In Vitro activities of plant extracts from Saudi Arabia against malaria,leishmaniasis, sleeping sickness and Chagas disease

The in vitro activity of the methanol extracts of 51 plants randomly collected from the Kingdom of Saudi Arabia and some of their fractions (petroleum ether, chloroform, ethyl acetate and aqueous) were evaluated against Plasmodium falciparum, Trypanosoma brucei brucei, T. cruzi and Leishmania infantum, as well as toxicity against MRC‐5 fibroblast cells. Ten crude methanolic extracts that demonstrated potent and adequately selective antiprotozoal activity were subjected to solvent fractionation using petroleum ether, ethyl acetate and chloroform. Only three samples showed promising antiprotozoal activity. Argemone ochroleuca (CHCl₃ fraction) showed pronounced activity against P. falciparum_GHA (IC₅₀ 0.32 μg/mL) and T. cruzi (IC₅₀ 0.30 μg/mL) with low cytotoxicity against MRC‐5 cells (CC₅₀ 11.6 μg/mL). Capparis spinosa (EtOAc fraction) showed pronounced activity against P. falciparum_GHA with an IC₅₀ 0.50 μg/mL in the absence of toxicity against MRC‐5 cell line (CC₅₀ > 30 μg/mL). Heliotropium curassavicum (CHCl₃ fraction) showed similar activity against P. falciparum (IC₅₀ 0.65 μg/mL; MRC‐5 CC₅₀ > 30 μg /mL). These three extracts will be subjected for further extensive studies to isolate and identify their active constituents. Copyright © 2010 John Wiley & Sons, Ltd.     

Evaluation of the flora of Puerto Rico for in vitro antiplasmodial and antimycobacterial activities.

The emergence of resistant strains of Plasmodium falciparum and Mycobacterium tuberculosis underscores the need for novel drugs that are effective against these microorganisms. As part of our screening programme of the flora of Puerto Rico, we tested a number of ethanol extracts of higher plants for antiplasmodial and antimycobacterial activities. A total of 40 extracts belonging to 23 plant families and 37 species were tested for antiplasmodial activity. Five extracts demonstrated activity against Plasmodium falciparum in vitro (50%-100% parasite suppression at 5 microg/mL). Another 63 extracts belonging to 30 plant families and 50 species were tested in vitro against Mycobacterium tuberculosis. Two extracts were found to be active, Ficus citrifolia and Pisonia borinquena (85% or more inhibition of microbial growth at 100 microg/mL of extract).     

In vitro cytotoxic,antiprotozoal and antimicrobial activities of medicinal plants from Vanuatu

Sixty‐three extracts obtained from 18 plants traditionally used in the South Pacific archipelago Vanuatu for the treatment of infectious diseases were screened for antimicrobial and antiprotozoal activities. In addition, the extracts were subjected to a detailed analysis on cytotoxic effects toward a panel of human cancer cell lines, designed as a smaller version of the NCI60 screen. Intriguingly, 15 plant extracts exhibited strong cytotoxic effects specific for only one cancer cell line. Extracts of the leaves of Acalypha grandis Benth . significantly affected Plasmodium falciparum without showing obvious effects against the other protozoa tested. The leaves of Gyrocarpus americanus Jacq . displayed significant activity against Trypanosoma b. brucei and the leaves of Tabernaemontana pandacaqui Lam . I as well as the stems of Macropiper latifolium (L.f .) against Trypanosoma cruzi. In contrast none of the extracts showed relevant antibacterial or antifungal activity. Copyright © 2009 John Wiley & Sons, Ltd.     

钩毛茜草的化学成分及其细胞毒活性研究

综合采用多种色谱分离技术对钩毛茜草Rubia oncotricha根及根茎的甲醇提取物进行化学成分研究,结合NMR、MS等波谱技术,共分离鉴定了14个化合物,分别为rubiprasin D(1)、rubiprasin B(2)、rubiprasin C(3)、齐墩果酸(oleanolic acid,4)、methyl-5-hydroxy-dinaphtho[1,2-2’3’]furan-7,12-dione-6-carboxylate(5)、rubioncolin C(6)、大叶茜草素(mollugin,7)、呋喃大叶茜草素(furomollugin,8)、3-氨基-2-甲氧羰基-1,4-萘醌(3-amino-2-methoxycarbonyl-1,4-naphthoquinone,9)、1-羟基-2-甲基蒽醌(1-hydroxy-2-methyl-9,10-anthraquinone,10)、2-羟基-6-甲基蒽醌(2-hydroxy-6-methyl-9,10-anthraquinone,11)、1,4-二羟基-2-羟甲基蒽醌(1,4-dihydroxy-2-hydroxymethyl-9,10-anthraquinone,12)、2-羟基-1-甲氧基蒽醌(2-hydroxy-1-methoxy-9,10-anthraquinone,13)、1-羟基-2-甲氧基-6-甲基蒽醌(1-hydroxy-2-methoxy-6-methyl-9,10-anthraquinone,14)。化合物类型涉及萜类和醌类,其中化合物1为新的齐墩果烷型三萜类化合物,化合物25,9,1113为首次从该植物中分离得到。对所有化合物进行细胞毒和杀线虫活性筛选,结果显示化合物4,6,11,12对人非小细胞肺癌细胞(A549),人胃癌细胞株(SGC-7901)和人宫颈癌细胞(He La)具有一定的生长抑制作用,以6活性最强,其IC50分别为19.42,2.74,8.07μmol·L^-1。     

Antiplasmodial and cytotoxic activity of phloroglucinol derivatives from Hypericum erectum thunb

The chloroform extracts of whole plants of Hypericum erectum were investigated for antiplasmodial activity against chloroquine‐sensitive strains of Plasmodium falciparum. Five phloroglucinol derivatives, otogirin (1), otogirone (2), erectquione A (3), erectquione B (4), and erectquione C (5) were isolated from the whole plants of H. erectum. Also, five compounds were evaluated for in vitro antiplasmodial activities as well as their cytotoxic potential on SK‐OV‐3 cancer cell line cells. Compounds 2, 4 showed notable growth inhibitory activity against chloroquine‐sensitive strains of Plasmodium falciparum with IC₅₀ values from 5.6 and 7.2 μM. This compound showed no significant cytotoxicity (IC₅₀ > 150 μM) evaluated using SK‐OV‐3 cancer cell line cells. Copyright © 2010 John Wiley & Sons, Ltd.     

Evaluation of Turkish seaweeds for antiprotozoal, antimycobacterial and cytotoxic activities

As part of our continuing research on seaweeds, crude MeOH extracts of two green, three brown and six red algae collected from Marmara, Black, Aegean and Mediterranean Seas were screened. Four parasitic protozoa, i.e. Plasmodium falciparum, Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani and the tubercle bacillus Mycobacterium tuberculosis were used as test organisms for the in vitro assays. The selective toxicity of the extracts was also determined against mammalian L6 cells. All seaweed extracts were active against T. brucei rhodesiense; the Dasya pedicellata extract was the most potent (IC₅₀ value 0.37 µg/mL). The same extract also weakly inhibited the growth of T. cruzi (IC₅₀ 62.02 µg/mL). All seaweed extracts also showed leishmanicidal activity (IC₅₀ values 16.76–69.98 µg/mL). The majority of the extracts also exhibited antiplasmodial potential and the most potent extracts were those from D. pedicellata (IC₅₀ 0.38 µg/mL), Codium bursa (IC₅₀ 1.38 µg/mL) and Caulerpa rasemosa (IC₅₀ 3.12 µg/mL). One brown and two red algal extracts showed some weak activity against Mycobacterium tuberculosis (MIC values 125–256 µg/mL). Except for the extract of Dasya pedicellata, none of the extracts displayed any cytotoxicity. This is the second study investigating the antiprotozoal activities of Turkish marine algae and identifies Dasya pedicellata, an understudied algal species, as a candidate for further studies. Copyright © 2010 John Wiley & Sons, Ltd.     

Antioxidant and cytotoxic activities of Hypericum sp. on brine shrimps and human cancer cell lines

Ten different samples of five Hypericum sp. were tested on brine shrimps, human colon carcinoma and human hepatoma cell lines for their cytotoxic activities. H. triquetrifolium Turra. (Rafina) showed the highest activity (LC50 = 22 mg/mL) on brine shrimps, while the extracts of the other nine samples showed significant to moderate activities (LC50 from 37 to 107 mg/mL). H. empetrifolium Wild. (Parnon) showed the highest activity in human colon carcinoma and human hepatoma cell lines, with LC50 values 29 and 25.1 mg/mL, respectively, while the LC50 values of the other samples were more than 45 mg/mL. It is very interesting to observe that most Hypericum samples showed good antioxidant activity in vitro.     

Flow cytometric estimation on cytotoxic activity of leaf extracts from seashore plants in subtropical Japan: isolation,quantification and cytotoxic action of (-)-deoxypodophyllotoxin

The cytotoxic activity of methanol extracts of leaves collected from 39 seashore plants in Iriomote Island, subtropical Japan was examined on human leukaemia cells (K562 cells) using a flow cytometer with two fluorescent probes, ethidium bromide and annexin V-FITC. Five extracts (10 microg/mL) from Hernandia nymphaeaefolia, Cerbera manghas, Pongamia pinnata, Morus australis var. glabra and Thespesia populnea greatly inhibited the growth of K562 cells. When the concentration was decreased to 1 microg/mL, only one extract from H. nymphaeaefolia still inhibited the cell growth. A cytotoxic compound was isolated from the leaves by bioassay-guided fractionation and was identified as (-)-deoxypodophyllotoxin (DPT). The fresh leaves of H. nymphaeaefolia contained a remarkably high amount of DPT (0.21 +/- 0.07% of fresh leaf weight), being clarified by a quantitative HPLC analysis. DPT at 70-80 pM started to inhibit the growth of K562 cells in an all-or-none fashion and at 100 pM or more it produced complete inhibition in all cases. Therefore, the slope of the dose-response curve was very steep. DPT at 100 pM or more decreased the cell viability to 50%-60% and increased the number of cells undergoing apoptosis (annexin V-positive cells). The results indicate that DPT contributes to the cytotoxic action of the extract from the leaves of H. nymphaeaefolia on K562 cells.     

Leishmanicidal, antiplasmodial, and cytotoxic activity of novel diterpenoid 1,2-quinones from Perovskia abrotanoides: new source of tanshinones.

Cryptotanshinone (1), a quinoid diterpene with a nor-abietane skeleton, and three new natural products, 1beta-hydroxycryptotanshinone (2), 1-oxocryptotanshinone (3), and 1-oxomiltirone (4), were isolated from roots of the Iranian medicinal plant Perovskia abrotanoides. Their structures were established using homo- and heteronuclear two-dimensional NMR experiments, supported by HRMS. The total amount of tanshinones isolated from dry roots of Perovskia abrotanoides was about 1.5%. The compounds exhibited leishmanicidal activity in vitro (IC(50) values in the range 18-47 microM). These findings provide a rationale for traditional use of the roots in Iran as a constituent of poultices for treatment of cutaneous leishmaniasis. The isolated tanshinones also inhibited growth of cultured malaria parasites (3D7 strain of Plasmodium falciparum), drug-sensitive KB-3-1 human carcinoma cell line, multidrug-resistant KB-V1 cell line, and human lymphocytes activated with phytohaemagglutinin A (IC(50) values in the range 5-45 microM). The toxicity of tanshinones toward the drug-sensitive KB-3-1 and the multidrug-resistant KB-V1 cells was the same, indicating that the compounds are not substrates for the P-glycoprotein drug efflux pump.     

Isolation of spirastrellolides A and B from a marine sponge Epipolasis sp. and their cytotoxic activities

Spirastrellolides A (1) and B (3) have been isolated as free acids from a marine sponge Epipolasis sp. collected in the East China Sea. These compounds had been isolated from the Caribbean marine sponge Spirastrella coccinea after conversion to the methyl ester. We examined the cytotoxic activities of 1 and 3 and found that the activities of the free acids are comparable to those of the corresponding methyl esters.     

Antimycobacterial,antiprotozoal and cytotoxic potential of twenty‐one brown algae (phaeophyceae) from British and Irish waters

In the continuation of our research on seaweeds, crude extracts of 21 brown algae collected from the south coast of England and the west coast of Ireland were screened for in vitro trypanocidal, leishmanicidal and antimycobacterial activities. Mammalian stages of a small set of parasitic protozoa; i.e. Trypanosoma brucei rhodesiense, T. cruzi and Leishmania donovani, and the tubercle bacillus Mycobacterium tuberculosis were used as test organisms. The extracts were also evaluated for selectivity by testing on a mammalian cell line (L6 cells). Only four extracts were moderately active against T. cruzi, whereas all algal extracts showed significant activity against T. brucei rhodesiense, with Halidrys siliquosa and Bifurcaria bifurcata (Sargassaceae) being the most potent (IC₅₀ values 1.2 and 1.9 μg/mL). All algal extracts also displayed leishmanicidal activity, with H. siliquosa and B. bifurcata again being the most active (IC₅₀s 6.4 and 8.6 μg/mL). When tested against M. tuberculosis, only the B. bifurcata extract was found to have some antitubercular potential (MIC value 64.0 μg/mL). Only three seaweed extracts, i.e. H. siliquosa, B. bifurcata and Cystoseira tamariscifolia showed some cytotoxicity. To our knowledge, this is the first study on the antiprotozoal and antimycobacterial activity of brown algae from British and Irish waters. Copyright © 2010 John Wiley & Sons, Ltd.     

Antiprotozoal,antimycobacterial and cytotoxic potential of twenty‐three British and Irish red algae

As part of our continuing research on seaweeds, we have screened the crude extracts of 23 red marine algae collected from England and Ireland. The clinically important blood‐stage life forms of Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani and Mycobacterium tuberculosis were used as test organisms in the in vitro assays. The selectivity of the extracts was determined by using mammalian skeletal myoblast (L6) cells. All algal extracts showed activity against T. brucei rhodesiense, with Corallina officinalis and Ceramium virgatum being the most potent (IC₅₀ values 4.8 and 5.4 μg/ml), whilst none of the algal extracts inhibited the growth of T. cruzi. Except for Porphyra leucosticta, extracts from all seaweeds also showed leishmanicidal activity with IC₅₀ values ranging from 16.5 to 85.6 μg/ml. Only the crude extract of Calliblepharis jubata showed some weak activity against Mycobacterium tuberculosis (MIC value 256 μg/ml), while the others were inactive at this concentration. Corallina officinalis was the only seaweed that displayed some marginal cytotoxicity (IC₅₀ value 88.6 μg/ml), and all remaining extracts were non‐toxic towards L6 cells at 90 μg/ml concentration. To our knowledge, this is the first study reporting antiprotozoal and antimycobacterial activity of British and Irish red algae. Copyright © 2010 John Wiley & Sons, Ltd.     

In vitro antileishmanial activity of three saponins isolated from ivy, alpha-hederin, beta-hederin and hederacolchiside A(1), in association with pentamidine and amphotericin B.

The in vitro antileishmanial activity of three saponins isolated from ivy, alpha-hederin, beta-hederin and hederacolchiside A(1), was investigated on parasites of the species Leishmania mexicana, in their promastigote and amastigote forms compared with their toxicity versus human monocytes. The results showed that saponins exhibited a strong antiproliferative activity on all stages of development of the parasite but demonstrated a strong toxicity versus human cells. Association of subtoxic concentrations of saponins with antileishmanial drugs such as pentamidine and amphotericin B demonstrated that saponins could enhance the efficiency of conventional drugs on both the promastigote and the amastigote stages of development of the parasite. The results demonstrated moreover that the action of saponins on promastigote membrane was cumulative with those of amphotericin B.     

Antioxidant, antimicrobial and cytotoxic activities of selected medicinal plants from Yemen

Ninety crude extracts, including dichloromethane, methanol and aqueous extracts from 30 medicinal plants used in the Yemeni ethnomedicine to treat common infections, were screened in vitro for antimicrobial activities against three Gram-positive bacteria and two Gram-negative bacteria, Candida maltosa and five opportunistic human fungal pathogens (two yeasts, three hyphomycetes). Most of the plants showed antibacterial activities. Extracts from Tamarindus indica flowers and Ficus vasta fruits have been the most active. Of the 30 plants tested, 13 showed antifungal activity (40%) against one ore more human pathogenic fungi. The strongest inhibition was exhibited by Azima tetracantha (fruits), Sansevieria ehrenbergii (fruits) and Solanum incanum (fruits). Ten methanol extracts, especially those of Acacia asak barks and Solanum nigrum fruits, showed effective free radical scavenging activities in the DPPH assay. Remarkable cytotoxic activity against FL-cells was shown only for five plants, among them Plicosepalus curviflorus (stems).     

Determination of genotoxic, antigenotoxic and cytotoxic potential of the extract from lichen Cetraria aculeata (Schreb.) Fr. in vitro

Naturally occurring compounds can have protective effects towards mutagens and carcinogens as shown by numerous studies. In the present study, the genotoxic/antigenotoxic activities of the extract from lichen Cetraria aculeata (Schreb.) Fr., which has been identified as an antibacterial agent in former studies, were investigated against known mutagens such as 4-nitro-o-phenylenediamine (4-NPD) and 2-aminofluorene (2-AF) in TA98 and TA100 strains of Salmonella typhimurium in the presence or absence of metabolic activity. Further genotoxicity/antigenotoxicity of the extract against mitomycin C for micronucleus formation was also evaluated in human lymphocytes. The cytotoxic effects of the extract on mammalian cells were investigated in three different cell line types by MTT assay. The results obtained show that the extract of C. aculeata has a significant antigenotoxic activity in bacterial systems, but not in mammalian cells and cytotoxic activity in some mammalian cancer cells. However, it was not mutagenic in all systems. The findings suggest that the lichen extract may have a possible therapeutic potential and therefore this must be further investigated by other multiple in vitro bioassays for the development of therapeutic agents.     

重组葡萄球菌肠毒素B突变体蛋白D9N的表达、纯化及生物学活性的研究

 目的表达、纯化重组葡萄球菌肠毒素B突变体蛋白D9N(rSEB-D9N),了解表达产物rSEB-D9N的细胞毒性、促淋巴细胞增殖和肿瘤生长抑制作用。方法不同浓度IPTG诱导SEB-D9N突变体原核表达系统pET32a-SEB-D9N-E.coliBL21DE3表达rSEB-D9N,经Ni-NTA亲和层析法纯化rSEB-D9N,10%SDS-PAGE和高效液相色谱检测其纯度。以Vero细胞为靶细胞,进行rSEB-D9N的细胞毒性作用,并计算TCID₅₀值。采用MTT法分别检测不同浓度的rSEB-D9N促人淋巴细胞增殖及抑制KB及MCF-7癌细胞株生长的作用。流式细胞术检测rSEB-D9N刺激人淋巴细胞后CD3、CD4、CD8的表达。结果rSEB-D9N表达产量约占细菌总蛋白30%,纯化后获得纯度为90.48%的rSEB-D9N。rSEB和rSEB-D9N对Vero细胞的TCID₅₀值分别为3.12,8.85μg,10.0,20.0mg·L^-1的rSEB-D9N具有显著的促PBMC增殖的作用(P<0.05),且主要上调CD3,CD4和CD8的表达。5.0～20.0mg·L^-1rSEB-D9N作用的PBMC上清对KB和MCF-7细胞生长均可产生明显抑制作用(P<0.05)。结论获得并纯化了重组葡萄球菌肠毒素B突变体蛋白(rSEB-D9N),其细胞毒性作用有所降低,但促人淋巴细胞增殖和抑制肿瘤细胞生长作用仍较强,可作为研制升白细胞、抗肿瘤相关药物的候选突变体。     

Anti‐inflammatory Effects of Ginsenosides Rg5, Rz1, and Rk1: Inhibition of TNF‐α‐induced NF‐κB,COX‐2, and iNOS transcriptional expression

In the course of this experiment on the anti‐inflammatory effect of ginsenosides, protopanaxdiol ginsenosides have shown inhibition activities in inflammatory responses: NF‐κB, COX‐2, and iNOS were induced by TNF‐α. The responses of this experiment were evaluated by NF‐κB‐luciferase assay and RT‐PCR experiment of COX‐2 and iNOS genes. The NF‐κB expressions were inhibited by ginsenosides Rd, Rg₅, Rz₁, and Rk₁ in a dose‐dependent manner. The IC₅₀ values were 3.47, 0.61, 0.63, and 0.75 μM, respectively. Particularly, ginsenosides Rg₅, Rz₁, and Rk₁ as converted ginsenosides from primary protopanaxdiol ginsenosidess significantly inhibited COX‐2 and iNOS gene expression. These inhibition levels were similar to sulfasalazine as reference material. Copyright © 2014 John Wiley & Sons, Ltd.     

Antiplasmodial, anti-inflammatory and cytotoxic activities of various plant extracts from the Mascarene Archipelago

Aim of the study

Antiplasmodial activity, inhibition of nitric oxide (NO) overproduction, and anti-proliferative activity were investigated in vitro to evaluate the bioactive potential of the traditional pharmacopoeia of the Mascarene Archipelago, which is known for its biodiversity and for the richness of its endemic flora.

Materials and methods

A total of 45 methanol (MeOH) and dichloromethane (DCM) extracts were prepared from 19 plant species collected on Réunion and Mauritius Islands. Ninety-six-well microplate assays were performed on chloroquine sensitive Plasmodium falciparum 3D7 strain, on LPS-stimulated Raw 264.7 murine macrophages and on A-549, DLD-1 and WS1 human cells. Activity was evaluated through spectrophotometric methods.

Results

Activity was attributed to plant extracts expressing IC₅₀ < 50 μg/ml for antiplasmodial response, IC₅₀ < 100 μg/ml for cytotoxicity, and IC₅₀ < 130 μg/ml for anti-inflammatory reaction. The majority of the extracts tested (69%) exhibited potency in at least one of these three types of activity. This is the first report describing promising antiplasmodial activity (IC₅₀ < 15 μg/ml) for Psiadia dentata DCM extract and Terminalia bentzoe MeOH bark extract. NO inhibition assay revealed seven interesting plants, described for the first time as anti-inflammatory: Aphloia theiformis, Buddleja salviifolia, Eupatorium riparium, Hiptage benghalensis, Psiadia arguta, Psiadia dentata, and Scutia commersonii. Finally, anti-proliferative activity was observed for two endemic species, Geniostoma borbonicum and Nuxia verticillata.

Conclusion

Using the criterion of endemism as part of the criteria for traditional medicinal use raises the chances of finding original active principles. In our case, 86% of the endemic plants tested displayed pharmacological interest.