IkSoo Lee

Vitexin, orientin and other flavonoids from Spirodela polyrhiza inhibit adipogenesis in 3T3‐L1 cells

To investigate the adipogenesis inhibitory effect on lipid accumulation, 3T3‐L1 cells were treated with fractions and isolated flavonoids of Spirodela polyrhiza. An ethanol extract of S. polyrhiza was fractionated into three fractions. The butanol soluble fraction (SPB) exhibited potent antiadipogenesis activity and decreased C/EBPα and PPARγ protein expression level in 3T3‐L1 cells without significant cytotoxicity. The flavonoids were isolated from SPB and their chemical structures were identified as chrysoeriol (1), apigenin (2), luteolin (3), vitexin (4), cosmosin (5), orientin (6) and luteolin‐7‐O‐β‐d‐glucoside (7) by spectroscopic analysis. Studies on the adipogenesis and intracellular triglyceride accumulation inhibitory effect showed that compounds 4 and 6 had the highest activity and decreased C/EBPα and PPARγ protein expression level in 3T3‐L1 cells. These results suggest that the flavonoids isolated from SPB, especially compounds 4 and 6, contribute to the inhibitory activity of S. polyrhiza in 3T3‐L1 cells. Copyright

Antioxidant and lipoxygenase inhibitory activity of oligostilbenes from the leaf and stem of Vitis amurensis.

ETHNOPHARMACOLOGICAL RELEVANCE The root and stem of Vitis amurensis (Vitaceae) have popularly used as traditional medicine for treatment of cancer and various pains in Korea and Japan. Recent studies, its root and stem possess anti-inflammatory, anti-tumor activities, and protective effects against beta-amyloid-induced oxidative stress. AIM OF THE STUDY This study deals with the isolation, structural identification of the potent bioactive compounds from the leaf and stem, and their antioxidant capacity, as well as anti-inflammatory effect via lipoxygenase inhibitory assay. MATERIALS AND METHODS All isolated compounds yielded after using column chromatography were identified base on the physico-chemical properties and 1D, 2D NMR spectra. The scavenge ability against DPPH and ABTS(+) radicals, and to inhibit lipid peroxidation, as well as lipoxygenase type I inhibitory activity of all isolates were performed using in vitro assays. RESULTS Eleven resveratrol derivatives (1-11), including a new oligostilbene cis-amurensin B (9), whose structures were determined on the basis of extensively spectral analyses, were isolated from the leaf and stem of Vitis amurensis. The isolates (1-11) were examined for their antioxidant activities by evaluating scavenge ability against DPPH and ABTS(+) radicals, and to inhibit lipid peroxidation. Stilbenes 1 and 4, and oligostilbenes 5-10 displayed moderate anti-lipid peroxidation activities, but all the isolates exhibited strong ABTS(+) radical scavenging activity in the dose-dependent manner. In addition, the isolates showed stronger inhibitory capacity against soybean lipoxygenase type I than that of baicalein, a positive control. Of the isolates, r-2-viniferin (8) exhibited the strongest scavenging activity against ABTS(+) radical with TEAC value of 5.57, and the most potential inhibitory effect on soybean lipoxygenase with the IC(50) value of 6.39 microM. CONCLUSION This is the first report on the potential antioxidant and LOX-1 inhibitory effects of oligostilbenes isolated from the leaf and stem of Vitis amurensis. In addition, chemical compositions isolated from the leaf and stem are almost similar to those isolated from the root of Vitis amurensis. Therefore, the results may explain, in part, the uses of the leaf and stem, as well as the root of Vitis amurensis in the Korean traditional medicine.

Selective cholinesterase inhibition by lanostane triterpenes from fruiting bodies of Ganoderma lucidum.

Two new lanostane triterpenes, named methyl ganoderate A acetonide (1) and n-butyl ganoderate H (2), were isolated from the fruiting bodies of Ganoderma lucidum together with 16 known compounds (3-18). Extensive spectroscopic and chemical studies established the structures of these compounds as methyl 7β,15α-isopropylidenedioxy-3,11,23-trioxo-5α-lanost-8-en-26-oate (1) and n-butyl 12β-acetoxy-3β-hydroxy-7,11,15,23-tetraoxo-5α-lanost-8-en-26-oate (2). Because new compounds exhibiting specific anti-acetylcholinesterase activity are being sought as possible drug candidates for the treatment of Alzheimers and related neurodegenerative diseases, compounds 1-18 were examined for their inhibitory activities against acetylcholinesterase and butyrylcholinesterase. All of the compounds exhibited moderate acetylcholinesterase-inhibitory activity, with IC(50) values ranging from 9.40 to 31.03μM. In contrast, none of the compounds except lucidadiol (13) and lucidenic acid N (14) exhibited butyrylcholinesterase-inhibitory activity at concentrations up to 200μM. These results indicate that these lanostane triterpenes are preferential inhibitors of acetylcholinesterase and may be suitable drug candidates.

Steroids and triterpenes from the fruit bodies of Ganoderma lucidum and their anti-complement activity.

To determine the anti-complement activity of natural triterpenes, chromatographic separation of the EtOAc-soluble fraction from the fruiting body of Ganoderma lucidum led to the isolation of three steroids and five triterpenoids. They were identified as ergosterol peroxide (1), ergosterol (2), genoderic acid Sz (3), stella sterol (4), ganoderic aic C1 (5), ganoderic acid A (6), methyl ganoderate A (7), and lucidenic acid A (8) based on spectroscopic evidence and physicochemical properties. These compounds were examined for their anti-complement activity against the classical pathway of the complement system. Compounds 2 and 3 showed potent anti-complement activity with IC50 values of 52.0 and 44.6 µM, respectively. Compound 1 exhibited significant inhibitory activity with an IC50 value of 126.8 µM, whereas compounds 4–8 were inactive. Our findings suggested that in addition to the ketone group at C-3, the Δ7(8), Δ9(11)-lanostadiene type triterpene also plays an important role in inhibiting the hemolytic activity of human serum against erythrocytes.

Lipoxygenase inhibitory constituents from rhubarb.

Phytochemical study on the ethanol extract of rhubarb led to the isolation of fifteen compounds, including five anthraquinones: chrysophanol (1), physcion (2), emodin (7), chrysophanol-8-O-β-d-glucopyranoside (9) and emodin-8-O-β-d-glucopyranoside (15), and ten stilbenes: desoxyrhaponticin (3), rhaponticin (4), resveratrol (5), desoxyrhapotigenin (6), rhapontigenin (8), piceatannol-3′-O-β-d-glucopyranoside (10), piceid (11), ε-viniferin (12), ampelopsin B (13) and isorhaponticin (14). Their structures were identified by comparing the physicochemical data with those of published papers. Among the isolated compounds, stilbene derivatives (3–6, 8 and 10–14) showed remarkable inhibitory effect on lipoxygenase with IC50 values ranging from 6.7 to 74.1 μM. The inhibition kinetics analyzed by Lineweaver-Burk plots found that they were competitive inhibitors with the linoleic acid at the active site of lipoxygenase. In addition, stilbenes exhibited significantly free radical scavenging activity against ABTS·+ with trolox equivalent activity capacity (TEAC) values ranging from 1.16 to 4.64. Whereas, anthraquinone derivatives (1–2, 7, 9 and 15) neither inhibited lipoxygenase nor scavenged free radical ABTS·+. These results indicated that stilbene derivatives were considerate to be mainly lipoxygenase inhibitor and free radical scavenger constituents of rhubarb.

Cytotoxic and COX-2 inhibitory constituents from the aerial parts ofAralia cordata

Three diterpenes (1, 8, and9), three triterpenes (3, 4, and7), one saponin (11), four sterols (2, 5, 6, and12), and one cerebroside (10) were isolated from the EtOH extract of the aerial parts ofAralia cordata by repeated silica gel column chromatography. Their chemical structures were identified by comparing their physicochemical and spectral data with those published in literatures. All isolated compounds were evaluated for their cytotoxicity against L 1210, K562, and LLC tumor cell lines using MTT assay. Of which, 3β, 5α-dihydroxy-6β-methoxyergosta-7,22-diene (6) showed a potent cytotoxicity against all cell lines with IC50 values of 11.7, 11.9, and 15.1 μM, respectively, while compounds1, 5, and11 showed a moderate or weak cytotoxicity. These isolates were also examined for their inhibitory activity against COX-1 and COX-2. Although most compounds, except for2, 10, and12, showed a strong inhibitory activity against COX-1, they exhibited a moderate or weak inhibitory activity against COX-2.

Iridoid glycosides from Gardeniae Fructus for treatment of ankle sprain.

The iridoid glycosides, genipin 1-O-beta-D-isomaltoside (1) and genipin 1,10-di-O-beta-D-glucopyranoside (2), together with six known iridoid glycosides, genipin 1-O-beta-D-gentiobioside (3), geniposide (4), scandoside methyl ester (5), deacetylasperulosidic acid methyl ester (6), 6-O-methyldeacetylasperulosidic acid methyl ester (7), and gardenoside (8) were isolated from an EtOH extract of Gardeniae Fructus. The structures and relative stereochemistries of the metabolites were elucidated on the basis of 1D- and 2D-NMR spectroscopic techniques, high-resolution mass spectrometry, and chemical evidence. Geniposide (4), one of the main compounds of Gardeniae Fructus, was tested for treatment of ankle sprain using an ankle sprain model in rats. From the second to fifth day, the geniposide (4) (100mg/ml) treated group exhibited significant differences (p<0.01) with approximately 21-34% reduction in swelling ratio compared with those of the vehicle treated control group. This indicated the potential effect of geniposide (4) for the treatment of disorders such as ankle sprain.

Acetylcholinesterase inhibitory effect of lignans isolated from Schizandra chinensis.

The hexane extract of the fruit ofSchizandra chinensis (Schisandraceae) was found to show significant inhibition of the activity of acetylcholinesterase enzyme (AChE). In further studies, fourteen lignans were isolated, and evaluated for their inhibitory effect on AChE. The compounds having both aromatic methylenedioxy and hydroxyl groups on their cyclooctadiene ring, such as gomisin C (6), gomisin G. (7), gomisin D (8), schisandrol B (11) and gomisin A (13), entirely inhibited AChE in dose dependent manners, with IC50 values of 6.71 ± 0.53, 6.55 ± 0.31, 7.84 ± 0.62, 12.57 ± 1.07 and 13.28 ± 1.68 ¼M, respectively. These results indicate that the lignans could potentially be a potent class of AChE inhibitors.

Cytotoxic constituents from angelicae sinensis radix.

Cytotoxic bioassay-guided fractionation of methanol extract of Angelicae Sinensis Radix led to the isolation of a new dimericZ-ligustilide, named neodiligustilide (1), together with three known compounds,Z-ligustilide (2), 11(S),16(R)-dihydroxy-octadeca-9Z, 17-dien-12, 14-diyn-1-yl acetate (3), and 3(R), 8(S)-falcarindiol (4). Among them, 2 showed the strongest cytotoxicity against L1210 and K562 cell lines with IC50 values of 2.27 ± 0.10 and 4.78 ± 0.18 μM, respectively, while 1 showed moderate cytotoxicity with IC50 values of 5.45 ±0.19 and 9.87 ±0.14 μM. Two polyacetylenes, 3 and 4, showed cytotoxicity only against L1210 cell line with IC50 values of 2.60 ± 0.90 and 2.87 ± 0.49 μM, respectively.

Lanostane triterpenes from Ganoderma lucidum suppress the adipogenesis in 3T3-L1 cells through down-regulation of SREBP-1c

Several lanostane triterpenes [butyl ganoderate A (1), butyl ganoderate B (2), butyl lucidenate N (3), and butyl lucidenate A (4)] bearing a butyl ester side chain from the fruiting bodies of Ganoderma lucidum exhibited considerable inhibitory effects on adipogenesis in 3T3-L1 cells. The inhibitory mechanism of 1 and 3 on adipogenesis in 3T3-L1 cells was investigated; we found that the mRNA and protein expression levels of SREBP-1c were reduced by treatment with 1 and 3 versus the untreated control. Furthermore, compounds 1 and 3 suppressed the mRNA expression levels of FAS and ACC. These results demonstrate that inhibition of adipogenesis in 3T3-L1 cells by treatment with 1 and 3 may be mediated in part through down-regulation of the adipogenic transcription factor SREBP-1c and its target genes, such as FAS and ACC.