Reduction of the oxidative damage to H_(2)O_(2)-induced HepG2 cells via the Nrf2 signalling pathway by plant flavonoids Quercetin and Hyperoside

Hyperoside and quercetin are similar in molecular structures.In this study,the antioxidant regulatory targets of hyperoside and quercetin are mainly in the nuclear factor(erythroid-2-derived)-related factor 2(Nrf2)pathway predicted by network pharmacology.And the antioxidant effect and mechanism of hyperoside and quercetin were measured and compared in H_(2)O_(2)-induced Hep G2 cells and Caenorhabditis elegans.The findings indicated that quercetin was more effective than hyperoside in reducing oxidative damage,which was proved by improved cell viability,decreased reactive oxygen species(ROS)production,decreased cellular apoptosis,and alleviated mitochondrial damage.In addition,quercetin was more efficient than hyperoside in enhancing the expression of Nrf2-associated m RNAs,increasing the activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),and catalase(CAT),and reducing the cellular malondialdehyde(MDA)content.Quercetin was superior to hyperoside in prolonging the lifespan of worms,decreasing the accumulation of lipofuscin,inhibiting ROS production,and increasing the proportion of skn-1 in the nucleus.With the Nrf2 inhibitor ML385,we verified that quercetin and hyperoside primarily protected the cells against oxidative damage via the Nrf2 signalling pathway.Furthermore,molecular docking and dynamics simulations demonstrated that the quercetin-Kelch-like ECH-associated protein 1(Keap1)complex was more stable than the hyperoside-Keap1 complex.The stable structure of the complex might hinder the binding of Nrf2 and Keap1 to release Nrf2 and facilitate its entry into the nucleus to play an antioxidant role.Overall,quercetin had a better antioxidant than hyperoside.

Protective effect of hyperoside on cardiac ischemia reperfusion injury through inhibition of ER stress and activation of Nrf2 signaling

Objective:To study the protective effect of hyperoside(Hyp) on cardiac ischemia reperfusion injury and its potential mechanism.Methods:Rats were divided into two groups for the evaluation,the Hyp(50 uM Hyp;n=8) and the control group(n=8).Rat hearts were isolated and perfused with Krebs-Henseleit buffer(KHB) for 30 min.After being inhibited with cardioplegic solution,they were stored for 4 h in B21 solution at 4℃.Afterwards,rat hearts were perfused with KHB again for 45 min.In this period.Hyp was added into solutions of cardioplegia for storage and KHB.Parameters of cardiac functions,including heart rate,the systolic pressure of the left ventricle,the end-diastolic pressure of the left ventricle,the developed pressure of the left ventricle,the left-ventricular systolic pressure and the peak rise rate of the pressure of the left ventricle were recorded.The levels of adenosine triphosphate(ATP),the content of malondialdehyde and apoptotic cells were determined to evaluate the protective effect of Hyp on hearts suffered from ischemia reperfusion injury.Moreover,cultured cardiac myocytes were subjected to the process simulating ischemia/reperfusion.What were analyzed included the endoplasmic reticulum(ER) stress hallmarks expressions,such as binding immunoglobulin protein and C/EBP homologous protein,using the western blot and real-time PCR.Besides,the NF-E2-related factor 2(Nrf2) expression was measured to explore the potential mechanism.Results:Compared with the control group,the Hyp group had better cardiac functional parameters and higher ATP levels;pretreatment of Hyp greatly relieved the apoptosis of myocyte,decreased oxidative stress as well as ER stress and activated the signaling pathway of anti-oxidative Nrf2 to a further extent.Conclusions:Hyp plays an important role in preserving cardiac function by improving ATP levels of tissue,easing oxidative injury of myocardium and reducing apoptosis following IRI dramatically,while the ER stress inhibition and the downstream Nrf2 signaling activation may contribute to the effects of protection.

Hyperoside Suppresses Lipopolysaccharide-induced Inflammation and Apoptosis in Human Umbilical Vein Endothelial Cells

Finding the novel drug from the effective components of traditional Chinese herbal medicine is a hotspot of the modem pharmacological research. Hyperoside （HYP） belongs to flavonoid glycosides, and it has various properties, such as anti-inflammation, anti-spasm, anti-diuretic, antitussive, lowering blood pressure, and lowering cholesterol effects as well as protective effects for the cardiac and cerebral blood vessels. The purpose of this study was to investigate the effects of HYP on inflammatory and apoptotic responses in vascular endothelial cells stimulated by lipopolysaccharide （LPS） and further to identify the possible mechanisms underlying these effects. In our study, human umbilical vein endothelial cells （HUVECs） were stimulated with 1 Bg/mL LPS in the presence or absence of HYP （10, 20 and 50 μmol/L）. Our results indicated that HYP alone exerted no cytotoxicity on HUVECs, while it had an upregulatory effect on the viability of HUVECs induced by LPS in a dose-dependent manner; increased mRNA expression of IL-1β, IL-6, TNFα and iNOS induced by LPS was attenuated after treatment with HYP both in a dose- and time-dependent manner; LPS-induced HUVECs apoptosis and cleaved-caspase 8, 9, 3 were all significantly reduced by HYP. Furthermore, the possible pathway involved in apoptosis and inflammation by HYP was detected, and the results showed that when treated with HYP, LPS-induced mitochondrial membrane instability was significantly inhibited through up-regulation of Bcl-2 and down-regulation of Bax. Furthermore, the expression of TLR4 and the phosphorylation of IκBα and p65 in LPS-treated cells were blocked by HYP. Our results suggested that HYP treatment prevented HUVECs from LPS- induced inflammation and apoptosis responses, which might be mediated by inhibiting TLR4/ NFκB pathway.

Hyperoside protects the blood-brain barrier from neurotoxicity of amyloid beta 1–42

Mounting evidence indicates that amyloid β protein（Aβ） exerts neurotoxicity by disrupting the blood-brain barrier（BBB） in Alzheimer＇s disease. Hyperoside has neuroprotective effects both in vitro and in vivo against Aβ. Our previous study found that hyperoside suppressed Aβ1-42-induced leakage of the BBB, however, the mechanism remains unclear. In this study, bEnd.3 cells were pretreated with 50, 200, or 500 μM hyperoside for 2 hours, and then exposed to Aβ1-42 for 24 hours. Cell viability was determined using 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl-2-H-tetrazolium bromide assay. Flow cytometry and terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling assay were used to analyze cell apoptosis. Western blot assay was carried out to analyze expression levels of Bax, Bcl-2, cytochrome c, caspase-3, caspse-8, caspase-9, caspase-12, occludin, claudin-5, zonula occludens-1, matrix metalloproteinase-2（MMP-2）, and MMP-9. Exposure to Aβ1-42 alone remarkably induced bEnd.3 cell apoptosis; increased ratios of cleaved caspase-9/caspase-9, Bax/Bcl-2, cleav ed caspase-8/caspase-8, and cleaved caspase-12/caspase-12; increased expression of cytochrome c and activity of caspase-3; diminished levels of zonula occludens-1, claudin-5, and occludin; and increased levels of MMP-2 and MMP-9. However, hyperoside pretreatment reversed these changes in a dose-dependent manner. Our findings confirm that hyperoside alleviates fibrillar Aβ1-42-induced BBB disruption, thus offering a feasible therapeutic application in Alzheimer＇s disease.

Ionic Liquid and HP-β-CD Modified Capillary Zone Electrophoresis to Separate Hyperoside, Luteolin and Chlorogenic Acid

Ionic liquid （1-ethyl-3-methylimidazolium tetrafluoroborate, 1E-3MI-TFB） and HP-β- CD as modifier was added to the buffer to separate hyperoside, luteolin and chlorogenic acid. Experiments explored the effect of concentration of 1E-3MI-TFB and HP-β-CD on separation. The results indicated that 1.0 mmol/L HP-β-CD and 1%0 （v/v） 1E-3MI-TFB added to the buffer simultaneously could achieve a good compromise of resolution and analysis time. Capillary experiments and UV spectra indicated that there was interaction between 1E-3MI-TFB and analytes.

By regulating IP3/PKC/TRPV4 pathway hyperoside induces endothelium-dependent vasodilatation in rat basilar artery following four vessel occlusion ischemia reperfusion

OBJECTIVE To investigate regulatory effects of hyperoside(Hyp)on IP3/PKC/TRPV4 pathway in rat cerebral basilar artery(CBA)subjected to global cerebral ischemia-reperfusion(I/R).METHODS The model of global cerebral I/R in rats was established by four-vessel occlusions methods.The treated rats were administrated with Hyp(50 mg·kg^-1)group,Hyp(50 mg·kg^-1)+HC-067047(10 mg·kg^-1),Hyp(50 mg·kg^-1)+2APB(2 mg·kg^-1),Hyp(50 mg·kg^-1)+BisI(2.5 mg·kg^-1),Hyp(50 mg·kg^-1)+2APB(2 mg·kg^-1)+BisI(2.5 mg·kg^-1).Hematoxylin-eosin(HE)and Nissl staining were performed and the contents of methane dicarboxylic aldehyde(MDA),neuron-specific enolase(NSE),S100β and the activity of lactic dehydrogenase(LDH)in serum were measured by enzyme-linked immunosorbnent assay(ELISA).The specific blocker N-nitro-L-arginine-methyl-ester(L-NAME)and indomethacin(Indo)were used to delete the prostacyclin(PGI2)and nitric oxide(NO)dependent relaxation.The protein expression level of TRPV4 was detected by Western blotting.Ca2+intensity in vascular smooth muscle cells was measured by confocal laser scanning microscope and flow cytometry was performed to observe the apoptosis of CBA endothelial cells after in vivo administration.RESULTS Hyp induced a dose-dependent relaxation of CBA in IR rats via a PGI2 and NO independent manner,as evidenced by alleviated patho⁃logical changes and up-regulated expression of TRPV4 protein in the endothelial cells from cerebral vessels.Hyp signifi⁃cantly reduced the contents of MDA,NSE,S100βand the activity of LDH in serum and decreased the fluorescence intensity of Ca2+in cerebral vascular smooth muscle cells by in vivo administration.The apoptotic rate of endothelial cells in Hyp treated group was significantly less than that in IR group.CONCLUSION Hyp does in fact ameliorate I/R injury by regulatingIP3/PKC/TRPV4 pathway.

Study on potential mechanism of hyperoside on improving ischemia/reperfusion injury based on network pharmacology

OBJECTIVE To predict the potential targets of hyperoside(Hyp)on improving ischemia/reperfusion injury by network pharmacology,and explore its possible mechanism combined with related literature.METHODS The action targets of Hyp and ischemia/reperfusion injury were obtained by TCMSP,Swiss Target Prediction,Pharm Mapper,Similarity ensemble approach,Online Mendelian Inheritance in Man,DisGENT and database.The common targets of drugs and diseases were screened by Omishare and STRING database respectively,and the protein-protein interaction(PPI)network map was constructed.Then the interaction network between Hyp and disease targets was constructed by Cytoscape software and topological cross-linking analysis was carried out.Then the interaction network between Hyp and disease targets was constructed and cross-linked analysis was carried out by using Cytoscape software.The gene ontology(GO)of the core target was analyzed by David database,and then the related pathways of the core target were enriched by KEGG database.RESULTS A total of 54 GO enrichment processes were obtained by GO enrichment analysis of 44 common genes,including 38 biological processes(BP),15 cell composition(CC)processes,and 1 molecular functional(MF)process.43 items were obtained by signal pathway enrichment analysis in KEGG database.CONCLUSION It is suggested that the mechanism of Hyp may be related to PI3K-Akt,RAP1,RAS,VEGF and other signal transduction pathways.The above results laid a theoretical foundation for the study of the mechanism and clinical application of the treatment of ischemia/reperfusion injury.

Determination of icariside,hyperoside and psoralen in food by liquid chromatography-tandem mass spectrometry

A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was built to determine icarside,hyperoside and psoralen in food.The samples were extracted with 70%methanol,the solid and semi-solid hotpot seasoning samples were purified by solid phase extraction column,and then determined by HPLC-MS/MS.Acetonitrile and 0.1%formic acid solution were used as the mobile phase,and the gradient elution was adopted for analysis.As shown in the results,the analytes had good linearity in the range of 0.05−100 ng/mL,and the correlation coeffificients(R^(2))were greater than 0.999.In this method,the limits of quantitation(LOQ)of psoralen,icariside and hyperoside in liquid samples were 1.25,25.0 and 12.5μg/L respectively;while the LOQs of psoralen,icariside and hyperoside in solid samples and hotpot seasoning samples were 1.25,25.0 and 12.5μg/kg,respectively.The liquid beverage,solid beverage,health food(in the form of oral liquid,capsule,tablet),integrated alcoholic beverage and solid hotpot seasoning were selected as representative samples and used for method validation.The average spiked recoveries at 3 levels(LOQ,2 LOQ,10 LOQ)were in the range of 83.7%−115.0%,and the relative standard deviations were in range of 0.5%−9.4%(n=6).The method is rapid,accurate and sensitive,which is suitable for the simultaneous determination of icariside,hyperoside and psoralen in different food matrices.

Pharmacokinetic Study on Hyperoside in Beagle’s Dogs

Objective To develop and validate a simple, rapid, sensitive, and reproducible HPLC method for determination of hyperoside in plasma of dogs and for the subsequent pharmacokinetic (PK) study. Methods An accurate and reproducible HPLC-UV method was developed and validated for the determination of hyperoside in plasma of dogs, using kaempferol as internal standard. The plasma samples of dogs following ig administration of hyperoside were analyzed for the detection of quercetin after enzymatic hydrolysis treatment with combined β-glucuronidase and sulphatase. The analytes were separated on a Diamonsil C 18 column (250 mm × 4.6 mm, 5 μm). The mobile phase consisted of methanol-buffer solution (0.1 mol/L NH 4 Ac + 0.3 mmol/L EDTA-Na 2 )-acetic acid (60:40:1) and was delivered at a flow rate of 1 mL/min. The UV detector was set at 370 nm and the column temperature was maintained at 35 ℃. The sample injection volume was 20 μL. Data were collected and analyzed using the ANASTAR software. PK parameters were calculated with DAS software (2.0). Results Linear relationships were validated over the range of 0.01-1 μg/mL for hyperoside (r = 0.9997). The intra- and inter-day precision values for all samples were within 10.0%, and the accuracies of intra- and inter-day assays were within the range of 92.4%-102.4%. The validated method was successfully used to determine the hyperoside concentration in plasma of dogs for up to 12 h, after a single ig administration (25 mg/kg). The mean PK parameters for male and female dogs were as follows: C max (0.18 ± 0.05) and (0.16 ± 0.05) μg/mL, AUC 0-∞ (0.79 ± 0.34) and (0.86 ± 0.27) μg/(mL·h), t 1/2(ka) (0.89 ± 0.41) and (0.88 ± 0.28) h, respectively. Statistical analysis on the PK of hyperoside in male and female groups showed that sex had no significant impact on the PK of hyperoside (P > 0.05). Conclusion The method is able and sufficient to be used in drug PK studies of hyperoside.

Houttuyniacordata extracts and constituents inhibit the infectivity of dengue virus type 2 in vitro

OBJECTIVE Dengue virus belongs to the Flaviviridaefamily,and causes dengue fever and its related complications.Currently,there are no antiviral agents or licensed vaccines against dengue in humans.Houttuyniacordata Thunb.(Saururaceae)is documented to possess antiviral activity against several medically important viruses.METHODS The in vitro activities of the total ethyl acetate(EA)extracts of two batches of H.cordata,five EA fractions,and four of its constituent polyphenols(chlorogenic acid,hyperoside,quercetin,and quercitrin)against the new guinea C strain of dengue-2 virus were investigated.RESULTS Using the plaque reduction test,the total EA extracts of H.cordatainhibited viral infectivity when pre-incubated with virus before the viral adsorption stage,but exhibited no dose-dependent response when added to the cells at 6h post-infection.The 50% inhibitory concentration(IC50)of total EA extracts from two batches of H.cordata added before the viral adsorption stage were 0.24±3.1μg·mL-1 and 0.04±4.6μg·mL-1.However,only one out of five tested EA fractions showed considerably- weaker IC50 of 333μg·mL1.The pure polyphenol compounds displayed some anti-dengue activity,with their combinations yielding greater antiviral effects,especially the combination of chlorogenic acid and hyperoside with a high selectivity index.However,the enhanced efficacy of the polyphenol combinations was still less than that of the total EA extracts which revealed absence of cytotoxicity.Therefore,there may be other compounds in H.cordatathat contribute to the superior efficacy of the EA extracts.CONCLUSION We conclude that H.cordata possesses anti-dengue-2 virus activity,and harbors potential for the development of antiviral agents against dengue.

Determination of 2 Flavonoids in Psidium guajava Linn. from Different Habitats in Guizhou

[ Objective] This study was conducted to determinate the contents of hyperoside and isoquercitrin in the leaves of Psidium guajava Linn. from different areas of Guizhou Province, which would provide data support for production and quality control of P. guajava leaf material. [ Method] The contents of hypereside and isoquercitrin were measured by HPLC under following conditions： Agilent XDB-C18,4.6 mm x 250 ram, 5 ttm, CH3CN-0.1% HCOOH （13： 87） as mobile phase, column temporature at 25 ℃, detection wavelength of 257 mn and flow rate at 1.0 ml/min. [ Result ] The results showed that leaves of P. guajava from dif- ferent producing areas contained variable hypereaide and isoquercitrin contents in the same period, and the differences in quality were obvious between different are- as. [ Conclusion] The method for detecting the contents of hypereside and isoquercitrin in P. guajava leaf materials is simple with reliable accurate results. The P. guajava leaf material produced in Gouting Township, Luedian County has better quality.

Sorbitol induces flower bud formation via the MADS-box transcription factor EjCAL in loquat

Sorbitol is an important signaling molecule in fruit trees. Here, we observed that sorbitol increased during flower bud differentiation(FBD) in loquat(Eriobotrya japonica Lindl.). Transcriptomic analysis suggested that bud formation was associated with the expression of the MADS-box transcription factor(TF) family gene, EjCAL. RNA fluorescence in situ hybridization showed that EjCAL was enriched in flower primordia but hardly detected in the shoot apical meristem. Heterologous expression of EjCAL in Nicotiana benthamiana plants resulted in early FBD. Yeast-one-hybrid analysis identified the ERF12 TF as a binding partner of the EjCAL promoter. Chromatin immunoprecipitation-PCR confirmed that EjERF12 binds to the EjCAL promoter, and β-glucuronidase activity assays indicated that EjERF12 regulates EjCAL expression.Spraying loquat trees with sorbitol promoted flower bud formation and was associated with increased expression of EjERF12 and EjCAL. Furthermore, we identified EjUF3GaT1 as a target gene of EjCAL and its expression was activated by EjCAL. Function characterization via overexpression and RNAi reveals that EjUF3GaT1 is a biosynthetic gene of flavonoid hyperoside. The concentration of the flavonoid hyperoside mirrored that of sorbitol during FBD and exogenous hyperoside treatment also promoted loquat bud formation. We identified a mechanism whereby EjCAL might regulate hyperoside biosynthesis and confirmed the involvement of EjCAL in flower bud formation in planta. Together,these results provide insight into bud formation in loquat and may be used in efforts to increase yield.

Difference analysis of different parts of chicory based on HPLC fingerprint and multi-component content determination

Objective:To establish HPLC fingerprints of different parts of chicory stems,leaves,roots,flowers and seeds,and compare the similarities and differences of chemical components in different parts,so as to provide a scientific basis for the comprehensive utilization of chicory.Methods:To establish the HPLC fingerprint of chicory,the chromatographic column was chosen with Agilent ZORBAX Eclipse XDB-C_(18),the mobile phase was methanol(A)-0.2%formic acid(B),the flow rate was 1 mL/min,the column temperature was 30℃,and the detection wavelength was 254 nm.The Similarity Evaluation System of Chromatographic Fingerprint of Traditional Chinese Medicine(2012 Edition)was used to evaluate the similarity of different parts of decoction pieces,and the determination method of multi-component content was established based on fingerprint identification chromatographic peaks,and the determination results were analyzed.Results:The HPLC fingerprinting method of chicory was established.Sixteen chromatographic peaks were identified and 10 of them were identified as:caftaric acid(1),esculin(2),chlorogenic acid(3),esculetin(4),caffeic acid(5),cichoric acid(8),hyperoside(11),rutin(12),isochlorogenic acid C(14)and luteolin(16).The similarity of different parts was 0.084–0.701.At the same time,the total content of detected chemical components was ranked as flower>leaf>stem>root>seed.Roots did not contain caftaric acid,rutin,and luteolin,flowers did not contain luteolin,and seeds did not contain caftaric acid,cichoric acid,and luteolin.The content of cichoric acid in leaves was the most,and esculin in flowers was the most.Conclusion:The results of HPLC fingerprint and multi-component content determination revealed the similarity and difference of different parts of chicory from chemical composition,indicating that there were certain differences in different parts of chicory.The established HPLC fingerprinting method can provide a reference for quality control and evaluation of different parts of the chicory.

Analgesic target:NMDA NR2B receptors in the rodent midbrain periaqueductal grey

Hyperoside (Hyp) is one of the flavonoids compound isolated from Balbisia calycina (Gris.). It exhibits anti-inflammation and analgesic activities in the mice. The