Boglárka Csupor-Löffler

Antiproliferative effect of flavonoids and sesquiterpenoids from Achillea millefolium s.l. on cultured human tumour cell lines

The antiproliferative activities of n‐hexane, chloroform, aqueous‐methanol and aqueous extracts of the aerial parts of the Achillea millefolium aggregate on three human tumour cell lines were investigated by means of MTT assays. The chloroform‐soluble extract exerted high tumour cell proliferation inhibitory activities on HeLa and MCF‐7 cells, and a moderate effect on A431 cells; accordingly, it was subjected to detailed bioactivity‐guided fractionation. As a result of the multistep chromatographic purifications (VLC, CPC, PLC, gel filtration), five flavonoids (apigenin, luteolin, centaureidin, casticin and artemetin) and five sesquiterpenoids (paulitin, isopaulitin, psilostachyin C, desacetylmatricarin and sintenin) were isolated and identified by spectroscopic methods. The antiproliferative assay demonstrated that centaureidin is the most effective constituent of the aerial parts of yarrow: high cell growth inhibitory activities were observed especially on HeLa (IC50 0.0819 µm) and MCF‐7 (IC50 0.1250 µm) cells. Casticin and paulitin were also highly effective against all three tumour cell lines (IC50 1.286–4.76 µm), while apigenin, luteolin and isopaulitin proved to be moderately active (IC50 6.95–32.88 µm). Artemetin, psilostachyin C, desacetylmatricarin and sintenin did not display antiproliferative effects against these cell lines. This is the first report on the occurrence of seco‐pseudoguaianolides (paulitin, isopaulitin and psilostachyin C) in the Achillea genus. Copyright

Antiproliferative activity of Hungarian Asteraceae species against human cancer cell lines. Part II

The antiproliferative activities of aqueous and organic extracts prepared from 26 Hungarian species of the tribes Cynereae and Lactuceae (Asteraceae) were tested in vitro against HeLa (cervix epithelial adenocarcinoma), A431 (skin epidermoid carcinoma) and MCF7 (breast epithelial adenocarcinoma) cells by using the MTT assay. Of the tested 200 extracts of different plant parts obtained with n‐hexane, chloroform, 50% methanol and water, 16 extracts displayed noteworthy cell growth inhibitory activity (>50% inhibition at a concentration of 10 µg/mL). The IC50 values of these extracts were determined, and their direct cytotoxic effects were measured. High differences between the antiproliferative and cytotoxic activities, demonstrating a real cell proliferation inhibitory activity rather than direct killing effects, were found for some Centaurea, Cirsium, Cichorium, Lactuca, Onopordum and Scorsonera extracts. Copyright

Antiproliferative constituents of the roots of conyza canadensis

Bioassay-guided fractionation of the N-hexane and CHCl₃ phases of the methanol extract of the roots of Conyza canadensis (L.) Cronquist led to the isolation of two new dihydropyranones named conyzapyranone A (1) and B (2), and the known 4 Z,8 Z-matricaria- γ-lactone (3), 4 E,8 Z-matricaria- γ-lactone (4), 9,12,13-trihydroxy-10(E)-octadecenoic acid (5), epifriedelanol (6), friedeline (7), taraxerol (8), simiarenol (9), spinasterol (10), stigmasterol, β-sitosterol, and apigenin. The structures were determined by means of ESIMS and 1D and 2D NMR spectroscopy, including ¹H-¹H COSY, NOESY, HSQC, and HMBC experiments. The isolated compounds were evaluated for their antiproliferative activities and were demonstrated to exert considerable cell growth-inhibitory activity against human cervix adenocarcinoma (HeLa), skin carcinoma (A431), and breast adenocarcinoma (MCF-7) cells. Some of the active components, including 2, 4, and 10, proved to be substantially more potent against these cell lines than against noncancerous human foetal fibroblasts (MRC-5) and can therefore be considered selective antiproliferative natural products.

Inhibition of COX-2 and NF-κB1 Gene Expression, NO Production, 5-LOX, and COX-1 and COX-2 Enzymes by Extracts and Constituents of Onopordum acanthium

The present study focused on the investigation of the inhibition of cyclooxygenase-2 and nuclear factor kappa B1 gene expression, nitric oxide production, leukotriene biosynthesis (5-lipoxygenase), and cyclooxygenase-1 and cyclooxygenase-2 enzymes of Onopordum acanthium, and the isolation and identification of its active compounds. From the chloroform soluble part of the MeOH extract prepared from aerial parts, lignans [pinoresinol (1), syringaresinol (2), and medioresinol (3)] and flavonoids [hispidulin (4), nepetin (5), apigenin (6), and luteolin (7)] were isolated by a combination of different chromatographic methods. The structures of the compounds were determined by means of mass spectrometry and 1D- and 2D-nuclear magnetic resonance spectroscopy, and by comparison of the spectral data with literature values. Extracts of different polarity and the isolated compounds obtained from the aerial parts, together with those previously isolated from the roots of the plant [4β,15-dihydro-3-dehydrozaluzanin C (8), zaluzanin C (9), 4β,15,11β,13-tetrahydrozaluzanin C (10), nitidanin diisovalerianate (11), 24-methylenecholesterol (12), and 13-oxo-9Z,11E-octadecadienoic acid (13)], were evaluated for their inhibitory effects on cyclooxygenase-2 and nuclear factor kappa B1 gene expression, inducible nitric oxide synthase, 5-lipoxygenase, and cyclooxygenase-1 and cyclooxygenase-2 enzymes in in vitro assays. It was found that O. acanthium extracts exert strong inhibitory activities in vitro and some lignans, flavonoids, and sesquiterpenes may play a role in these activities. 4β,15-Dihydro-3-dehydrozaluzanin C and zaluzanin C at 20 µM were the most active constituents tested against lipopolysaccharide/interferon-γ-induced nitric oxide production (100.4 ± 0.5 % and 99.4 ± 0.8 %) in the inhibition of cyclooxygenase-2 (98.6 ± 0.2 % and 97.0 ± 1.1 %) and nuclear factor kappa B1 gene expression (76.7 ± 7.3 % and 69.9 ± 3.4 %). Furthermore, it was shown that these inhibitory effects are not due to cytotoxicity of the compounds.

Antifungal Activity and Composition of Essential Oils of Conyza canadensis Herbs and Roots

Essential oils from herbs and roots of Conyza canadensis (horseweed), collected in Hungary, were obtained by hydrodistillation. The chemical compositions of the oils were analysed by combination of GC and GC/MS. The major constituent of the oil obtained from the aerial parts of horseweed was limonene (78%), while the main component of root oil was 2Z,8Z-matricaria ester. The antimicrobial activities of the oils were tested on Gram-positive (Enterococcus faecalis, Staphylococcus aureus, and Streptococcus pyogenes), Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, reference fungal strains, and fungal strains isolated from patients (Candida, Cryptococcus, Trichophyton, Rhodotorula, and Aspergillus) by agar disc diffusion and broth dilution methods. None of the oils showed any activity against the tested bacterial strains, but exhibited moderate-to-strong activity against all fungi with the only exception of A. fumigatus. The highest zone of inhibition was observed in case of Cryptococcus neoformans and Trichophyton interdigitalis

Investigation of the Antiproliferative Properties of Natural Sesquiterpenes from Artemisia asiatica and Onopordum acanthium on HL-60 Cells in Vitro.

Plants and plant extracts play a crucial role in the research into novel antineoplastic agents. Four sesquiterpene lactones, artecanin (1), 3β-chloro-4α,10α-dihydroxy-1α,2α-epoxy-5α,7αH-guaia-11(13)-en-12,6α-olide (2), iso-seco-tanapartholide 3-O-methyl ether (3) and 4β,15-dihydro-3-dehydrozaluzanin C (4), were isolated from two traditionally used Asteraceae species (Onopordum acanthium and Artemisia asiatica). When tested for antiproliferative action on HL-60 leukemia cells, these compounds exhibited reasonable IC50 values in the range 3.6–13.5 μM. Treatment with the tested compounds resulted in a cell cycle disturbance characterized by increases in the G1 and G2/M populations, while there was a decrease in the S phase. Additionally, 1–3 elicited increases in the hypodiploid (subG1) population. The compounds elicited concentration-dependent chromatin condensation and disruption of the membrane integrity, as revealed by Hoechst 33258–propidium staining. Treatment for 24 h resulted in significant increases in activity of caspases-3 and -9, indicating that the tested sesquiterpenes induced the mitochondrial pathway of apoptosis. The proapoptotic properties of the sesquiterpene lactones were additionally demonstrated withannexin V staining. Compounds 1 and 2 increased the Bax/Bcl-2 expression and decreased the expressions of CDK1 and cyclin B2, as determined at the mRNA level by means of RT-PCR. These experimental results indicate that sesquiterpene lactones may be regarded as potential starting structures for the development of novel anticancer agents.

Antiproliferative and Antimicrobial Activities of Selected Bryophytes

One-hundred and sixty-eight aqueous and organic extracts of 42 selected bryophyte species were screened in vitro for antiproliferative activity on a panel of human gynecological cancer cell lines containing HeLa (cervix epithelial adenocarcinoma), A2780 (ovarian carcinoma), and T47D (invasive ductal breast carcinoma) cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and for antibacterial activity on 11 strains using the disc-diffusion method. A total of 99 extracts derived from 41 species exerted ≥25% inhibition of proliferation of at least one of the cancer cell lines at 10 μg/mL. In the cases of Brachythecium rutabulum, Encalypta streptocarpa, Climacium dendroides, Neckera besseri, Pleurozium schreberi, and Pseudoleskeella nervosa, more than one extract was active in the antiproliferative assay, whereas the highest activity was observed in the case of Paraleucobryum longifolium. From the tested families, Brachytheciaceae and Amblystegiaceae provided the highest number of antiproliferative extracts. Only 19 samples of 15 taxa showed moderate antibacterial activity, including the most active Plagiomnium cuspidatum, being active on 8 tested strains. Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus were the most susceptible to the assayed species. This is the first report on the bioactivities of these 14 species.

Phenanthrenes from Juncus Compressus Jacq. with Promising Antiproliferative and Anti-HSV-2 Activities

Juncaceae species are rich sources of phenanthrenes. The present study has focused on the isolation and structure determination of biologically active components from Juncus compressus. Eleven compounds (nine phenanthrenes and two flavonoids) have been isolated from the plant by the combination of different chromatographic methods. Two compounds (compressins A (Compound 1) and B (Compound 2)) are novel natural products, while seven phenanthrenes (effusol (Compound 3), effususol (Compound 4), juncusol (Compound 5), 2-hydroxy-1-methyl-4-oxymethylene-5-vinyl-9,10-dihydrophenanthrene (Compound 6), 7-hydroxy-1-methyl-2-methoxy-5-vinyl-9,10-dihydrophenanthrene (Compound 7), effususin A (Compound 8), and dehydroeffusol (Compound 9)), and two flavonoids (apigenin (Compound 10) and luteolin (Compound 11) were isolated for the first time from the plant. Compressin B (Compound 2) is a dimeric phenanthrene, in which two juncusol monomers (Compound 5) are connecting through their C-3 atoms. The structure elucidation of the isolated compounds was carried out using 1D, 2D NMR spectroscopic methods and HR-MS measurements. In vitro investigation of the antiproliferative effect of the phenanthrenes on two cervical (HeLa and SiHa) and an ovarian human tumor cell line (A2780) revealed that compounds have remarkable antiproliferative activity, mainly on the HeLa cell line. Moreover, juncusol (Compound 5) proved to possess significant antiviral activity against the herpes simplex 2 virus (HSV-2).

Bioactivity-Guided isolation of antimicrobial and antioxidant metabolites from the mushroom tapinella atrotomentosa

Bioassay-guided fractionation of the chloroform extract of Tapinella atrotomentosa led to the isolation of four secondary metabolites 1–4. Two of the compounds are lactones—osmundalactone (1) and 5-hydroxy-hex-2-en-4-olide (2)—while 3 and 4 were identified as terphenyl quinones, spiromentins C and B, respectively. The structures of the compounds were established on the basis of NMR and MS spectroscopic analysis. The isolated fungal metabolites were evaluated for their antibacterial activities against several Gram-positive and negative bacteria. In addition, their synergistic effect with cefuroxime against methicillin-resistant Staphylococcus aureus (MRSA) was also evaluated. Compounds 1–3 proved to possess significant antibacterial activity against multiresistant Acinetobacter baumannii and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. The investigation of the antioxidant effect of the isolated compounds in DPPH and ORAC assays revealed that spiromentins C (3) and B (4) have remarkable antioxidant activity.

Hazai mohafajok fitokémiai és farmakológiai vizsgálata

A virágos növények mintegy 10-15%-át vizsgálták valamilyen mértékben fitokémiai és farmakológiai szempontból, azonban a virágtalan, spórás felsőbbrendű növények közé tartozó mohákra kisebb tudományos figyelem irányult. Ugyanakkor a mohák másodlagos anyagcseretermékeinek vizsgálata érdeklődésre tarthat számot, mivel kórés károkozókkal szembeni védekezésük hátterében citotoxikus és/vagy antimikróbás hatású vegyületek állhatnak. Különböző mohafajokat elsősorban az ázsiai népi gyógyászatban alkalmaztak. Az amerikai őslakosok is használtak mohakivonatot hamuval keverve sebek kezelésére, Kínában pedig a mai napig megtalálhatók a gyógyászatban, külsőlegesen és belsőlegesen alkalmazva egyaránt. Az eddig vizsgált fajok jellemző vegyületei közé tartoznak monoés szeszkviterpének, aromás észterek, növényi savak. Nagy felfedezésnek számít a korábban a Maytenus serrata kérgéből származó tubulingátló hatású maytanzinoidok azonosítása mohákból. A hazai mohaflóra 659 fajt tartalmaz, ebből 58 fajt vizsgáltunk antiproliferatív és antimikrobiális hatásra in vitro szűrővizsgálatban. Legaktívabbnak a Paraleucobryum longifolium bizonyult. Célunk ebből a fajból az aktív vegyületek izolálása és azonosítása. A preparatív növénykémiai munka során oszlopkromatográfiát, preparatív rétegkromatográfiát, rotációs planárkromatográfiát, közepes és nagy nyomású folyadékkromatográfiát alkalmazunk, normál és fordított fázisokon egyaránt. A szerkezetmeghatározás mágneses magrezonancia és tömegspektrometria segítségével történik.