 20, or 40 mg/kg) was able to reduce the infarct volume, increase cerebral blood flow, improve neurological function, and bolster the expression of vascular endothelial growth factor (VEGF), vasohibin-2 (Vash-2), angiopoietin-1 (Ang-1), phosphorylated human angiopoietin receptor tyrosine kinase 2 (p-Tie2), and platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) in MCAO rats. Similarly, engeletin (100, 200, or 400 nM) markedly enhanced the migration, tube formation, and VEGF expression of HUVECs in an OGD/R model system, while the VEGF receptor (R) inhibitor axitinib reversed the observed changes in HUVEC tube formation activity and Vash-2, VEGF, and CD31 expression. These data suggested that engeletin exhibited significant neuroprotective effects against cerebral ischemia and reperfusion injury in rats, and improved cerebrovascular angiogenesis by modulating the VEGF/vasohibin and Ang-1/Tie-2 pathways.
Subject(s)
Animals , Rats , Reperfusion Injury/prevention & control , Brain Ischemia/prevention & control , Infarction, Middle Cerebral Artery , Endothelial Cells , Flavonols , Angiopoietin-1 , Vascular Endothelial Growth Factors , Vascular Endothelial Growth Factor A , GlycosidesABSTRACT
Objective: To study the chemical constituents from the green walnut husks of Juglans mandshurica. Methods: The chemical constituents from the green walnut husks of J. mandshurica were isolated and purified by repeated silica gel, Sephadex LH-20 column chromatography and ODS column chromatography, and their structures were identified by NMR spectral analysis. Results: A total of 14 compounds were isolated from the green walnut husks of J. mandshurica, and identified as apigenin (1), tricin (2), eupatilin (3), 3,7,8,3’-tetrahydroxy-4’-methoxyflavone (4), 3,5-dihydroxy-7-methoxy-3’,4-methylenedioxyflavone (5), taxifolin (6), quercetin-3-O-(6″-galloyl)-β-D-galactopyranoside (7), quercetin-3-O-(4″-O-acetyl)-α-L-rhamnopyranoside (8), engeletin (9), isoengeletin (10), kaempferol-3-O-β-D-glucopyranoside (11), quercetin-3-O-β-D-glucuronide (12), quercetin-3-O-β-D- glucopyranoside (13), and myricetin-3-O-β-D-glucuronide (14). Conclusion: Compounds 1-10, 12, and 14 are isolated from the green walnut husks of J. mandshurica for the first time.
ABSTRACT
Objective: To establish a method of quantitative analysis of multi-components by single-marker (QAMS) for simultaneously determination of neoastilbin, astilbin, neoisoastilbin, isoastilbin, and engeletin in Smilax glabra, and research the tendency of content changes in different growth years by QAMS. Methods: An HPLC method was established to determine the relative correction factors of four other flavonoids by using astilbin as the internal reference standard. Then the method was used to determine the various content of five flavonoids in different growth years and validate the feasibility and accuracy by comparing the content results determined by the external standard method with QAMS. The dynamic change regularity of flavonoids in S. glabra was investigated. Results: A total of 23 samples from five batches in different growth years were simultaneously determined by external standard method and QAMS, the results deviation were all less than 1.0%. The content of five flavonoids in different growth years was different, astilbin decreased with the increase of growth years, neoastilbin, neoisoastilbin and isoastilbin had the reverse trend. Conclusion: The established QAMS method is feasible and accurate for the simultaneous determination of five flavonoids in S. glabra. Growth years have a certain impact on the content of each component.
ABSTRACT
OBJECTIVE:To optimize the extraction and purification technology of total flavonoids from Engelhardia roxburghi-ana,and to establish the method for the content determination of 3 kinds of effective components. METHODS:Using the extrac-tion transfer rate of astilbin as index,single factor test was used to investigate extraction solvent,extraction method,volume frac-tion of percolation solvent ethanol,percolation material-liquid ration,soaking time before percolation and percolation rate of extrac-tion technology,and volume fraction of eluant ethanol in AB-8 resin purification technology. The contents of 3 effective compo-nents as astilbin,texifolin and engelitin in total flavonoids from E. roxburghiana were determined by HPLC. RESULTS:The opti-mal extraction technology was using 70% ethanol as extraction and percolation solvent,percolation extraction,soaking for 8 h be-fore percolation,percolation material-liquid ratio of 1∶16(g/ml),percolation rate of 30 ml/(min·kg). The purification technology was diluting the solution to 0.5 g (crude drug)/ml with water,ethyl acetate extraction,dissolved extract with 50% ethanol after evaporated to dryness,AB-8 resin for sampling,eluted with 50% ethanol,concentrating and drying. In verification test,extraction transfer rate of astilbin was more than 80%(RSD=0.42%,n=3). The contents of astilbin,taxifolin and engeletin in total flavo-noids from E. roxburghiana by purified were 57.94%,3.72% and 2.83%,respectively;the contents of 3 components accounted for 64.00% of total flavonoids. CONCLUSIONS:The extraction and purification technology is stable,rational and reliable;the content determination method of 3 effective components in total flavonoids of E. roxburghiana is accurate,simple and producible.