scholarly journals Cyclosporin Analogs Inhibit In Vitro Growth of Cryptosporidium parvum

1998 ◽  
Vol 42 (4) ◽  
pp. 843-848 ◽  
Author(s):  
Margaret E. Perkins ◽  
Teresa W. Wu ◽  
Sylvie M. Le Blancq
Keyword(s):  
Cryptosporidium Parvum ◽  
Mammalian Cells ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Short Term ◽  
Apicomplexan Parasites ◽  
Psc 833 ◽  
Drug Assays ◽  
Sdz Psc 833

ABSTRACT Cyclosporine and nonimmunosuppressive cyclosporin (CS) analogs were demonstrated to be potent inhibitors of the growth of the intracellular parasite Cryptosporidium parvum in short-term (48-h) in vitro cultures. Fifty-percent inhibitory concentrations (IC50s) were 0.4 μM for SDZ 033-243, 1.0 μM for SDZ PSC-833, and 1.5 μM for cyclosporine. Two other analogs were less effective than cyclosporine: the IC50 of SDZ 205-549 was 5 μM, and that of SDZ 209-313 was 7 μM. These were much lower than the IC50 of 85 μM of paromomycin, a standard positive control for in vitro drug assays for this parasite. In addition, intracellular growth of excysted sporozoites that had been incubated for 1 h in cyclosporine was significantly reduced, suggesting that the drug can inhibit sporozoite invasion. The cellular activities of the CS analogs used have been characterized for mammalian cells and protozoa. The two analogs that were most active in inhibiting C. parvum, SDZ PSC-833 and SDZ 033-243, bind weakly to cyclophilin, a peptidyl proline isomerase which is the primary target of cyclosporine and CS analogs. However, they are potent modifiers of the activity of the P glycoproteins/multidrug resistance (MDR) transporters, members of the ATP-binding cassette (ABC) superfamily. Hence, both cyclophilin and some ABC transporters may be targets for this class of drugs, although drugs that preferentially interact with the latter are more potent. Cyclosporine (0.5 μM) had no significant chemosensitizing activity. That is, it did not significantly increase sensitivity to paromomycin, suggesting that an ABC transporter is not critical in the efflux of this drug. Cyclosporine at concentrations up to 50 μM was not toxic to host Caco-2 cells in the CellTiter 96 assay. The results of this study complement those of studies of the inhibitory effect of cyclosporine and CS analogs on other apicomplexan parasites, Plasmodium falciparum, Plasmodium vivax, and Toxoplasma gondii.

scholarly journals In vivo hypotensive effect and in vitro inhibitory activity of some Cyperaceae species

2013 ◽  
Vol 49 (4) ◽  
pp. 803-809
Author(s):  
Monica Lacerda Lopes Martins ◽  
Henrique Poltronieri Pacheco ◽  
Iara Giuberti Perini ◽  
Dominik Lenz ◽  
Tadeu Uggere de Andrade ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Colorimetric Assay ◽  
Hypotensive Effect ◽  
Ace Inhibition ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Total Phenolic ◽  
Before And After

In 1820, French naturalist August Saint Hillaire, during a visit in Espírito Santo (ES), a state in southeastern Brazil, reported a popular use of Cyperaceae species as antidote to snake bites. The plant may even have a hypotensive effect, though it was never properly researched. The in vitro inhibitory of the angiotensin converting enzyme (ACE) activity of eigth ethanolic extracts of Cyperaceae was evaluated by colorimetric assay. Total phenolic and flavonoids were determined using colorimetric assay. The hypotensive effect of the active specie (Rhychonospora exaltata, ERE) and the in vivo ACE assay was measured in vivo using male Wistar Kyoto (ERE, 0.01-100mg/kg), with acetylcholine (ACh) as positive control (5 µg/kg, i.v.). The evaluation of ACE in vivo inhibitory effect was performed comparing the mean arterial pressure before and after ERE (10 mg/kg) in animals which received injection of angiotensin I (ANG I; 0,03, 03 and 300 µg/kg, i.v.). Captopril (30 mg/kg) was used as positive control. Bulbostylis capillaris (86.89 ± 15.20%) and ERE (74.89 ± 11.95%, ERE) were considered active in the in vitro ACE inhibition assay, at 100 µg/mL concentration. ACh lead to a hypotensive effect before and after ERE's curve (-40±5% and -41±3%). ERE showed a dose-dependent hypotensive effect and a in vivo ACE inhibitory effect. Cyperaceae species showed an inhibitory activity of ACE, in vitro, as well as high content of total phenolic and flavonoids. ERE exhibited an inhibitory effect on both in vitro and in vivo ACE. The selection of species used in popular medicine as antidotes, along with the in vitro assay of ACE inhibition, might be a biomonitoring method for the screening of new medicinal plants with hypotensive properties.

scholarly journals Simple Silica Column–Based Method to Quantify Inorganic Polyphosphates in Cartilage and Other Tissues

Cartilage ◽  
2017 ◽  
Vol 9 (4) ◽  
pp. 417-427 ◽  
Author(s):  
Whitaik David Lee ◽  
Rahul Gawri ◽  
Toshikazu Shiba ◽  
Ae-Ri Ji ◽  
William L. Stanford ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Inhibitory Effect ◽  
Proteinase K ◽  
Inorganic Polyphosphates ◽  
Column Method ◽  
Spin Column ◽  
Mammalian Tissues ◽  
Biological Sources ◽  
Low Levels

Objective. Inorganic polyphosphates (polyP) play a multitude of roles in mammalian biology. PolyP research is hindered by the lack of a simple and sensitive quantification method. The aim of this study was to develop a robust method for quantifying the low levels of polyP in mammalian tissue such as cartilage, which is rich in macromolecules that interfere with its determination. Design. Native and in vitro formed tissues were digested with proteinase K to release sequestrated polyP. The tissue digest was loaded on to silica spin columns, followed by elution of bound polyP and various treatments were assessed to minimize non-polyP fluorescence. The eluent was then quantified for polyP content using fluorometry based on DAPI (4′,6-diamidino-2-phenylindole) fluorescence shift occurring with polyP. Results. Proteinase K pretreatment reduced the inhibitory effect of proteins on polyP recovery. The eluent was contaminated with nucleic acids and glycosaminoglycans, which cause extraneous fluorescence signals. These were then effectively eliminated by nucleases treatment and addition of concentrated Tris buffer. PolyP levels were quantified and recovery ratio determined using samples spiked with a known amount of polyP. This silica spin column method was able to recover at least 80% of initially loaded polyP, and detect as little as 10−10 mol. Conclusions. This sensitive, reproducible, easy to do method of quantifying polyP will be a useful tool for investigation of polyP biology in mammalian cells and tissues. Although the protocol was developed for mammalian tissues, this method should be able to quantify polyP in most biological sources, including fluid samples such as blood and serum.

scholarly journals Synthesis, Spectroscopic Characterization, Antibacterial and Short Term in vitro Cytotoxicity Studies of Copper(II) Complexes of Novel Tridentate N,N,S Donor Ligand 2-Benzoylpyridine-N(4),N(4)-(N,N-diethyl-N-methylamine-2,2'-diyl)thiosemicarbazone

2019 ◽  
Vol 31 (10) ◽  
pp. 2269-2274
Author(s):  
Janey Mary Mathew ◽  
Varughese Philip ◽  
Jesty Thomas
Keyword(s):  
Spectroscopic Characterization ◽  
Positive Control ◽  
In Vitro Cytotoxicity ◽  
Planar Geometry ◽  
Blue Dye ◽  
Short Term ◽  
Donor Ligand ◽  
Cytotoxicity Studies ◽  
Uv Visible

A tridentate N,N,S-donor ligand, 2-benzoylpyridine-N(4),N(4)-(N,N-diethyl-N-methylamine-2,2'-diyl)thiosemicarbazone (Hbptsc) has been synthesized and characterized by elemental CHN analysis, UV-visible, FT-IR and 1H NMR spectroscopy. Copper(II) complexes of the ligand, Hbptsc synthesized have been characterized by elemental analysis, UV-visible spectra, FTIR spectra and EPR spectroscopic simulation. The complexes hold the stoichiometry of the type [CuLX] where X= Cl (1), NO3 (2), SO4 (3), N3 (4), SCN (5) confirmed by the molar conductivity studies of 10-3 M solutions in DMF at room temperature. The EPR spectra of the complexes recorded in DMF at 77 K shows an axial type spectra with two distinct g-values, g|| and g⊥ indicating a four coordinated planar geometry. The antimicrobial studies of the copper(II) complexes shows an appreciable activity against both gram positive and gram negative bacteria using streptomycin as positive control. The short term in vitro cytotoxicity studies following trypan blue dye exclusion method exhibits pronounced activity against the Dalton’s Lymphoma Ascites tumour cells extruded from the peritoneal cavity of mice.

scholarly journals In vitro evaluation of the inhibitory effect of 3, 5-dichloro-2- pyridone on Mycobacterium tuberculosis H37Rv

2020 ◽  
Vol 19 (1) ◽  
pp. 163-168
Author(s):  
Lin Ling ◽  
Chen Ling ◽  
Hua Wu
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Bovine Serum ◽  
Antimicrobial Effect ◽  
Bactericidal Effect ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Current Treatment ◽  
Tuberculosis H37rv ◽  
Mycobacterium Tuberculosis H37rv

Purpose: To investigate the anti-tuberculosis potential of twelve commercially available pyridone analogues against Mycobacterium tuberculosis H37Rv strain.Methods: Twelve commercially available pyridone-based compounds were screened against M. tuberculosis H37Rv using different susceptibility tests. The most active or lead compound was further evaluated in detail for its anti-tuberculosis (anti-TB) potential. Kill kinetics was used to determine the dynamics of its anti-TB activity in vitro.Results: Compounds d, j and k were potent against M. tuberculosis H37Rv, with minimum inhibitory concentrations (MICs) of 10, 5 and 10 μg/mL, respectively. The standard anti-TB drugs used in this study (positive control drugs) demonstrated MIC of 2.5 μg/mL. The anti-TB effect of compound j was comparable with those of the standard drugs (RIF, LVX, AMK, EMB and INH). The minimum bactericidal concentration (MBC) of compound j was 10 μg/mL. It produced an MIC of 5 μg/mL in agar proportion method (APM). However, its MIC in Middlebrook 7H9 broth supplemented with 10 % fetal bovine serum (FBS) and 4 % bovine serum albumin (BSA) increased 4- and 8-fold, respectively. The bactericidal effect of compound j was time- and concentration-dependent at dilutions above 2x MIC. Combination of compound j with RIF, LVX or AMK exhibited fractional inhibitory concentration index (ΣFIC) of 1, indicative of additive drug-drug interactions. However, combination with INH or EMB produced a ΣFIC of 2. None of the tested drug combinations was antagonistic.Conclusion: Compound j exhibits potent time- and concentration-dependent antimicrobial effect against M. tuberculosis H37Rv. Thus, it may be suitable as an adjunct to current treatment of drug sensitive and drug-resistant TB. Keywords: Tuberculosis, Mycobacterium tuberculosis, Pyridone analogs, Antimicrobial activity, Antibiotics

scholarly journals Clastogenic Effect of Atranorin, Evernic acid, and Usnic Acid on Human Lymphocytes

2014 ◽  
Vol 9 (4) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Gordana S. Stojanović ◽  
Miroslava Stanković ◽  
Igor Ž. Stojanović ◽  
Ivan Palić ◽  
Vesna Milovanović ◽  
...  
Keyword(s):  
Human Lymphocytes ◽  
Usnic Acid ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Proliferation Index ◽  
Culture Solution ◽  
Antiproliferative Effects ◽  
Clastogenic Effect ◽  
And Control

Three lichen secondary metabolites atranorin (1), evernic acid (2), and usnic acid (3), were evaluated for their in vitro clastogenic and antiproliferative effects on human lymphocytes using the cytochalasin-B blocked micronucleus (CBMN) assay at concentrations of 2 μg/mL, 4 μg/mL and 6 μg/mL of final culture solution. The frequency of micronucleus (MN) was scored in binucleated cells, and cytokinesis-block proliferation index (CBPI) was calculated. Among the tested compounds, 3 exhibited the most prominent effect decreasing the frequency of MN in the range of 42.5% - 48.9%, that is about double of the positive control amifostin WR-2721 that reduces MN frequency for 22.0%. The effect of evernic acid was approximately equal to action of amifostin (23.2% −32.9%). Atranorin at concentrations of 2 μg/mL and 4 μg/mL decreasing the frequency of MN only for 11.1% and 1.8%, while in concentration of 6 μg/mL increases the frequency of MN for 9.6 %. The comparable CBPI values of the investigated compounds and control suggested that they did not show a statistically significant inhibitory effect on lymphocyte cell proliferation at applied concentrations.

Comparative Study on Reversal Efficacy of SDZ PSC 833, Cyclosporin a and Verapamil on Multidrug Resistance in vitro and in vivo

1995 ◽  
Vol 34 (2) ◽  
pp. 235-241 ◽  
Author(s):  
Toru Watanabe ◽  
Harumi Tsuge ◽  
Tomoko Oh-Hara ◽  
Mikihiko Naito ◽  
Takashi Tsuruo
Keyword(s):  
Multidrug Resistance ◽  
Comparative Study ◽  
Cyclosporin A ◽  
Psc 833 ◽  
Sdz Psc 833

scholarly journals Interleukin-4 and Transforming Growth Factor β Have Opposing Regulatory Effects on Gamma Interferon-Mediated Inhibition of Cryptosporidium parvum Reproduction

2003 ◽  
Vol 71 (8) ◽  
pp. 4580-4585 ◽  
Author(s):  
I.-Sarah Lean ◽  
Stuart A. C. McDonald ◽  
Mona Bajaj-Elliott ◽  
Richard C. G. Pollok ◽  
Michael J. G. Farthing ◽  
...  
Keyword(s):  
Growth Factor ◽  
Cryptosporidium Parvum ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Inhibitory Effect ◽  
Gamma Interferon ◽  
Interleukin 4 ◽  
Effector Cells ◽  
Ifn Γ

ABSTRACT It was shown previously that enterocytes activated by gamma interferon (IFN-γ) are efficient effector cells in the killing of Cryptosporidium parvum. How this function is regulated is not clearly understood, but transforming growth factor β (TGF-β) and the Th2 regulatory cytokines may play a role. Using an in vitro cell culture system, we investigated how the key regulatory cytokines interleukin-4 (IL-4), IL-10, IL-13, and TGF-β might modulate the effect of IFN-γ in inducing resistance to infection in enterocyte cell lines. The results showed that TGF-β can abolish the inhibitory effect on C. parvum development and that neither IL-13 nor IL-10 influenced the action of IFN-γ. In contrast, IL-4 cooperated with low concentrations of IFN-γ (1 and 10 U/ml) to enhance parasite killing. One mechanism that appeared to be involved in the combined activity of IFN-γ and IL-4 was intracellular Fe2+ deprivation, but induction of nitric oxide production was not involved. In one cell line, the extents and durations of phosphorylation of STAT1, a transcription factor involved in IFN-γ signaling, were similar when cells were stimulated with IFN-γ alone and with IFN-γ and IL-4γ, suggesting that the cooperative effect of the cytokines was not related to STAT1 activation. The effects of the presence of TGF-β and IL-4 on IFN-γ function did not appear to involve any alteration in the level of expression of IFN-γ receptors.

scholarly journals Sequence-Directed Base Mispairing in Human Oncogenes

1998 ◽  
Vol 18 (8) ◽  
pp. 4659-4669 ◽  
Author(s):  
Lavanya Lall ◽  
Richard L. Davidson
Keyword(s):  
Mammalian Cells ◽  
Point Mutations ◽  
Inhibitory Effect ◽  
Relative Difference ◽  
Human Tumors ◽  
Sequence Specificity ◽  
Klenow Polymerase ◽  
Free Environment ◽  
Base Mispairing

ABSTRACT The most frequently observed mutations in ras oncogenes in solid human tumors are GC→AT transitions at the 3′ G residue of the GG doublet in codon 12 of these oncogenes. We had shown previously that mutagenesis by thymidine occurred with the same sequence specificity in mammalian cells, in that mutagenesis occurred preferentially at the 3′ G of GG doublets. In this study, in vitro DNA synthesis experiments were carried out to assess the effect of local DNA sequence on base mispairing in order to determine the mechanism of sequence-directed mutagenesis by thymidine and its possible relationship to activating point mutations in N-, Ki- and Ha-ras oncogenes in solid human tumors. To avoid complicating the interpretation of the results because of the occurrence of mismatch repair as well as base misincorporation, the experiments were carried out in a repair-free environment with exonuclease-free Klenow polymerase. The results of these experiments showed that misincorporation of deoxyribosylthymine (dT) occurred with several-fold-greater efficiency opposite the 3′ G compared to the 5′ G of the GG doublet in codon 12 of human ras oncogenes. These results further demonstrated that the relative difference in the extent of dT misincorporation opposite the 3′ G and the 5′ G of GG doublets in codon 12 in the various ras oncogenes was affected by the base immediately upstream of the doublet. Within the GG doublet, it was seen that the 5′ G and 3′ G residues had an effect on the extent of dT misincorporation opposite each other. The 5′ G was shown to have a stimulatory effect on dT misincorporation opposite the 3′ G, while the 3′ G was shown to have an inhibitory effect on dT misincorporation opposite the 5′ G. Presumably, these mutual interactions within GG doublets are additive, such that the large differential in dT misincorporation observed between the 3′ G and 5′ G residues in GG doublets is the end result of the combined stimulatory and inhibitory effects within these doublets. Since the observed pattern of dT misincorporation within GG doublets corresponds to the most frequent mode of activation of ras oncogenes in solid human tumors, the results of these experiments suggest that sequence-directed dT misincorporation may be involved in the pattern of activation of humanras oncogenes, by causing GC→AT transitions preferentially at the 3′ G of the GG doublet in codon 12 of these oncogenes.

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