How do you calculate the IC50 value of antioxidant activity?

How do you calculate the IC50 value of antioxidant activity?

Most recent answer. you can calculate the IC50 as follows: IC50 = (0.5 – b)/a.

What is the IC50 value?

IC50 represents the concentration at which a substance exerts half of its maximal inhibitory effect. As reported by the FDA, the IC50 value represents the minimal concentration of a drug that is required for 50% inhibition in vitro.

How do you calculate IC50 on a graphpad?

How to determine an IC50

1. From the Welcome dialog, choose the XY tab, drop the list of sample data sets and choose “RIA or ELISA”.
2. Note that the X values are logarithms of concentration.
3. Click Analyze and then Nonlinear regression.

How is IC50 value calculated?

To calculate the IC50 value: The inhibitor concentration against the percent activity is plotted ([I]-Activity % graph). Using the linear (y=mx+n) or parabolic (y=ax2+bx+c) equation on this graph for y=50 value x point becomes IC50 value.

How is IC50 calculated from MTT assay?

then generate the equation for curve in ‘y=mx+c’ option. Using this equation i will put value of y=50 and calculate the value of x, and treat it as IC50.

How is MTT assay calculated?

Assay protocol

1. Discard media from cell cultures.
2. Add 50 µL of serum-free media and 50 µL of MTT solution into each well.
3. Incubate the plate at 37°C for 3 hours.
4. After incubation, add 150 µL of MTT solvent into each well.
5. Wrap plate in foil and shake on an orbital shaker for 15 minutes.
6. Read absorbance at OD=590 nm.

What does IC50 stand for?

Half-maximal inhibitory concentration (IC50) is the most widely used and informative measure of a drug’s efficacy. It indicates how much drug is needed to inhibit a biological process by half, thus providing a measure of potency of an antagonist drug in pharmacological research.

What is the unit of IC50?

pIC50 is usually given in terms of molar concentration (mol/L, or M), thus requiring IC50 in units of M. The IC50 terminology is also used for some behavioral measures in vivo, such as a two bottle fluid consumption test.

What is the difference between IC50 and EC50?

The EC50 is the concentration of a drug that gives half-maximal response. The IC50 is the concentration of an inhibitor where the response (or binding) is reduced by half.

What is a good IC50 for a drug?

Generally, less than 10 micromolar concentration of a drug in plasma is accepted because higher than 10 uM of a drug inhibit necessary enzymes. The most of the drugs on the market have less than 10 micromolar therapeutic plasma concentrations.

What is IC50 in MTT assay?

MTT assay to determine the IC50 value of the different drugs and analyze their effect on cell viability. The IC50 value (that is, the concentration of drug which exhibited 50% cell viability for MCF-7 and MDA-MB-231 cells) were 15, 15, 10 μM, and 100 nM, respectively, for AZA, SAM, SFN, and TSA, respectively.

Why do we use IC50?

The half maximal inhibitory concentration (IC50) is a measure of the effectiveness of a substance in inhibiting a specific biological or biochemical function. According to the FDA, IC50 represents the concentration of a drug that is required for 50% inhibition in vitro. It is comparable to an EC50 for agonist drugs.

What is IC50 in antioxidant activity?

IC50 is the concentration required to result in a 50% antioxidant activity, for example, a 50% DPPH free radical scavenging, or 50% reducing power, compared with control. A smaller IC50 means higher antioxidant activity.

How do you convert pIC50 to IC50?

What is IC50 in the First Place?

1. An IC50 of 1 µM is 10-6 M, which is pIC50 = 6.0.
2. An IC50 of 1 nM is 10-9 M, which is pIC50 = 9.0.
3. An IC50 of 10 nM is 10-8 M, which is pIC50 = 8.0.
4. An IC50 of 100 nM is 10-7 M, which is pIC50 = 7.0.
5. An IC50 of 30 nM is 3 x10-8 M, which is also 10-7.5 M, which is pIC50 = 7.5.

What is logic50?

Ligand lipophilicity efficiency (LLE) is a parameter used in drug discovery to evaluate the quality of research compounds through linking potency and lipophilicity in an attempt to estimate drug-likeness and is defined as the pIC50 (or pEC50) of interest minus the log P of the compound (52).

What does a negative IC50 mean?

If you mean by negative, that the cells grow faster or an assay gives a higher signal after adding your drug, then yes it is a known phenomenon. Quercetin is one example of such a compound that at low doses improves cell growth. Once a threshold is reached the growth rate shows no difference.

What is pEC50?

The pEC50 is defined as the negative logarithm of the EC50. If the EC50 equals 1 micromolar (10-6 molar), the log(EC50) is -6 and the pEC50 is 6. The advantage to expressing potency this way is that drugs with larger pEC50 values are more potent.

What is effective concentration?

In pharmacology, an effective dose (ED) or effective concentration (EC) is a dose or concentration of a drug that produces a biological response. This is generally defined by the range between the minimum effective dose (MED) and the maximum tolerated dose (MTD).

How do you determine the potency of a drug?

Potency: the amount of drug required to produce an effect of given intensity. Differences in drug potency are evaluated by comparing EC50 (or ED50) values. (Example: the drugs in Figure 3 vary only by their potency or receptor affinity, and not in terms of their maximal response.)

How is drug potency calculated?

The formula provided by CLSI to calculate the potency is shown as: Potency = (Assay purity) * (Active fraction) * (1-Water Content).

What is the potency of a drug?

Potency (strength) refers to the amount of drug (usually expressed in milligrams) needed to produce an effect, such as relief of pain or reduction of blood pressure. For instance, if 5 milligrams of drug A relieves pain as effectively as 10 milligrams of drug B, drug A is twice as potent as drug B.

What is high potency?

The term “high potency” may be used on the label or in labeling of a multi-ingredient product to describe the product (as opposed to describing the level of individual ingredients) if the product contains 100 percent or more of the RDI for at least two-thirds of the vitamins and minerals that are listed in 21 CFR 101.9 …

What is the difference between drug purity and drug potency?

Purity includes but is not limited to relative freedom from residual moisture or other volatile substances and pyrogenic substances. The word potency is interpreted to mean the specific ability or capacity of the product, as indicated by appropriate laboratory tests, to yield a given result.

Why assay is more than 100?

There is a simple reason to have the purity greater than 100% for this compound. If the substance was exposed to a dry environment for several hours, a small amount of the water of hydration could be lost, causing the calculation to have a higher purity.

What is difference between potency and assay?

It is a procedure to analysed and determine the percentage of the drug present in the product. In the pharmaceutical industry, an assay is the main test for any drug product. As there are multiple tests for the drug product but the assay is a test that gives proper information on drug content percentage.

What is difference between purity and assay?

The main difference between assay and purity is that an assay is the determination of one of the main component in a sample whereas purity is the determination of impurities in a sample. Assay and purity are two types of measurements used to determine the components of a sample.

How is assay calculated?

It may be of following types:

1. On as is basis = (Area of sample / Area of standard) x (conc. of standard / conc. of sample) x potency or assay of standard.
2. On anhydrous basis = (Assay on as is basis / 100 – moisture) x 100.
3. On dried basis = (Assay on as is basis / 100 – LOD) x 100.

How do you calculate impurities?

We have developed / validated a method where impurities are calculated by the known formula: %imp= (Atest/Aref)* limit. Comparison of the % percentage for an unknown imp.