Unwoo Kang

Heme oxygenase-1-mediated anti-inflammatory effects of tussilagonone on macrophages and 12-O-tetradecanoylphorbol-13-acetate-induced skin inflammation in mice

The dried flower buds of Tussilago farfara L. have been used in traditional medicine, mainly as an antitussive in the treatment of cough and other respiratory problems. In the present study, we investigated the anti-inflammatory signaling pathway via the upregulation of heme oxygenase-1 (HO-1) in response to tussilagonone (TGN), a sesquiterpene compound isolated from T. farfara. TGN induced HO-1 expression and nuclear factor-E2-related factor 2 (Nrf2) activation in RAW 264.7 cells. Nuclear translocation of Nrf2 by TGN also increased in a time- and dose-dependent manner, indicating that TGN induced HO-1 via the Nrf2 pathway. Consistent with the notion that HO-1 has anti-inflammatory properties, TGN suppressed inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression and reduced the mRNA expression of proinflammatory cytokines, as well as nitric oxide (NO) and prostaglandin E2 (PGE2) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. TGN inhibited the phosphorylation and degradation of inhibitory κB-α (IκB-α) and the nuclear translocation of nuclear factor (NF)-κB. However, a specific inhibitor of HO-1 reversed the TGN-mediated suppression of NO production and knockdown of HO-1 by small interfering RNA abrogated inhibitory effects of TGN on iNOS and COX-2 protein expression and NF-κB nuclear translocation. Furthermore, TGN reduced iNOS and COX-2 expression in a 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin inflammation mouse model. Taken together, these findings suggest an important role for TGN-induced HO-1 activation in regulating inflammatory responses. Moreover, TGN is a potent therapeutic candidate for targeting the crosstalk between Nrf2/HO-1 and the NF-κB signaling pathway in the prevention or treatment of inflammation-associated diseases.

A new secoiridoid glycoside from the fruits of Cornus officinalis (Cornaceae).

Abstract A new secoiridoid glycoside, 7β-O-dimethyl butanedioate morroniside (1) was isolated from the fruits of Cornus officinalis (Cornaceae) along with the known compound, caffeoyltartaric acid dimethyl ester (2) which was isolated from the family Cornaceae for the first time. Their structures were elucidated by physical and spectroscopic data analysis, including 1D and 2D NMR, ESI-MS and CD experiments. Graphical Abstract

A Comparative Study on Hulled Adlay and Unhulled Adlay through Evaluation of Their LPS‐Induced Anti‐Inflammatory Effects, and Isolation of Pure Compounds

Coicis semen (=the hulled seed of Coix lacryma‐jobi L. var. ma‐yuen (Rom.Caill.) Stapf; Gramineae), commonly known as adlay and Jobs tears, is widely used in traditional medicine and as a nutritious food. Bioassay‐guided fractionation of the AcOEt fraction of unhulled adlays, using measurement of nitric oxide (NO) production on lipopolysaccharide (LPS)‐stimulated RAW 264.7 macrophage cells, led to the isolation and identification of two new stereoisomers, (+)‐(7′S,8′R,7″S,8″R)‐guaiacylglycerol β‐O‐4′‐dihydrodisinapyl ether (1) and (+)‐(7′S,8′R,7″R,8″R)‐guaiacylglycerol β‐O‐4′‐dihydrodisinapyl ether (2), together with six known compounds, 3–8. Compounds 3 and 4 exhibited inhibitory activities on LPS‐induced NO production with IC50 values of 1.4 and 3.7 μM, respectively, and suppressed inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2) protein expressions in RAW 264.7 macrophage cells. Simple high‐performance liquid chromatography with ultraviolet detection (HPLC/UV) was used to compare the AcOEt fraction of unhulled adlays responsible for the anti‐inflammatory activity in RAW 264.7 cells and the inactive AcOEt fraction of hulled adlays.

Identification of cytoprotective constituents of the flower buds of Tussilago farfara against glucose oxidase-induced oxidative stress in mouse fibroblast NIH3T3 cells and human keratinocyte HaCaT cells

A new cytoprotective compound, 1-[(4S)-3,4-dihydro-4-hydroxy-2,2-dimethyl-2H-1-benzopyran-6-yl]-ethanone (1) was isolated from the flower buds of Tussilago farfara L. (Compositae), together with eight known compounds, 3,4-dicaffeoyl isoquinic acid (2), trans-cinnamic acid (3), 4-hydroxyacetophenone (4), 4,5-dicaffeoylquinic acid methyl ester (5), 3,5-dicaffeoylquinic acid methyl ester (6), 4-hydroxybenzoic acid (7), isoquercetrin (8), and ligucyperonol (9). Compounds 2–4 were found in this plant for the first time. The isolates 1–9, were tested for their cytoprotective activities against glucose oxidase-induced oxidative stress in mouse fibroblast NIH3T3 cells and human keratinocyte HaCaT cells. Among them, 1 and 3 showed significant cytoprotective activities as determined by MTT assay and lactate dehydrogenase leakage, indicating their possibility as the potent cytoprotective agents. The structure of 1 was determined by spectroscopic data analysis including 1D- and 2D-NMR experiments, and its absolute configuration was elucidated by a circular dichroism.

CHEMICAL CONSTITUENTS OF THE RADICES OF Angelica tenuissima

Angelica tenuissima Nakai (=Ligusticum tenuissimum Kitagawa, Umbelliferae) is widely used to treat headache, diarrhea, epilepsy, and rheumatic arthralgias in oriental traditional medicine [1]. There have been phytochemical reports on various types of compounds from this plant, including phthalides, coumarins, terpenoids, and phenylpropanoids [2, 3]. Some of these compounds were found to have diverse biological activities such as antioxidative [3], anticancer [4], angiotensin converting enzyme (ACE) inhibitory [5], and antifungal [6] effects. In the present study, eight compounds, 3-butylidene-4hydroxyphthalide (1) [7], senkyunolide B (2) [8], senkyunolide C (3) [8], wallichilide (4) [9], calycanthoside (5) [10], 2-methoxy2-(4 -hydroxyphenyl)ethanol (6) [11], succinic acid (7) [12], and docosanoic acid (8) [13] were isolated from A. tenuissima by various chromatographic techniques. The structures of 1–8 were identified by interpretation of their 1D and 2D NMR spectroscopic data as well as by comparison with the published values. To the best of our knowledge, this is the first report on the isolation of compounds 1–8 from A. tenuissima.

Tussilagonone-induced Nrf2 pathway activation protects HepG2 cells from oxidative injury

Tussilagonone is a compound derived from the medicinal plant Tussilago farfara L., which is used as a traditional medicine for respiratory diseases, including asthma and pneumonia. Recent reports suggest that tussilagonone exhibits anti-inflammatory effects; however, the scope of protective functions has not been elucidated yet. In this study, we demonstrate that tussilagonone enhances cellular detoxification by increasing quinone reductase activity in Hepa1c1c7 cells. In addition, tussilagonone decreased tert-butyl hydroperoxide(t-BHP)-induced ROS production and cell death, suggesting that it also acts as a potent antioxidant. To verify the molecular mechanism underlying tussilagonone activity, we examined the expression of nuclear factor erythroid 2-related factor 2(Nrf2)-a transcription factor that regulates antioxidant protein expression-in HepG2 cells. Significantly, these results showed that tussilagonone induces Nrf2 activation and nuclear accumulation, resulting in the upregulation of the detoxifying enzymes NAD(P)H quinone dehydrogenase 1(NQO1) and heme oxygenase-1(HO-1) that protect cells from oxidative stress. Further molecular analyses revealed that tussilagonone-induced Nrf2 activation was mediated by ERK1/2 in HepG2 cells. Collectively, these data indicate that tussilagonone attenuates t-BHP-induced ROS and activates quinone reductase activity via Nrf2 pathway activation and target gene expression, and thereby acts as an antioxidant that protects HepG2 cells from oxidative stress and associated damage.

Chemical Constituents of the Leaves of Vitis labruscana cv. Steuben

There are ten thousand grape varieties (the genus Vitis, the family Vitaceae) in the world. Vitis labruscana cv. Steuben (Wayne Sheridan) is one of them and was produced from an interspecific cross in New York, United States. It features large clusters of blue slipskin grapes with fruity and spicy tastes. The cultivar is also favored as an arbor grape due to its natural red fall color [1]. Thus far, there has been no study on the phytochemical constituents of this cultivar. As part of our ongoing research to find bioactive compounds from leaves of grapes [2, 3], we investigated V. labruscana cv. Steuben which were collected from the Oha Farm in Ansung, South Korea, in September 2010. A voucher specimen was identified by Prof. Nam Sook Lee (Ewha Womans University, Seoul 03760, Korea) and was deposited at the Natural Product Chemistry Laboratory, College of Pharmacy, Ewha Womans University, Korea, under accession number EA313. In the present study, the BuOH-soluble extract of the leaves of V. labruscana cv. Steuben was investigated, leading to the isolation of 12 known compounds: quercetin (1) [4], quercetin-3-O-D-glucoside (2) [5], quercetin-3-O-D-glucuronide (3) [4, 6], quercetin-3-O-D-glucuronide 6 -methyl ester (4) [3, 7], kaempferol-3-O-D-glucuronide (5) [3, 4], resveratrol (6) [8], icariside B1 (7) [9], (–)-(3R,9S)-3-hydroxy-7,8-dihydro-ionol 9-O-D-glucoside (8) [10–12], gentisic acid 5-OD-glucopyranoside (9) [13, 14], hydrangeifolin I (10) [15], (+)-cis-viniferin (11) [16], and (+)-viniferin (12) [17]. The structures of 1–12 were identified by interpretation of their physical ([ ]D) and spectroscopic (1H, 13C, COSY, NOESY, HSQC, and HMBC NMR, and HR-ESI-MS) data as well as by comparison with the published values. To the best of our knowledge, this is the first report on the phytochemical constituents of V. labruscana cv. Steuben. Furthermore, 8 has not been identified from the family Vitaceae.

Dehydrocostus lactone, a sesquiterpene from Saussurea lappa Clarke, suppresses allergic airway inflammation by binding to dimerized translationally controlled tumor protein

BACKGROUND We previously reported that the biologically active form of histamine releasing factor (HRF) is dimerized translationally controlled tumor protein (dTCTP) which is involved in a number of allergic diseases. HYPOTHESIS/PURPOSE Hoping that agents that modulate dTCTP may provide new therapeutic targets to allergic inflammatory diseases, we screened a library of natural products for substances that inhibit dTCTP. One such inhibitor we found was dehydrocostus lactone (DCL), a natural sesquiterpene present in rhizome of Saussurea lappa Clarke, the subject of this study. METHODS We evaluated the therapeutic efficacy of DCL in a mouse model of ovalbumin (OVA)-induced allergic airway inflammation, employing the ELISA system using BEAS-2B cells and splenocytes, and confirmed that DCL interacts with dTCTP using SPR assay. RESULTS DCL inhibited dTCTP-induced secretion of IL-8 in BEAS-2B cells. From kinetic analysis of dTCTP and DCL, we found that KD value was 5.33 ± 0.03 μM between dTCTP and DCL. DCL also significantly reduced inflammatory lung eosinophilia, type 2 cytokines in BALF, as well as OVA specific IgE and mucus production in a mouse model of ovalbumin induced allergy. Moreover, DCL suppressed NF-κB activation. CONCLUSION DCLs therapeutic potential in allergic airway inflammation is based on its anti-inflammatory activity of suppressing the function of dTCTP.

Chemical Constituents of the Leaves of Brassica oleracea var. acephala

The family Brassicaceae consists of about 350 genera, 13 tribes, and 3200 species. Brassica oleracea species, which belongs to this family, include cabbage (B. oleracea var. capitata), cauliflower (B. oleracea var. botrytis), broccoli (B. oleracea var. italica), brussel sprout (B. oleracea var. gemmifera), and kale (B. oleracea var. acephala) [1]. Although B. oleracea species have been reported to contain isothiocyanates [2, 3], glucosinolates [4–6], vitamins [7, 8], carotenoids [8, 9], phenolics [8, 10], polyphenols [11], and anthocyanins [12], and showed anioxidant [8, 11, 13], antiulcer [14], and anticancer activities [2, 13], there have not been many phytochemical investigations on the single species of B. oleracea var. acephala. In the present phytochemical study, 13 known compounds (1–13) were isolated from the leaves of B. oleracea L. var. acephala DC. The isolates include 1-methoxyindole-3-acetonitrile (1) [15], 4-methoxyindole-3-acetonitrile (2) [16], methyl indole-3-acetate (3) [17], methyl 1-methoxyindole-3-acetate (4) [18], nicotinamide (5) [19], byzantionoside B (6) [20], (9R)-4-oxo-β-inol β-D-glucopyranoside (7) [21], (9S)-4-oxo-β-inol β-D-glucopyranoside (8) [20, 21], phlomisionoside (9) [22], icariside D2 (10) [23], adenine (11) [24], adenosine (12) [25], and uridine (13) [26]. Their structures were determined by analysis of their physical ([α]D) and spectroscopic ( 1H, 13C, COSY, NOESY, HSQC, and HMBC NMR, ESIMS and circular dichroism (CD)) data as well as by comparison of their data with the published values. All compounds were isolated from B. oleracea var. acephala for the first time. Moreover, to the best of our knowledge, compounds 6–9 have never been reported previously from Brassicaceae. General Methods. Optical rotations, P-1010 polarimeter (JASCO, Japan); circular dichroism, J-715 CD/ORD spectropolarimeter (JASCO, Japan); 1D and 2D NMR, UNITY INOVA 400 MHz FT-NMR (Varian, CA, USA); ESI-MS, Waters Q-TOF micromass spectrometer (USA); column chromatography (CC), silica gel (230–400 mesh, Merck, Germany), YMC Gel ODS-A (S-150 μm, YMC Co., Ltd., Japan), and Sephadex LH-20 (GE Healthcare Bio-Sciences AB, Sweden); TLC, Kieselgel 60 F254 and RP-18 F254s silica gel plates (Merck, Germany), compounds observed with UV light (254 and 365 nm) and visualized using 10%, v/v, sulfuric acid spray followed by heating (120°C, 5 min); HPLC, Waters (1525 and 2487) equipped with YMC-Pack Pro C18 (5 μm, 250 × 20 mm i.d.); MPLC, CombiFlash equipped with RediSepRf (13 g C18 Column, reversed phase).

Isoquinoline Alkaloids from Corydalis pallida

Corydalis pallida (Thunb.) Pers. (Papaveraceae) has been used as a traditional medicine for removing fever, toxins, and edema in Southeast Asia [1]. There have not been many researches on the single species of C. pallida, although some alkaloids have been isolated from C. pallida [2], mixtures of C. pallida and C. montana [3], mixtures of C. pallida and C. aurea [4], or mixtures of C. pallida and C. bulbosa [5]. Several Corydalis plants were reported to have diverse biological activities such as chemopreventive [6], antitumor [2, 6–8], gastrointestinal motility inducing [9], anti-inflammatory [10], and anti-allergic [11] activities from the major constituents, isoquinoline alkaloids. As part of our ongoing research to find bioactive compounds from traditional herbal medicines [2], phytochemical investigations on the ethyl acetate extract of the whole plants of C. pallida resulted in the isolation of six known protoberberine alkaloids, (–)-corydalidzine (1) [12–14], (–)-corybulbine (2) [11, 12, 15, 16], (–)-yuanhunine (3) [11], (–)-ophiocarpine (4) [14, 17], dehydrocorydaline (5) [18], and 8-oxocoptisine (6) [19] and a benzophenanthridine alkaloid, 6-acetonyldihydrosanguinarine (7) [20]. Their structures were determined by analysis of their physical ([α]D) and spectroscopic (1H, 13C, COSY, NOESY, HSQC, and HMBC NMR, and HR-ESI-MS) data as well as by comparison with the published values. To the best of our knowledge, all isolates 1–7 have not been isolated from the single species of C. pallida previously. The dried and milled whole plants of C. pallida (2.4 kg) were extracted with 95% MeOH (3 L × 10) overnight at room temperature. The MeOH extract (500 g) was then suspended in water (1 L) and partitioned with n-hexane (2 L × 8), EtOAc (2 L × 6), and n-BuOH (2 L × 5), sequentially. The EtOAc fraction (25 g) was subjected to column chromatography (CC; SiO2 (500 g), 0–50% MeOH–CH2Cl2; Frs. I–XI). Fraction III (5 g) was subjected to CC (SiO2 (400 g), 1–100% MeOH–CHCl3), yielding 4 (140 mg) and subfractions (Subfrs. III-1–III-18). The combined subfraction III-1–III-3 (156 mg) was chromatographed over Sephadex LH-20 (100% MeOH), furnishing 6 (4 mg). Fraction II (350 mg) was subjected to CC (SiO2 (50 g), 5–50% n-hexane–EtOAc; Subfrs. II-1–II-12). Compound 7 (21 mg) was purified from subfraction II-6 (1.2 g) by CC (ODS-A (50 g), 20–50% MeOH–H2O). Fraction VI (1.25 g) was subjected to CC (SiO2 (100 g), 1.5–17% MeOH– CHCl3; Subfrs. VI-1–VI-12). Compound 3 (40 mg) was isolated from subfraction VI-2 (684 mg) by repeated CC (SiO2 (50 g), 1–9% MeOH–CHCl3). Passage over Sephadex LH-20 (2% CHCl3–MeOH) of the combined subfractions VI-6 and VI-7 (100 mg), afforded 1 (20 mg). Fraction IV (2.83 g) was subjected to CC (SiO2 (200 g), 1.5–17% MeOH–CHCl3), yielding 2 (35 mg). Fraction VIII (1.57 g) was subjected to CC (SiO2 (70 g), 1–25% MeOH–CHCl3), affording 5 (30 mg).