IcarisideⅡ alleviates oxygen-glucose deprivation and reoxygenation-induced PC12 celloxidative injury by activating Nrf2 / SIRT3signaling pathway

OBJECTIVE To investigate icariside(ICS)Ⅱ protects against PC12 cel damage induced by oxygen-glucose deprivation and reoxygenation and explore its mechanism.METHODS The oxidative stress injury model was induced by oxygen-glucose deprivation/reoxygenation(OGD/R) 2 h/24 h in PC12 cells.N-acetyl-lcysteine(NAC),a classical anti-oxidant,was used as positive control.Pharmacodynamic experimental study groups as follows:control,control+ICS Ⅱ50 μmol·L^(-1),OGD/R,OGD/R+ICSⅡ 12.5 μmol·L^(-1),OGD/R + ICS Ⅱ 25 μmol·L^(-1),OGD/R + ICS Ⅱ50 μmol·L^(-1),and OGD/R+NAC 100 μmol·L^(-1) groups.Cell viability and lactate dehydrogenase(LDH) leakage rate were measured by MTT assay and LDH ELISA kit,respectively.Moreover,reactive oxygen species(ROS) ELISA kit was used for detection of intracellular ROS generation,Mito-SOX fluorescence staining was used for detecting production of ROS in mitochondria and mitochondrial membrane potential(MMP)was detected by rhodamine 123 dye.In addition,PC12 cells apoptosis was detected by one-step TUNEL assay.Furthermore,the expressions of nuclear factor erythroid 2-related factors(Nrf2),Keap1,HO^(-1),NQO^(-1),silent information regulator 3(SIRT3),IDH2,Bax,Bcl-2 and caspase 3 were detected by Western blotting analysis.RESULTS The results of MTT and LDH assay showed that OGD/R reduced the cell viability and improved LDH release compared with the control or ICSⅡ 50 μmol·L^(-1) alone(P<0.01).Meanwhile,OGD/R not only increased intracellular and mitochondrial ROS generation,but also elevated the fluorescence intensity of TUNEL staining,at the same time,the MMP was declined when challenged by OGD/R.Furthermore,the Western blotting results showed that OGD/R induced the increase in the expression of cytoplasm-Nrf2,Keap1,Bax and cleaved-caspase 3 level,while the decrease in the expression of nucleus-Nrf2,HO^(-1),NQO^(-1),SIRT3,IDH2 and Bcl-2(P<0.05).However,ICS Ⅱ significantly increased the viability of PC12 cells and reduced LDH leakage(P<0.01).Notably,ICS Ⅱ also suppressed ROS generation both in the intracellular and mitochondria,as well as restored MMP.It was also worthy to note that ICS Ⅱ decreased the expressions of cytoplasmNrf2,Keap1,Bax and the level of cleaved-caspase3,whereas,it increased the expressions of nucleus-Nrf2,HO^(-1),NQO^(-1),SIRT3,IDH2 and Bcl-2(P<0.05).CONCLUSION ICSⅡ reduced OGD/Rinduced oxidative damage in PC12 cells under the laboratory conditions,and its underlying mechanism may be related to the regulation of Nrf2/SIRT3 signaling pathway.

Protective effect of icarisideⅡ on oxygen-glucose deprivation and reoxygenation-induced injury incerebral cortical neurons

OBJECTIVE To explore the effect of icariside Ⅱ(ICS Ⅱ) on oxygen-glucose deprivation and reoxygenation(OGD/R)-induced injury in cerebral cortical neuronal cels.METHODS Primary cerebral cortical neuronal cells were deprived of oxygen and glucose for 2 h to simulate ischemic stroke injury in vitro.The experiment was divided into 8 groups,which were control,control+ICSⅡ 25 μmol·L^(-1),OGD/R,OGD/R+ICSⅡ(6.25,12.5,25 μmol·L^(-1)),OGD/R+3-methyladenine(3-MA) and OGD/R+Rapamycin(Rap).The protective effect of ICS Ⅱ were detected by MTT assay and lactate dehydrogenase(LDH),respectively.Autophagic flux and autophagy related proteins expressions were detected by using adenovirus harboring tf-LC3 and Western blotting,respectively.RESULTS Compared with OGD/R group,the cell viability treated with ICSⅡwas elevated in a concentration-dependent manner,and the leakage rate of LDH was lowed.Moreover,ICSⅡ not only suppressed OGD/R-induced autophagic flux,but also inhibited the increase of LC3-Ⅱ/LC3-Ⅰ ratio and Beclin 1 after OGD/R insulted.CONCLUSION ICS Ⅱ exerts protective effects on OGD/R-induced cerebral cortical neuronal cells through inhibiting excessive autophagy.

Icariside Ⅱ, a PDE5 inhibitor, attenuates cerebral ischemia/reperfusion injury through activating BDNF/TrkB/CREB signaling pathway

OBJECTIVE To explore the effects and mechanism of icariside Ⅱ(ICS Ⅱ),a pharmacologically active compound derived from herbal Epimedii with previous study-proved phosphodiesterase 5(PDE5) inhibitors,was investigated in vivo using a middle cerebral artery occlusion/reperfusion(MCAO/R) model in rats and in vitro using an oxygen-glucose deprivation/reperfusion(OGD/R) model in primary hippocampal neurons.METHODS Laser Doppler flowmeter was introduced to examine the cerebral blood flow of MCAO/R rats.The neurological deficits scores,brain water content and infarction volume were assessed after MCAO/R.OGD/R-induced primary hippocampal neuronal injury and apoptosis were examined by MTT,lactate dehydrogenase(LDH) release,TUNEL staining and flow cytometry,respectively.Expressions of PDE5 A and memory-related signaling pathways were measured using Western blotting analysis.The direct interaction between ICS Ⅱand PDE5 was further evaluated by molecular docking.RESULTS ICS Ⅱ significantly decreased the infraction volume in MCAO/R rats.Furthermore,ICS Ⅱ significantly abrogated OGD/R-induced hippocampal neuronal death.Moreover,ICSⅡ not only effectively restored the 3′ 5′-cyclic guanosine monophosphate(cGMP) level and protein kinase G(PKG) activity both in vivo and in vitro,but also increased brain-derived neurotrophic factor(BDNF),tyrosine protein kinase B(TrkB) and cAMP response element-binding protein(CREB) expressions,thereby inhibited hippocampal neuronal apoptosis.Mechanistically,the beneficial effects of ICS Ⅱ was attributed to its activation of the PKG/TrkB/BDNF via increasing BDNF expression,evidenced by that the inhibition effects of ICSⅡ was abrogated by Rp-8-BrcGMPS,a PKG inhibitor,or ANA-12,a TrkB inhibitor.ICSⅡ also decreased both protein level and activity of PDE5.Notably,ICSⅡ might effectively bind and inhibite PDE5 as demonstrated by relatively high binding score.CONCLUSION ICSⅡ significantly protect against cerebral ischemia/reperfusion injury in rats and rescues OGD/Rinduced hippocampal neuronal injury,and the underling mechanisms are,at least partly,due to inhibition of PDE5 and activation of BDNF/TrkB/CREB signaling pathway.Hence ICS Ⅱ may be an effective agent for combating cerebral ischemia/reperfusion injury.

IcarisideⅡ inhibits lipopolysaccharide-induced inflammation and amyloid production in astrocytes by regulating IKK/IκB/NF-κB signaling pathway

OBJECTIVE To investigate the effect of icariin Ⅱ(ICS Ⅱ) on lipopolysaccharide(LPS)-induced inflammation and amyloid production in astrocytes.METHODS The cerebral cortex of newborn SD rats was isolated in vitro,and the primary astrocytes were extracted and cultured.Astrocytes were pre-treated with ICSⅡ(5,10 and20 μmol·L^(-1)) or dexamethasone(1 μmol·L^(-1)) for1 h.Cell inflammation models were established with LPS and treated with ICS Ⅱ or dexamethasone for another 24 h.The anti-neuroinflammation and anti-amyloid effects of ICS Ⅱ in astrocytes were detected by ELISA and Western blotting respectively.RESULTS ICS Ⅱ decreased the levels of beta secretase 1(BACE1),Aβ1-40 and Aβ1-42 in astrocytes in a concentration-dependent manner.Moreover,the levels of tumor necrosis factor-alpha,interleukin-1β,reactive oxygen species,inducible nitric oxide synthase,cyclooxygenase-2 and transforming growth factor-β1 in astrocytes were significantly inhibited by ICS II(5,10 and 20 μmol·L^(-1)).In addition,ICSⅡhas a significant inhibitory effect on LPS-induced IκB-α degradation and NF-κB activation.CONCLUSION ICS Ⅱ exerts neuroprotective effects on LPS-induced inflammation in astrocytes,through regulating IKK/IκB/NF-κB signaling pathway.

Metabolites of Icariin in the Gastrointestine of Rats Following Oral Administration

Further investigation of the metabolites of orally administered icariin in rats was made. Two minor metabolites, icariside I and icariside II, were identified in gastric content, and two metabolites, icariside II and icaritin, in intestinal content. The major metabolic route of icariin was proposed.

Metabolites of Icariin in Urine Following Oral Administration

Urinary metabolites of icariin, present in Epimedium, were investigated using rats. In the urine of rats administered icariin orally, two major metabolites were detected, which were identified as icariside II and icaritin by means of spectral data.

Effect of icarisid II on diabetic rats with erectile dysfunction and its potential mechanism via assessment of AGEs, autophagy, roTOR and the NO-cGMP pathway

Erectile dysfunction （ED） is a major complication of diabetes mellitus. Icariin has been shown to enhance erectile function through its bioactive form, icarisid Ih This study investigates the effects of icarisid Ⅱ on diabetic rats with ED and its potential mechanism viathe assessment of advanced glycosylation end products （AGEs）, autophagy, mTOR and the NO-cGMP pathway. Icarisid Ⅱ was extracted from icariin by an enzymatic method. In the control and diabetic ED groups, rats were administered normal saline; in the icarisid Ⅱ group, rats were administered icarisid Ⅱ intragastrically. Erectile function was evaluated by measuring intracavernosal pressure/mean arterial pressure （ICP/MAP）. AGE concentrations, nitric oxide synthase （NOS） activity and cGMP concentration were assessed by enzyme immunoassay. Cell proliferation was analysed using methyl thiazolyl tetrazolium assay and flow cytometry. Autophagosomes were observed by transmission electron microscopy, monodansylcadaverine staining and GFP-LC3 Iocalisation. The expression of NOS isoforms and key proteins in autophagy were examined by western blot. Our results have shown that Icarisid Ⅱ increased ICP/MAP values, the smooth muscle cell （SMC） growth curve, S phase and SMC/collagen fibril （SMC/CF） proportions and decreased Beclin 1 （P〈0.05）. Icarisid Ⅱ significantly increased the proliferative index and p-p70S6K（Thr389） levels and decreased the numbers of autophagosomes and the levels of LC3-11 （P〈0.01）. Icarisid Ⅱ decreased AGE concentrations and increased cGMP concentration, NOS activity （P〈0.05） and cNOS levels （P〈0.01） in the diabetic ED group. Therefore, Icarisid Ⅱ constitutes a promising compound for diabetic ED and might be involved in the upregulation of SMC proliferation and the NO-cGMP pathway and the downregulation of AGEs, autophagy and the mTOR pathway.

Metabolites of Icariin in Rat Bile Following Oral Administration

The biliary metabolites of orally administered icariin in rats were investigated. Two metabolites B-l and B-2 were isolated and identified as icaritin 3-O-alpha-L-rhamnopyranosyl-7-O-beta-D-glucopyranuronoside and icariside II, respectively, on the basis of chemical and spectroscopic evidences.

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.

刺桑皮正丁醇部位化学成分研究

为研究刺桑(Taxotrophis ilicifolia)皮正丁醇部位的化学成分,该研究采用硅胶、ODS、Sephadex LH-20、反相半制备高效液相等色谱法对刺桑皮正丁醇萃取部位进行分离纯化,并综合理化性质及波谱数据鉴定其化合物的结构。结果表明:从刺桑皮正丁醇萃取物中分离得到16个化合物,分别鉴定为icariside E5(1)、裂环异落叶松脂醇-9-O-β-吡喃葡萄糖苷(2)、2,4,6-三甲氧基苯酚-1-O-β-D-葡萄糖苷(3)、9-O-β-glucopyranosyl trans-cinnamyl alcohol(4)、3,4,5-三甲氧基苯酚-1-O-β-呋喃芹糖基-(1″→6′)-β-吡喃葡萄糖苷(5)、3-羟基-4,5-二甲氧基苯酚-β-D-吡喃葡萄糖苷(6)、2,6-二甲氧基-4-羟基苯酚-1-O-β-D-吡喃葡萄糖苷(7)、isotachioside(8)、ficuscarpanoside A(9)、uridine(10)、methyl syringate 4-O-β-D-glucopyranoside(11)、3,4,5-三甲氧基苯酚-β-D-吡喃葡萄糖苷(12)、木犀草素(13)、人参皂苷Rg1(14)、(+)-lyonirenisol-3α-O-β-D-glucopyranoside(15)、myricetin 3-neohesperidoside(16)。所有化合物均为首次从该属植物中分离得到。

小叶臭黄皮中的苯丙素苷和降类胡萝卜素苷

从云南西双版纳的小叶臭黄皮(C lausena excavataBurm.f.)中分离到三苯丙素苷和两个降类胡萝卜素苷,他们的结构分别鉴定为4-丙烯基-2,6-二甲氧基苯酚1-O-β-葡萄糖苷,4-烯丙基-2,6-二甲氧基苯酚1-O-β-葡萄糖苷,4-丙基-2,6-二甲氧基苯酚1-O-β-葡萄糖苷,icariside B1和B6。这五个化合物均为首次从黄皮属植物中首次分离得到。

Icariside Ⅱ, a main compound in Epimedii Folium, induces idiosyncratic hepatotoxicity by enhancing NLRP3 inflammasome activation

Idiosyncratic drus-induced liver injury(IDILI)is an intrequent but potentially serious disease that develops the main reason for post-marketing safety warnings and withdrawals of drugs.Epimedii Folium(EF),the widely used herbal medicine,has shown to cause idiosyncratic liver injury,but the underlying mechanisms are poorly understood.Increasing evidence has indicated that most cases of IDILI are immune mediated.Here,we report that icarisideⅡ(ICSⅡ),the major active and metabolic constituent of EF,causes idiosyncratic liver injury by promoting NLRP3 inflammasome activation.ICSⅡexacerbates NLRP3 inflammasome activation triggered by adenosine triphosphate(ATP)and nigericin,but not silicon dioxide(SiO2),monosodium urate(MSU)crystal or cytosolic lipopolysaccharide(LPS).Additionally,the activation of NLRC4 and AIM2 inflammasomes is not affected by ICSⅡ.Mechanistically,synergistic induction of mitochondrial reactive oxygen species(mtROS)is a crucial contributor to the enhancing effect of ICSⅡon ATP-or nigericin-induced NLRP3 inflammasome activation.Importantly,in vivo data show that a combination of non-hepatotoxic doses of LPS and ICSⅡcauses the increase of aminotransferase activity,hepatic inflammation and pyroptosis,which is attenuated by Nlrp3 deficiency or pretreatment with MCC950(a specific NLRP3 inflammasome inhibitor).In conclusion,these findings demonstrate that ICSⅡcauses idiosyncratic liver injury through enhancing NLRP3 inflammasome activation and suggest that ICSⅡmay be a risk factor and responsible for EF-induced liver injury.

Complete Pathway Elucidation and Heterologous Reconstitution of Rhodiola Salidroside Biosynthesis

Salidroside is a bioactive tyrosine-derived phenolic natural product found in medicinal plants under the Rhodiola genus. In addition to their anti-fatigue and anti-anoxia roles in traditional medicine, Rhodiola total extract and salidroside have also displayed medicinal properties as anti-cardiovascular diseases and anticancer agents. The resulting surge in global demand of Rhodiola plants and salidroside has driven some species close to extinction. Here, we report the full elucidation of the Rhodiola salidroside biosynthetic pathway utilizing the first comprehensive transcriptomics and metabolomics datasets for Rhodiola rosea. Unlike the previously proposed pathway involving separate decarboxylation and deamination enzymatic steps from tyrosine to the key intermediate 4-hydroxyphenylacetaldehyde （4-HPAA）, Rhodiola contains a pyridoxal phosphate-dependent 4-HPAA synthase that directly converts tyrosine to 4-HPAA. We further identified genes encoding the subsequent 4-HPAA reductase and tyrosohUDP-glucose 8-O-glucosyltransferase, respectively, to complete salidroside biosynthesis in Rhodiola. We show that heterologous production of salidroside can be achieved in the yeast Saccharomyces cerevisiae as well as the plant Nicotiana benthamiana through transgenic expression of Rhodiola salidroside biosynthetic genes. This study provides new tools for engineering sustainable production of salidroside in heterologous hosts.

苍耳子的化学成分研究

目的研究菊科植物苍耳Xanthium sibiricum的干燥成熟带总苞果实(苍耳子)的化学成分。方法采用硅胶柱色谱、ODS反相柱色谱、Sephadex LH-20、MCI gel CHP 20P和HPLC等色谱方法进行分离纯化,并结合HR-ESI-MS与现代波谱学技术鉴定化合物结构。结果从苍耳子70%已醇提取物中分离得到14个化合物,分别鉴定为xanthiazone(1)、羟基苍耳子噻嗪双酮苷(2)、尿苷(3)、3-吲哚甲醛(4)、naphthisoxazol A(5)、氨基苯丙酰胺(6)、N-benzoyl-2-aminoethyl-β-D-glucopyranoside(7)、ω-hydroxypropioguaiacone(8)、arbutin(9)、icariside D1(10)、lcariside F2(11)、(+)-erythroguaiacylglycerol-8-O-4'-(coniferyl alcohol)ether(12)、(-)-threo-guaiacylglycerol-8-O-4'-(coniferyl alcohol)ether(13)和coniferine(14)。结论化合物3~14为首次从苍耳属植物中分离得到。