Two New Phenylpropanoid Derivatives from Codonopsis tangshen Oliv.

Two new 3‐hydroxy‐3‐methylglutaric acid derived phenylpropanoid glucosides, tangshenoside V ( 1 ) and tangshenoside VI ( 2 ), were isolated from the roots of Codonopsis tangshen Oliv ., along with the two known compounds tangshenoside I ( 3 ) and tangshenoside III ( 4 ). Their structures were elucidated by spectroscopic methods (IR and 1D‐ and 2D‐NMR) and by mass spectrometry (HR‐ESI‐MS).     

Two New Phenylpropanoid Glycosides from the Leaves and Flowers of Erica arborea

Two new phenylpropanoid glucosides, 1,2‐erythro‐1‐(3,4,5‐trimethoxyphenyl)‐2‐(β‐D ‐glucopyranosyloxy)propan‐1,3‐diol ( 1 ) and 7,8‐threo‐2′,8‐epoxysyringylglycerol‐7‐O‐α‐D ‐glucopyranoside (ericarboside; 2 ) have been isolated together with four known compounds 2′,7‐epoxysyringylglycerol‐8‐O‐β‐D ‐glucopyranoside (ficuscarpanoside B; 3 ), benzylrutinoside (hydrangeifolin; 4 ), phenethylrutinoside ( 5 ), and caffeic acid from the BuOH soluble part of the MeOH extract of the leaves and flowers of E. arborea L. Final purification of the compounds was achieved on a reversed‐phase HPLC. Their structures have been elucidated by extensive 1D‐ and 2D‐NMR, and mass spectroscopic techniques.     

Lagotoside: A New Phenylpropanoid Glycoside from Lagotis stolonifera

From the aerial parts of Lagotis stolonifera (Scrophulariaccae), a new phenylpropanoid glycoside, lagotoside ( 8 ), and the three known glycosides ehrenoside ( 5 ), verbascoside (= acteoside; 6 ), and plantamajoside ( 7 ) were isolated, together with the four known iridoid glucosides aucubin ( 1 ), catalpol( 2 ), globularin ( 4 ), and lythantosalin ( 3 ). The structure of the new compound 8 was elucidated on the basis of chemical and spectral data as 2-(3-hy-droxy-4-methoxyphenyl)ethyl O-[α-L -arabinopyranosyl-(1 → 2)]-O-[α-L -rhamnopyranosyl-(1 → 3)]-4-O-feruloyl-β-D -glucopyranoside.     

Effects of Shosaikoto (kampo medicine) on lipid metabolism in macrophages.

We investigated effects of Shosaikoto treatment on cholesterol metabolism in macrophages. Although macrophages, harvested from mice treated with Shosaikoto, took up a small amount of control low density lipoprotein (LDL) (thiobarbituric acid-reactive substance (TBA-RS) value was 0.27 pmol/mg of protein) as control macrophages, they took up more LDL modified with CuSO4 (TBA-RS value was 6.12 pmol/mg of protein) than control macrophages. Degradation of both control LDL and oxidized LDL was enhanced in Shosaikoto treated macrophages. In the presence of control LDL or in the absence of LDL, incorporation of [3H]oleic acid into chlesteryl oleate was significantly reduced in Shosaikoto treated macrophages. This suggests that acyl-coenzyme A:cholesterol acyltransferase (ACAT) activity in macrophages was partly inhibited by Shosaikoto treatment. On the other hand, in the present of oxidized LDL, cholesteryl ester accumulated in Shosaikoto treated macrophages as much as in controls. However, cholesteryl oleate efflux from macrophages in the presence of high density lipoprotein (HDL) was enhanced in Shosaikoto treated macrophages. These result indicate that Shosaikoto facilitates oxidized LDL catabolism in macrophages, resulting in the augmentation of oxidized LDL uptake and the elimination of cholesterol from macrophages by HDL. These Shosaikoto effects may prevent foam cell formation and the progression of atherosclerotic lesions.     

IMB2026791, a xanthone, stimulates cholesterol efflux by increasing the binding of apolipoprotein A-I to ATP-binding cassette transporter A1

It is known that the ATP-binding cassette transporter A1 (ABCA1) plays a major role in cholesterol homeostasis and high density lipoprotein (HDL) metabolism. Several laboratories have demonstrated that ABCA1 binding to lipid-poor apolipoprotein A-I (apoA-I) will mediate the assembly of nascent HDL and cellular cholesterol efflux, which suggests a possible receptor-ligand interaction between ABCA1 and apoA-I. In this study, a cell-based-ELISA-like high-throughput screening (HTS) method was developed to identify the synthetic and natural compounds that can regulate binding activity of ABCA1 to apoA-I. The cell-based-ELISA-like high-throughput screen was conducted in a 96-well format using Chinese hamster ovary (CHO) cells stably transfected with ABCA1 pIRE2-EGFP (Enhanced Green Fluorecence Protein) expression vector and the known ABCA1 inhibitor glibenclamide as the antagonist control. From 2,600 compounds, a xanthone compound (IMB 2026791) was selected using this HTS assay, and it was proved as an apoA-I binding agonist to ABCA1 by a flow cytometry assay and western blot analysis. The [3H] cholesterol efflux assay of IMB2026791 treated ABCA1-CHO cells and PMA induced THP-1 macrophages (human acute monocytic leukemia cell) further confirmed the compound as an accelerator of cholesterol efflux in a dose-dependent manner with an EC(50) of 25.23 μM.     

三对节中两个新环烯醚萜甙的研究

从三对节的叶子中分离得到４个化合物,经化学和光谱方法鉴定其为７－Ｏ－ｐ－Ｃｏｕｍａｒｏｙｌｏｘｙｕｇａｎｄｏｓｉｄｅ（１）,７－Ｏ－ｃｉｎｎａｍｏｙｌｏｘｙｕｇａｎｄｏｓｉｄｅ（２）,ａｃｔｅｏｓｉｄｅ（３）和ｍａｒｔｙｎｏｓｉｄｅ（４）,其中前两者是新环烯醚萜甙化合物,后两者为首次从该植物中获得的苯丙素甙类化合物。     

Chemical composition and antioxidant activity of a polar extract of Thymelaea microphylla Coss. et Dur.

Thymelaea microphylla Coss. et Dur. (Thymelaeaceae) is a rare medicinal plant endemic to Algeria. In order to continue our studies on this species, herein we report the isolation and characterisation of 20 compounds from a hydroalcoholic extract (EtOH–H₂O 7:3) of the aerial parts. They include monoterpene glucosides (1–3), phenolic acid derivatives (4, 8 and 9), phenylpropanoid glucosides (5 and 6), flavonoids (7, 10 and 11), a benzyl alcohol glucoside (12), ionol glucosides (13–16), lignans (17–19) and a bis-coumarin (20). All the structures were elucidated by spectroscopic methods including 1D and 2D NMR experiments, as well as ESI-MS analysis. Moreover, the extract of T. microphylla showed a significant and concentration-dependent free radical-scavenging activity in vitro, correlated to the presence of phenolic and chlorogenic acid derivatives (8, 9 and 4).     

Pycnogenol attenuates atherosclerosis by regulating lipid metabolism through the TLR4–NF-κB pathway

Atherosclerosis is a leading cause of death worldwide and is characterized by lipid-laden foam cell formation. Recently, pycnogenol (PYC) has drawn much attention because of its prominent effect on cardiovascular disease (CVD). However, its protective effect against atherosclerosis and the underlying mechanism remains undefined. Here PYC treatment reduced areas of plaque and lipid deposition in atherosclerotic mice, concomitant with decreases in total cholesterol and triglyceride levels and increases in HDL cholesterol levels, indicating a potential antiatherosclerotic effect of PYC through the regulation of lipid levels. Additionally, PYC preconditioning markedly decreased foam cell formation and lipid accumulation in lipopolysaccharide (LPS)-stimulated human THP-1 monocytes. A mechanistic analysis indicated that PYC decreased the lipid-related protein expression of adipose differentiation-related protein (ADRP) and adipocyte lipid-binding protein (ALBP/aP2) in a dose-dependent manner. Further analysis confirmed that PYC attenuated LPS-induced lipid droplet formation via ADRP and ALBP expression through the Toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) pathway, because pretreatment with anti-TLR4 antibody or a specific inhibitor of NF-κB (PDTC) strikingly mitigated the LPS-induced increase in ADRP and ALBP. Together, our results provide insight into the ability of PYC to attenuate bacterial infection-triggered pathological processes associated with atherosclerosis. Thus PYC may be a potential lead compound for the future development of antiatherosclerotic CVD therapy.     

The role of microscopy in understanding atherosclerotic lysosomal lipid metabolism.

Microscopy has played a critical role in first identifying and then defining the role of lysosomes in formation of atherosclerotic foam cells. We review the evidence implicating lysosomal lipid accumulation as a factor in the pathogenesis of atherosclerosis with reference to the role of microscopy. In addition, we explore mechanisms by which lysosomal lipid engorgement occurs. Low density lipoproteins which have become modified are the major source of lipid for foam cell formation. These altered lipoproteins are taken into the cell via receptor-mediated endocytosis and delivered to lysosomes. Under normal conditions, lipids from these lipoproteins are metabolized and do not accumulate in lysosomes. In the atherosclerotic foam cell, this normal metabolism is inhibited so that cholesterol and cholesteryl esters accumulate in lysosomes. Studies of cultured cells incubated with modified lipoproteins suggests this abnormal metabolism occurs in two steps. Initially, hydrolysis of lipoprotein cholesteryl esters occurs normally, but the resultant free cholesterol cannot exit the lysosome. Further lysosomal cholesterol accumulation inhibits hydrolysis, producing a mixture of cholesterol and cholesteryl esters within swollen lysosomes. Various lipoprotein modifications can produce this lysosomal engorgement in vitro and it remains to be seen which modifications are most important in vivo.     

A new phenylpropanoid from the roots of Euphorbia nematocypha

A phytochemical investigation of the ethanolic extracts of the dried roots of Euphorbia nematocypha resulted in the isolation of a new phenylpropanoid, 16-O-caffeoyl-16-hydroxylhexadecanoic acid (1), together with 23 known compounds (2–24). Their structures were elucidated on the basis of spectroscopic data. Compound 1 was first to be isolated as a caffeic acyl long chain alkyl acid from the family Euphorbiaceae. The new isolated phenylpropanoid showed potent cytotoxic activities against the MCF-7 and HeLa cell lines.     

Antiangiogenic phenylpropanoid glycosides from Gynura cusimbua

A new phenylpropanoid glycoside, named α-L-rhamnopyranosyl-(1?2)-β-D-[4″-(8E)-7-(3,4-dihydroxyphenyl)-8-propenoate, 1″-O-(7S)-7-(3,4-dihydroxyphenyl)-7-methoxy-ethyl]-glucopyranoside (1), together with nine known compounds (2–10) were isolated from the active fraction (n-Butanol fraction) of Gynura cusimbua for the first time. The known compounds (2–10) were identified as phenylpropanoid glycosides on the basis of extensive spectral data and references. The antiangiogenic activities of compounds (1–10) were evaluated by MTT assay on HUVECs and wild-type zebrafish in vivo model assay. As a result, compounds 1, 6, 7, 8 and 10 exhibited certain antiangiogenic activities.     

Potential Vasculoprotective Effects of Blackcurrant (Ribes nigrum) Extract in Diabetic KK-Ay Mice

Polyphenols are bioactive compounds found naturally in fruits and vegetables; they are widely used in disease prevention and health maintenance. Polyphenol-rich blackcurrant extract (BCE) exerts beneficial effects on vascular health in menopausal model animals. However, the vasculoprotective effects in diabetes mellitus (DM) and atherosclerotic vascular disease secondary to DM are unknown. Therefore, we investigated whether BCE is effective in preventing atherosclerosis using KK-A^y mice as a diabetes model. The mice were divided into three groups and fed a high-fat diet supplemented with 1% BCE (BCE1), 3% BCE (BCE2), or Control for 9 weeks. The mice in the BCE2 group showed a considerable reduction in the disturbance of elastic lamina, foam cell formation, and vascular remodeling compared to those in the BCE1 and Control groups. Immunohistochemical staining indicated that the score of endothelial nitric oxide synthase staining intensity was significantly higher in both BCE2 (2.9) and BCE1 (1.9) compared to that in the Control (1.1). Furthermore, the score for the percentage of alpha-smooth muscle actin was significantly lower in the BCE2 (2.9%) than in the Control (2.1%). Our results suggest that the intake of anthocyanin-rich BCE could have beneficial effects on the blood vessels of diabetic patients.     

Annexin A6 is highly abundant in monocytes of obese and type 2 diabetic individuals and is downregulated by adiponectin in vitro

Adiponectin stimulates cholesterol efflux in macrophages and low adiponectin may in part contribute to disturbed reverse cholesterol transport in type 2 diabetes. Monocytes express high levels of annexin A6 that could inhibit cholesterol efflux and it was investigated whether the atheroprotective effects of adiponectin are accompanied by changes in annexin A6 levels. Adiponectin reduces annexin A6 protein whereas mRNA levels are not affected. Adiponectin-mediated activation of peroxisome proliferator-activated receptor α (PPARα) and AMP-activated protein kinase (AMPK) does not account for reduced annexin A6 expression. Further, fatty acids and lipopolysaccharide that are elevated in obesity do not influence annexin A6 protein levels. Annexin A6 in monocytes from overweight probands or type 2 diabetic patients is significantly elevated compared to monocytes of normal-weight controls. Monocytic annexin A6 positively correlates with body mass index and negatively with systemic adiponectin of the blood donors. Therefore, the current study demonstrates that adiponectin reduces annexin A6 in monocytes and thereby may enhance cholesterol efflux. In agreement with these in vitro finding an increase of monocytic annexin A6 in type 2 diabetes monocytes was observed.     

Study on the Chemical Constituents of Daphniphyllum angustifolium

Seven new iridoid glucosides, 1 – 7 , two new phenyl glucosides, 8 and 9 , along with eight known compounds were isolated from the bark of Daphniphyllum angustifolium. Their structures were established by ESI‐MS and by 1D‐ and 2D‐NMR spectroscopic methods.     

Shancigusins E‐I,five new glucosides from the tubers of Pleione yunnanensis

Five new glucosides, shancigusins E‐I (1–5) were isolated from the tubers of Pleione yunnanensis (Rolfe) together with 18 known compounds. The structures of these compounds were determined by extensive analyses of their spectroscopic data. Copyright © 2013 John Wiley & Sons, Ltd.     

Eremosides A – C,New Iridoid Glucosides from Eremostachys loasifolia

Eremosides A–C ( 1 – 3 ), three new iridoid glucosides, were isolated from the AcOEt‐soluble fraction of the EtOH extract of the whole plant of Eremostachys loasifolia, along with buddlejoside B ( 4 ), 10‐O‐benzoylcatalpol ( 5 ), and pakiside A ( 6 ) reported for the first time from this species. The structures of these compounds were elucidated by spectroscopic data including 2D‐NMR, FAB‐MS, ESI‐MS, as well as by acid and basic hydrolyses.     

Inhibition of acyl-coenzyme A:cholesterol acyltransferase stimulates cholesterol efflux from macrophages and stimulates farnesoid X receptor in hepatocytes

We investigated the mechanism of spontaneous cholesterol efflux induced by acyl-coenzyme A:cholesterol acyltransferase (ACAT) inhibition, and how an alteration of cholesterol metabolism in macrophages impacts on that in HepG2 cells. Oleic acid anilide (OAA), a known ACAT inhibitor reduced lipid storage substantially by promotion of cholesterol catabolism and repression of cholesteryl ester accumulation without further increase of cytotoxicity in acetylated low-density lipoprotein-loaded THP-1 macrophages. Analysis of expressed mRNA and protein revealed that cholesterol 7alpha-hydroxylase (CYP7A1), oxysterol 7alpha- hydroxylase (CYP7B1), and cholesterol 27-hydroxylase (CYP27) were highly induced by ACAT inhibition. The presence of a functional cytochrome P450 pathway was confirmed by quantification of the biliary cholesterol mass in cell monolayers and extracelluar medium. Notably, massively secreted biliary cholesterol from macrophages suppressed the expression of CYP7 proteins in a farnesoid X receptor (FXR)-dependent manner in HepG2 cells. The findings reported here provide new insight into mechanisms of spontaneous cholesterol efflux, and suggest that ACAT inhibition may stimulate cholesterol-catabolic (cytochrome P450) pathway in lesion-macrophages, in contrast, suppress it in hepatocyte via FXR induced by biliary cholesterol (BC).     

Caragisides A – C,New Isoflavone Glucosides from Caragana conferta with Inhibition of Platelet Aggregation

Caragisides A–C ( 1 – 3 , resp.), three new isoflavone glucosides, were isolated from the BuOH sub‐fraction of the EtOH extract of the whole plant of Caragana conferta, along with ononoside ( 4 ), reported for the first time from this species. The structures of the new compounds were elucidated by spectroscopic techniques including MS and 2D‐NMR spectroscopy. Compounds 1 – 3 showed significant inhibition of platelet aggregation.