Palbinone from Paeonia suffruticosa protects hepatic cells via up-regulation of heme oxygenase-1.

Paeonia suffruticosa has been traditionally employed for vitalizing blood circulation and alleviating liver and inflammatory diseases. The pathways by which palbinone (PB) isolated from P. suffruticosa mediates heme oxygenase-1 (HO-1) induction were investigated using the specific inhibitors for PI3K and mitogen activated protein kinases pathways. The effect of PB-treatment on Nrf2 translocalization and HO-1-antioxidant response element (ARE) regulation was examined employing Western blot and luciferase assays. PB induced HO-1 expression via the activation of Nrf2 in the hepatic cells, and ARE-dependent genes were stimulated via the PB-mediated Nrf2 activation. PB-mediated HO-1 expression could be involved with PI3K/Akt and ERK1/2 pathways. Our study suggests the mechanism by which PB induces HO-1 expression in the hepatic cells. This might substantiate the traditional applications of P. suffruticosa for the treatment of oxidative stress-related diseases including oxidant and inflammatory-mediated vascular and liver diseases.

Magnolol inhibits angiogenesis by regulating ROS-mediated apoptosis and the PI3K/AKT/mTOR signaling pathway in mES/EB-derived endothelial-like cells.

Magnolol, a neolignan from the traditional medicinal plant Magnolia obovata, has been shown to possess neuroprotective, anti-inflammatory, anticancer and anti-angiogenic activities. However, the precise mechanism of the anti-angiogenic activity of magnolol remains to be elucidated. In the present study, the anti-angiogenic effect of magnolol was evaluated in mouse embryonic stem (mES)/embryoid body (EB)-derived endothelial-like cells. The endothelial-like cells were obtained by differentiation from mES/EB cells. Magnolol (20 µM) significantly suppressed the transcriptional and translational expression of platelet endothelial cell adhesion molecule (PECAM), an endothelial biomarker, in mES/EB-derived endothelial-like cells. To further understand the molecular mechanism of the suppression of PECAM expression, signaling pathways were analyzed in the mES/EB-derived endothelial-like cells. Magnolol induced the generation of reactive oxygen species (ROS) by mitochondria, a process that was associated with the induction of apoptosis as determined by positive Annexin V staining and the activation of cleaved caspase-3. The involvement of ROS generation by magnolol was confirmed by treatment with an antioxidant, N-acetyl-cysteine (NAC). NAC inhibited the magnolol-mediated induction of ROS generation and suppression of PECAM expression. In addition, magnolol suppressed the activation of MAPKs (ERK, JNK and p38) and the PI3K/AKT/mTOR signaling pathway in mES/EB-derived endothelial-like cells. Taken together, these findings demonstrate for the first time that the anti-angiogenic activity of magnolol may be associated with ROS-mediated apoptosis and the suppression of the PI3K/AKT/mTOR signaling pathway in mES/EB-derived endothelial-like cells.

Anti-inflammatory properties of anthraquinones and their relationship with the regulation of P-glycoprotein function and expression.

There is a growing interest in natural products that potentially have anti-inflammatory properties and inhibit P-glycoprotein (P-gp) function. In this report, we assessed the effects of anthraquinone derivatives from rhubarb on LPS-induced RAW 264.7 macrophages to determine their anti-inflammatory potential. The derivatives were also tested in Caco-2 cell lines to evaluate the inhibition of the drug efflux function of P-gp. The transport abilities were examined and the cellular accumulation of rhodamine-123 (R-123) was also measured. Electorphoretic mobility shift assay (EMSA) was performed to check the activator protein-1 (AP-1) DNA binding affinity. Five anthraquinones were tested to determine their inhibitory activities on NO production and the protein and mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, the level of prostaglandin E(2) (PGE(2)) was determined in LPS-induced RAW264.7 macrophages. Emodin was found to be the most potent inhibitor, and it also reduced paw swelling in the mouse model of carrageenan-induced paw edema. In Caco-2 cells, emodin elevated the accumulation of R-123 and decreased the efflux ratio of R-123, which indicates the inhibition of P-gp function. The inhibition of COX-2 protein by emodin paralleled the decrease in P-gp expression. In addition, mitogen-activated protein kinase (MAPK) expression was decreased through the prevention of AP-1 DNA binding, which leads to downregulation in the expression of P-gp. Our data indicate that the decrease of P-gp expression is caused by the decreased expression of COX-2 through the MAPK/AP-1 pathway. Based on our results, we suggest that anti-inflammatory drugs with COX-2 inhibitory activity might be used to modulate P-gp function and expression.

Neuroprotection of the leaf and stem of Vitis amurensis and their active compounds against ischemic brain damage in rats and excitotoxicity in cultured neurons.

Vitis amurensis (Vitaceae) has been reported to have anti-oxidant and anti-inflammatory activities. The present study investigated a methanol extract from the leaf and stem of V. amurensis for neuroprotective effects on cerebral ischemic damage in rats and on excitotoxicity induced by glutamate in cultured rat cortical neurons. Transient focal cerebral ischemia was induced by 2h middle cerebral artery occlusion followed by 24h reperfusion (MCAO/reperfusion) in rats. Orally administered V. amurensis (25-100 mg/kg) reduced MCAO/reperfusion-induced infarct and edema formation, neurological deficits, and neuronal death. Depletion of glutathione (GSH) level and lipid peroxidation induced by MCAO/reperfusion was inhibited by administration of V. amurensis. The increase of phosphorylated mitogen-activated protein kinases (MAPKs), cyclooxygenase-2 (COX-2), and pro-apoptotic proteins and the decrease of anti-apoptotic protein in MCAO/reperfusion rats were significantly inhibited by treatment with V. amurensis. Exposure of cultured cortical neurons to 500 µM glutamate for 12h induced neuronal cell death. V. amurensis (1-50 µg/ml) and (+)-ampelopsin A, γ-2-viniferin, and trans-ε-viniferin isolated from the leaf and stem of V. amurensis inhibited glutamate-induced neuronal death, the elevation of intracellular calcium ([Ca(2+)](i)), the generation of reactive oxygen species (ROS), and changes of apoptosis-related proteins in cultured cortical neurons, suggesting that the neuroprotective effect of V. amurensis may be partially attributed to these compounds. These results suggest that the neuroprotective effect of V. amurensis against focal cerebral ischemic injury might be due to its anti-apoptotic effect, resulting from anti-excitotoxic, anti-oxidative, and anti-inflammatory effects and that the leaf and stem of V. amurensis have possible therapeutic roles for preventing neurodegeneration in stroke.

Biphenyl and biphenyl ether quinolizidine N-oxide alkaloids from Lagerstroemia indica L.

Four new biphenyl and biphenyl ether quinolizidine N-oxide alkaloids, 5- EPI-dihydrolyfoline N-oxide (1), decamine N-oxide (2), lagerstroemine N-oxide (3), and lagerine N-oxide (4), were isolated from the aerial parts of Lagerstroemia indica, and their structures were established by extensive spectroscopic studies. In addition, the inhibitory effects of isolated compounds on rat lens aldose reductase (RLAR) were examined.

Anti-inflammatory activity of constituents from Glechoma hederacea var. longituba.

Rosmarinic acid, its analogues, and a phenolic compound were obtained from G. hederacea var. longituba. There were two new compounds, methyl isoferuloyl-7-(3,4-dihydroxyphenyl) lactate (1) and benzyl-4'-hydroxy-benzoyl-3'-O-ß-D-glucopyranoside (4), and four known compounds (2, 3, 5 and 6). The structures of these compounds were determined on the basis of spectroscopic methods. Each compound was tested by NF-κB luciferase assay and three rosmarinic acid analogues inhibited NF-κB production and the induction of COX-2 and iNOS mRNA in HepG2 cells.

Inhibition of experimental atopic dermatitis by rhubarb (rhizomes of Rheum tanguticum) and 5-lipoxygenase inhibition of its major constituent, emodin.

The antiallergic activity of rhubarb and its constituents, anthraquinones, has been reported previously. For further evaluation of the antiallergic activity, a 70% ethanol extract of the rhizomes of Rheum tanguticum (RTE) was prepared and its inhibitory activity on an animal model of atopic dermatitis (AD) was examined for the first time. Oral administration of RTE (30-300 mg/kg/day) for 5 weeks significantly inhibited hapten-induced dermatitis in NC/Nga mice based on the skin severity score. In addition, treatment with RTE at 100 mg/kg/day also reduced the numbers of white blood cells, neutrophils and eosinophils in the blood, and led to a significant reduction in the IgE concentration in the serum. In rat basophilic leukemia (RBL)-1 cells, RTE inhibited 5-lipoxygenase (5-LOX)-catalysed leukotriene production (IC(50) = 43.6 µg/mL). Among the anthraquinone derivatives isolated, emodin strongly inhibited this parameter (IC(50) = 4.3 µM). Taken together, these findings suggest that rhubarb exerts inhibitory activity against AD, and that the 5-LOX inhibitory activity of its major constituent, emodin, may contribute to this inhibitory action.

Ergosta-7,22-diene-2ß,3α,9α-triol from the fruit bodies of Ganoderma lucidum induces apoptosis in human myelocytic HL-60 cells.

Ganoderma lucidum is known as a medicinal mushroom used in traditional medicine. In our study, the cytotoxic activities of 17 compounds (1-17) isolated from the fruiting bodies of G. lucidum were investigated. Among them, ergosta-7,22-diene-2ß,3α,9α-triol (EGDT) induced apoptosis in HL-60 human premyelocytic leukemia cells. EGDT activated the apoptotic process, including DNA fragmentation and caspase-3 activity. In immunoblotting analysis, treatment with EGDT resulted in the cleavage of procaspase-3 and poly(ADP-ribose) polymerase (PARP) into active forms. In the in vivo study, the administration (i.p.) of EGDT to Lewis lung carcinoma (LLC)-inoculated mice evidenced a significant inhibition of tumor growth. These results indicate that EGDT was one of the apoptotic constituents of G. lucidum, and might be an antitumor agent.

New sesquiterpene lactones from Glechoma hederacea L. and their cytotoxic effects on human cancer cell lines.

Three new sesquiterpene lactones, 1 α,10 ß-epoxy-4-hydroxy-glechoma-5-en-olide (1), 1 ß,10 α-epoxy-4,8-dihydroxy-glechoma-5-en-olide (2), and 1 ß,10 α;4 α,5 ß-diepoxy-8-methoxy-glechoman-8 α,12-olide (3), were isolated from the whole plant of Glechoma hederacea, together with four known sesquiterpene lactones. The structures of the three new sesquiterpene lactones were determined by spectroscopic evidence. Cytotoxic effects of the isolated compounds were examined against MDA-MB-231 (breast), HCT116 (colon), SW620 (colon), and DU145 (prostate) human cancer cell lines.

Two new lignans from the roots of Pulsatilla koreana.

Two new lignans, (2 R,3 R)-2 ß-(4''-hydroxy-3''-methoxybenzyl)-3 α-(4'-hydroxy-3'-methoxybenzyl)-γ-butyrolactone 2-O-( ß-D-glucopyranoside) (1) and (1 S,2 R,3 S)-dimethyl-1,2,3,4-tetrahydro-3,6,7-trihydroxy-1-(3',4'-dihydroxyphenyl)naphthalene-2,3-dicarboxylate (2) together with nine known compounds (3-11) were isolated from the ethyl acetate fraction of the roots of Pulsatilla koreana. Their chemical structures were established based on physicochemical and spectroscopic data analyses. All isolates were investigated for their inhibition effects against the classical pathway of the complement system. Among them, compound 6 showed significant inhibitory activity with an IC (50) value of 75.9 µM, compounds 8 and 9 had moderate effects with IC (50) values of 182.2 and 166.5 µM, respectively.

Protective effect of Ilex latifolia, a major component of "kudingcha", against transient focal ischemia-induced neuronal damage in rats.

AIMS OF THE STUDY: Ilex latifolia (Aquifoliaceae), a primary component of "kudingcha", has been used in Chinese folk medicine to treat various kinds of diseases including headaches, inflammatory diseases, and cardiac ischemic injury. The present study investigated the protective effect of the ethanol extract of Ilex latifolia against transient, focal, ischemia-induced neuronal damage. MATERIALS AND METHODS: Transient focal ischemia was induced by 2 h middle cerebral artery occlusion followed by 24 h reperfusion (MCAO/reperfusion) in rats. After MCAO/reperfusion, brain infarction and neuronal death were measured by triphenyltetrazolium chloride and hematoxylin and eosin staining, respectively. Glutathione concentration and lipid peroxidation rate were measured. The expression levels of phosphorylated mitogen activated proteins kinases (MAPKs), cyclooxygenase 2 (COX-2), and anti-apoptotic and pro-apoptotic proteins were detected by Western blot. RESULTS: Ilex latifolia (50-200 mg/kg) significantly reduced MCAO/reperfusion-induced infarction and edema formation, neurological deficits, and brain cell death. Depletion of glutathione level and lipid peroxidation induced by MCAO/reperfusion were inhibited by administration of Ilex latifolia. The increase of phosphorylated MAPKs, COX-2, and proapoptotic proteins and the decrease of antiapoptotic protein in MCAO/reperfusion rats were significantly inhibited by treatment with Ilex latifolia. CONCLUSION: Ilex latifolia ameliorated ischemic injury induced by MCAO/reperfusion in rats, and this neuroprotective effect might be associated with its anti-apoptotic effect, resulting from anti-oxidative and anti-inflammatory actions.

Discrimination of cinnamon bark and cinnamon twig samples sourced from various countries using HPLC-based fingerprint analysis.

A simple and efficient HPLC method was developed to evaluate the quality of traditional herbal medicines made from cinnamon bark (CB) and cinnamon twig (CT). Seven major bioactive ingredients in 56 samples (24 CB and 32 CT) collected from China, Vietnam, and Indonesia were separated and quantified. The method was validated following the International Conference on Harmonisation (ICH) guidelines. A fingerprint analysis method to discriminate between CB and CT using major component content levels was developed. The discrimination process included the use of similarity indices and partial least-squares discriminant analysis (PLS-DA). Classification accuracy by the PLS-DA method was about 98%. The pattern analysis method was specific and could be readily used for the comprehensive evaluation of cinnamon samples. Therefore, an HPLC fingerprint in combination with pattern analysis provides a very flexible and reliable method for quality assessment of herbal drugs.

Adlay seed extract (Coix lachryma-jobi L.) decreased adipocyte differentiation and increased glucose uptake in 3T3-L1 cells.

The aim of the present study was to investigate effects of the ethyl acetate fraction of an ethanol extract of Coix lachryma-jobi (ECLJ) on glucose uptake and adipocyte differentiation in 3T3-L1 cells. ECLJ phosphorylated AMP-activated protein kinase (AMPK) and its downstream substrate acetyl-coenzymeA carboxylase in 3T3-L1 cells in a time- and dose-dependent manner. Moreover, we discovered that compound C inhibits ECLJ-stimulated ACC phosphorylation. In addition, ECLJ exhibited a dose-dependent stimulation of glucose uptake in 3T3-L1 cells, and this increase was obviously attenuated by compound C. ECLJ also caused a decrease in the expression levels of adipogenesis factors such as fatty acid synthase, sterol-regulatory-element-binding protein-1c, peroxisome proliferator-activated receptor γ, and CAATT/enhancer binding protein α in a dose-dependent manner. Differentiation was examined by Oil red O staining activity after ECLJ treatment for 6 days. ECLJ decreased mean droplet size. These results suggest a possible role for AMPK in the process of adipose differentiation and that ECLJ targeted for adipocyte functions could be effective in improving the symptoms of metabolic syndrome.

Leaf and stem of Vitis amurensis and its active components protect against amyloid ß protein (25-35)-induced neurotoxicity.

This study investigated a methanol extract from the leaf and stem of Vitis amurensis (Vitaceae) for possible neuroprotective effects on neurotoxicity induced by amyloid ß protein (Aß) (25-35) in cultured rat cortical neurons and also for antidementia activity in mice. Exposure of cultured cortical neurons to 10 µM Aß (25-35) for 36 h induced neuronal apoptotic death. At concentrations of 1-10 µg/mL, V. amurensis inhibited neuronal death, the elevation of intracellular calcium ([Ca(2+)](i)) and the generation of reactive oxygen species (ROS), all of which were induced by Aß (25-35) in primary cultures of rat cortical neurons. Memory loss induced by intracerebroventricular injection of ICR mice with 16 nmol Aß (25-35) was inhibited by chronic treatment with V. amurensis extract (50 and 100 mg/kg, p.o. for 7 days), as measured by a passive avoidance test. Amurensin G, r-2-viniferin and trans-ɛ-viniferin isolated from V. amurensis also inhibited neuronal death, the elevation of [Ca(2+)](i) and the generation of ROS induced by Aß (25-35) in cultured rat cortical neurons. These results suggest that the neuroprotective effect of V. amurensis may be partially attributable to these compounds. These results suggest that the antidementia effect of V. amurensis is due to its neuroprotective effect against Aß (25-35)-induced neurotoxicity and that the leaf and stem of V. amurensis have possible therapeutic roles for preventing the progression of Alzheimer's disease.

Platelet anti-aggregatory and blood anti-coagulant effects of compounds isolated from Paeonia lactiflora and Paeonia suffruticosa.

The roots of two Paeoniaceae family members have long been used as traditional medicines in Korea, China, and Japan. Dry roots of Paeonia lactiflora and dry root bark of P. suffruticosa are used under the traditional names of Paeoniae Radix and Moutan Cortex, respectively. Both Paeoniae Radix and Moutan Cortex have been used as remedies for cardiovascular diseases, for improving blood circulation, or for other uses. It was postulated that both plants may contain common active constituents that contribute to inhibiting blood coagulation and/or platelet aggregation. Eighteen compounds, which have been reported to be present in both plant medicines, were evaluated for their effects on platelet aggregation and blood coagulation. Paeonol (5), paeoniflorin (9), benzoylpaeoniflorin (11), and benzoyloxypaeoniflorin (12) were found to be the major common active constituents and they would collectively contribute to improving blood circulation through their inhibitory effects on both platelet aggregation and blood coagulation. In addition, methylgallate (4), (+)-catechin (7), paeoniflorigenone (8), galloylpaeoniflorin (13), and daucosterol (16) may also take part in improving blood circulation by inhibiting ether platelet aggregation and/or blood coagulation.

Platelet anti-aggregation activities of compounds from Cinnamomum cassia.

Cinnamomum cassia is a well-known traditional medicine for improvement of blood circulation. An extract of this plant showed both platelet anti-aggregation and blood anti-coagulation effects in preliminary testing. Among the 13 compounds obtained from this plant, eugenol (2), amygdalactone (4), cinnamic alcohol (5), 2-hydroxycinnamaldehyde (7), 2-methoxycinnamaldehyde (8), and coniferaldehyde (9) showed 1.5-73-fold greater inhibitory effects than acetylsalicylic acid (ASA) on arachidonic acid (AA)-induced aggregation (50% inhibitory concentration [IC50] = 3.8, 5.16, 31.2, 40.0, 16.9, and 0.82 µM, respectively, vs. 60.3 µM) and 6.3-730-fold stronger effect than ASA on U46619 (a thromboxane A2 mimic)-induced aggregation (IC50 = 3.51, 33.9, 31.0, 51.3, 14.6, and 0.44 µM, respectively, vs. 321 µM). The other compounds, coumarin (3), cinnamaldehyde (6), cinnamic acid (10), icariside DC (11), and dihydrocinnacasside (12), also inhibited (2.5 to four times greater than ASA) U46619-induced aggregation. In addition, compounds 2, 4, 5, 6, 7, 8, and 9 were 1.3-87 times more effective than ASA against epinephrine-induced aggregation (IC50 = 1.86, 1.10, 37.7, 25.0, 16.8, 15.3, and 0.57 µM, respectively, vs. 50.0 µM). However, the 13 compounds were only very mildly effective against blood coagulation, if at all. In conclusion, compounds 2, 4, 8, and 9 showed stronger inhibitory potencies than others on AA-, U46619-, and epinephrine-induced platelet aggregation. Eugenol (2) and coniferaldehyde (9) were the two of the most active anti-platelet constituents of C. cassia.

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-ß-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.

Hydoroxyhibiscone A, a novel human neutrophil elastase inhibitor from Hibiscus syriacus.

In an ongoing investigation of compounds from natural products that exhibit anti-aging properties, hydroxyhibiscone A (1), a new furanosesquiterpenoid, together with hibiscone D (2), was isolated from the root bark of Hibiscus syriacus. Utilizing UV, IR, NMR, and MS spectroscopic analyses, these chemical structures were revealed. Compounds 1 and 2 were found to possess significant anti-aging properties on the human neutrophil elastase (HNE) assay, exhibiting HNE inhibitory activities with IC50 values of 5.2 and 4.6 micronM, respectively.

Selected compounds derived from Moutan Cortex stimulated glucose uptake and glycogen synthesis via AMPK activation in human HepG2 cells.

AIM OF THE STUDY: To evaluate the effect of selected compounds derived from Moutan Cortex on glucose uptake and glycogen synthesis associated with AMPK activation in insulin-resistant human HepG2 cell. MATERIALS AND METHODS: The effect of isolated compounds (1-16) on glucose uptake and glycogen synthesis was performed using HepG2 cells. The western blot was used to determine the expression of AMPK and its downstream substrates, ACC, p-ACC, and p-GSK-3beta. RESULTS: The effects of the 16 compounds from Moutan Cortex on glucose metabolism in HepG2 cells under high glucose conditions were evaluated. Compounds 2, 3, and 6 displayed highly potent effects on the stimulation of glucose uptake and glycogen synthesis in human HepG2 cells under high glucose conditions. Compounds 2, 3, and 6 phosphorylate AMPK (AMP-activated protein kinase), and resulted in increased phosphorylation of GSK-3beta and suppression of lipogenic expression (ACC and FAS) in a dose-dependent manner. Compounds 2, 3, and 6 also demonstrated interesting, strong eNOS phosphorylation in human umbilical vein endothelial cells (HUVECs). Compounds 1, 4, 5-12, and 14 displayed considerable effects on hepatic glucose production, AMPK activation, and phosphorylation of GSK-3beta in HepG2 cells under high glucose conditions. CONCLUSIONS: These effects may indicate that the activation of AMPK by the active compounds from Moutan Cortex has considerable potential for reversing the metabolic abnormalities associated with type-2 diabetes.

Activation of AMP-activated protein kinase on human gastric cancer cells by apoptosis induced by corosolic acid isolated from Weigela subsessilis.

Corosolic acid is one of the triterpenoids present in the leaves of Weigela subsessilis. The antidiabetic activity of corosolic acid has been reported previously, but to date, the anticancer effects on gastric cancer have been poorly studied. In this study, corosolic acid showed growth inhibition on SNU-601 human gastric cancer cells, with an IC50 value of 16.9 ± 2.9 µM. Corosolic acid also triggered the activation of caspase-3 and poly (ADP-ribose) polymerase, while it was recovered by Z-VAD-FMK. Moreover, the cell growth/apoptosis activities of corosolic acid were regulated by the AMP-activated protein kinase-mammalian target of rapamycin (AMPK-mTOR) signals. These results showed that corosolic acid-mediated AMPK activation leads to inhibition of mTOR, thus providing a possible mechanism of action of corosolic acid in the inhibition of cancer cell growth and the induction of apoptosis.