The Effects of 1-O-Acetylbritannilactone Isolated from Inula britannica Flowers on Human Neutrophil Elastase and Inflammation of RAW 264.7 Cells and Zebrafish Larvae.

During a search for natural inflammatory inhibitors, 1-O-acetylbritannilactone (ABL), a sesquiterpene lactone, was isolated from the flowers of Inula britannica. ABL significantly inhibited human neutrophil elastase (HNE) with a half-maximal inhibitory concentration (IC50) of 3.2 ± 0.3 µM, thus did so more effectively than the positive control material (epigallocatechin gallate) (IC50 7.2 ± 0.5 µM). An enzyme kinetic study was performed. ABL noncompetitively inhibited HNE with an inhibition constant Ki of 2.4 µM. ABL inhibited lipopolysaccharide-induced nitric oxide and prostaglandin E2 production by RAW 264.7 cells in a dose-dependent manner, as well as the protein-level expression of inducible nitric oxide synthase and cyclooxygenase-2. The anti-inflammatory effect of ABL was confirmed using a transgenic Tg(mpx:EGFP) zebrafish larval model. The exposure of the larvae to ABL inhibited neutrophil recruitment to the site of injury after tail fin amputation.

Microbial Transformation of Yakuchinone A and Cytotoxicity Evaluation of Its Metabolites.

Yakuchinone A (1) is a bioactive diarylheptanoid isolated from the dried fruits of Alpinia oxyphylla. Microbial transformation has been recognized as an efficient method to produce new biologically active derivatives from natural products. In the present study, microbial transformation of yakuchinone A was performed with the fungus Mucor hiemalis KCTC 26779, which led to the isolation of nine new metabolites (2, 3a, 3b, and 4-9). Their structures were elucidated as (3S)-oxyphyllacinol (2), (3S,7R)- and (3S,7S)-7-hydroxyoxyphyllacinol (3a and 3b), (3S)-oxyphyllacinol-4'-O-ß-d-glucopyranoside (4), (3S)-4″-hydroxyoxyphyllacinol (5), (3S)-3″-hydroxyoxyphyllacinol (6), (3S)-2″-hydroxyoxyphyllacinol (7), (3S)-2″-hydroxyoxyphyllacinol-2″-O-ß-d-glucopyranoside (8), and (3S)-oxyphyllacinol-3-O-ß-d-glucopyranoside (9) based on the comprehensive spectroscopic analyses and the application of modified Mosher's method. All compounds were evaluated for their cytotoxic activities against melanoma, as well as breast, lung, and colorectal cancer cell lines. Compound 9, which was O-glucosylated on the diarylheptanoid alkyl chain, exhibited the most selective cytotoxic activities against melanoma cell lines with the IC50 values ranging from 6.09 to 9.74 µM, indicating that it might be considered as a possible anti-cancer lead compound.

Microbial Transformation and Biological Activities of the Prenylated Aromatic Compounds from Broussonetia kazinoki.

Broussonetia kazinoki has been used as a traditional medicine for the treatment of burns and acne, and its extracts have been found to show tyrosinase inhibitory and anticancer activities. In this study, the tyrosinase inhibitory and cytotoxic activities of B. kazinoki were explored, leading to the isolation of kazinol C (1), kazinol E (2), kazinol F (3), broussonol N (4), and kazinol X (5), of which the compounds 4 and 5 have not been previously reported. Microbial transformation has been recognized as an efficient tool to generate more active metabolites. Microbial transformation of the major compounds 1 and 3 was conducted with Mucor hiemalis, where four glucosylated metabolites (6-9) were produced from 1, while one hydroxylated (10) and one glucosylated (11) metabolites were obtained from 3. Structures of the isolated metabolites were determined by extensive spectroscopic analyses. All compounds were evaluated for their tyrosinase inhibitory and cytotoxic activities. Compound 3 and its metabolites, kazinol Y (10) and kazinol F-4″-O-ß-d-glucopyranoside (11), exhibited the most potent tyrosinase inhibitory activities with the IC50 values ranging from 0.71 to 3.36 µM. Meanwhile, none of the metabolites, except for kazinol C-2',3″-di-O-ß-d-glucopyranoside (7), showed moderate cytotoxic activities (IC50 17.80 to 24.22 µM) against A375P, B16F10 and B16F1 cell lines.

Antimelanogenic activity of patuletin from Inula japonica flowers in B16F10 melanoma cells and zebrafish embryos.

During the search for natural melanogenesis inhibitors, patuletin, a flavonoid, was isolated from Inula japonica flowers. We investigated the antimelanogenic effects of patuletin on B16F10 melanoma cells and zebrafish embryos. Patuletin dose-dependently reduced melanocyte-stimulating hormone-induced melanogenesis and L-DOPA oxidation in B16F10 cells. Western blot analysis showed that patuletin reduced cellular tyrosinase expression in a dose-dependent manner. Patuletin treatment significantly decreased melanin pigmentation in the embryo compared to the untreated controls.

Extract of Moutan radicis cortex and Cinnamomi ramulus ameliorates laser-induced choroidal neovascularization in Brown-Norway rats.

BACKGROUND: Moutan radicis cortex (MRC) and Cinnamomi ramulus (CR) are commonly used in eastern Asian traditional medicine to treat various diseases including cerebrovascular and cardiovascular, and have wide spectrum of pharmacological activities. However, the effect against laser-induced choroidal neovascularization (CNV) of extract of MRC and CR (1:1) (MRCCR) has not yet been studied. PURPOSE: Our aim was to investigate the inhibitory effect of MRCCR on pathological CNV in laser-treated Brown-Norway (BN) rats. METHODS: MRCCR (60, 90 mg/kg) was orally administered twice per day for 15 days from the day of CNV formation in laser-treated BN rats. Effects of MRCCR or its constituents on cell migration, tube formation, hyperpermeability and phosphorylation of FAK/p38 MAPK were confirmed in humane retinal microvascular endothelial cells or human retinal pigment epithelial cells. RESULTS: MRCCR significantly reduced the CNV lesions areas and the extent of fluorescein leakage. MRCCR and its constituents such as ellagic acid, paeonol or gallic acid decreased cell migration, tube formation or hyperpermeability. MRCCR inhibited the phosphorylation of FAK and p38 MAPK. CONCLUSION: Combining the oral MRCCR and intravitreal injection of anti-VEGF medicine may result in a more potent therapeutic effect and consequently bring the reduction in eye injection numbers for patients with wet AMD.

Cimicifugae Rhizoma Extract Attenuates Oxidative Stress and Airway Inflammation via the Upregulation of Nrf2/HO-1/NQO1 and Downregulation of NF-κB Phosphorylation in Ovalbumin-Induced Asthma.

Cimicifugae Rhizoma has been used as a medicinal herb for fever, pain, and inflammation in East Asia. We conducted this study because the effect of Cimicifugae Rhizoma extract (CRE) on allergic asthma has not yet been evaluated. To induce allergic airway inflammation, we intraperitoneally injected ovalbumin (OVA) mixed with aluminum hydroxide into mice twice at intervals of 2 weeks (Days 0 and 14) and then inhaled them thrice with 1% OVA solution using a nebulizer (Days 21 to 23). CRE (30 and 100 mg/kg) was administered orally daily for 6 days (Days 18 to 23). The mice showed remarkable reduction in allergic inflammation at 100 mg/kg of CRE, as evidenced by decreased inflammatory cell counts, pro-inflammatory cytokine levels, OVA-specific immunoglobulin E level, airway hyperresponsiveness, and production of mucus. Additionally, these effects were involved with the enhancement of heme oxygenase-1 (HO-1), NAD(P)H: quinone oxidoreductase (NQO1), and nuclear factor erythroid 2-related factor 2 (Nrf2) expression and reduction of nuclear factor-κB (NF-κB) phosphorylation and matrix metalloproteinase-9 expression. Our findings indicated that CRE effectively protected against OVA-induced inflammation and oxidative stress via upregulation of the Nrf2/HO-1/NQO1 signaling and downregulation of NF-κB phosphorylation in asthma caused by OVA.

Biotransformation of the Phenolic Constituents from Licorice and Cytotoxicity Evaluation of Their Metabolites.

Biotransformation of four bioactive phenolic constituents from licorice, namely licoisoflavanone (1), glycyrrhisoflavone (2), echinatin (3), and isobavachalcone (4), was performed by the selected fungal strain Aspergillus niger KCCM 60332, leading to the isolation of seventeen metabolites (5-21). Structures of the isolated compounds were determined on the basis of extensive spectroscopic methods, twelve of which (5-7, 10-17 and 19) have been previously undescribed. A series of reactions including hydroxylation, hydrogenation, epoxidation, hydrolysis, reduction, cyclization, and alkylation was observed in the biotransformation process. All compounds were tested for their cytotoxic activities against three different human cancer cell lines including A375P, MCF-7, and HT-29. Compounds 1 and 12 exhibited most considerable cytotoxic activities against all the cell lines investigated, while compounds 2 and 4 were moderately cytotoxic. These findings will contribute to expanding the chemical diversity of phenolic compounds, and compounds 1 and 12 may serve as leads for the development of potential cancer chemopreventive agents.

POCU1b, the n-Butanol Soluble Fraction of Polygoni Cuspidati Rhizoma et Radix, Attenuates Obesity, Non-Alcoholic Fatty Liver, and Insulin Resistance via Inhibitions of Pancreatic Lipase, cAMP-Dependent PDE Activity, AMPK Activation, and SOCS-3 Suppression.

This study investigated the effects of the n-BuOH soluble fraction of Polygoni Cuspidati 80% ethanol extract (POCU1b) on high-fat diet (HFD)-induced obesity, non-alcoholic fatty liver (NAFL), and insulin resistance (IR) to find a safe and more effective agent. HPLC profiling of POCU1b identified seven marker compounds. POCU1b increased glycerol release, cyclic adenosine monophosphate (cAMP) level, and inhibited phosphodiesterase (PDE) activity. Seven weeks of POCU1b treatment decreased body weight gain, weight and adipocyte size in fat tissues, serum lipids, and triglyceride and lipid droplets in the livers of HFD-fed rats. POCU1b improved blood glucose, insulin sensitivity, and impaired insulin secretion in the pancreas. Further, POCU1b ameliorated adiponectin, leptin, IL-6 and TNF-α levels, increased AMPK and p-ACC expression, activated CPT-1 activity, and suppressed FAS mRNA, SOCS-3 protein expression, and NF-κB DNA-binding activity. When compared with the Xenical®-treated group, a positive group, the action of POCU1b on body weight was more effective than that of Xenical. POCU1b did not show side effects, such as oily spotting and loss of appetite. These results suggest that POCU1b possesses therapeutic or preventive potential for obesity, NAFL and IR via inhibitions of pancreatic lipase and cAMP-dependent PDE activity, AMPK activation, and SOCS-3 suppression, without oily spotting and loss of appetite.

Constituents of Coreopsis lanceolata Flower and Their Dipeptidyl Peptidase IV Inhibitory Effects.

A new polyacetylene glycoside, (5R)-6E-tetradecene-8,10,12-triyne-1-ol-5-O-ß-glucoside (1), was isolated from the flower of Coreopsis lanceolata (Compositae), together with two known compounds, bidenoside C (10) and (3S,4S)-5E-trideca-1,5-dien-7,9,11-triyne-3,4-diol-4-O-ß-glucopyranoside (11), which were found in Coreopsis species for the first time. The other known compounds, lanceoletin (2), 3,2'-dihydroxy-4-3'-dimethoxychalcone-4'-glucoside (3), 4-methoxylanceoletin (4), lanceolin (5), leptosidin (6), (2R)-8-methoxybutin (7), luteolin (8) and quercetin (9), were isolated in this study and reported previously from this plant. The structure of 1 was elucidated by analyzing one-dimensional and two-dimensional nuclear magnetic resonance and high resolution-electrospray ionization-mass spectrometry data. All compounds were tested for their dipeptidyl peptidase IV (DPP-IV) inhibitory activity and compounds 2-4, 6 and 7 inhibited DPP-IV activity in a concentration-dependent manner, with IC50 values from 9.6 to 64.9 µM. These results suggest that C. lanceolata flower and its active constituents show potential as therapeutic agents for diseases associated with type 2 diabetes mellitus.

Apoptosis in Leukemic Cells Induced by Anti-proliferative Coumarin Isolated from the Stem Bark of Fraxinus rhynchophylla.

Esculetin 6-O-ß-D-arabinofuranosyl-(1→6)-ß-D-glucopyranoside (EAG) is a coumarin glycoside isolated from the stem bark of Fraxinus rhynchophylla. This study scrutinized the anti-proliferative activity of EAG on blood cancer-derived Jurkat leukemic cells. Cell viability assays in leukemic cancer cells determined that EAG possesses potent anti-proliferative effects. Moreover, treatment with EAG increased the proportion of apoptotic cells, resulted in cell cycle arrest being induced at the subG0/ G1 phase, and reduced the proportion of cells present in the S phase. In addition, mitochondrial membrane potential was reduced by EAG in Jurkat cells. Additionally, EAG triggered apoptosis that was mediated by the downregulation of BCL-XL, p-IκBα, and p-p65 expressions in addition to the upregulation of cleaved Caspase 3 and BAX expressions. These findings revealed that the toxic effect of EAG was mediated by intracellular signal transduction pathways that involved a mechanism in which reactive oxygen species (ROS) were upregulated. Thus, this study concludes that EAG could potentially serve as a therapeutic agent for leukemia.

The Herbal Combination CPA4-1 Inhibits Changes in Retinal Capillaries and Reduction of Retinal Occludin in db/db Mice.

Increased formation of advanced glycation end products (AGEs) plays an important role in the development of diabetic retinopathy (DR) via blood-retinal barrier (BRB) dysfunction, and reduction of AGEs has been suggested as a therapeutic target for DR. In this study, we examined whether CPA4-1, a herbal combination of Cinnamomi Ramulus and Paeoniae Radix, inhibits AGE formation. CPA4-1 and fenofibrate were tested to ameliorate changes in retinal capillaries and retinal occludin expression in db/db mice, a mouse model of obesity-induced type 2 diabetes. CPA4-1 (100 mg/kg) or fenofibrate (100 mg/kg) were orally administered once a day for 12 weeks. CPA4-1 (the half maximal inhibitory concentration, IC50 = 6.84 ± 0.08 µg/mL) showed approximately 11.44-fold higher inhibitory effect on AGE formation than that of aminoguanidine (AG, the inhibitor of AGEs, IC50 = 78.28 ± 4.24 µg/mL), as well as breaking effect on AGE-bovine serum albumin crosslinking with collagen (IC50 = 1.30 ± 0.37 µg/mL). CPA4-1 treatment ameliorated BRB leakage and tended to increase retinal occludin expression in db/db mice. CPA4-1 or fenofibrate treatment significantly reduced retinal acellular capillary formation in db/db mice. These findings suggested the potential of CPA4-1 as a therapeutic supplement for protection against retinal vascular permeability diseases.

The Antimelanogenic Effect of Inularin Isolated from Flowers of Inula britannica on B16F10 Melanoma Cells and Zebrafish Embryos.

In the search for novel, natural melanogenesis inhibitors, a new sesquiterpene, inularin, was isolated from the flowers of Inula britannica, and the structure was determined using spectroscopic and chemical methods. The antimelanogenic effects of inularin on B16F10 melanoma cells and zebrafish embryos were evaluated. Inularin dose-dependently reduced melanocyte-stimulating hormone-induced melanin production and L-DOPA oxidation in B16F10 cells. Zebrafish embryos were used to confirm the antimelanogenic activity. Inularin significantly decreased the pigmentation of embryos compared with untreated controls.

Osteomeles schwerinae Extract and Its Major Compounds Inhibit Methylglyoxal-Induced Apoptosis in Human Retinal Pigment Epithelial Cells.

The accumulation and formation of advanced glycation end products (AGEs) are related to diabetes and age-related disease. Osteomeles schwerinae C. K. Schneid. (Rosaceae, OSSC) is used traditionally for the treatment of various diseases in Asia. Previous studies have shown that OSSC elicits preventive effects in an in vivo model of diabetes. This study was to evaluate the antiapoptotic effects of dried leaves and twigs of OSSC extract and its major compounds in ARPE-19 cells-spontaneously arising human retinal pigment epithelial cells-under diabetic conditions. To examine the effects of an OSSC extract and its active compounds (acetylvitexin, hyperoside and quercitrin) on apoptosis in methylglyoxal (MG, the active precursor in the formation of AGEs)-treated ARPE-19 cells and the mechanism by which these effects occur, apoptosis was measured using flow cytometry analysis. Protein expression levels of phospho-p53 (p-p53), Bax and Bcl-2 were determined by western blot analyses. The OSSC extract inhibited apoptosis in MG-treated ARPE-19 cells in a dose-dependent manner. The major compounds also reduced the rate of apoptosis. Both the extract and major compounds also inhibited the expression of p-p53 and Bax and increased the levels of Bcl-2 that had been previously reduced by MG treatment. The OSSC extract (0.1 µg/mL) and its major compounds (0.01 µM) attenuated apoptosis in ARPE-19 cells under toxic diabetic conditions by downregulating of expression of p-p53 and Bax. OSSC may serve as an alternative therapy to retard the development of diabetic retinopathy.

Achyranthis radix Extract Improves Urban Particulate Matter-Induced Dry Eye Disease.

Dry eye disease (DED) is a multifactorial inflammatory disease that severely impairs patients' quality of life. Particulate matter comprises a harmful mixture of particles less than 10 µm in size, which on contact with the eye, causes inflammation in the cornea/conjunctival epithelium, threatening eye health and triggering the onset of DED. Achyranthis radix is an ingredient of traditional medicine generally used for treating osteoporosis, trauma, and thrombosis in Asian countries. However, the effect of Achyranthis radix on eye health has not been elucidated. In this study, we evaluate the protective effect of Achyranthis radix hot water extract (ARE) in a rat model of urban particulate matter (UPM)-induced DED. UPM with or without ARE were topically administered on both eyes thrice daily for 10 days. ARE induced tear secretion and improved corneal irregularity. Additionally, ARE treatment protected the corneal epithelial cells from UPM-induced apoptosis. It also restored rMuc4 expression in the cornea and increased goblet cell density in the conjunctiva. These results are suggestive of the potential of ARE as a topical therapeutic agent for treating DED.

Pueraria lobata Extract Protects Hydrogen Peroxide-Induced Human Retinal Pigment Epithelial Cells Death and Membrane Permeability.

BACKGROUND: Pueraria lobata is used in traditional Asian medicine to treat cardiovascular diseases, diarrhea, diabetes mellitus, and diabetic complications such as diabetic retinopathy. Oxidative stress in retinal pigment epithelial cells is implicated in the pathogenesis of retinopathy and age-related macular degeneration (AMD). Here, we evaluated whether the P. lobata extract can prevent cell death and decrease membrane permeability in oxidative stress-induced human retinal pigment epithelial cells. METHODS: The effects of P. lobata extract on hydrogen peroxide- (H2O2-) induced oxidative stress were investigated using 2',7'-dichlorofluorescin diacetate, western blotting, and immunohistochemistry in human retinal pigment epithelial cells. The effects of puerarin, daidzein, and daidzin isolated from P. lobata extract were also studied by determining cell death, reactive oxygen species (ROS) generation, and p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) phosphorylation. RESULTS: Our results showed that the P. lobata extract inhibited ROS generation, suppressed the disruption of zonula occludens-1 (ZO-1), and reduced membrane permeability in H2O2-induced human retinal pigment epithelial cells. Additionally, the P. lobata extract prevented the inhibition of p38 MAPK and JNK phosphorylation. CONCLUSION: Our findings suggest that the P. lobata extract has the potential to prevent AMD development by inhibiting the mechanism underlying oxidative stress-mediated ocular disorders.

Identification of Two New Phenanthrenes from Dendrobii Herba and Their Cytotoxicity towards Human Hypopharynx Squamous Carcinoma Cell (FaDu).

Two new phenanthrenes, (1R,2R)-1,7-hydroxy-2,8-methoxy-2,3-dihydrophenanthrene-4(1H)-one (1) and 2,7-dihydroxy-phenanthrene-1,4-dione (2), were isolated from the ethyl acetate-soluble fraction of Dendrobii Herba, together with seven known phenanthrenes (3-9), two bibenzyls (10-12), and a lignan (13). Structures of 1 and 2 were elucidated by analyzing one-dimensional (1D) and two-dimensional (2D)-NMR and High-resolution electrospray ionization mass spectra (HR-ESI-MS) data. The absolute configuration of compound 1 was confirmed by the circular dichroism (CD) spectroscopic method. In cytotoxicity assay using FaDu human hypopharynx squamous carcinoma cell line, compounds 3-6, 8, 10, and 12 showed activities, with IC50 values that ranged from 2.55 to 17.70 µM.

Improvement in Diabetic Retinopathy through Protection against Retinal Apoptosis in Spontaneously Diabetic Torii Rats Mediated by Ethanol Extract of Osteomeles schwerinae C.K. Schneid.

Retinal apoptosis plays a critical role in the progression of diabetic retinopathy (DR), a common diabetic complication. Currently, the tight control of blood glucose levels is the standard approach to prevent or delay the progression of DR. However, prevalence of DR among diabetic patients remains high. Focusing on natural nutrients or herbal medicines that can prevent or delay the onset of diabetic complications, we administered an ethanol extract of the aerial portion of Osteomeles schwerinae (OSSCE), a Chinese herbal medicine, over a period of 17 weeks to spontaneously diabetic Torii (SDT) rats. OSSCE was found to ameliorate retinal apoptosis through the regulation of advanced glycation end product (AGE) accumulation, oxidative stress, and mitochondrial function via the inhibition of NF-κB activity, in turn, through the downregulation of PKCδ, P47phox, and ERK1/2. We further demonstrated in 25 mM glucose-treated human retinal microvascular endothelial cells (HRMECs) that hyperoside (3-O-galactoside-quercetin), quercitrin (3-O-rhamnoside-quercetin), and 2″-O-acetylvitexin (8-C-(2″-O-acetyl-glucoside)-apigenin) were the active components of OSSCE that mediated its pharmacological action. Our results provide evidence that OSSCE is a powerful agent that may directly mediate a delay in the development or disease improvement in patients of DR.

The Protective Effect of Polygonum cuspidatum (PCE) Aqueous Extract in a Dry Eye Model.

Dry eyes are caused by highly increased osmolarity of tear film, inflammation, and apoptosis of the ocular surface. In this study, we investigated the effect of Polygonum cuspidatum (PCE) aqueous extract in in vivo and in vitro dry eye models. Dry eye was induced by excision of the lacrimal gland and hyperosmotic media. In vivo, oral administration of PCE in exorbital lacrimal gland-excised rats recovered tear volume and Mucin4 (MUC4) expression by inhibiting corneal irregularity and expression of inflammatory cytokines. In vitro, hyperosmotic media induced human corneal epithelial cell (HCEC) cytotoxicity though increased inflammation, apoptosis, and oxidative stress. PCE treatment significantly inhibited expression of cyclooxygenase-2 and inflammatory cytokines (interleukin-6 and tumor necrosis factor-α), and activation of NF-κB p65 in hyperosmolar stress-induced HCECs. Hyperosmolarity-induced increase in Bcl-2-associated X protein (BAX) expression and activation of cleaved poly (ADP-ribose) polymerase and caspase 3 were attenuated in a concentration-dependent manner by PCE. PCE treatment restored anti-oxidative proteins such as heme oxygenase-1 (HO-1), superoxide dismutase-1 (SOD-1), and glutathione peroxidase (GPx) in hyperosmolar stress-induced HCECs. These data demonstrate that PCE prevents adverse changes in the ocular surface and tear fluid through inhibition of hyperosmolar stress-induced inflammation, apoptosis, and oxidation, suggesting that PCE may have the potential to preserve eye health.

Inhibition of Human Neutrophil Elastase by Sesquiterpene Lactone Dimers from the Flowers of Inula britannica.

A new sesquiterpene lactone dimer [1], together with five known compounds (2-6), was isolated from the flowers of Inula britannica. The structures of these compounds were established by extensive spectroscopic studies and chemical evidence. The inhibitory activities of these isolated compounds (1-6) against human neutrophil elastase (HNE) were also evaluated in vitro; compounds 1 and 6 exhibited significant inhibitory effects against HNE activity, with IC50 values of 8.2 and 10.4 µM, respectively, comparable to that of epigallocatechin gallate (EGCG; IC50 = 10.9 µM). In addition, compounds 3 and 5 exhibited moderate HNE inhibitory effects, with IC50 values of 21.9 and 42.5 µM, respectively. In contrast, compounds 2 and 4 exhibited no such activity (IC50 ＞ 100 µM). The mechanism by which 1 and 3 inhibited HNE was noncompetitive inhibition, with inhibition constant (Ki) values of 8.0 and 22.8 µM, respectively.

Polyphenols from Euphorbia pekinensis Inhibit AGEs Formation In Vitro and Vessel Dilation in Larval Zebrafish In Vivo.

To identify active compounds in the roots of Euphorbia pekinensis for treatment of diabetic complications, an active column fraction from a 70% EtOH extract of E. pekinensis root was purified by preparative reversed-phase high-performance liquid chromatography, leading to the isolation of a new ellagic acid derivative, 3,3'-di-O-methylellagic acid 4-O-(6"-O-galloyl)-ß-D-galactopyranoside (1: ), along with three known compounds, geraniin (2: ), 3,3'-di-O-methylellagic acid 4-O-ß-D-xylopyranoside (3: ), and ellagic acid 3,3'-dimethyl ether (4: ). The structure of the new compound was established by extensive spectroscopic studies and chemical evidence. The inhibitory effects of isolated compounds 1: -4: on advanced glycation end-products (AGEs) formation were examined. All compounds exhibited considerable inhibition of AGEs formation and IC50 values of 0.41 - 12.33 µM, compared with those of the positive controls aminoguanidine (IC50 = 1122.34 µM) and quercetin (IC50 = 27.80 µM). In addition, the effects of 2: and 4: on the dilation of hyaloid-retinal vessels induced by high glucose (HG) in larval zebrafish were investigated; both compounds significantly reduced the HG-induced dilation of hyaloid-retinal vessels relative to the HG-treated control group.