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Soluble Extract (soluble + extract)

Distribution by Scientific Domains
Medical Sciences66%

Selected Abstracts

A Novel Secobetulinic Acid 3,4-Lactone from Viburnum aboricolum

HELVETICA CHIMICA ACTA, Issue 3 2003
Yuan-Ling Ku
Bio-assay-guided fractionation of the CHCl3 -soluble extract from the leaves of Viburnum aboricolum led to the isolation of a novel secobetulinic acid 3,4-lactone, viburolide (=(6,)-4,6-dihydroxy-3,4-secolup-20(29)-ene-3,28-dioic acid 3,4-lactone; 1). This is the first lupane-type compound possessing such a lactone skeleton from natural products. Its structure was elucidated by spectral analysis and comparison with 6-dehydroxy-20,29-dihydroviburolide (6) prepared from benzyl betulinate (2). Compound 6 was found to inhibit androgen-independent human prostate cancer cells (PC-3) with an IC50 of 12.3,,M. [source]

Dolichandroside A, a new , -glucosidase inhibitor and DPPH free-radical Scavenger from Dolichandrone falcata seem

PHYTOTHERAPY RESEARCH, Issue 4 2009
P. Aparna
Abstract A new phenylpropanoid glycoside, dolichandroside-A, together with seven known compounds , -lapachone, lapachol, aloesaponarin II, 8-hydroxydehydroiso- , -lapachone, , -sitosterol, 3,8-dihydroxydehydroiso- , -lapachone and verbascoside were isolated from the active ethyl acetate soluble extract of heartwood of Dolichandrone falcata. All except for dolichandroside-A are known compounds, but have been isolated for the first time from this plant. The structure of all these compounds was determined on the basis of 1D- and 2D-NMR spectral data. All the isolates were tested for , -glucosidase inhibitory and DPPH radical scavenging activity. This is the first report identifying DPPH scavenging activity and , -glucosidase inhibitory activity in D. falcata. Furthermore, along with a new compound, dolichandroside-A, this study also assigns for the first time , -glucosidase inhibitory activity to verbascoside and aloe saponarin-II. Copyright © 2008 John Wiley & Sons, Ltd. [source]

A water soluble extract from Uncaria tomentosa (Cat's Claw) is a potent enhancer of DNA repair in primary organ cultures of human skin

PHYTOTHERAPY RESEARCH, Issue 3 2006
Thomas Mammone
Abstract Cat's Claw (Uncaria tomentosa) water extracts, essentially free of oxindole alkaloids, have been shown to possess a broad spectrum of biological activity including DNA repair enhancement and antiinflammatory properties. These two biological mechanisms are key molecular targets to develop treatments that protect skin exposed to ultraviolet light from the sun. Because C-Med-100, a Cat's Claw water extract, is the only documented natural source of components that can up-regulate simultaneously both DNA repair and antiinflammation, its ability to modulate DNA repair in human skin organ cultures was undertaken. For this purpose skin cultures were treated with or without 5 mg/mL C-Med-100, irradiated with 0,100 mJ/cm2 UVB, and microscopically analysed for necrosis as well as the level of pyrimidine dimers using immunofluorescent TT-dimer antibody staining. The data clearly demonstrated that co-incubation with C-Med-100 reduced skin cell death from UV exposure, and this protection was accounted for by a concomitant increase in DNA repair. Based on these results, it was concluded that C-Med-100 was a natural plant extract worthy of further consideration as a sunscreen product. Copyright © 2006 John Wiley & Sons, Ltd. [source]

A heat labile soluble factor from Bacteroides thetaiotaomicron VPI-5482 specifically increases the galactosylation pattern of HT29-MTX cells

CELLULAR MICROBIOLOGY, Issue 5 2001
Miguel Freitas
The aim of this work was to set up and validate an in vitro model to study a molecular response of an intestinal host cell line (HT29-MTX), to a non-pathogen microflora component. We found that Bacteroides thetaiotaomicron strain VPI-5482 had the capacity to change a specific glycosylation process in HT29-MTX cells via a mechanism that involved a soluble factor. Differentiated HT29-MTX cells were grown in the presence of 20% of spent culture supernatant from the B. thetaiotaomicron during 10 days. Glycosylation processes were followed using a large panel of lectins and analysed using confocal microscopy, western blotting and flow cytometry techniques. Our results show that a B. thetaiotaomicron soluble factor modified specifically the galactosylation pattern of HT29-MTX cells, whereas other glycosylation steps remained mainly unaffected. Further characterization of this soluble factor indicates that it is a heat labile, low molecular weight compound. Reverse transcript-PCR (RT-PCR) analysis was unable to show any significant change in mRNA expression level of the main galactosyltransferases expressed in HT29-MTX cells. By contrast, galactosyltransferase activities dramatically increased in HT29-MTX cells treated by the soluble extract of B. thetaiotaomicron, suggesting a post-translational regulation of these activities. Our in vitro model allowed us to study the cross-talk between a single bacteria and intestinal cells. The galactosylation process appears to be a target of this communication, thus uncovering a new window to study the functional consequences of co-operative symbiotic bacterial,host interactions. [source]

Characterization of human sperm N -acetylglucosaminidase

INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 3 2008
S. L. Perez Martinez
Summary N -acetylglucosaminidase (NAG) is particularly active in mammalian spermatozoa and appears to be involved in fertilization. Although it is assumed that this enzyme is acrosomal, previous results from our laboratory suggest the presence of NAG at the sperm plasma membrane level. The present study attempted to analyse the subcellular distribution of this enzyme in human spermatozoa. Sperm were incubated under different conditions and NAG activity measured in the soluble extracts and cell pellets using a specific fluorometric substrate. A significant proportion of NAG activity was released when sperm were incubated in culture medium, suggesting a weak association with the plasma membrane. This location was confirmed by western blot analysis of plasma membrane fractions and immunofluorescence on non-permeabilized sperm, which showed a positive signal mainly on the acrosomal domain. The distribution of NAG activity between plasma membrane and acrosome was analysed after cell disruption by freezing and thawing. Triton X-100 stimulated sperm and epididymal NAG activity but not the enzyme obtained from other sources. In addition, biotinylated human recombinant NAG was able to bind to human sperm. Finally, after sperm incubation under capacitating conditions, NAG total activity increased and the sperm enzyme lost its ability to be stimulated by Triton X-100. The possible connection of these results with sperm maturation, capacitation and NAG participation in primary binding to the zona pellucida, was discussed. [source]

Peripheral blood mononuclear cells proliferation and Th1/Th2 cytokine production in response to streptococcal M protein in psoriatic patients

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 5 2006
Rolando Pérez-Lorenzo
Background, Psoriasis is a chronic skin disease that is probably a T cell-mediated autoimmune condition which is strongly associated with streptococcal throat infections. Although some groups have associated the involved response with different streptococcal antigens, M protein has been described as the major virulence factor of Streptococcus pyogenes. Thus, it is necessary to describe some features of the cellular responses to this streptococcal antigen. Methods, Proliferation and Th1/Th2 cytokine production of peripheral blood mononuclear cells (PBMC) in response to total soluble extracts from type M5 S. pyogenes with (TSE37Sp) and without (M,TSESp) M protein were analyzed in 10 psoriatic patients and 10 healthy controls. Results, PBMC from both patients and controls proliferated to both extracts. Responses to M,TSESp were significantly lower than those to TSE37Sp (P < 0.05). PBMC IL-2 and ,IFN production after TSE37Sp stimulus was much higher than after M,TSESp antigenic stimulation in both groups (P < 0.05). Meanwhile, IL-4 production was quite low in both groups and in response to both extracts. We found a differential production of IL-10 between groups. PBMC from healthy controls responded to TSE37Sp with a much higher production of this cytokine as compared to the responses showed to M,TSESp while the cells from psoriatic patients responded without differences in the production of IL-10. Conclusion, Results obtained suggest an important Th1 response to M protein in psoriatic patients which could be associated with the cellular responses involved in psoriasis, while healthy subjects respond in a probably non-Th2 IL-10 producing regulatory T cells fashion. [source]