Hae Ju Ko

Phenolic compounds with IL-6 inhibitory activity from Aster yomena

A new biflavonoid, named asteryomenin (1), as well as six known phenolic compounds, esculetin (2), 4-O-β-d-glucopyranoside-3-hydroxy methyl benzoate (3), caffeic acid (4), isoquercitrin (5), isorhamnetin-3-O-glucoside (6), and apigenin (7) were isolated from the aerial parts of Aster yomena. The structures of compounds (1–7) were identified based on 1D and 2D NMR, including 1H–1H COSY, HSQC, HMBC and NOESY spectroscopic analyses. Compounds 2–7 were isolated from this plant for the first time. For these isolates, the inhibitory activity of IL-6 production in the TNF-α stimulated MG-63 cell was examined. Among these isolates, compounds 4 and 7 appeared to have potent inhibitory activity of IL-6 production in the TNF-α stimulated MG-63 cell, while compounds 1–3 and 5–6 showed moderate activity.

Moracin M inhibits airway inflammation by interrupting the JNK/c-Jun and NF-κB pathways in vitro and in vivo.

The therapeutic effectiveness of moracins as 2-arylbenzofuran derivatives against airway inflammation was examined. Moracin M, O, and R were isolated from the root barks of Morus alba, and they inhibited interleukin (IL)-6 production from IL-1β-treated lung epithelial cells (A549) at 101-00μM. Among them, moracin M showed the strongest inhibitory effect (IC50=8.1μM). Downregulation of IL-6 expression by moracin M was mediated by interrupting the c-Jun N-terminal kinase (JNK)/c-Jun pathway. Moracin derivatives inhibited inducible nitric oxide synthase (iNOS)-catalyzed NO production from lipopolysaccharide (LPS)-treated alveolar macrophages (MH-S) at 50-100μM. In particular, moracin M inhibited NO production by downregulating iNOS. When orally administered, moracin M (20-60mg/kg) showed comparable inhibitory action with dexamethasone (30mg/kg) against LPS-induced lung inflammation, acute lung injury, in mice with that of dexamethasone (30mg/kg). The action mechanism included interfering with the activation of nuclear transcription factor-κB in inflamed lungs. Therefore, it is concluded that moracin M inhibited airway inflammation in vitro and in vivo, and it has therapeutic potential for treating lung inflammatory disorders.

Chemical constituents on the aerial parts of Artemisia selengensis and their IL-6 inhibitory activity

Ten compounds, 1′,3′-propanediol,2′-amino-1′-(1,3-benzodioxol-5-yl) (1), artanomaloide (2), canin (3), eupatilin (4), quercetin-3-O-β-d-glucoside-7-O-α-l-rhamnoside (5), 1,3-di-O-caffeoylquinic acid (6), isoquercitrin (7), pinoresinol-4-O-β-d-glucoside (8), scopolin (9), and isofraxidin-7-O-β-d-glucopyranoside (10) were isolated from the aerial parts of A. selengensis. The structures of compounds (1–10) were identified based on 1D and 2D NMR, including 1H–1H COSY, HSQC, HMBC and NOESY spectroscopic analyses. Among them, compound 1 was isolated from this plant for the first time as a naturally occurring compound. The inhibitory activity of these isolated compounds against interleukin-6 (IL-6) production in TNF-α stimulated MG-63 cells was also examined.

The memory-enhancing effect of erucic acid on scopolamine-induced cognitive impairment in mice.

Erucic acid is a monounsaturated omega-9 fatty acid isolated from the seed of Raphanus sativus L. that is known to normalize the accumulation of very long chain fatty acids in the brains of patients suffering from X-linked adrenoleukodystrophy. Here, we investigated whether erucic acid enhanced cognitive function or ameliorated scopolamine-induced memory impairment using the passive avoidance, Y-maze and Morris water maze tasks. Erucic acid (3mg/kg, p.o.) enhanced memory performance in normal naïve mice. In addition, erucic acid (3mg/kg, p.o.) ameliorated scopolamine-induced memory impairment, as assessed via the behavioral tasks. We then investigated the underlying mechanism of the memory-enhancing effect of erucic acid. The administration of erucic acid increased the phosphorylation levels of phosphatidylinositide 3-kinase (PI3K), protein kinase C zeta (PKCζ), extracellular signal-regulated kinase (ERK), cAMP response element-binding protein (CREB) and additional protein kinase B (Akt) in the hippocampus. These results suggest that erucic acid has an ameliorative effect in mice with scopolamine-induced memory deficits and that the effect of erucic acid is partially due to the activation of PI3K-PKCζ-ERK-CREB signaling as well as an increase in phosphorylated Akt in the hippocampus. Therefore, erucic acid may be a novel therapeutic agent for diseases associated with cognitive deficits, such as Alzheimers disease.

A new megastigmane glycoside from Akebia quinata

A new megastigmane glycoside, 8S*,9R*-megastigman-3-one-4,6-diene-8,9-diol-9-O-β-d-glucopyranoside, named akequintoside D (1), as well as six known compounds, roseoside II (2), 3-O-caffeoylquinic acid (3), methyl-3-O-caffeoylquinate (4), 3,4,5-trimethoxyphenyl-β-d-glucopyranoside (5), cuneataside D (6), 3,4-dimethoxyphenyl-6-O-(α-l-rhamnopyranosyl)-β-d-glucopyranoside (7) were isolated from the stem of Akebia quinata. The structures of compounds (1-7) were identified based on 1D and 2D NMR, including 1H–1H COSY, HSQC, HMBC and NOESY spectroscopic analyses. The inhibitory activity of these isolated compounds against interleukin-6 (IL-6) production in TNF-α stimulated MG-63 cells was also examined.

Oleanane triterpenoids from Akebiae Caulis exhibit inhibitory effects on Aβ42 induced fibrillogenesis.

Previous phytochemical investigations of Akebiae Caulis resulted in the isolation of triterpenes, triterpene glycosides, phenylethanoid glycosides and megastigmane glycoside. Amyloid beta (Aβ), the main component of the senile plaques detected in Alzheimer’s disease, induces cell death. However, only a limited number of studies have addressed the biological and pharmacological effects of Akebiae Caulis. In particular, the inhibitory activity of Akebiae Caulis against Aβ42 fibrillogenesis remains unclear. Herein, a new triterpene glycoside, akequintoside F (1), along with nine known compounds pulsatilla saponin A (2), collinsonidin (3), akebonic acid (4), hederagenin (5), 1-(3′,4′-dihydroxycinnamoyl) cyclopentane-2,3-diol (6), asperosaponin C (7), leontoside A (8), quinatic acid (9), and quinatoside A (10) were isolated from Akebiae Caulis using repeated column chromatography with silica gel, LiChroprep RP-18, and MCI gel. The chemical structures of compounds 1–10 were illustrated based on 1D and 2D NMR spectroscopy, including 1H-1H COSY, HSQC, HMBC and NOESY spectroscopic analyses. Compound 1 a novel compound and known compounds 6 and 7 were isolated for the first time from this plant. Among these compounds, 1, 3, 4, 5 and 7 displayed significant inhibitory effects on Aβ42 induced fibrillogenesis. We present the first report of new compound 1 and the inhibitory effects of components from Akebiae Caulis on Aβ42 fibrillogenesis.