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The exacerbation of progressive multiple sclerosis (MS) is closely associated with obstruction of the differentiation of oligodendrocyte progenitor cells (OPCs). To discover novel therapeutic compounds for enhancing remyelination by endogenous OPCs, we screened for myelin basic protein expression using cultured rat OPCs and a library of small-molecule compounds. One of the most effective drugs was pinocembrin, which remarkably promoted OPC differentiation and maturation without affecting cell proliferation and survival. Based on these in vitro effects, we further assessed the therapeutic effects of pinocembrin in animal models of demyelinating diseases. We demonstrated that pinocembrin significantly ameliorated the progression of experimental autoimmune encephalomyelitis (EAE) and enhanced the repair of demyelination in lysolectin-induced lesions. Further studies indicated that pinocembrin increased the phosphorylation level of mammalian target of rapamycin (mTOR). Taken together, our results demonstrated that pinocembrin promotes OPC differentiation and remyelination through the phosphorylated mTOR pathway, and suggest a novel therapeutic prospect for this natural flavonoid product in treating demyelinating diseases.
Subject(s)
Animals , Mice , Rats , Cell Differentiation , Flavanones , Mice, Inbred C57BL , Myelin Sheath/metabolism , Oligodendroglia/metabolism , Remyelination , Signal Transduction , TOR Serine-Threonine Kinases/metabolismABSTRACT
The exacerbation of progressive multiple sclerosis (MS) is closely associated with obstruction of the differentiation of oligodendrocyte progenitor cells (OPCs). To discover novel therapeutic compounds for enhancing remyelination by endogenous OPCs, we screened for myelin basic protein expression using cultured rat OPCs and a library of small-molecule compounds. One of the most effective drugs was pinocembrin, which remarkably promoted OPC differentiation and maturation without affecting cell proliferation and survival. Based on these in vitro effects, we further assessed the therapeutic effects of pinocembrin in animal models of demyelinating diseases. We demonstrated that pinocembrin significantly ameliorated the progression of experimental autoimmune encephalomyelitis (EAE) and enhanced the repair of demyelination in lysolectin-induced lesions. Further studies indicated that pinocembrin increased the phosphorylation level of mammalian target of rapamycin (mTOR). Taken together, our results demonstrated that pinocembrin promotes OPC differentiation and remyelination through the phosphorylated mTOR pathway, and suggest a novel therapeutic prospect for this natural flavonoid product in treating demyelinating diseases.
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La angiogénesis es el proceso por el cual se forman nuevos vasos sanguíneos a partir de otros ya existentes. Para que esto se lleve a cabo de forma correcta debe existir un balance entre los factores proangiogénicos y los factores antiangiogénicos dentro del microambiente tisular. Por otra parte, la existencia de productos químicos naturales como los polifenoles, que son capaces de adquirirse en la dieta, inducen a estos factores a intervenir en el proceso de angiogénesis. Se administraron los polifenoles en filtros de metilcelulosa sobre la membrana alantocoriónica de huevos White Leghorn, manteniendo el posterior desarrollo normal del feto. Se utilizaron 15 fetos de pollo fijados en formalina tamponada, a los cuales se extrajo el corazón. El procesamiento de las muestras de corazón se realizó a través de técnicas histológicas, histoquímicas e inmunohistoquímica. Finalmente se evaluó la presencia del VEGF y la capacidad de formar vasos sanguíneos bajo el tratamiento con los polifenoles. La inmunorreactividad fue cuantificada mediante Image J®. Los resultados indican que Ácido cafeico y Pinocembrina disminuyen la densidad microvascular y la expresión de VEGF en corazones de fetos de pollo tratados con estos polifenoles. Tanto el Ácido Cafeico como la Pinocembrina cumplen un rol inhibitorio en el proceso de angiogénesis fisiológica en corazón de pollo, pudiendo modular las vías de señalización mediadas por los VEGFR o modulando la disponibilidad de VEGF. Estos polifenoles podrían utilizarse para el estudio de otros tejidos asociados a angiogénesis patológica.
Angiogenesis is the process by which new blood vessels are formed from other existing ones. A balance between proangiogenic factors and anti-angiogenic factors within the microenvironment must exist for the process to be carried out correctly. Similarly, the existence of natural chemicals such as polyphenols, which are capable of being acquired in the diet, induce these factors in the angiogenic process. Polyphenols were administered in the methylcellulose filters on the of chorioallantoic membrane of White Leghorn eggs, maintaining the normal posterior development of the fetus. 15 chicken fetuses were fixed in buffered formalin, obtaining the hearts to histological processing, performing histological, histochemical and immunohistochemical techniques. VEGF levels and the ability of the blood vessels growing under the stimulation of the polyphenols were evaluated. Immunoreactivity was quantified by Image J. The results indicate that caffeic acid and pinocembrin decreased microvascular density and VEGF expression in hearts stimulated with these polyphenols. Both the caffeic and pinocembrin acids play an inhibitory role in the physiological angiogenesis process in the chicken heart, which decrease the microvascular density and could act by modulating the signaling pathways mediated by the VEGFR or by modulating the availability of VEGF. The use of these polyphenols could be useful in studies of other tissues associated with pathological angiogenesis.
Subject(s)
Animals , Caffeic Acids/pharmacology , Neovascularization, Physiologic/drug effects , Chick Embryo , Polyphenols/pharmacologyABSTRACT
ObjectiveTo investigate the protective effect of pinocembrin (PIN) in a mouse model of liver injury induced by acetaminophen (APAP). MethodsA total of 50 healthy male C57BL/6J mice were randomly divided into blank group, PIN (50 mg/kg) group, APAP (300 mg/kg) model group, PIN (30 mg/kg)+APAP (300 mg/kg) experimental group, and PIN (50 mg/kg)+APAP (300 mg/kg) experimental group, with 10 mice in each group. The mice in the blank group and the model group were given an equal volume of normal saline by gavage, and those in the PIN group and the PIN+APAP groups were given PIN by gavage once a day, for 7 consecutive days. At 2 hours after the last administration, the mice in the model group and the PIN+APAP groups were given intraperitoneal injection of APAP 300 mg/kg once, and those in the blank group and the PIN group were given intraperitoneal injection of an equal volume of normal saline. Serum samples were collected to measure the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST); liver tissue homogenate was prepared to measure the biochemical parameters of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH); HE staining was used to observe liver histopathology. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the blank group, the APAP (300 mg/kg) model group had significant increases in the activities of ALT and AST (P＜0.01), suggesting that a model was successfully established, while the PIN (30 mg/kg)+APAP (300 mg/kg) group and the PIN (50 mg/kg)+APAP (300 mg/kg) group had significant reductions in the levels of ALT and AST (P＜0.01). Compared with the blank group, the APAP (300 mg/kg) model group had a significant increase in the level of MDA and significant reductions in SOD activity and GSH level in the liver (P＜001); compared with the APAP (300 mg/kg) model group, the PIN (30 mg/kg)+APAP (300 mg/kg) group and the PIN (50 mg/kg)+APAP (300 mg/kg) group had a significant reduction in the level of MDA and significant increases in SOD activity and GSH level in the liver (P＜0.05). Histopathological observation showed that PIN significantly improved liver injury caused by APAP and helped to maintain normal liver histomorphology. ConclusionPIN exerts a marked protective effect on liver injury induced by APAP, possibly by inhibiting oxidative stress in the liver.
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Hemorrhagic transformation (HT) is a frequent complication of ischemic stroke, especially after thrombolytic therapy. This event is associated with increased morbidity and mortality. Tissue plasminogen activator (t-PA), the only FDA proved drug for breaking blood clots, is underutilized in ischemic stroke, because of its limited therapeutic window and hemorrhagic complications. Due to the lack of clear understanding of the pathological mechanism, there are no effective drugs to decrease the incidence of HT. Pinocembrin is a natural flavonoid compound and has neuroprotective effects in animal ischemic stroke models. In this study, we investigated the role of pinocembrin in t-PA thrombolysis-induced HT in rat thromboembolic stroke model. t-PA was administrated 6 h after ischemia and pinocembrin (5, 10 and 20 mg·kg-1) was given 5 min before t-PA administration. Infarct volume, neurological score and hemoglobin content were evaluated at 24 h after ischemia. Evans blue leakage was used to detect blood-brain barrier (BBB) permeability. All procedures were approved by the Institutional Animal Care and Use Committee of the Peking Union Medical College. The results showed that treatment with t-PA at 6 h after ischemia aggravated brain injury and increased the risk of HT, with infarct volume and brain water content reached 39% and 83.4%, respectively. Pretreatment with pinocembrin decreased the infarct volume and brain water content to 28.5% and 80.3%, and improved neurological function. In addition, the combined application of pinocembrin with t-PA reduced hemoglobin content and Evans blue content in brain tissue by 50% and 40%, indicating that pinocembrin could protect the BBB permeability and reduce the occurrence of HT. Among these doses, 10 mg·kg-1 is most effective. In conclusion, our results demonstrate that the combination of pinocembrin with t-PA protects against cerebral ischemia, reduces the occurrence of HT induced by t-PA thrombolysis. Thus, pinocembrin may be a potential therapeutic drug for t-PA induced HT.
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Objective To establish a method for the simultaneous content determination ofquercetin,kaempferol and pinocembrin in Penthorum Chinense Pursh.Methods The HPLC analysis was carried out on Alltima C18 (250 mm × 4.6 mm,5 μm) with a mixture of methanol-0.2％ phosphate (45:55) as the mobile phase.The determination wavelength was set at 270 nm with the flow rate of 1.0 ml/min.The column temperature was set at 30 ℃.Results The quercetin,kaempferol and pinocembrin showed good linearity in the range of 0.316-10.120 μg (r=0.999 9),0.012-0.397 μg (r=0.999 6) and 0.063-2.016 μg (r=0.999 8) respectively.The average recovery rates of quercetin,kaempferol and pinocembrin were 99.34％ (RSD=1.51％),99.76％ (RSD=l.96％) and 98.34％ (RSD=1.56％) respectively.Conclusions The method is accurate and sensitive,which can be used for the content determination of quercetin,kaempferol and pinocembrin in Penthorum Chinense Pursh.
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Pinocembrin (5, 7-dihydroxyflavanone), a flavanone, is a natural flavonoid compound extracted from honey, propolis, ginger roots, wild marjoram, and other plants. In preclinical studies, it has shown to have neuroprotective effects as well as the ability to reduce reactive oxygen species, protect the blood-brain barrier, modulate mitochondrial function, and regulate apoptosis. Considering these a variety of pharmacological activities, pinocembrin has potential as a drug to treat ischemic stroke and neurodegenerative disease. Its pharmacologic characteristics are summarized and mechanistic details relating preclinical studies are discusses.
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Objcetive To investigate protective effect of pinocembrin ( PIN)on hepatocytes induced by hypoxia/reoxygenation ( H/R) as well as its relationship to the TLR 4/NF-κB signaling pathway .Methods The cells were randomly divided into 4 groups: control group, PIN group, hypoxia/reoxygenation injury group and PIN pretreatment group .The cell viability was measured with CCK-8.The apoptosis rate was determined by Annexin V-FITC/PI staining.The activity of ALT was detected .ELISA was used to evaluate the contents of TNF-αand IL-β.The mRNA and protein expression level of TLR 4, IκB-αand NF-κB P65 in cells was observed by quantita-tive real-time PCR or Western blot .Results The H/R stimulation decreased cell survival rate and enhanced the apoptosis .The activity of ALT was increased .The contents of TNF-αand IL-1βwere significantly enhanced , and the expression level of TLR4 and NF-κB P65 was markedly increased while IκB-αdecreased.After pretreatment with PIN, the cell survival rate increased while the apoptosis rate decreased .The activity of ALT was decreased. TNF-αand IL-1βwere reduced significantly and the expression level of TLR 4 and NF-κB P65 were decreased while IκB-αincreased.Conclusions PIN has protective effects on hypoxia/reoxygenation injury, which might be mediated in part by TLR4/NF-κB signaling pathway .
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Objective To study the chemical constituents of Pinus yunnanensis. Methods The whole plant of air-dried P. yunnanensis was extracted with methnol. The methnol extract was suspended in H2O and extracted with petroleum, ethyl acetate, and n-BuOH, successively. The compounds were isolated and purified by column chromatography from the petroleum and ethyl acetate fractions, and identified based on spectral analyses (MS, 1D- and 2D-NMR, IR, UV). Results Fourteen compounds were isolated from P. yunnanensis and characterized as (7R,8R)-7,8-dihydro-3'-hydroxyl-7-(4-hydroxyl-3-methoxyphenyl)-8-hydroxymethyl-1'-benzofuranpropanol- 4-O-(3-O-methyl-α-L-rhamnopyranoside) (1), pinosylvine (2), stigmast-4-en-3-one (3), kaempferol (4), isopimarinol (5), quercetin (6), pinocembrin (7), taxifilin (8), 3-hydroxyl-5-methoxy-stilbene (9), 5-O-β-D-glucopyranosyl-thymoquinol (10), icariside E4 (11), 3,4-dimethoxyphenyl-1-O-β-D-glucopyranoside (12), schizandriside (13), and β-stitosterol (14). Conclusion Compounds 1, 3-7, and 10-13 are obtained from Pinus yunnanensis Lamb. for the first time.
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Objective: To study the chemical constituents of Alpinia coriacea. Methods: The chemical constituents were separated and purified by silica gel, ODS, Sephadex LH-20 column chromatographies, and preparative HPLC. Their structures were determined by physicochemical properties and spectral data analyses. Results: Fifteen compounds were isolated from A. coriacea, and identified as 4-hydroxybenzaldehyde (1), anisic acid (2), pinocembrin (3), apigenin (4), izalpinin (5), kaempferol (6), 5,7,3',4'-tetrahydroxy-flavanone (7), 3,5-dihydroxy-7,4'-dimethoxyflavone (8), α-tocospiro A (9), stigmast-4-ene-6α-ol-3-one (10), stigmast-4-en-3-one (11), 7-keto-β-sitosterol (12), (22E,24R)-5α, 8α-epidioxyergosta-6,22-dien-3β-ol (13), stigmasterol (14), and β-sitosterol (15). Conclusion: All compounds are isolated from A. coriacea for the first time, among which compounds 2,7, and 9-13 are isolated from the plants of Alpinia L. for the first time.
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Objective: To investigate the chemical constituents of the Ziziphora clinopodioides. Methods: The compounds were isolated and purified by means of various chromatographic techniques and their structures were identified on the basis of NMR spectral data. Results: Twenty-one known compounds were isolated from the ethanol extract of the dry stems of P. amarus and their structures were identified as protocatechuic acid (1), picein (2), rosmarinic acid (3), cafferic acid (4), luteolin (5), 4', 5, 7-trihydroxy isoflavone (6), irisdichotototin D (7), pinocembrin-7-O-rutinoside (8), acacetin-7-O-rutinoside (9), 4-hydroxy-3-methoxy-acetophenone-4-O-β-D-apiofuranosy-(1→6)-β-D-glucopyranoside (10), baicalein (11), kaempferide (12), chrysin-7-O-rutinoside (13), quercetin (14), apigenin (15), ploybotrin (16), 1-O-p-coumaroylglycerol (17), 5-(hydroxymethyl)-2-furancarboxaldehyde (18), acacetin (19), 6, 8-di-C-β-D-glucosylchrysin (20), and dibutyl phthalate (21). Conclusion: Compounds 5-8, 10-12, 16-18, and 20-21 are first obtained from this plant for the first time.
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Objective: To establish the preparation technology of propolis extract. Methods: With the contents of total flavonoids, chrysin, pinocembrin, and galangin and extract yield as evaluation indexes, the extraction methods, extraction solvent, extraction times, extraction time, and amount of solvent extraction were optimized with single factor test and orthogonal design to investigate the effect on the preparation technology of propolis extract. Results: The optimal extraction technology was that propolis was refrigerated, grinded, soaked with 95% five times the amount of ethanol, shaked, then extracted for 4 h, filtrated, concentrated, and dried after ethanol recovery. Conclusion: The optimial extracting technology of propolis is stable and feasible, and suitable for further application.
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OBJECTIVE: To summarize the sources, types, chemical composition of propolis and the correlation between propolis and source plants, thus to provide a reference for the research, development and utilization of the chemical composition and pharmacological activity of propolis and its source plants. METHODS: The sources and chemical composition of propolis were reviewed and classified based on the literature. RESULTS: The extremely complex chemical composition of propolis depends on the local flora at different geographic locations. Propolis can be classified according to characteristic chemical compounds of the source plants. Propolis is a good research material for plant chemists to study the chemical composition and pharmacological activity of propolis source plants. CONCLUSION: Studies of the chemical composition and pharmacological activity of propolis and its source plants will greatly promote the development and utilization of propolis and source plants.
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OBJECTIVE: To develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determination of pinocembrin in human urine, and to investigate its urinary excretory after intravenous drip administration of pinocembrin in healthy volunteers.
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The MeOH extract of Piper ecuadorense Sodiro, Piperaceae, was chosen for metabolite isolation and elucidation due to the strong antifungal activity exhibited, measured by means of the broth microdilution method. Two known flavonoids: pinostrobin (1) and pinocembrin (2) were isolated from 4.16 g. of dichloromethane extract by column chromatography, using a gradient of hexane/EtOAc. A total of 20 mg of 1 were obtained from the fraction eluted with hexane-EtOAc 95:5 v/v, and 100 mg of 2 were obtained from the fraction eluted with hexane-EtOAc 85:15 v/v. The MIC values of the MeOH extract was 31.25 µg/mL for Trichophyton mentagrophytes ATCC® 28185 and 62.5 µg/mL for Trichophyton rubrum ATCC® 28188. The MIC value of pinocembrin was 125 µg/mL for Trichophyton mentagrophytes ATCC® 28185 and Trichophyton rubrum ATCC® 28188. Pinostrobin in antifungal test was not active against fungi tested.
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Objective: To study the chemical constituents in the roots of Goniothalamus cheliensis. Methods: Silica gel, ODS, and Sephadex LH-20 column chromatographic techniques were used to isolate and purify the chemical constituents and their structures were elucidated by spectral analyses. Results: Seven compounds were isolated and identified as acetylgoniofupyrone A (1), protocatechuic acid (2), pinocembrin (3), pinoresinol (4), goniodiol (5), 8-epi-goniotriol (6), and cardiobutanolide (7). Conclusion: Compound 1 is a new goniofupyrone-type of styryllactone, named acetylgoniofupyrone A.
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ObjectiveTo investigate the protective effect of pinocembrin (PIN) in a mouse model of liver injury induced by acetaminophen (APAP). MethodsA total of 50 healthy male C57BL/6J mice were randomly divided into blank group, PIN (50 mg/kg) group, APAP (300 mg/kg) model group, PIN (30 mg/kg)+APAP (300 mg/kg) experimental group, and PIN (50 mg/kg)+APAP (300 mg/kg) experimental group, with 10 mice in each group. The mice in the blank group and the model group were given an equal volume of normal saline by gavage, and those in the PIN group and the PIN+APAP groups were given PIN by gavage once a day, for 7 consecutive days. At 2 hours after the last administration, the mice in the model group and the PIN+APAP groups were given intraperitoneal injection of APAP 300 mg/kg once, and those in the blank group and the PIN group were given intraperitoneal injection of an equal volume of normal saline. Serum samples were collected to measure the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST); liver tissue homogenate was prepared to measure the biochemical parameters of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH); HE staining was used to observe liver histopathology. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the blank group, the APAP (300 mg/kg) model group had significant increases in the activities of ALT and AST (P＜0.01), suggesting that a model was successfully established, while the PIN (30 mg/kg)+APAP (300 mg/kg) group and the PIN (50 mg/kg)+APAP (300 mg/kg) group had significant reductions in the levels of ALT and AST (P＜0.01). Compared with the blank group, the APAP (300 mg/kg) model group had a significant increase in the level of MDA and significant reductions in SOD activity and GSH level in the liver (P＜001); compared with the APAP (300 mg/kg) model group, the PIN (30 mg/kg)+APAP (300 mg/kg) group and the PIN (50 mg/kg)+APAP (300 mg/kg) group had a significant reduction in the level of MDA and significant increases in SOD activity and GSH level in the liver (P＜0.05). Histopathological observation showed that PIN significantly improved liver injury caused by APAP and helped to maintain normal liver histomorphology. ConclusionPIN exerts a marked protective effect on liver injury induced by APAP, possibly by inhibiting oxidative stress in the liver.