Lupane-type triterpenoids from the steamed leaves of Acanthopanax koreanum and their inhibitory effects on the LPS-stimulated pro-inflammatory cytokine production in bone marrow-derived dendritic cells

Impressic Acid Ameliorates Atopic Dermatitis-Like Skin Lesions by Inhibiting ERK1/2-Mediated Phosphorylation of NF-κB and STAT1

Impressic acid (IPA), a lupane-type triterpenoid from Acanthopanax koreanum, has many pharmacological activities, including the attenuation of vascular endothelium dysfunction, cartilage destruction, and inflammatory diseases, but its influence on atopic dermatitis (AD)-like skin lesions is unknown. Therefore, we investigated the suppressive effect of IPA on 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin symptoms in mice and the underlying mechanisms in cells. IPA attenuated the DNCB-induced increase in the serum concentrations of IgE and thymic stromal lymphopoietin (TSLP), and in the mRNA levels of thymus and activation regulated chemokine (TARC), macrophage derived chemokine (MDC), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13), tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) in mice. Histopathological analysis showed that IPA reduced the epidermal/dermal thickness and inflammatory and mast cell infiltration of ear tissue. In addition, IPA attenuated the phosphorylation of NF-κB and IκBα, and the degradation of IκBα in ear lesions. Furthermore, IPA treatment suppressed TNF-α/IFN-γ-induced TARC expression by inhibiting the NF-κB activation in cells. Phosphorylation of extracellular signal-regulated protein kinase (ERK1/2) and the signal transducer and activator of transcription 1 (STAT1), the upstream signaling proteins, was reduced by IPA treatment in HaCaT cells. In conclusion, IPA ameliorated AD-like skin symptoms by regulating cytokine and chemokine production and so has therapeutic potential for AD-like skin lesions.

Impressic Acid Attenuates the Lipopolysaccharide-Induced Inflammatory Response by Activating the AMPK/GSK3β/Nrf2 Axis in RAW264.7 Macrophages

Inflammatory diseases are caused by excessive inflammation from pro-inflammatory mediators and cytokines produced by macrophages. The Nrf2 signaling pathway protects against inflammatory diseases by inhibiting excessive inflammation via the regulation of antioxidant enzymes, including HO-1 and NQO1. We investigated the anti-inflammatory effect of impressic acid (IPA) isolated from Acanthopanax koreanum on the lipopolysaccharide (LPS)-induced inflammation and the underlying molecular mechanisms in RAW264.7 cells. IPA attenuated the LPS-induced production of pro-inflammatory cytokines and reactive oxygen species, and the activation of the NF-κB signaling pathway. IPA also increased the protein levels of Nrf2, HO-1, and NQO1 by phosphorylating CaMKKβ, AMPK, and GSK3β. Furthermore, ML385, an Nrf2 inhibitor, reversed the inhibitory effect of IPA on LPS-induced production of pro-inflammatory cytokines in RAW264.7 cells. Therefore, IPA exerts an anti-inflammatory effect via the AMPK/GSK3β/Nrf2 signaling pathway in macrophages. Taken together, the findings suggest that IPA has preventive potential for inflammation-related diseases.

Impressic Acid, a Lupane-Type Triterpenoid from Acanthopanax koreanum, Attenuates TNF-α-Induced Endothelial Dysfunction via Activation of eNOS/NO Pathway

Atherosclerosis is one of the most reported diseases worldwide, and extensive research and trials are focused on the discovery and utilizing for novel therapeutics. Nitric oxide (NO) is produced mainly by endothelial nitric oxide synthase (eNOS) and it plays a key role in regulating vascular function including systemic blood pressure and vascular inflammation in vascular endothelium. In this study hypothesized that Impressic acid (IPA), a component isolated from Acanthopanax koreanum, acts as an enhancer of eNOS activity and NO production. IPA treatment induced eNOS phosphorylation and NO production, which was correlated with eNOS phosphorylation via the activation of JNK1/2, p38 MAPK, AMPK, and CaMKII. In addition, the induction of eNOS phosphorylation by IPA was attenuated by pharmacological inhibitor of MAPKs, AMPK, and CaMKII. Finally, IPA treatment prevented the adhesion of TNF-α-induced monocytes to endothelial cells and suppressed the TNF-α-stimulated ICAM-1 expression via activation of NF-κB, while treatment with L-NAME, the NOS inhibitor, reversed the inhibitory effect of IPA on TNF-α-induced ICAM-1 expression via activation of NF-κB. Taken together, these findings show that IPA protects against TNF-α-induced vascular endothelium dysfunction through attenuation of the NF-κB pathway by activating eNOS/NO pathway in endothelial cells.

Quantitative determination of 15 bioactive triterpenoid saponins in different parts of Acanthopanax henryi by HPLC with charged aerosol detection and confirmation by LC-ESI-TOF-MS

Triterpenoid saponins are difficult to analyze using high-performance liquid chromatography coupled to UV/vis spectrophotometry due to their lack of chromophores. This study describes the first analytical method for the determination of 15 triterpenoid saponins from the leaves, stems, root bark, and fruits of Acanthopanax henryi, using a high-performance liquid chromatography with charged aerosol detection coupled with electrospray ionization mass spectrometry method. The separation was carried out on a Kinetex XB-C18 column with an acetonitrile/water gradient as the mobile phase, followed by charged aerosol detection. The operating conditions of charged aerosol detection were set at 24 kPa for nitrogen pressure and 100 pA for the detection range. Liquid chromatography with electrospray ionization mass spectrometry is described for the identification of compounds in plant samples. The electrospray ionization mass spectrometry method involved the use of the [M + Na](+) and [M + NH4 ](+) ions for compounds 1-15 in the positive ion mode with an extracted ion chromatogram. The developed method was fully validated in terms of linearity, sensitivity, precision, repeatability, and recovery, then subsequently applied to evaluate the quality of A. henryi.

Inhibition of Lung Inflammation by Acanthopanax divaricatus var. Albeofructus and Its Constituents

In order to find potential therapeutic agents on lung inflammatory conditions, the extracts of Acanthopanax divaricatus var. albeofructus were prepared and its constituents were isolated. They include lignans such as (+)-syringaresinol (1), acanthoside B (2), salvadoraside (3) and acanthoside D (4), lariciresinol-9-O-β-D-glucopyranoside (5) and phenylpropanoids such as 4-[(1E)-3-methoxy-1-propenyl]phenol (6), coniferin (7), and methyl caffeate (8). The extracts and several constituents such as compound 1, 6 and 8 inhibited the production of inflammatory markers, IL-6 and nitric oxide, from IL-1β-treated lung epithelial cells and lipopolysaccharide (LPS)-treated alveolar macrophages. Furthermore, the extracts and compound 4 significantly inhibited lung inflammation in lipolysaccharide-treated acute lung injury in mice by oral administration. Thus it is suggested that A. divaricatus var. albeofructus and its several constituents may be effective against lung inflammation.

Terpenoid composition and the anticancer activity of Acanthopanax trifoliatus

The petroleum ether and ethyl acetate fractions of extract from an edible and medicinal plant Acanthopanax trifoliatus were found to show significant inhibitory effects against SF-268, MCF-7, HepG2 and NCI-H460 cancer cells. Two new ursane-type triterpenoids, acantrifoic acid C (1) and acantrifoic acid D (2), along with five known triterpenoids (3-7) and eight known diterpenoids (8-15) were obtained from these two fractions. To the best of our knowledge, this is the first report concerning the isolation of compounds (5-12, 14, 15) from A. trifoliatus. Among all the isolated compounds, 3, 5 and 8 from the ethyl acetate fraction showed the strongest inhibitory effects against cancer cells, while 12 and 13 from the petroleum ether fraction showed moderate activities. These terpenoid compounds may be responsible for the anticancer activities of A. trifoliatus. Our study provides the first evidence that terpenoids from A. trifoliatus exert anticancer activities and indicates that A. trifoliatus may be a useful edible plant for further development of anticancer health supplement.

Phenolic components from the stem of Acanthopanax koreanum and their inhibitory effects on NF-kappa B

Two novel phenolic glucosides (1-2), as well as seven known compounds (3-9), were isolated from the stem of Acanthopanax koreanum; their chemical structures were determined by chemical and spectroscopic methods and subsequently compared with previously reported data. Their inhibition of nuclear factor kappa B (NF-κB) was measured in human embryonic kidney (293T) cells by using an NF-κB luciferase assay.

Sterols isolated from seeds of Panax ginseng and their antiinflammatory activities

Background:

Panax ginseng C. A. Meyer, a perennial herb from the Araliaceae family, is a commonly used medicinal plant. Many studies have been conducted on the biologically active constituents of whole parts of P. ginseng (i.e., roots, leaves, flower buds, and fruits). However, the seeds of P. ginseng have not been intensively investigated. A new sterol glucoside,3-O-b-d-glucopyranosyl-5,22,24-stigmastatrienol (1), and a known sterol, 5,22-stigmastadienol (2), were isolated from seeds of P. ginseng and were evaluated for their inhibitory activities on tumor necrosis factor (TNF)α-induced nuclear factor (NF)-κB and inducible nitric oxide synthase (iNOS) transcription in transfected HepG2 cells. The present work deals with the isolation, identification, and antiinflammatory activities of the two compounds.

Materials and Methods:

The compounds were isolated by a combination of silica gel and YMC R-18 column chromatography, and their structures were identified by analysis of spectroscopic data (1D, 2D-NMR, and MS). The antiinflammatory activities of the isolated compounds 1 and 2 were evaluated by luciferase reporter gene assays.

Results:

Two sterols have been isolated from the seeds of P. ginseng. Compound 1 is a previously unreported glucosidyl sterol. Compounds 1 and 2 both inhibited NFκB-luciferase activity, with IC₅₀ values of 8.1 and 4.8΅M, respectively. They also inhibited iNOS-luciferase activity in TNFα-induced HepG2 cells, with IC₅₀ values of 2.2 and 2.9΅M, respectively.

Conclusion:

The two isolatedsterols have inhibitory effects on inflammation-related factors in HepG2 cells, as determined by luciferase reporter gene assays. Thus, seeds of P. ginseng are worthy of consideration for the development and research of antiinflammatory agents.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids, including squalene derivatives, protostanes, lanostanes, holostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes and saponins; 305 references are cited.

Effects of impressic acid from Acanthopanax koreanum on NF-κB and PPARγ activities

Impressic acid, 3α,11α-dihydroxylup-20(29)-en-28-oic acid, is a lupane-type triterpenoid isolated from Acanthopanax koreanum, which has been used as a Korean folk medicine for rheumatism, hepatitis, diabetes, and inflammatory disorders. Recently, it was reported that impressic acid has inhibitory effects on the LPS-stimulated pro-inflammatory cytokine production in bone marrow-derived dendritic cells and on the nuclear factor of activated T-cells transcription factor activity. Thus, to investigate whether impressic acid has effects on the inhibition of nuclear factor kappa B (NF-κB) and activation of peroxisome proliferator-activated receptor gamma (PPARγ), luciferase reporter assays were used. The effects on the expression of NF-κB and PPARγ target genes were also examined by reverse transcription-polymerase chain reaction. In this study, impressic acid was found to inhibit tumor necrosis factor (TNF)-α induced NF-κB activity and to up-regulate transcriptional activity of PPARγ.

Components from the Steamed Leaves of Acanthopanax koreanum and their Effects on PPAR Activity in HepG2 Cells

Three ent-kaurane diterpenes (1-3), four lupane-triterpene glycosides (4-7), and an oleanane-triterpene glycoside (8) were isolated from the ethyl acetate and water extracts of the steamed leaves of Acanthopanax koreanum using a combination of various column chromatographies. The structures of the isolates were determined by 1H-, 13C-NMR spectroscopy and mass spectrometry. To investigate the biological effects of the eight compounds (1-8) on peroxisome proliferator-activated receptor gamma (PPARγ), luciferase reporter assays were used. Among the tested compounds, ent-kaur-16-en-19-oic acid (1), 16α-hydroxy- ent-kauran-19-oic acid (2), and 17-hydroxy- ent-kaur-15-en-19-oic acid (3) showed considerable effects on PPARγ activity, compared with the positive control, troglitazone. To evaluate specificity and sensitivity of the active compounds (1-3) in the regulation of transactivation of PPARs, Gal4-PPARs-LBD luciferase reporter assays were examined. In this study, the three ent-kaurane diterpenes (1-3) were found to up-regulate PPARβ/δ and PPARγ activities, whereas they did not activate PPARα activity.

Isoconiferoside, a new phenolic glucoside from seeds of Panax ginseng

A new phenolic glucoside, isoconiferoside (1), was isolated from the seeds of Panax ginseng (Araliaceae). The structure was determined to be 9-O-[β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl]-trans-coniferyl alcohol based on spectroscopic analyses (¹H- and ¹³C-NMR, DEPT, COSY, HMQC, and HMBC) and acid hydrolysis.

New monoterpene glycosides and phenolic compounds from Distylium racemosum and their inhibitory activity against ribonuclease H

Two new monoterpene glycosides, distyloside A-B (1-2), and a new megastigmane glucoside, iso-dihydrodendranthemoside A (3) were isolated from twigs and leaves of Distylium racemosum, along with five known phenolic compounds (4-8). The structures were established via spectroscopic techniques and chemical transformations, and the absolute stereochemistry of 3 was determined by Mosher's esterification. A homogeneous fluorescence resonance energy transfer (FRET) quenching assay was used to determine the inhibitory activity of isolates (1-8) on the ribonuclease H enzymes from HIV-1, 2, human, and Escherichia coli. Among them, 6″-O-galloylsalidroside (6) showed potent inhibitory effects with an IC(50) value of 3.5 μM on HIV-2, and 1.7 μM on human RNase H, respectively.