Active Components from Cassia abbreviata Prevent HIV-1 Entry by Distinct Mechanisms of Action.

Cassia abbreviata is widely used in Sub-Saharan Africa for treating many diseases, including HIV-1 infection. We have recently described the chemical structures of 28 compounds isolated from an alcoholic crude extract of barks and roots of C. abbreviata, and showed that six bioactive compounds inhibit HIV-1 infection. In the present study, we demonstrate that the six compounds block HIV-1 entry into cells: oleanolic acid, palmitic acid, taxifolin, piceatannol, guibourtinidol-(4α→8)-epiafzelechin, and a novel compound named as cassiabrevone. We report, for the first time, that guibourtinidol-(4α→8)-epiafzelechin and cassiabrevone inhibit HIV-1 entry (IC50 of 42.47 µM and 30.96 µM, respectively), as well as that piceatannol interacts with cellular membranes. Piceatannol inhibits HIV-1 infection in a dual-chamber assay mimicking the female genital tract, as well as HSV infection, emphasizing its potential as a microbicide. Structure-activity relationships (SAR) showed that pharmacophoric groups of piceatannol are strictly required to inhibit HIV-1 entry. By a ligand-based in silico study, we speculated that piceatannol and norartocarpetin may have a very similar mechanism of action and efficacy because of the highly comparable pharmacophoric and 3D space, while guibourtinidol-(4α→8)-epiafzelechin and cassiabrevone may display a different mechanism. We finally show that cassiabrevone plays a major role of the crude extract of CA by blocking the binding activity of HIV-1 gp120 and CD4.

Chemical Constituents of Cassia abbreviata and Their Anti-HIV-1 Activity.

Three new (1-3) and 25 known compounds were isolated from the crude extract of Cassia abbreviata. The chemical structures of new compounds were established by extensive spectroscopic analyses including 1D and 2D NMR and HRESIMS. Cassiabrevone (1) is the first heterodimer of guibourtinidol and planchol A. Compound 2 was a new chalcane, while 3 was a new naphthalene. Cassiabrevone (1), guibourtinidol-(4α→8)-epiafzelechin (4), taxifolin (8), oleanolic acid (17), piceatannol (22), and palmitic acid (28), exhibited potent anti-HIV-1 activity with IC50 values of 11.89 µM, 15.39 µM, 49.04 µM, 7.95 µM, 3.58 µM, and 15.97 µM, respectively.

Conservation and sustainable use of medicinal plants: problems, progress, and prospects.

Medicinal plants are globally valuable sources of herbal products, and they are disappearing at a high speed. This article reviews global trends, developments and prospects for the strategies and methodologies concerning the conservation and sustainable use of medicinal plant resources to provide a reliable reference for the conservation and sustainable use of medicinal plants. We emphasized that both conservation strategies (e.g. in situ and ex situ conservation and cultivation practices) and resource management (e.g. good agricultural practices and sustainable use solutions) should be adequately taken into account for the sustainable use of medicinal plant resources. We recommend that biotechnical approaches (e.g. tissue culture, micropropagation, synthetic seed technology, and molecular marker-based approaches) should be applied to improve yield and modify the potency of medicinal plants.

CRP2, a new invadopodia actin bundling factor critically promotes breast cancer cell invasion and metastasis.

A critical process underlying cancer metastasis is the acquisition by tumor cells of an invasive phenotype. At the subcellular level, invasion is facilitated by actin-rich protrusions termed invadopodia, which direct extracellular matrix (ECM) degradation. Here, we report the identification of a new cytoskeletal component of breast cancer cell invadopodia, namely cysteine-rich protein 2 (CRP2). We found that CRP2 was not or only weakly expressed in epithelial breast cancer cells whereas it was up-regulated in mesenchymal/invasive breast cancer cells. In addition, high expression of the CRP2 encoding gene CSRP2 was associated with significantly increased risk of metastasis in basal-like breast cancer patients. CRP2 knockdown significantly reduced the invasive potential of aggressive breast cancer cells, whereas it did not impair 2D cell migration. In keeping with this, CRP2-depleted breast cancer cells exhibited a reduced capacity to promote ECM degradation, and to secrete and express MMP-9, a matrix metalloproteinase repeatedly associated with cancer progression and metastasis. In turn, ectopic expression of CRP2 in weakly invasive cells was sufficient to stimulate cell invasion. Both GFP-fused and endogenous CRP2 localized to the extended actin core of invadopodia, a structure primarily made of actin bundles. Purified recombinant CRP2 autonomously crosslinked actin filaments into thick bundles, suggesting that CRP2 contributes to the formation/maintenance of the actin core. Finally, CRP2 depletion significantly reduced the incidence of lung metastatic lesions in two xenograft mouse models of breast cancer. Collectively, our data identify CRP2 as a new cytoskeletal component of invadopodia that critically promotes breast cancer cell invasion and metastasis.

The pH sensibility of actin-bundling LIM proteins is governed by the acidic properties of their C-terminal domain.

Actin-bundling Arabidopsis LIM proteins are subdivided into two subfamilies differing in their pH sensitivity. Widely-expressed WLIMs are active under low and high physiologically-relevant pH conditions, whereas pollen-enriched PLIMs are inactivated by pH values above 6.8. By a domain swapping approach we identified the C-terminal (Ct) domain of PLIMs as the domain responsible for pH responsiveness. Remarkably, this domain conferred pH sensitivity to LIM proteins, when provided "in trans" (i.e., as a single, independent, peptide), indicating that it operates through the interaction with another domain. An acidic 6xc-Myc peptide functionally mimicked the Ct domain of PLIMs and efficiently inhibited LIM actin bundling activity under high pH conditions. Together, our data suggest a model where PLIMs are regulated by an intermolecular interaction between their acidic Ct domain and another, yet unidentified, domain.

Chemical constituents of Abies fabri.

Systematic phytochemical investigations on Abies fabri resulted in the isolation of 94 compounds, consisting of 68 terpenoids, six lignans, seven flavonoids, and 13 other miscellaneous chemical constituents. Their structures were elucidated on the basis of spectroscopic methods, and the absolute configurations of three of these previously unknown compounds were determined by Cu-Kα X-ray crystallographic analysis. Twelve previously unreported compounds, one artifact, and one potential artifact were identified, including six triterpenoids, four diterpenoids, two sesquiterpenoids, one lignan, and one phenol. 23-Hydroxy-3-oxolanosta-8,24-dien-26,23-olide showed weak cytotoxic activity against A549 and THP-1 cells with the IC50 values of 5.3 and 5.1 µM, respectively.

Chemical constituents of Abies nukiangensis.

During a survey on chemical constituents of Abies nukiangensis, seven previously unreported compounds, including six triterpenes (1-6) and one phenol (7) were isolated and characterized, together with 37 known miscellaneous chemical constituents. The structures of compounds 1-7 were established mainly by extensive analysis of the 1D and 2D NMR, as well as HRMS data. The absolute configurations of compounds 1 and 8 were confirmed unambiguously by the Cu-Kα X-ray crystallography. Compounds 3 and 8-10 showed significant anti-hepatitis C virus effects with EC50 values of 3.73, 2.67, 1.33 and 2.25µM, respectively.

Differential effects of antofine N-oxide on solid tumor and leukemia cells.

We have studied the anti-cancer activities of antofine N-oxide isolated and purified from the medicinal plant Cynanchum vincetoxicum. Antofine N-oxide displayed a strong inhibitory effect on several solid tumor cell lines (glioblastoma, breast carcinoma and lung carcinoma) and on a T-cell leukemia cell line. Remarkably, its cytotoxic effect was considerably weaker in non-cancer cells. Antofine N-oxide was found to inhibit proliferation of the solid tumor cells whereas it caused apoptotic cell death in the leukemia cells. A microarray analysis after a short treatment revealed that the number of differentially expressed genes was considerably higher in solid tumor than in leukemia cells. Up-regulated genes in the three solid tumor cell lines include genes related to TNFα signaling, of which TNFα was among the most significantly induced. A functional analysis revealed that TNFR1 signaling was most likely activated in the solid tumor cells. The increased mRNA levels of several genes of this pathway (namely TNFα, TNFAIP3 and BIRC3) were confirmed by real-time quantitative PCR after different treatment durations. Finally a slight inhibition of NFκB-mediated transcription was observed in the same cells. Together our results suggest that inhibition of cell proliferation in solid tumor cells essentially occurs through TNFα signaling whereas this pathway is not activated in leukemia cells. Apoptotic cell death in the latter is induced by a distinct yet unknown pathway.

Chemical constituents of Abies delavayi.

Systematic phytochemical investigations on Abies delavayi afforded 110 compounds, including 49 terpenoids, 13 lignans, 20 flavonoids, three coumarins, and 25 other chemical constituents. By detailed analysis of one- and two-dimensional NMR spectroscopic and high-resolution mass spectrometric data, 10 previously unreported compounds were identified: they comprised three sesquiterpenoids, two diterpenoids, one triterpenoid, one monoterpenoid, one flavonoid, and two phenols. These 10 compounds and some previously known ones were subjected to two cytotoxic bioassays against three human tumor cell lines and NO production inhibition on RAW264.7 macrophages, respectively. (25R)-24,25-Dihydroabieslactone had the strongest cytotoxic activity against Colo-205 cells with an IC50 value of 19.0±3.7µg/mL. (+)-T-cadinol, 8,11,13-abietatrien-15-ol-18-yl acetate, 18-acetoxy-13-epi-manool, imperatorin, bergapten, and 5,7-O-dimethyl poriol exhibited weak inhibitory activity against LPS-induced NO production in RAW264.7 macrophages with IC50 values of approximately 50µg/mL.

Human muscle LIM protein dimerizes along the actin cytoskeleton and cross-links actin filaments.

The muscle LIM protein (MLP) is a nucleocytoplasmic shuttling protein playing important roles in the regulation of myocyte remodeling and adaptation to hypertrophic stimuli. Missense mutations in human MLP or its ablation in transgenic mice promotes cardiomyopathy and heart failure. The exact function(s) of MLP in the cytoplasmic compartment and the underlying molecular mechanisms remain largely unknown. Here, we provide evidence that MLP autonomously binds to, stabilizes, and bundles actin filaments (AFs) independently of calcium and pH. Using total internal reflection fluorescence microscopy, we have shown how MLP cross-links actin filaments into both unipolar and mixed-polarity bundles. Quantitative analysis of the actin cytoskeleton configuration confirmed that MLP substantially promotes actin bundling in live myoblasts. In addition, bimolecular fluorescence complementation (BiFC) assays revealed MLP self-association. Remarkably, BiFC complexes mostly localize along actin filament-rich structures, such as stress fibers and sarcomeres, supporting a functional link between MLP self-association and actin cross-linking. Finally, we have demonstrated that MLP self-associates through its N-terminal LIM domain, whereas it binds to AFs through its C-terminal LIM domain. Together our data support that MLP contributes to the maintenance of cardiomyocyte cytoarchitecture by a mechanism involving its self-association and actin filament cross-linking.

A Chinese medicine preparation induces neuroprotection by regulating paracrine signaling of brain microvascular endothelial cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Tong Luo Jiu Nao injection (TLJN), a Chinese medicine preparation, was extracted from the Chinese herbs Panax notoginseng and Gardenia jasminoides. Its pharmacological effect on cerebral ischemia was observed in the study. We previously reported that paracrine signaling of brain microvascular endothelial cells (BMECs) had a direct impact on the survival of neurons in mimicked cerebral ischemia in vitro. The current study was designed to investigate whether paracrine signaling of BMECs could be regulated by drug to achieve neuroprotection. MATERIALS AND METHODS: First, an in vitro model of cerebral ischemia in BMECs or neurons was established by oxygen-glucose-deprivation (OGD). TLJN was used as a medicine of intervention. Injured neurons were cultured in the conditioned media from normal and injured BMECs treated with TLJN. The changes in neurons, including the expression of N-methyl-D-aspartate receptor 1(NMDAR1), Ca(2+) concentration, cytochrome c release, the mitochondrial membrane potential, were determined by the immunofluorescence staining and molecular Probes. The content of Vascular endothelial growth factor (VEGF) and platelet activating factor (PAF) in various BMECs were also examined by Western blotting and Elisa. RESULTS: The results showed the activity of injured neurons was significantly increased when they were grown in conditioned media of normal or injured BMECs treated with TLJN, compared with that of normal or injured BMECs. These changes include a decrease of Ca(2+) concentration, of NMDAR1 expression, and of cytochrome c release, also an increase of the mitochondrial membrane potential. Moreover, the VEGF expression was up-regulated and the PAF expression was down-regulated by TLJN in BMECs. CONCLUSION: The results suggest that a neuroprotective effect of TLJN could be achieved by regulating paracrine signaling of BMECs, which could in part be explained by a TLJN-induced up-regulation of VEGF and a down-regulation of PAF in BMECs. Therefore, regulating the paracrine of BMECs could be the important target of the drug action on injured-neurons, which may be a novel path for therapeutic intervention in ischemic injury.

Live cell imaging reveals actin-cytoskeleton-induced self-association of the actin-bundling protein WLIM1.

Crosslinking of actin filaments into bundles is essential for the assembly and stabilization of specific cytoskeletal structures. However, relatively little is known about the molecular mechanisms underlying actin bundle formation. The two LIM-domain-containing proteins define a novel and evolutionarily conserved family of actin-bundling proteins whose actin-binding and -crosslinking activities primarily rely on their LIM domains. Using TIRF microscopy, we describe real-time formation of actin bundles induced by tobacco NtWLIM1 in vitro. We show that NtWLIM1 binds to single filaments and subsequently promotes their interaction and zippering into tight bundles of mixed polarity. NtWLIM1-induced bundles grew by both elongation of internal filaments and addition of preformed fragments at their extremities. Importantly, these data are highly consistent with the modes of bundle formation and growth observed in transgenic Arabidopsis plants expressing a GFP-fused Arabidopsis AtWLIM1 protein. Using two complementary live cell imaging approaches, a close relationship between NtWLIM1 subcellular localization and self-association was established. Indeed, both BiFC and FLIM-FRET data revealed that, although unstable NtWLIM1 complexes can sporadically form in the cytosol, stable complexes concentrate along the actin cytoskeleton. Remarkably, disruption of the actin cytoskeleton significantly impaired self-association of NtWLIM1. In addition, biochemical analyses support the idea that F-actin facilitates the switch of purified recombinant NtWLIM1 from a monomeric to a di- or oligomeric state. On the basis of our data, we propose a model in which actin binding promotes the formation and stabilization of NtWLIM1 complexes, which in turn might drive the crosslinking of actin filaments.

Intestinal transport of 3,6'-disinapoylsucrose, a major active component of Polygala tenuifolia, using Caco-2 cell monolayer and in situ rat intestinal perfusion models.

3,6'-Disinapoylsucrose is a major active component of the herb Polygala tenuifolia which has long been used for relieving tranquilization, uneasiness of the mind, and improving learning and memory. Our previous study found that 3,6'-disinapoylsucrose had a very low oral bioavailability. Its mechanisms of absorption in the small intestine have so far been unclear. In the present study, the absorption mechanisms of 3,6'-disinapoylsucrose were investigated by using the Caco-2 cell monolayer and in situ rat intestinal perfusion models. The 3,6'-disinapoylsucrose concentration was determined by an LC/MS/MS method. In a Caco-2 cell transport study, the results showed that 3,6'-disinapoylsucrose had very limited intestinal permeability with average apparent permeability coefficient values around (1.11-1.34) × 10(-7) cm/s from the apical (A) to the basolateral (B) side and (1.37-1.42) × 10(-7) cm/s from B to A, at concentrations of 5, 20, and 33 µM. No concentration dependence in the 3,6'-disinapoylsucrose transport was observed. The apparent permeability coefficient value of 3,6'-disinapoylsucrose (5 µM) from A to B greatly increased to 4.49 × 10(-7) and 1.81 × 10(-7) cm/s, respectively, when the cells were preincubated with EDTA (17 mM) and sodium caprate (5.14 mM). No significant effect on the 3,6'-disinapoylsucrose transport by the inhibitors including verapamil, cyclosporine A, and sodium azide was observed. Similar results were found in the small intestinal perfusion study. The apparent permeability coefficient value of 3,6'-disinapoylsucrose greatly increased from 3.97 × 10(-6) to 23.4 × 10(-6) and 20.0 × 10(-6) cm/s in the presence of EDTA (17 mM) and sodium caprate (5.14 mM), respectively, in perfusion buffer. An in vitro stability evaluation of 3,6'-disinapoylsucrose in the gastrointestinal tract showed that it was relatively stable both in the stomach and small intestine contents, while it was found to be more instable in the colon contents. All of the above results indicate that 3,6'-disinapoylsucrose might be transported across the intestinal mucosa by paracellular passive penetration and paracellular enhancers could increase the intestinal permeability of this compound and thus slightly improve its oral bioavailability.

A LIM domain protein from tobacco involved in actin-bundling and histone gene transcription.

The two LIM domain-containing proteins from plants (LIMs) typically exhibit a dual cytoplasmic-nuclear distribution, suggesting that, in addition to their previously described roles in actin cytoskeleton organization, they participate in nuclear processes. Using a south-western blot-based screen aimed at identifying factors that bind to plant histone gene promoters, we isolated a positive clone containing the tobacco LIM protein WLIM2 (NtWLIM2) cDNA. Using both green fluorescent protein (GFP) fusion- and immunology-based strategies, we provide clear evidence that NtWLIM2 localizes to the actin cytoskeleton, the nucleus, and the nucleolus. Interestingly, the disruption of the actin cytoskeleton by latrunculin B significantly increases NtWLIM2 nuclear fraction, pinpointing a possible novel cytoskeletal-nuclear crosstalk. Biochemical and electron microscopy experiments reveal the ability of NtWLIM2 to directly bind to actin filaments and to crosslink the latter into thick actin bundles. Electrophoretic mobility shift assays show that NtWLIM2 specifically binds to the conserved octameric cis-elements (Oct) of the Arabidopsis histone H4A748 gene promoter and that this binding largely relies on both LIM domains. Importantly, reporter-based experiments conducted in Arabidopsis and tobacco protoplasts confirm the ability of NtWLIM2 to bind to and activate the H4A748 gene promoter in live cells. Expression studies indicate the constitutive presence of NtWLIM2 mRNA and NtWLIM2 protein during tobacco BY-2 cell proliferation and cell cycle progression, suggesting a role of NtWLIM2 in the activation of basal histone gene expression. Interestingly, both live cell and in vitro data support NtWLIM2 di/oligomerization. We propose that NtWLIM2 functions as an actin-stabilizing protein, which, upon cytoskeleton remodeling, shuttles to the nucleus in order to modify gene expression.

Strepsesquitriol, a rearranged zizaane-type sesquiterpenoid from the deep-sea-derived actinomycete Streptomyces sp. SCSIO 10355.

Strepsesquitriol, a new caged sesquiterpene, was isolated from Streptomyces sp. SCSIO 10355. Its absolute structure was established as (1R,2R,4S,5S,8S,10S)-4,9,9,10-tetramethyl-2,5,10-trihydroxytricyclo[6.2.1.0(1,5)]undecane by NMR analysis and a theoretical optical rotation derived from quantum-chemical calculations. It showed moderate inhibitory activity against lipopolysaccharide-induced TNFα production in RAW264.7 macrophages.

Isolation, characterization, and bioactivity evaluation of 3-((6-methylpyrazin-2-yl)methyl)-1H-indole, a new alkaloid from a deep-sea-derived actinomycete Serinicoccus profundi sp. nov.

One new alkaloid, 3-((6-methylpyrazin-2-yl)methyl)-1H-indole (1) was obtained from the deep-sea actinomycete Serinicoccus profundi sp. nov., along with five known compounds (2-6). Their structures were determined on the basis of detailed analysis of the 1D and 2D NMR as well as MS data. The new indole alkaloid displayed weak antimicrobial activity against Staphylococcus aureus ATCC 25923 with an MIC value of 96 µg/mL. It showed no cytotoxicity on a normal human liver cell line (BEL7402) and a human liver tumor cell line (HL-7702).

Cytotoxic triterpenoids from Abies recurvata.

Nine triterpenoids (neoabiestrines A-I, 1-9) including six rearranged lanostanes (1-6) and a rare cycloart-7-ene (7) were isolated from Abies recurvata together with ten known compounds. Their structures were determined by detailed analysis of NMR and MS spectroscopic data. The absolute configurations of 1 and 8 were determined by Cu-Ka X-ray crystallography. Compound 6 showed potent anti-proliferative effect against THP-1 tumor cells with an IC(50) value of 17.8 µg/mL.

Sesquiterpenoids and triterpenoids from Abies holophylla and their bioactivities.

Six previously unreported and 11 known terpenoids were isolated from Abies holophylla. The structures of the six compounds were established as two unusual bisabolane sesquiterpenoids, three nortriterpenoids, and one 3,4-seco-triterpenoid based on the detailed analysis of their 1D and 2D NMR spectroscopic data. In addition, electronic circular dichroism (ECD) calculations and molecular orbital (MO) analysis were used to assign the absolute configuration of one bisabolane sesquiterpenoid, abiesesquine A. Abiesesquine A showed the strongest inhibitory effects against LPS-induced nitric oxide (NO) production in RAW264.7 macrophages with an IC(50) value of 113.1 µM. Lanosta-7,9(11),24-trien-26-oic acid showed potent cytotoxic activity against COLO-205, LOVO, and QGY-7703 tumor cells with IC(50) values of 0.9, 4.2, and 2.0 µM, respectively. (23R,25R)-3,4-seco-9ßH-Lanosta-4(28),7-dien-26,23-olid-3-oic acid, exhibited a significant antiproliferation effect against A549 cells (IC(50)=14.7 µM).

Protective effect of dammarane sapogenins against chemotherapy-induced myelosuppression in mice.

Chemotherapy is the most common way to treat malignancies, but myelosuppression, one of its common side-effects, is a formidable problem. The present study described the protective role of dammarane sapogenins (DS), an active fraction from oriental ginseng, on myelosuppression induced by cyclophosphamide (CP) in mice. DS was orally administered at different dosages (37.5, 75, and 150 mg/kg) for 10 d after CP administration (200 mg/kg intraperitoneally). The results showed that DS increased the number of white blood cells (WBC) on day 3 and day 7 (P < 0.05), such that WBC levels were increased by 105.7 ± 29.5% at 75 mg/kg of DS on day 3 (P < 0.05, compared with the CP group). Similar results were observed in red blood cells and platelets in DS-treated groups. The colony-forming assay demonstrated that the depressed numbers of CFU-GM (colony-forming unit-granulocyte and macrophage), CFU-E (colony-forming unit-erythroid), BFU-E (burst-forming unit-erythroid), CFU-Meg (colony-forming unit-megakaryocyte) and CFU-GEMM (colony-forming unit-granulocyte, -erythrocyte, -monocyte and -megakaryocyte) induced by CP were significantly reversed after DS treatment. Moreover, the ameliorative effect of DS on myelosuppression was also observed in the femur by hematoxylin/eosin staining. In DS-treated groups, ConA-induced splenocyte proliferation was enhanced significantly at all the doses (37.5, 75, 150 mg/kg) on day 3 at the rate of 50.3 ± 8.0%, 77.6 ± 8.5% and 44.5 ± 8.4%, respectively, while lipopolysaccharide-induced proliferation was increased mainly on day 7 (P < 0.01), with an increased rate of 39.8 ± 5.6%, 34.9 ± 6.6% and 38.3 ± 7.3%, respectively. The thymus index was also markedly increased by 70.4% and 36.6% at 75 mg/kg on days 3 and 7, respectively, as compared with the CP group. In summary, DS has a protective function against CP-induced myelosuppression. Its mechanism might be related to stimulating hematopoiesis recovery, as well as enhancing the immunological function.

Arabidopsis actin-depolymerizing factors (ADFs) 1 and 9 display antagonist activities.

We provide evidence that one of the 11 Arabidopsis actin-depolymerizing factors (ADFs), namely ADF9, does not display typical F-actin depolymerizing activity. Instead, ADF9 effectively stabilizes actin filaments in vitro and concomitantly bundles actin filaments with the highest efficiency under acidic conditions. Competition experiments show that ADF9 antagonizes ADF1 activity by reducing its ability to potentiate F-actin depolymerization. Accordingly, ectopic expression of ADF1 and ADF9 in tobacco cells has opposite effects. ADF1 severs actin filaments/bundles and promotes actin cytoskeleton disassembly, whereas ADF9 induces the formation of long bundles. Together these data reveal an additional degree of complexity in the comprehension of the biological functions of the ADF family and illustrate that antagonist activities can be displayed by seemingly equivalent actin-binding proteins.