Why do we do DPPH assay?

The DPPH assay is used to predict antioxidant activities by mechanism in which antioxidants act to inhibit lipid oxidation, so scavenging of DPPH radical and therefore determinate free radical scavenging capacity. The method is widely used due to relatively short time required for the analysis.

Why do we do antioxidant assay?

Assays developed to evaluate the antioxidant activity of plants and food constituents vary. Therefore, to investigate the antioxidant activity of chemical(s), choosing an adequate assay based on the chemical(s) of interest is critical. There are two general types of assays widely used for different antioxidant studies.

What is the DPPH radical scavenging activity?

DPPH free radical scavenging is an accepted mechanism for screening the antioxidant activity of plant extracts. In the DPPH assay, violet color DPPH solution is reduced to yellow colored product, diphenylpicryl hydrazine, by the addition of the extract in a concentration dependent manner.

How do you calculate antioxidant activity by DPPH?

The percentage of DPPH scavenging effect was calculated by following equation. DPPH scavenging effect (\%)/\% Inhibition=A0-A1/A0 × 100 Where A0=The absorbance of control. A1=The absorbance of sample.

Why is DPPH used for antioxidants?

DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical method is an antioxidant assay based on electron-transfer that produces a violet solution in ethanol (10). This free radical, stable at room temperature, is reduced in the presence of an antioxidant molecule, giving rise to colorless ethanol solution.

What is the absorbance of DPPH?

DPPH is a stable free radical in a methanolic solution. In its oxidized form, the DPPH radical has an absorbance maximum centered at about 520 nm (Molyneux, 2004).

What is DPPH?

Definition. DDPH. Diploma in Dental Public Health (UK)

What does DPPH stand for?

DPPH is a common abbreviation for the organic chemical compound 2,2-diphenyl-1-picrylhydrazyl. It is a dark-colored crystalline powder composed of stable free radical molecules.

Why methanol is used in DPPH assay?

The standard DPPH assay uses methanol or ethanol as solvents, or buffered alcoholic solutions in a ratio of 40\%/60\% (buffer/alcohol, v/v) to keep the hydrophobic hydrazyl radical and phenolic test compounds soluble while offering sufficient buffering capacity at different pHs tested.

What is hydroxyl radical scavenging assay?

Hydroxyl radical is the most reactive oxygen centered species and causes severe damage to adjacent biomolecule. Hydroxyl radical scavenging activity was estimated by generating the hydroxyl radicals using ascorbic acid–iron EDTA. The MKF exhibited highest hydroxyl radical scavenging activity compared to other extracts.

Why do we do antioxidant activity?

Antioxidants are substances that can prevent or slow damage to cells caused by free radicals, unstable molecules that the body produces as a reaction to environmental and other pressures. They are sometimes called “free-radical scavengers.” The sources of antioxidants can be natural or artificial.

What is inhibition in DPPH assay?

The percent DPPH inhibition was calculated by the equation: \% inhibition= A0 – A1 / A0 x 100 Where A0 was the absorbance of control and A1 was the absorbance of reaction mixture. The site-specific deoxyribose assay was performed following Arouma et al. (1987) and Halliwell et al.