HepG2 cells were obtained from American type culture collection (ATCC), USA (ATCC No. HB-8065). This cell line is derived from a liver hepatocellular carcinoma of a 15 year old Caucasian male. After thawing, cells were maintained as a sub confluent monolayer in a 75 cm2 culture flask using the modified DMEM medium with 10% (v/v) FBS + penicillin-streptomycin (50 units/ml). The cells were used to experiments after two weeks of thawing from cryopreserved stock. On the day of harvest, the cell monolayer was rinsed with 1 x PBS and pre-warmed 0.25% trypsin-EDTA solution was added. The cells (1×104 cells/well) were seeded into 96 well plates and allowed to attach for 24 h before chemical treatment. During the experiment period, cells were maintained
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This solution contains a tetrazolium compound, MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] and an electron coupling reagent PES (phenazine ethosulfate). The principle of this assay is based on the metabolic reduction of tetrazolium salts. Viable cells with an active metabolism convert MTS salt into a purple colored formazan product. The exact mechanism of the metabolic reduction is not well understood, enzymes from the endoplasmic reticulum, mitochondria and from the cell surface is attributed to the observed metabolic reduction …show more content…
The predictive dose response for CI method is computed by using equation (6). CI= = (∑_(i=1)^n▒├ p_i/(〖EC〗_(xi )× 〖CI〗_xcomp )) ┤^(-1) ---------------------------------------------------------------- (6)
CIxcomp is the computed CI value for each mixtures at different effect level (0.1-97%) from independent experimental toxicity data of the mixtures.35 The dose response for each mixture was predicted using computed CI values from individual mixture toxicity experiment and different fa levels.
The quantitative relationship between the predicted and observed effect was determined by the index on prediction quality (IPQ). 43 The predicted dose response from three different models CA, IA and CI was compared with the experimental dose response of multi-component mixtures of B[a]P, As, Cd and Pb.
If the predicted effect is greater than the observed value, the prediction quality is determined by using equation (7)
For ECpredicted> ECobserved, IPQ= (〖EC〗_predicted/〖EC〗_observed )-1----------------------------------------------- (7)
If the predicted value is less than the observed value, the predictive quality is determined by using equation
This solution contains a tetrazolium compound, MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] and an electron coupling reagent PES (phenazine ethosulfate). The principle of this assay is based on the metabolic reduction of tetrazolium salts. Viable cells with an active metabolism convert MTS salt into a purple colored formazan product. The exact mechanism of the metabolic reduction is not well understood, enzymes from the endoplasmic reticulum, mitochondria and from the cell surface is attributed to the observed metabolic reduction …show more content…
The predictive dose response for CI method is computed by using equation (6). CI= = (∑_(i=1)^n▒├ p_i/(〖EC〗_(xi )× 〖CI〗_xcomp )) ┤^(-1) ---------------------------------------------------------------- (6)
CIxcomp is the computed CI value for each mixtures at different effect level (0.1-97%) from independent experimental toxicity data of the mixtures.35 The dose response for each mixture was predicted using computed CI values from individual mixture toxicity experiment and different fa levels.
The quantitative relationship between the predicted and observed effect was determined by the index on prediction quality (IPQ). 43 The predicted dose response from three different models CA, IA and CI was compared with the experimental dose response of multi-component mixtures of B[a]P, As, Cd and Pb.
If the predicted effect is greater than the observed value, the prediction quality is determined by using equation (7)
For ECpredicted> ECobserved, IPQ= (〖EC〗_predicted/〖EC〗_observed )-1----------------------------------------------- (7)
If the predicted value is less than the observed value, the predictive quality is determined by using equation