The Mixture of Gotu Kola, Cnidium Fruit, and Goji Berry Enhances Memory Functions by Inducing Nerve-Growth-Factor-Mediated Actions Both In Vitro and In Vivo.

Nerve growth factor (NGF), a typical neurotrophin, has been characterized by the regulation of neuronal cell differentiation and survival involved in learning and memory functions. NGF has a main role in neurite extension and synapse formation by activating the cyclic adenosine monophosphate-response-element-binding protein (CREB) in the hippocampus. The purpose of this study was to determine whether a mixture of Gotu Kola, Cnidium fruit, and Goji berry (KYJ) enhances memory function by inducing NGF-mediated actions both in vitro and in vivo. The KYJ combination increased NGF concentration and neurite length in C6 glioma and N2a neuronal cells, respectively. Additionally, we discovered memory-enhancing effects of KYJ through increased NGF-mediated synapse maturation, CREB phosphorylation, and cell differentiation in the mouse hippocampus. These findings suggest that this combination may be a potential nootropic cognitive enhancer via the induction of NGF and NGF-dependent activities.

ESP-102, a Combined Herbal Extract of Angelica gigas, Saururus chinensis, and Schisandra chinensis, Changes Synaptic Plasticity and Attenuates Scopolamine-Induced Memory Impairment in Rat Hippocampus Tissue.

ESP-102, an extract from Angelica gigas, Saururus chinensis, and Schisandra chinensis, has been used as herbal medicine and dietary supplement in Korea. Despite the numerous bioactivities in vitro and in vivo studies, its effects on neuronal networks remain elusive. To address the neuronal effect, we examined synaptic plasticity in organotypic hippocampal slice culture with multielectrode array. Our results showed an increase in excitatory postsynaptic potential (EPSP), indicating the induction of long-term potentiation (LTP), in the presence of ESP-102. In addition, the neuroprotective effect of ESP-102 was also tested by application of scopolamine to the hippocampal slice. Interestingly, ESP-102 competitively antagonized the preventative LTP effect induced by scopolamine. The scopolamine-induced reduction in brain-derived neurotrophic factor (BDNF) and GluR-2 expression was also rescued by ESP-102. In terms of mode of action, ESP-102 appears to act on the presynaptic region independent of AMPA/NMDA receptors. Based on these findings, ESP-102 can be suggested as a novel herbal ingredient with memory enhancing as well as neuroprotective effects.

Antifibrotic compounds from Liriodendron tulipifera attenuating HSC-T6 proliferation and TNF-α production in RAW264.7 cells.

The inhibition of hepatic stellate cell (HSC) proliferation has been considered as an effective therapeutic target for the treatment of liver fibrosis. The methanolic extract of Liriodendron tulipifera showed significant inhibitory activity against the proliferation of HSCs. Bioactivity-guided isolation afforded twelve compounds including (-)-sesamin (1), (-)-syringaresinol (2), (+)-dihydrodehydrodiconiferyl alcohol (3), salvinal (4), (+)-guaiacylglycerol-8-O-4'-dihydroconiferyl ether (5), (±)-guaiacylglycerol-8-O-4'-sinapyl alcohol ether (6), tanegool (7), (+)-5,5'-dimethoxy-7-oxolariciresinol (8), 3-hydroxy-4-methoxyacetophenone (9), 4-acetoxymethylphenol (10), (-)-paramicholide (11), and blumenol A (12). Among the compounds isolated, 2, 3 and 4 significantly attenuated the proliferation of the activated HSC-T6 cells. The maximal dose of these compounds, however, showed no cytotoxicity in primary cultured rat hepatocytes. Collagen deposition in the activated HSC-T6 cells was reduced by 2, 3 and 4. Also, the increased production of the pro-inflammatory cytokine tumor necrosis factor (TNF)-α induced by lipopolysaccharide was decreased by 3 and 4 in RAW264.7 macrophage cells. Collectively, (-)-syringaresinol (2), (+)-dihydrodehydrodiconiferyl alcohol (3), and salvinal (4) isolated from L. tulipifera leaves and twigs exhibited selective antifibrotic activities toward the activated HSCs and suppressed TNF-α production in RAW264.7 macrophages. These compounds may be useful candidates for developing therapeutic agents for the prevention and treatment of hepatic fibrosis.

Chemical constituents isolated from Disporum viridescens leaves and their inhibitory effect on nitric oxide production in BV2 microglial cells.

Excessive NO (nitric oxide) has been associated with the pathogenesis of various neurodegenerative diseases including Alzheimer's disease (AD). In our screening system using LPS-activated BV2 microglial cells, the methanolic extract of Disporum viridescens leaves was found to have significant NO inhibitory activity. Bioactivity-guided isolation yielded a new phenylpropanoid characterized as 4-ally-2,6-dimethoxyphenyl 1-O-ß-D-apiofuranosyl (1→6)-ß-D-glucopyranoside (12) with 21 known compounds from the leaves of D. viridescens. Among them, compounds 2 and 4 significantly inhibited NO production. Thus, we further elucidated the anti-inflammatory mechanism of these lignans. Especially, compound 4 inhibited the expression of both inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) through the suppression of the MAPK signaling pathway. Taken together, the anti-inflammatory activities of the active constituents isolated from D. viridescens leaves could have therapeutic potential against neurodegenerative diseases.

The effects of Betula platyphylla bark on amyloid beta-induced learning and memory impairment in mice.

Alzheimer's disease (AD) is closely associated with amyloid ß (Aß)-induced neurotoxicity and oxidative stress in the brain. Betula platyphylla, which has been used to treat various oxidative-stressed related diseases, has recently received attention for its preventive activity on age-related neurodegenerative diseases. In this study, we attempted to investigate the effects of B. platyphylla bark (BPB-316) on Aß(1-42)-induced neurotoxicity and memory impairment. Oral treatment using BPB-316 significantly attenuated Aß-induced memory impairment which was evaluated by behavioral tests including the passive avoidance, Y-maze and Morris water maze test. BPB-316 also inhibited the elevation of ß-secretase activity accompanying the reduced Aß(1-42) levels in the hippocampus of the brain. Furthermore, BPB-316 significantly decreased the acetylcholinesterase activity and increased the glutathione content in the hippocampus. In addition, we confirmed that the expression of both cAMP responsive element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in the hippocampus of Aß(1-42)-injected mice were markedly upregulated by the treatment of BPB-316. Our data suggest that the extracts of B. platyphylla bark might be a potential therapeutic agent against AD.

Dammarane triterpenes as potential SIRT1 activators from the leaves of Panax ginseng.

During a search for SIRT1 activators originating in nature, three new dammarane triterpenes, 6α,20(S)-dihydroxydammar-3,12-dione-24-ene (1), 6α,20(S),24(S)-trihydroxydammar-3,12-dione-25-ene (2), and 6α,20(S),25-trihydroxydammar-3,12-dione-23-ene (3), as well as two known triterpenes, dammar-20(22),24-diene-3ß,6α,12ß-triol (4) and 20(S)-ginsenoside Rg3 (5), were isolated from Panax ginseng leaves. Compounds 1 and 3-5 showed potential as SIRT1 activators, as analyzed by in vitro enzyme-based SIRT1-NAD/NADH and SIRT1-p53 luciferase cell-based assays. They were also found to increase the level of NAD(+)/NADH ratio in HEK293 cells. This study presents a new class of chemical entities that may be able to be developed as SIRT1 activators for antiaging and treatment of age-associated diseases.

Salicortin-derivatives from Salix pseudo-lasiogyne twigs inhibit adipogenesis in 3T3-L1 cells via modulation of C/EBPα and SREBP1c dependent pathway.

Obesity is reported to be associated with excessive growth of adipocyte mass tissue as a result of increases in the number and size of adipocytes differentiated from preadipocytes. To search for anti-adipogenic phytochemicals, we screened for inhibitory activities of various plant sources on adipocyte differentiation in 3T3-L1 preadipocytes. Among the sources, a methanolic extract of Salix pseudo-lasiogyne twigs (Salicaceae) reduced lipid accumulation in a concentration-dependent manner. During our search for anti-adipogenic constituents from S. pseudo-lasiogyne, five salicortin derivatives isolated from an EtOAc fraction of this plant and bearing 1-hydroxy-6-oxo-2-cyclohexene-carboxylate moieties, namely 2',6'-O-acetylsalicortin (1), 2'-O-acetylsalicortin (2), 3'-O-acetylsalicortin (3), 6'-O-acetylsalicortin (4), and salicortin (5), were found to significantly inhibit adipocyte differentiation in 3T3-L1 cells. In particular, 2',6'-O-acetylsalicortin (1) had the most potent inhibitory activity on adipocyte differentiation, with an IC50 value of 11.6 µM, and it significantly down-regulated the expressions of CCAAT/enhancer binding protein α (C/EBPα) and sterol regulatory element binding protein 1 (SREBP1c). Furthermore, 2',6'-O-acetylsalicortin (1) suppressed mRNA expression levels of C/EBPß during the early stage of adipocyte differentiation and stearoyl coenzyme A desaturase 1 (SCD-1), acetyl-CoA carboxylase (ACC), and fatty acid synthase (FAS) expression, target genes of SREBP1c. In the present study, we demonstrate that the anti-adipogenesis mechanism of 2',6'-O-acetylsalicortin (1) may be mediated via down-regulation of C/EBPα and SREBP1c dependent pathways. Through their anti-adipogenic activity, salicortin derivatives may be potential novel therapeutic agents against obesity.

Neuroprotective compounds from Salix pseudo-lasiogyne twigs and their anti-amnesic effects on scopolamine-induced memory deficit in mice.

Bioassay-guided fractionation of an 80% methanolic extract of Salix pseudo-lasiogyne twigs has resulted in the isolation of two new compounds (1-2) along with ten known ones (3-12). The new compounds were determined to be 3'-O-acetylsalicin (1) and 2',6'-O-acetylsalicortin (2) by using spectroscopic analyses. Compounds (3-12) were identified as salicin (3), 2'-O-acetylsalicin (4), salicortin (5), 2'-O-acetylsalicortin (6), 3'-O-acetylsalicortin (7), 6'-O-acetylsalicortin (8), 2'-O-(E)-ρ-coumaroylsalicortin (9), grandidentatin (10), isograndidentatin (11), and saligenin (12). Among the isolated compounds, compounds 2, 5, 6, 7, and 8 bearing 1-hydroxy-6-oxo-2-cyclohexenecarboxylate moiety significantly inhibited lipopolysaccharide-induced nitric oxide production in BV2 microglial cells in vitro. Further, we studied anti-amnesic activities of the 80% methanolic extract, the EtOAc fraction, and compound 6 from S. pseudo-lasiogyne. They exerted a significant cognitive-enhancing effect on scopolamine-induced memory deficit in mice. In addition, they also significantly increased the reduced activities of glutathione reductase and superoxide dismutase and the glutathione content in the hippocampus and cortex of scopolamine-induced amnesic mice.

Antifibrotic activity of diarylheptanoids from Betula platyphylla toward HSC-T6 cells.

A chemical investigation of the n-butanol fraction of the inner bark of Betula platyphylla led to the isolation of seven diarylhepanoids, (-)-centrolobol (1), aceroside VII (2), aceroside VIII (3), (3R)-1,7-bis-(4-hydroxyphenyl)-3-heptanol-3-O-[2,6-bis-O-(ß-D-apiofuranosyl)-ß-D-glucopyranoside (4), 1,7-bis-(4-hydroxyphenyl)-5-hepten-3-one (5), platyphyllone (6) and platyphylloside (7). The antifibrotic effects of these isolates were evaluated with HSC-T6 cells by assessing cell proliferation. Among them, compounds 1, 2, 5 and 6 significantly inhibited the proliferation of HSCs in a dose-dependent manner at concentrations from 10 µM to 100 µM. Compound 5 in particular dramatically decreased the collagen content and increased the Caspase-3/7 activity. Taken together, the antifibrotic activity of B. platyphylla and its constituents might suggest therapeutic potential against liver fibrosis.

First-pass metabolism of decursin, a bioactive compound of Angelica gigas, in rats.

Decursin is considered the major bioactive compound of Angelica gigas roots, a popular Oriental herb and dietary supplement. In this study, the pharmacokinetics of decursin and its active metabolite, decursinol, were evaluated after the administration of decursin in rats. The plasma concentration of decursin decreased rapidly, with an initial half-life of 0.05 h. It was not detectable at 1 h after intravenous administration at an area under the plasma concentration-time curve of 1.20 µg · mL-1·h, whereas the concentration of decursinol increased rapidly reaching a maximum concentration of 2.48 µg · mL-1 at the time to maximum plasma concentration of 0.25 h and an area under the plasma concentration-time curve of 5.23 µg · mL-1·h. Interestingly, after oral administration of decursin, only decursinol was present in plasma, suggesting an extensive hepatic first-pass metabolism of decursin. The extremely low bioavailability of decursin after its administration via the hepatic portal vein (the fraction of dose escaping first-pass elimination in the liver, FH = 0.11) is indicative of extensive hepatic first-pass metabolism of decursin, which was confirmed by a tissue distribution study. These findings suggest that decursin is not directly associated with the bioactivity of A. gigas and that it may work as a type of natural prodrug of decursinol.

Neuroprotective and anti-inflammatory effects of flavonoids isolated from Rhus verniciflua in neuronal HT22 and microglial BV2 cell lines.

The neuroprotective and anti-inflammatory activities of the methanolic extract of Rhus verniciflua Stokes (Anacardiaceae) were investigated with mouse hippocampal and microglial cells. Bioactivity-guided isolation yielded 10 flavonoids including fustin (1), fisetin (2), sulfuretin (3), butein (4), butin (5), eriodictyol (6), morin hydrate (7), quercetin (8), kaempferol (9) and isoliquiritigenin (10). Among the isolated flavonoids, compounds 2-5 significantly protected the murine hippocampal HT22 cells against glutamate-induced neurotoxicity and attenuated reactive oxygen species (ROS) generations. In addition, these flavonoids significantly maintained antioxidative defense systems preserving the activities of superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GSH-Px) and the content of glutathione (GSH) decreased by glutamate insult. These compounds also showed significant inhibitory effects on LPS-induced nitric oxide (NO) production in BV2 cells. Especially, compound 4 dose-dependently suppressed the expression of both inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). These results suggest that these flavonoids possess therapeutic potentials as a multipotent agent against neurodegenerative diseases related to oxidative stress and pathological inflammatory responses.

Neuroprotective iridoid glycosides from Cornus officinalis fruits against glutamate-induced toxicity in HT22 hippocampal cells.

The methanolic extract of the fruits of Cornus officinalis S et Z. (Cornaceae) showed the significant neuroprotective activity against glutamate-induced toxicity in HT22 hippocampal cells. Chemical profile of n-BuOH fraction of the methanolic extract of C. officinalis fruits, which showed the most potent activity, was established using HPLC-diode array detector-electrospray-MS (HPLC-DAD-ESI-MS). Through bioactivity-guided isolation, five iridoid glycosides including one new compound, 7-O-butylmorroniside (1), loganin (2), morroniside (3), 7R-O-methylmorroniside (4), 7S-O-methylmorroniside (5) were isolated from the n-BuOH fraction. The protective activities of the isolated compounds, themselves, were not statistically significant. However, the hydrolyzed products of compounds 1, 4 and 5 significantly protected glutamate-injured HT22 cells up to 78±2.2%, 60±3.2% and 59±2.5% of non-treated control, respectively.

Denbinobin, a phenanthrene from dendrobium nobile, inhibits invasion and induces apoptosis in SNU-484 human gastric cancer cells.

Dendrobium nobile is widely used as an analgesic, an antipyretic, and a tonic to nourish the stomach in traditional medicine. Mounting evidence suggests an antitumor activity of denbinobin, a major phenanthrene isolated from stems of Dendrobium nobile. The present study aimed to investigate the inhibitory effect of denbinobin on the invasive ability of human cancer cells. The cytotoxicity of denbonobin was examined in several human cancer cell lines including SK-Hep-1 hepato-carcinoma cells, SNU-484 gastric cancer cells, and HeLa cervix cancer cells. Because SNU-484 cells showed the lowest IC50 value, we examined the effect of denbinobin on the invasive ability of SNU-484 cells. The present study revealed, for the first time, that denbinobin inhibits the invasive phenotype of SNU-484 human gastric cancer cells in a dose-dependent manner. Expressions of matrix metalloproteinase (MMP)-2 and MMP-9 were significantly decreased by denbinobin, suggesting that MMP-2/-9 may be responsible for the anti-invasive activity of denbinobin. We also provide evidence that denbinobin induces apoptosis through down-regulation of Bcl-2 and an up-regulation of Bax. Taken together, this study demonstrates that denbinobin inhibits invasion and induces apoptosis in highly invasive SNU-484 human gastric cancer cells. Given that gastric cancer has been estimated to be one of the most common causes of cancer-related death among Asians and the major cause of death from gastric cancer is the metastatic spread of the disease, our findings may provide useful information regarding the application of denbinobin as a chemopreventive agent that could prevent or alleviate metastatic gastric cancer.

Chemical constituents of Polygala tenuifolia roots and their inhibitory activity on lipopolysaccharide-induced nitric oxide production in BV2 microglia.

A methanolic extract of the roots of Polygala tenuifolia (Polygalaceae) significantly attenuated nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated BV2 microglia cells. Five xanthones, 1-hydroxy-7-methoxyxanthone (1), 3,6-dihydroxy-1,2,7-trimethoxyxanthone (2), 1,3,6-trihydroxy-2,7-dimethoxyxanthone (3), 1,7-dihydroxy-2,3-dimethoxyxanthone (4) and 1,7-dihydroxy-3-methoxyxanthone (5), and five phenylpropanoids, 4-hydroxy-3-methoxypropiophenone (6), methyl 4-hydroxy-3-methoxycinnamic acid (7), 3,4,5-trimethoxycinnamic acid (8), 4-methoxycinnamic acid (9) and ß-d-(3-O-sinapoyl) fructofuranosyl-α-d-(6-O-sinapoyl)glucopyranoside (10), were isolated from CHCl(3) fraction using bioactivity-guided fractionation. Among these compounds, compounds 1, 2, 4, 5 and 7 showed significant inhibitory effects on LPS-induced NO production in BV2 microglia cells at the concentration ranging from 10.0 to 100.0 µM.

Selective apoptosis in hepatic stellate cells mediates the antifibrotic effect of phenanthrenes from Dendrobium nobile.

Regardless of the etiology, cellular death of the liver parenchymal hepatocyte seems to be a primary event of hepatic fibrogenesis, which ultimately results in hepatic stellate cell (HSC) activation and the synthesis of extracellular matrix proteins. Recently it has been demonstrated that hepatic fibrosis can be a reversible process when the stimulus is properly eliminated. Apoptotic removal of active HSC is considered an essential part of the resolution. By employing the HSC cell line, HSC-T6, it was found that the methanol extract of Dendrobium nobile stem significantly inhibited the proliferation of HSC-T6 cells. Three phenanthrenes, denbinobin, fimbriol B and 2,3,5-trihydroxy-4,9-dimethoxyphenanthrene isolated from D. nobile were proven to inhibit HSC proliferation. Growth arrest of HSCs by these compounds was accompanied by cellular loss via autophagy-linked apoptosis. The maximal dose of these compounds, however, had little effect on primary cultured hepatocytes in rats. Collagen deposition in HSC-T6 cells was attenuated by these phenanthrenes. Collectively, the above results demonstrated that denbinobin, fimbriol B and 2,3,5-trihydroxy-4,9-dimethoxyphenanthrene exhibited antifibrotic activities possibly by the induction of selective cell death in HSCs but not in hepatocytes, implying that these compounds may be useful candidates for developing therapeutic agents for the prevention and treatment of hepatic fibrosis.

Inhibitory alkaloids from Dictamnus dasycarpus root barks on lipopolysaccharide-induced nitric oxide production in BV2 cells.

The methanolic extract of Dictamnus dasycarpus root barks afforded one new glycosidic quinoline alkaloid, 3-[1ß-hydroxy-2-(ß-D-glucopyranosyloxy)-ethyl)-4-methoxy-2(1H)-quinolinone (1), together with nine known compounds, preskimmianine (2), 8-methoxy-N-methylflindersine (3), dictamine (4), γ-fagarine (5), halopine (6), skimmianine (7), dictangustine-A (8), iso-γ-fagarine (9), isomaculosidine (10). The isolated alkaloids significantly inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated BV2 cells. Among them, compounds 3 and 7 showed the most potent inhibitory activities on LPS-induced NO production.

Anti-inflammatory phenolics isolated from Juniperus rigida leaves and twigs in lipopolysaccharide-stimulated RAW264.7 macrophage cells.

Inflammation is an essential host defense system particularly in response to infection and injury; however, excessive or undesirable inflammatory responses contribute to acute and chronic human diseases. A high-throughput screening effort searching for anti-inflammatory compounds from medicinal plants deduced that the methanolic extract of Juniperus rigida S. et L. (Cupressaceae) inhibited significantly nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Activity-guided fractionation and isolation yielded 13 phenolic compounds, including one new phenylpropanoid glycosides, 3,4-dimethoxycinnamyl 9-O-ß-D-glucopyranoside (1). Among the isolated compounds, phenylpropanoid glycosides with p-hydroxy group (2, 4) and massoniaside A (7), (+)-catechin (10), amentoflavone (11) effectively inhibited LPS-induced NO production in RAW264.7 cells.

Antifibrotic constituents of Alnus firma on hepatic stellate cells.

Suppression of hepatic stellate cell (HSC) growth and activation have been proposed as therapeutic strategies for the treatment and prevention of liver fibrosis. In the course of screening antifibrotic activity of natural products, the methanolic extract of Alnus firma barks (Betulaceae) showed inhibitory activity of cell proliferation on HSC-T6 cells. A new triterpenoid characterized as lup-20(29) en-2,28-diol-3-yl caffeate (13) was isolated with 12 known diarylheptanoids (1-12) from the barks of A. firma using bioactivity-guided fractionation. Among these compounds, 2 and 13 significantly inhibited the proliferation of HSCs in dose- and time-dependent manners at concentrations from 10 to 100 µM. Taken together, antifibrotic activities of A. firma and its active constituents might suggest the therapeutic potentials against liver fibrosis.

Inhibitory constituents of Euonymus alatus leaves and twigs on nitric oxide production in BV2 microglia cells.

The excessive and prolonged nitric oxide (NO) production has been linked to various inflammatory diseases as well as tumourigenesis. On the search for anti-inflammatory and anti-cancer compounds from the medicinal plants, the methanolic extract of Euonymus alatus (Thunb.) Sieb. (Celastraceae) was found to have significant inhibitory activity on NO production in lipopolysaccharide (LPS)-stimulated BV2 microglia cells. Hence, we attempted to isolate the inhibitory constituent of E. alatus leaves and twigs on NO production. Thirteen compounds including two new glycerol derivates (1, 2), two C(13) isoprenoids (3, 4), two phenolics (5, 6) and seven flavonoids (7-13) were isolated, and the structures of 1-13 were elucidated by extensive 1D and 2D spectroscopic methods. The isolated compounds significantly inhibited NO production induced by LPS in BV2 microglia cells.

Hydroxyframoside B, a secoiridoid of Fraxinus rhynchophylla, inhibits adipocyte differentiation in 3T3-L1 cells.

Fraxinus rhynchophylla showed significant inhibitory activity on adipocyte differentiation in the 3T3-L1 preadipocyte cell line as assessed by measuring fat accumulation using Oil Red O staining. Further fractionation led to the isolation of two secoiridoids, oleuropein and hydroxyframoside B. Hydroxyframoside B significantly reduced fat accumulation and triglyceride content in differentiated 3T3-L1 cells without affecting cell viability, whereas oleuropein showed little effect. Further studies with interval treatment demonstrated that hydroxyframoside B exerted inhibitory activity on adipocyte differentiation when treated within 2 days (days 0-2) after differentiation induction. In addition, hydroxyframoside B significantly blocked the induction of adipogenic transcription factors such as C/EBP α, C/EBP ß, and PPAR γ. Taken together, these results suggest that hydroxyframoside B inhibited early/middle stage of adipogenic differentiation, in part, via inhibition of C/EBP α, C/EBP ß, and PPAR γ-dependent pathways.