What IC50 means?

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 does a low IC50 value mean?

Low IC₅₀ value means that the drug is effective at low concentrations, and thus will show lower systemic toxicity when administered to the patient.

What is a high IC50?

IC50 is the dose of the substance which inhibits the proliferation of half of the cells. It does not necessarily need to kill the cells. If you find high IC50, this means that the cell line is more resistant to drug1 than drug 2.

What is an IC50 curve?

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. … All the ideas can be applied to stimulatory curves and EC50 (E for effective) as well.

What is the difference between LC50 and EC50?

Terminology: EC50(50% Effective Concentration) The Lethal Concentration 50 (LC50) is the concentration of a substance in water causing a death (50% of the tested population) to aquatic life. The EC50 and the LC50 are often used in ecotoxicology as an indicator of the toxicity of a compound to the environment.

What is an IC value?

The IC₅₀ value is that concentration of a drug that reduces the activity (or binding) of another drug to an enzyme by 50%. Under certain conditions it can used to express the affinity of the enzyme inhibitor.

What is a good IC50 value for a drug?

10 micromolar In most cases, the IC50 of the best candidate compound should be lower to 10 micromolar, acceptable for NIH to screen the NCI60 program. In addition, the drug design should think over the related problem about the absorption, distribution, metabolism and excretion in our body.

What does an IC50 value tell you?

It is commonly used as a measure of antagonist drug potency in pharmacological research. According to the FDA, IC50 represents the concentration of a drug that is required for 50% inhibition in vitro. … IC50 value of the drug indicates the toxicity of the drug to other disease causing organisms.

How is IC50 value calculated?

The simplest estimate of IC50 is to plot x-y and fit the data with a straight line (linear regression). IC50 value is then estimated using the fitted line, i.e., Y = a * X + b, IC50 = (0.5 – b)/a.

What is the potency of a drug?

Results: Potency is an expression of the activity of a drug in terms of the concentration or amount of the drug required to produce a defined effect, whereas clinical efficacy judges the therapeutic effectiveness of the drug in humans.

How is drug potency determined?

Potency is defined as the concentration of the drug in a compounded preparation. 5 Potency tests are known as quantitative tests and are designed to determine how much of the drug is in the sample. 3 High-performance liquid chromatography (HPLC) is the method typically employed in determining potency.

What is ki of a drug?

The inhibitor constant, Ki, is an indication of how potent an inhibitor is; it is the concentration required to produce half maximum inhibition.

What is the hill slope?

Hillslopes constitute the flanks of valleys and the margins of eroding uplands. They are the major zones where rock and soil are loosened by weathering processes and then transported down gradient, often to a river channel.

How can I use IC50 assay?

What is Emax pharmacology?

E is the effect at drug concentration C, Emax is the maximal effect at high drug concentrations when all the receptors are occupied by the drug, and EC50 is the drug concentration to give the half-maximal effect.

What is LC50 used for?

The lethal concentration 50 (LC50) is the concentration of a chemical that will kill 50 percent of the sample population under scrutiny. The lethal concentration is usually applied to chemicals that are breathed into the body.

What is LOEL in toxicology?

Lowest Observed Effect Level (LOEL) The lowest observed adverse effect level (LOAEL) is defined as the lowest dose where the effects observed in the treated group imply an adverse effect to the subject.

What is Noel in toxicology?

The NOEL (no observable effect level) is the highest dose or exposure level of a substance or material that produces no noticeable (observable) toxic effect on tested animals. The LOAEL is the lowest dosage level at which chronic exposure to the substance shows adverse effects on tested animals.

Why is knowing IC50 important?

Since the concept of the half maximal inhibitory concentration (IC(50)) is used extensively for studying reversible inhibition enzymatic reactions, it is important to clearly understand the experimental design and the mathematical modeling techniques used to generate IC(50) values.

What is IC50 value in cytotoxicity?

The IC50 is defined as the concentration of an inhibitor where the response (or binding) is reduced by half. So, if you are testing viability via an MTT assay, the dose of cytotoxic compound at which you achieve 50% viability will be the IC50.

What is the difference between KI and KD?

The difference between Kd and Ki is that Kd is a more general, all-encompassing term, whilst Ki is more narrowly used to indicate the dissociation equilibrium constant of the enzyme-inhibitor complex.

What is the Cheng Prusoff equation?

The Cheng-Prusoff equation defines the theoretical relation- ship between the measured IC50 for a competitive inhibitor of given Ki, the concentration of labeled ligand, and the KD of the ligand-receptor interaction.

What is IC50 value for 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 calculate IC50 in antioxidant activity?

you can calculate the IC50 as follows: IC50 = (0.5 – b)/a. You replace (y) by 50 in the equation y = 1.3534 x + 0.58 and you deduce ( x) .

What is cytotoxic concentration?

The 50% cytotoxic concentration (CC50) was defined as the compound’s concentration (µg/mL) required for the reduction of cell viability by 50%, which were calculated by regression analysis.

How is IC50 calculated in origin?