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EN
Curcumin is reported as an anti proliferative and chemopreventive compound. However, it shows poor water solubility, low bioavailability, and rapid metabolism.. To address these problems, curcumin derivatives substituted with polyether chain were synthesised to improve the hydrophilicity of curcumin and thus its bioavailability. The biological activity of modified curcumin molecules were studied with human normal B-lymphocytes GM 14667 and human leukemia cells HL60 and covered: the denotation of IC50 values for each new compound with use of MTT test and the studies on apoptosis induction observed as morphological changes and the expression of apoptotic proteins, BAX, BCL-2 and survivin with use of Western Blot analysis. All effects were referenced to native curcumin. The derivatives with modified polyether chains number and the position of methoxy- groups were selected for further studies. As was shown, the solubility of the compound does not directly correlate with its cytotoxicity. The maintenance of the methoxy group in the meta position as well as the introduction of hydrophilic polyether chains but not the number of polyether chains may affect the cytotoxic activity of curcumin derivatives against cancer cells. Modifications of the curcumin molecule structure can determine its impact on the profile of pro or anti apoptotic proteins.
EN
Two recently synthesized groups of acridine cytostatics containing fused heterocyclic ring(s): pyrazoloacridines (PAC) and pyrazolopyrimidoacridines (PPAC) were tested in regard to their in vitro cytotoxic activity towards a panel of sensitive and resistant human tumor cell lines. The obtained results corroborate our earlier hypothesis on the essential role of heterocyclic ring fused to the acridine moiety in the ability of acridine cytostatics to overcome multidrug resistance of tumor cells. The presence, location and kind of substituents considerably influenced both the cytotoxic activity of the derivatives and their ability to overcome multidrug resistance. The same factors also affected the cytostatics ability to differentiate between tumor cell lines with various types of drug exporting pumps.
EN
The methanol extract of the aerial parts of Celosia trigyna (Amaranthaceae) was successively fractionated using n-hexane, dichloromethane, ethyl acetate and n-butanol. The cytotoxic activity of the obtained fractions was investigated using sulphorhodamine-B (SRB) assay against three carcinoma cell lines; breast adenocarcinoma (MCF-7), colorectal carcinoma (HCT-116) and hepatocellular carcinoma cells (HepG2). The dichloromethane fraction showed significant in vitro cytotoxic activities against the human cancer cell lines HCT-116 and HEP-G2 with IC50 values of 10.9 and 11.2 µg/mL, respectively, while all fractions revealed weak antioxidant activity using DPPH free radical scavenging method. The GC-MS analysis of the most cytotoxic dichloromethane fraction has resulted in the identification of 12 compounds. The main constituents were tetrahydroisoquinoline derivative (31.44%), 2,3-dimethylheptadecane (16.71%) and 3-octadecanone (15.56%). Moreover, the phytochemical study of the dichloromethane and n-butanol fractions led to the isolation and identification of five known compounds identified as β-amyrin acetate (1), acacetin 8-C-α-rhamnosyl-(1→2)-β-glucopyranoside (2), apigenin 8-C-α-rhamnosyl-(1→2)-β-glucopyranoside (3), quercetin 3-O-α-rhamnosyl-(1→6)-β-glucopyranoside (4) and 3-hydroxyglutaric acid (5).
EN
The aim of the present study was to compare carotenoid extracts of Rose hips (Rosa canina L.) with regard to their phytochemical profiles and their in vitro anti-Helicobacter pylori (H. pylori), cytotoxic, multidrug resistance (MDR) reversal and radical scavenging activity. Carotenoid composition was investigated in the different fractionation of rose hips, using extraction methods. Six main carotenoids - epimers of neochrome, lutein, zeaxanthin, rubixanthin, lycopene, β,β-carotene - were identified from Rose hips by their chromatographic behavior and UV-visible spectra, which is in accordance with other studies on carotenoids in this plant material. The active principles in the carotenoid extract might differ, depending upon the extraction procedures.
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2015
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vol. 62
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issue 4
885-894
EN
Cytotoxic activity is one of the major functions of Natural Killer (NK) cells and is a critical effector mechanism of innate immune responses against infected or cancer cells. A variety of assays have been developed to determine NK cell cytotoxic activity, however a receptor-based screening tool is still lacking. Here, we propose the CD25 receptor as a candidate for NK cell cytotoxicity marker. We have verified that there is a correlation between classic target cell induced cytotoxicity markers and the CD25 expression on NK cells. Non-adherent lymphocyte fractions pre-stimulated with Escherichia coli O55:B5 lipopolysaccharide were co-cultured with settled HeLa targets in a four hour long cytotoxic assay. The cytotoxic effect was evaluated by MTT reduction assay and quantification of soluble cytotoxicity markers (granzyme B, FasL, caspase-8, IFN-γ and IL-2) was done by ELISA. Lymphocytes were stained with anti-CD3-Cy-5, anti-CD56/CD16/Nkp46-FITC and anti-CD25-PE antibodies and analyzed by flow cytometry. We observed that the CD25 expression exclusively on the CD3-CD56+CD25+ NK cells was positively correlated with their cytotoxic function evaluated by the MTT test (r = 0.68), the upregulation of granzyme B (r = 0.89), IL-2 (r = 0.78) and IFN-γ (r = 0.57), however, it was not positively correlated with FasL and caspase-8. We conclude that the CD25 expression might serve as an in vitro receptor-based screening tool for NK cell activity.
EN
This study analyzed chemical composition of the essential oils (EOs) of Thymus vulgaris L., harvested in two regions of northwest Algeria (Tlemcen and Mostaganem), and evaluated their antimicrobial and cytotoxic activity. Fifty one compounds representing 99.99% and 100% of total thyme oil of Mostaganem (EO.TM) and Tlemcen (EO.TT), respectively were identified by GC-FID and GC-MS. Carvacrol was a dominant compound in both oils (89.15 and 82.42%). The antimicrobial activity, demonstrated by disc diffusion and broth macrodilution methods, showed a strong inhibitory effect of the oils on seven reference strains tested and particularly on Bacillus cereus ATCC 10876 and Candida albicans ATCC 10231. A cytotoxicity assay for two normal and two cancer cell lines indicated the highest sensitivity of canine B-cell lymphoma cell line (CLBL-1) for which IC50 values were 35.39 ± 9.0 (EO.TT) and 84.51± 3.2 (EO.TM). Murine fibroblast cell line (3T3), with IC50 116.97 ± 2.7 for EO.TT and 146.29 ± 0.5 for EO.TM was the most resistant line.
EN
Macroalgae from Fucus genus are a valuable source of bioactive components as they are abundant in complex polysaccharides, fatty acids and polyphenols. In this work, the biological activity and chemical composition of extracts and fractions obtained from endemic Fucus virsoides J. Agardh species collected in the summer and in the fall were investigated. From dichloromethane:methanol (1:1) extract three fractions were made: petroleum-ether, ethyl-acetate and n-butanol. The aim of the study was to examine the influence of the seasonal variations on algal composition and activity. The significant seasonal variation in content and biological activity of Fucus virsoides samples was found. Fall extract and fractions exerted higher cytotoxic effects on cancer cell lines in comparison with summer extract and fractions. The examined extracts and fractions showed higher cytotoxic activity towards cancer cells compared to normal fibroblast MRC5 cells. Morphological evaluation and cell cycle distribution analysis demonstrated their proapoptotic activity in human cervical adenocarcinoma HeLa cells. Fall extract and fractions better suppressed the migration and tube formation of EA.hy926 cells in comparison with summer extract and fractions. Fall extract and fractions were more potent in inhibition of α-glucosidase enzymatic activity. Ethyl-acetate fractions, from both seasons, exhibited the best antibacterial and antifungal activity on all tested bacteria and fungi. In conclusion, the two fall fractions ethyl-acetate and petroleum-ether rich in polyphenols and polyunsaturated fatty acids, were the most active and exhibited prominent anticancer and anti-α-glucosidase activities.
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