scholarly journals Differential Effects of the Flavonolignans Silybin, Silychristin and 2,3-Dehydrosilybin on Mesocestoides vogae Larvae (Cestoda) under Hypoxic and Aerobic In Vitro Conditions

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2999 ◽  
Author(s):  
Gabriela Hrčková ◽  
Terézia Kubašková ◽  
Oldřich Benada ◽  
Olga Kofroňová ◽  
Lenka Tumová ◽  
...  

Mesocestoides vogae larvae represent a suitable model for evaluating the larvicidal potential of various compounds. In this study we investigated the in vitro effects of three natural flavonolignans—silybin (SB), 2,3-dehydrosilybin (DHSB) and silychristin (SCH)—on M. vogae larvae at concentrations of 5 and 50 μM under aerobic and hypoxic conditions for 72 h. With both kinds of treatment, the viability and motility of larvae remained unchanged, metabolic activity, neutral red uptake and concentrations of neutral lipids were reduced, in contrast with a significantly elevated glucose content. Incubation conditions modified the effects of individual FLs depending on their concentration. Under both sets of conditions, SB and SCH suppressed metabolic activity, the concentration of glucose, lipids and partially motility more at 50 μM, but neutral red uptake was elevated. DHSB exerted larvicidal activity and affected motility and neutral lipid concentrations differently depending on the cultivation conditions, whereas it decreased glucose concentration. DHSB at the 50 μM concentration caused irreversible morphological alterations along with damage to the microvillus surface of larvae, which was accompanied by unregulated neutral red uptake. In conclusion, SB and SCH suppressed mitochondrial functions and energy stores, inducing a physiological misbalance, whereas DHSB exhibited a direct larvicidal effect due to damage to the tegument and complete disruption of larval physiology and metabolism.

1990 ◽  
Vol 17 (4) ◽  
pp. 325-333
Author(s):  
Paul J. Dierickx ◽  
Virginia C. Gordon

The neutral red uptake inhibition assay and the EYTEX™ system were investigated as alternative methods for the assessment of eye irritation, determined according to the EEC protocol. The 17 test chemicals used were mainly organic solvents. The xenobiotics were applied to Hep G2 cells for 24 hours at different concentrations. Neutral red uptake inhibition was then measured. The results are expressed as the NI50 value, which is the concentration of test compound required to induce a 50% reduction in neutral red uptake. The same chemicals were also tested as coded samples by the EYTEX™ test according to the manufacturer's directions. A nearly identical quantitative correlation was found for both in vitro methods with corneal opacity scores: r = 0.84 for EYTEX™ scores and r = 0.83 for log NI50, expressed in μg/ml. Whilst these correlations are certainly not perfect, it is clear that both in vitro methods can be used as valuable prescreening methods.


1993 ◽  
Vol 21 (4) ◽  
pp. 501-507 ◽  
Author(s):  
Guillermo Repetto ◽  
Pilar Sanz

Specific toxic interference in lysosomal activity was evaluated by the relative uptake of neutral red by lysosomes. In this adaptation of the standard neutral red cytotoxicity assay, the results are expressed relative to cell culture protein content to avoid misinterpretation due to the influence on cell proliferation of the chemicals tested. Neuro-2a mouse neuroblastoma cells were exposed in vitro to 24 metal compounds and the lysosomal activity was quantified. Five different patterns of alterations were identified. Group A (ZnCl2, NaAsO2, Na2HAsO4, CdCl2, SnCl2, HgCl2, HgCH3Cl and TlCOOCH3) produced an inhibition of the relative uptake of the dye, in marked contrast to the greater inhibition shown by the neutral red uptake assay. Group B (MgCl2, A1C13, KMnO4) NiCl2, BaCl2 and Pb[NO3]2) showed less inhibition with strong parallelism with the neutral red assay. In Group C (CrCl3, Na2Cr2O7, FeCl3, CoCl2, CuCl2 and Sn[C2H5]4), low-dose stimulation, and inhibition at higher concentrations were found. Group D (LiCl and CrCl2) stimulated uptake, and Group E (MnCl2 and Sr[NO3]2) produced no significant modifications. The relative uptake of neutral red can be a convenient tool for the study of specific toxic alterations of lysosomes.


1989 ◽  
Vol 37 (8) ◽  
pp. 1265-1271 ◽  
Author(s):  
A Vignery ◽  
T Niven-Fairchild ◽  
D H Ingbar ◽  
M Caplan

Giant cell formation was analyzed to determine whether it results in the high level of Na+,K+-ATPase expression that characterizes multinucleated cells such as osteoclasts. Giant cells and fusing alveolar macrophages were subjected to morphological, immunological, and biochemical studies. Both subunits of the Na+,K+-ATPase were found to be present on the plasma membrane of giant cells. Their localization was restricted to the non-adherent domain of the cell surface. Dynamic studies of giant cell differentiation demonstrated that on culture and/or multinucleation, an increase in sodium pump alpha-subunit synthesis occurred and led to a high level of expression of Na pumps. Conversely, the adherent plasma membrane of giant cells was enriched in a lysosomal membrane antigen. This study demonstrates that culture and/or multinucleation induces a significant increase in the expression of sodium pumps. The polarized distribution of these pumps and of a lysosomal component suggests that fusing macrophages undergo biochemical and morphological alterations which prepare them for a new and specialized function in chronic inflammatory reactions. Giant cells may offer a suitable model system to study the differentiation of other related multinucleated cells, such as osteoclasts.


1998 ◽  
Vol 26 (1) ◽  
pp. 61-68
Author(s):  
Annalaura Stammati ◽  
Franco Zampaglioni ◽  
Cristiana Zanetti

The neutral red uptake (NRU) assay was included, among others, in a validation study sponsored by the European Commission/British Home Office (EC/HO) study, for its reliability as an in vitro alternative to the Draize eye irritancy test. The test was performed in parallel by four laboratories (Istituto Superiore di Sanità [ISS], Microbiological Associates, Hatano Research Institute and Kurabo Industries) on 60 selected chemicals. The results obtained by the ISS are reported in this paper. A poor rank correlation was obtained between the in vivo endpoint and the ISS in vitro results for the full set of chemicals and for the subsets, with the exception of surfactants, by an independent statistics group. The same unsatisfactory results were obtained by the ISS group when the rank correlation was calculated for compounds divided into chemical groups. The performance of the NRU assay, as an alternative to the Draize eye irritancy test, is discussed.


Author(s):  
A. Wnuk ◽  
K. Przepiórska ◽  
B. A. Pietrzak ◽  
M. Kajta

AbstractNewly synthesized Pathway Preferential Estrogen-1 (PaPE-1) selectively activates membrane estrogen receptors (mERs), namely, mERα and mERβ, and has been shown to evoke neuroprotection; however, its effectiveness in protecting brain tissue against hypoxia and ischemia has not been verified in a posttreatment paradigm. This is the first study showing that a 6-h delayed posttreatment with PaPE-1 inhibited hypoxia/ischemia-induced neuronal death, as indicated by neutral red uptake in mouse primary cell cultures in vitro. The effect was accompanied by substantial decreases in neurotoxicity and neurodegeneration in terms of LDH release and Fluoro-Jade C staining of damaged cells, respectively. The mechanisms of the neuroprotective action of PaPE-1 also involved apoptosis inhibition demonstrated by normalization of both mitochondrial membrane potential and expression levels of apoptosis-related genes and proteins such as Fas, Fasl, Bcl2, FAS, FASL, BCL2, BAX, and GSK3β. Furthermore, PaPE-1-evoked neuroprotection was mediated through a reduction in ROS formation and restoration of cellular metabolic activity that had become dysregulated due to hypoxia and ischemia. These data provide evidence that targeting membrane non-GPER estrogen receptors with PaPE-1 is an effective therapy that protects brain neurons from hypoxic/ischemic damage, even when applied with a 6-h delay from injury onset.


1993 ◽  
Vol 21 (2) ◽  
pp. 281-284
Author(s):  
Alain Fautrel ◽  
Christophe Chesné ◽  
André Guillouzo ◽  
Georges De Sousa ◽  
Michel Placidi ◽  
...  

A multicentre validation study of the acute in vitro cytotoxicities of 31 liquid or solid chemicals was carried out by six laboratories, using primary rat hepatocyte cultures as a model system. We report here a comparison of neutral red uptake IC50 and LD50 values. Oral, i.p. and i.v. LD50 values were available for 27, 24 and 18 chemicals, respectively, and an IC50 value was obtained for 15, 14 and 11 of these compounds, respectively. A significant correlation was found only between IC50 and i.v. LD50 values.


1985 ◽  
Vol 24 (2-3) ◽  
pp. 119-124 ◽  
Author(s):  
Ellen Borenfreund ◽  
James A. Puerner

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