Uridine uptake inhibition assay: an automated micromethod for the screening of cytotoxicity

Toxicology ◽  
2002 ◽  
Vol 171 (2-3) ◽  
pp. 207-213 ◽  
Author(s):  
Isabelle Valentin-Severin ◽  
Laurence Laignelet ◽  
Jean-Claude Lhuguenot ◽  
Marie-Christine Chagnon
1988 ◽  
Vol 15 (4) ◽  
pp. 290-296
Author(s):  
Guido A. Jacobs ◽  
Paul J. Dierickx ◽  
Mark A. Martens

In vivo eye irritation tests were carried out on 17 substances (mainly solvents) according to the experimental protocols laid down in the European Community legislation on dangerous substances and the OECD Guidelines. Erythema, chemosis, corneal opacity and iritis were observed and evaluated according to the interpretation rules laid down in EEC legislation. The uridine uptake inhibition assay was carried out on Human Hep G2 cells according to the method of Shopsis & Sathe (1), modified by Dierickx & Martens (2). Inhibition of uridine uptake was expressed as the UI50 (Hep G2 cells, mM). Comparison of the results of our two studies revealed only a poor relationship between the UI50 values and the mean scores obtained for corneal opacity (Spearman rank correlation; r=0.57, p<0.02). Consideration of just the monoalcohols, together with the ketones and the formamides, gave a good linear correlation between the UI50 (Hep G2 cells) and the <<Se>> (r=0.93). If a UI50 value of 50mM is accepted as a limit for classification of irritancy for the eye, no false positives or false negatives are obtained. The UI50 can only be used within strictly defined chemical classes, as a first screening method for detecting possible irritants.


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.


1994 ◽  
Vol 30 (10) ◽  
pp. 113-124 ◽  
Author(s):  
L. Guzzella ◽  
M. Mingazzini

A biological monitoring program (1992-93) was undertaken with the aim of testing the toxic effect of the Lambro, one of the most polluted rivers in Northern Italy. The filtered river samples were tested with S. capricornutum in a 96h exposure growth inhibition assay and with a photobacterial inhibition assay with the LUMISTox System. The unfiltered samples were also tested with LUMISTox, in order to evaluate the role played by the suspended and colloidal material in the water toxicity. The river samples were passed through a series of columns filled with Carbopack B, XAD-2 and C-18 respectively to concentrate organic compound for chemical analysis and enriched with EDTA to complex metals. The Carbopack B procedure proved to be the most efficient among the tested extraction techniques. The de-toxificant effect of the sample treatments was evaluated in terms of percentage increase of the cell density by the algal assay, while the toxicity of the extracted organic compounds was evaluated by LUMISTox System. The comparison of algal assay with chemical analysis results pointed out that the toxicity of the Lambro waters was mainly related to pesticide contamination.


Author(s):  
Deedarul Hyder Sani ◽  
Ali Newaz Munna ◽  
Mohammad Salim ◽  
Md. Jahangir Alam ◽  
Md. Jahangir Alam

Background: Diabetes mellitus is the most occurring non-communicable disease resulting in a high blood glucose level. There has been an immense interest in the development of alternative medicines for diabetes treatment, specifically screening functional foods for phytochemicals with the capability of delaying or preventing glucose absorption through digestive enzymes (e.g. α-amylase) inhibition. So, the development of α-amylase inhibitors derived from natural food products is an alternative way to prevent diabetes mellitus Objective: In this study, organic solvent extracts of the Arachis hypogaea (Peanut) and Cinnamomum tamala (Indian bay leaf /Tejpata) were used to investigate their potential α-amylase inhibition and cytotoxic activities through α-amylase inhibition assay and brine shrimp lethality bioassay respectively Method: The α-amylase inhibition assay was performed using the 3,5-dinitrosalicylic acid method for different concentrations of plant extracts. The optical density (OD) of the solutions were measured to determine the inhibition activity at 540 nm using a spectrophotometer. The cytotoxicity of the plant extracts was measured using brine shrimp (Artemia salina) lethality bioassay Results: Among the different organic solvent extracts, peanut seed ethanol extract showed the highest α-amylase inhibition activity (67.68±8.67%) at 1.25 μg/mL concentration with an IC50 value of 0.61 μg/mL which is very close to standard α-amylase inhibitor Acarbose (72.34±4.23%) with an IC50 value of 0.32 μg/mL while acetone extract of Indian bay leaf exhibited the lowest inhibition activity (47.75±1.63%) with an IC50 value of 1.42 μg/mL at the same concentration. Besides, the maximum cytotoxic activity was found in acetone extract of peanut shell with an LC50 value of 57.87 μg/mL whereas ethanol extract of peanut seed showed the lowest cytotoxicity with an LC50 value of 413.90 μg/mL Conclusion: The result of the present work clearly indicates the potentiality of peanut seed ethanol extract to be used in the management of hyperglycemia as it significantly inhibits α-amylase activity while showing less cytotoxic activities


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