Isolation and hypoglycemic activity of eleutherans A, B, C, D, E, F, and G: glycans of Eleutherococcus senticosus roots

Intraperitoneal injection of an aqueous extract of the crude drug "shigoka" (Siberian ginseng), Eleutherococcus senticosus roots, remarkably diminished plasma-sugar level in mice. Fractionation of the extract by monitoring the activity yielded seven glycans, eleutherans A, B, C, D, E, F, and G, which exerted marked hypoglycemic effects in normal and alloxan-induced hyperglycemic mice.     

Isolation, structures, and structure - cytotoxic activity relationships of withanolides and physalins from Physalis angulata

Phytochemical investigation of Physalis angulata was initiated following primary biological screening. Fractionation of CHCl3 and n-BuOH solubles of the MeOH extract from the whole plant was guided by in vitro cytotoxic activity assay using cultured HONE-1 and NUGC cells and led to the isolation of seven new withanolides, withangulatins B-H (1-7), and a new minor physalin, physalin W (8), along with 14 known compounds, including physaprun A, withaphysanolide, dihydrowithanolide E, physanolide A, withaphysalin A, and physalins B, D, F, G, I, J, T, U, and V. New compounds (1-8) were fully characterized by a combination of spectroscopic methods (1D and 2D NMR and MS) and the relative stereochemical assignments based on NOESY correlations and analysis of coupling constants. Biological evaluation of these compounds against a panel of human cancer cell lines showed broad cytotoxic activity. Withangulatin B (1) and physalins D (10) and F (11) displayed potent cytotoxic activity against a panel of human cancer cell lines with EC50 values ranging from 0.2 to 1.6 microg/mL. Structure-activity relationship analysis indicated that withanolides and physalins with 4beta-hydroxy-2-en-1-one and 5beta,6beta-epoxy moieties are potential cytotoxic agents.     

Antimalarial activity of extracts of Abutilon grandiflorum G. Don - a traditional Tanzanian medicinal plant

The Tanzanian medicinal plant Abutilon grandiflorum G. Don was studied for its in vivo and in vitro antiplasmodial effects. The ethyl acetate extract showed prominent in vivo activity against P. vinckei vinckei in mice and in vitro against P. falciparum strains HB3 and FCB. The extract was only moderately cytotoxic if tested in vitro against the colon cell line HT29. In the in vivo study, the results were significantly influenced by the treatment schedule used, i.e. early treatment with higher doses was more successful than applying the same overall amount over a longer period. Phytochemical analysis of the extract provided no conclusive evidence for the observed parasitological effects.     

Antimalarial activity of some Colombian medicinal plants

Antimalarial activity of 10 vegetal extracts (9 ethanolic extracts and 1 crude alkaloid extract), obtained from eight species traditionally used in Colombia to treat malaria symptoms, was evaluated in culture using Plasmodium falciparum chloroquine resistant (FcB2) strain and in vivo on rodent malaria Plasmodium berghei. The activity on ferriprotoporphyrin biomineralization inhibition test (FBIT) was also assessed. Against Plasmodium falciparum, eight extracts displayed good activity Abuta grandifolia (Mart.) Sandwith (Menispermaceae) leaves, Acacia farnesiana (L.) Willd. (Mimosaceae) leaves, Acnistus arborescens (L.) Schltdl. (Solanaceae) aerial part, Croton leptostachyus Kunth (Euphorbiaceae) aerial part, Piper cumanense Kunth (Piperaceae) fruits and leaves, Piper holtonii C. DC. (Piperaceae) aerial part and Xylopia aromatica (Lam.) Mart. (Annonaceae) bark with IC(50) values ranging from <1 to 2.1 microg/ml, while in the in vivo model only Abuta grandifolia alkaloid crude extract exhibits activity, inhibiting 66% of the parasite growth at 250 mg/kg/day. In the FBIT model, five extracts were active (Abuta grandifolia, Croton leptostachyus, Piper cumanense fruit and leaves and Xylopia aromatica).     

Nocardimicins A, B, C, D, E, and F, siderophores with muscarinic M3 receptor inhibiting activity from Nocardia sp. TP-A0674

In the screening for muscarinic M3 receptor binding inhibitors from microbial secondary metabolites, the extract of Nocardia sp. TP-A0674 was found to be highly active. Bioassay-guided fractionation of it led to the isolation of six new siderophores, nocardimicins A (1), B (2), C (3), D (4), E (5), and F (6), as active principles. Their chemical structures were determined by spectroscopic and degradation analysis. Of these congeners, nocardimicin B (2) inhibited the binding of tritium-labeled N-methylscopolamine to the muscarinic M3 receptor most potently with a Ki value of 0.13 microM. Compound 2 showed more selective activity to M3 and M4 receptors than other subtypes.     

Antimalarial activity of alkaloids isolated from Stephania rotunda

Stephania rotunda (Menispermaceae) is used in traditional medicine for the treatment of fever. Four major alkaloids: dehydroroemerine, tetrahydropalmatine, xylopinine, cepharanthine as well as aqueous extract (SA), dichloromethane extracts (SD1 and SD2) from this plant were tested against Plasmodium falciparum W2 in vitro. Dehydroroemerine, cepharanthine and SD1 were the most active against W2 with IC(50) of 0.36, 0.61microM and 0.7microg/mL, respectively. Their IC(50) on human monocytic THP1 cells were 10.8, 10.3microM and >250microg/mL, respectively. Cepharanthine, SD1 and SA were selected for in vivo antimalarial test against Plasmodium berghei in mice. The results of SD1 and SA at dose of 150mg/kg showed a decrease of 89 and 74% of parasitaemia by intra-peritoneal injection and 62.5 and 46.5% of parasitaemia by oral administration, respectively. The result of cepharanthine at dose of 10mg/kg showed a decrease of 47% of parasitaemia by intra-peritoneal injection and 50% of parasitaemia by oral administration. Drug interaction of chloroquine and major alkaloids indicates that cepharanthine-chloroquine and tetrahydropalmatine-xylopinine associations are synergistic. These results are in agreement with the use of this plant in the treatment of malaria. This is the first report on in vivo antimalarial investigation for Stephania rotunda.     

Antimalarial activity and cytotoxicity of Evodia fatraina stem bark extracts

Stem bark extracts of Evodia fatraina (Rutaceae) were tested for antimalarial activity in vitro on Plasmodium falciparum using an isotopic semi-microtest and in vivo on Plasmodium berghei in mice. Ethyl acetate extract showed moderate antimalarial activity in vitro (IC50 = 8.5 micrograms ml-1). However, ethanolic extract exhibited significant potency in vivo (65% suppression of parasitaemia). Moreover, low toxicity against HeLa cells and L 929 fibroblasts was observed with ethanolic extract (IC50 = 95 micrograms ml-1 and 60 micrograms ml-1, respectively).     

Antimalarial activity of some plant remedies in use in Marracuene, southern Mozambique

Two plants, Spirostachys africana and Bridelia cathartica, were selected for investigation on the basis of a clinical study of four herbal antimalarial remedies used in southern Mozambique. Petroleum ether, ethanol and aqueous extracts were tested for activity in vitro against Plasmodium falciparum. Crude ethanolic and aqueous extracts of the root and the ethanolic extract of the stem of B. cathartica caused a 50% inhibition of parasite growth at an incubation concentration of 0.05 microgram/ml.     

Antimalarial activity of extracts of Malaysian medicinal plants.

In vitro and in vivo studies revealed that Malaysian medicinal plants, Piper sarmentosum, Andrographis paniculata and Tinospora crispa produced considerable antimalarial effects. Chloroform extract in vitro did show better effect than the methanol extract. The chloroform extract showed complete parasite growth inhibition as low as 0.05 mg/ml drug dose within 24 h incubation period (Andrographis paniculata) as compared to methanol extract of drug dose of 2.5 mg/ml but under incubation time of 48 h of the same plant spesies. In vivo activity of Andrographis paniculata also demonstrated higher antimalarial effect than other two plant species.     

Antimalarial agents, 2. Artesunate, an inhibitor of cytochrome oxidase activity in Plasmodium berghei

The activity of the cytochrome oxidase, which is located in the plasma and the nuclear and the food-vacuole-limiting membranes as well as in the mitochondria of the trophozoites of Plasmodium berghei, was inhibited completely by sodium artesunate, an antimalarial drug, in vitro at 1 mM and in vivo at 100 mg/kg iv. This enzyme appears to be a target for the antimalarial mechanism of action of artesunate and qinghaosu.     

The antibacterial ent-eusynstyelamide B and eusynstyelamides D, E, and F from the Arctic bryozoan Tegella cf. spitzbergensis

The brominated tryptophan-derived ent-eusynstyelamide B (1) and three new derivatives, eusynstyelamides D, E, and F (2-4), were isolated from the Arctic bryozoan Tegella cf. spitzbergensis. The structures were elucidated by spectroscopic methods including 1D and 2D NMR and analysis of mass spectrometric data. The enantiomer of 1, eusynstyelamide B, has previously been isolated from the Australian ascidian Eusynstyela latericius. Antimicrobial activities are here reported for 1-4, with minimum inhibitory concentrations (MIC) as low as 6.25 μg/mL for 1 and 4 against Staphylococcus aureus. Eusynstyelamides 2 and 3 showed weak cytotoxic activity against the human melanoma A 2058 cell line.     

Antimalarial agents, 4. Synthesis of a brusatol analog and biological activity of brusatol-related compounds

The quassinoids bruceoside-A [1], brusatol [2], and bruceolide [3] were tested for antimalarial activity in vitro against the chloroquine-resistant (Smith) isolates of Plasmodium falciparum. Compound 2 was quite active, 1 was not active, and 3 showed only a trace of activity. The fact that 15 [(E)-non-2-enoyl] bruceolide [7] synthesized from 2 was eight times less active than 2 would indicate that the requirement of a C-15 ester moiety for enhanced antimalarial activity among brusatol related quassinoids could be quite specific.     

Vaticanol（B，CandG），α—Viniferin和Hopeaphenol鼠骨髓生成的肥大细胞介质释放体外抑制小

目的：α-viniferin，vaticanol(B，C and G和hopeaphenol是白黎芦醇的低聚体，具有抗肿瘤和抗氧化等活性，而这些化学保护作用是与其抗炎作用有联系。本文研究旨在了解这些化合物对小鼠骨髓分化肥大细胞(BMMC)组织胺、肿瘤坏死因子和白三烯介质释放的影响，并观察对细胞外信号调节激酶(ERK)的激活作用。方法：分离小鼠骨髓细胞。培养4～5周(RPMI-1640，IL-310ng／ml)，抗-DNP IgE致敏，以DNP—BH(30ng／ml)刺激释放反应。在非免疫刺激释放实验中，A23187作为刺激剂。结果：所试化合物均表现出不同程度的抑制BMMC释放反应的作用。这些化合物对lgE刺激的1NFa和LTs释放表现出显著的抑制作用，而对IgE刺激的组织胺释放反应，只有vaticanol B和vaticarol C具有抑制作用(100tnnol／L)。在A23187介导的非免疫刺激释放反应中，vaticanol(B，C和G)和hopeaphenol对组织胺释放表现出明显的对抗作用，大多数所试化合物有效地抑制了TNF-α和LTs的释放，唯yaticanol C和vaticanol G对LTs的释放无明显影响。α-viriferin和vatztcanollc有效地抑制了IgE刺激的ERK酶的激活。结论：α-viruifenn，vaficanol(B，C和G)和hopesaphenol能有效地抑制肥大细胞的炎性介质的释放反应，而对BMMC的细胞活力无明显影响.     

Antimalarial activity screening of some alkaloids and the plant extracts from Amaryllidaceae

Four groups of Amaryllidaceae alkaloids, namely lycorine-, crinine-, tazettine-, and galanthamine-type, as well as plant extracts of the Amaryllidaceae plants (Pancratium maritimum, Leucojum aestivum, and Narcissus tazetta ssp. tazetta) growing in Turkey were evaluated in vitro for their ability to inhibit Plasmodium falciparum growth by a high-throughput screening method with a 96-well microtiter plate. All four groups of alkaloids exhibited antimalarial activity at different potencies. 6-Hydroxyhaemanthamine, haemanthamine and lycorine were found to be the most potent alkaloids against P. falciparum (T9.96) and galanthamine and tazettine had the least potent activity against P. falciparum (K1).     

Antimalarial activity of crude extracts from nine African medicinal plants

An ethnobotanical study was conducted in Comores (Ngazidja) about plant species used traditionally for the treatment of various diseases, including malaria. Antimalarial activity of 76 vegetal extracts obtained from 17 species traditionally used to treat malaria symptoms, was evaluated in vitro using Plasmodium falciparum chloroquine-resistant strain (W2). Antiproliferative activity was evaluated on human monocytic THP1 cells and the selectivity index of the plant extracts was calculated. The results showed that 10 plant extracts had a moderate activity (5相似文献   

Antimalarial activity of macrocyclic trichothecenes isolated from the fungus Myrothecium verrucaria

Bioassay-guided fractionation of an extract from the fungus Myrothecium verrucaria BCC 112 resulted in the first isolation of roridin E acetate (5) from nature together with four common macrocyclic trichothecene isomers (1-4). Trichothecenes 1-5, while known as mycotoxins, were evaluated for their high antimalarial activity.     

Antimalarial activity of sesquiterpenes from the marine sponge Acanthella klethra.

Five sesquiterpenoids containing isonitrile or isothiocyanate groups were isolated from the sponge Acanthella klethra. Compounds 1 and 2 were identified as axisonitrile 3 and the corresponding isothiocyanate derivative, respectively. Compounds 3-5 were found to be eudesmane sesquiterpenes. None of these compounds was cytotoxic toward cultured KB-3 cells, but varying degrees of activity were observed with cultured Plasmodium falciparum. Compound 1 demonstrated greatest promise as an antimalarial agent.     

Antimalarial activity of four plants used in traditional medicine in Mali

Mitragyna inermis (De Willd.) O. Kuntze Rubiaceae, Nauclea latifolia (Sm.) Rubiaceae, Glinus oppositofolius (Linn) Molluginaceae and Trichilia roka (Forsk.) Chiv. Meliaceae were investigated for their in vitro antimalarial activity. Leaves, roots and stem barks were submitted to aqueous, hydromethano and chloroform extractions and antimalarial activity was evaluated by microscopic and flow cytometric analysis. The results present evidence that the alkaloids contained in chloroform extracts and ursolic acid, purified from the hydromethanol extract of M. inermis induced a significant decrease of parasite proliferation. However, aqueous extracts, traditionally used for medication did not show high antimalarial activity. Statistical comparison between microscopic and cytometric analysis demonstrated the validity of this new technique for the screening of active antimalarial compounds isolated from plants.     

Antimalarial herbal remedies of Msambweni,Kenya

Malaria is a serious cause of mortality globally. The disease is of regional concern in Africa and of national interest in Kenya due to its high morbidity and mortality as a result of development of resistant strains of Plasmodium falciparum to many existing drugs such as chloroquine. Alternative medicine using herbal remedies are commonly used to treat malaria in Kenya. However, plants used in some rural areas in Kenya are not documented. Many antimalarial drugs have been derived from plants. This study was conducted to document medicinal plants that are traditionally used by the Msambweni community of Kenyan South Coast to treat malaria, where the disease is endemic. Herbalists were interviewed by administration of semistructured questionnaires in order to obtain information on medicinal plants traditionally used for the treatment of malaria. Focused group discussions held with the herbalists supplemented the interview and questionnaire survey. Twenty-seven species of plants in 24 genera distributed in 20 families were reported to be used in this region for the treatment of malaria. Labiatae, Rutaceae and Liliaceae families had each eleven percent of the plant species reported and represented the species that are most commonly used. Thirteen plant species, namely; Aloe deserti Berger (Liliaceae), Launea cornuta (Oliv and Hiern) C. Jeffrey (Compositae), Ocimum bacilicum L. (Labiatae), Teclea simplicifolia (Eng) Verdoon (Rutaceae), Gerranthus lobatus (Cogn.) Jeffrey (Cucurbitaceae), Grewia hexaminta Burret. (Tiliaceae), Canthium glaucum Hiern. (Rubiaceae), Amaranthus hybridus L. (Amaranthaceae), Combretum padoides Engl and Diels. (Combretaceae), Senecio syringitolius O. Hoffman. (Compositae), Ocimum suave Willd (Labiatae), Aloe macrosiphon Bak. (Liliaceae) and Laudolphia buchananii (Hall.f) Stapf. (Apocynaceae) are documented from this region for the first time for the treatment of malaria. These results become a basis for selection of plants for further pharmacological, toxicological and phytochemical studies in developing new plant based antimalarial drugs.