What is the principle of DPPH assay?

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 ABTS assay?

The ABTS assay measures the relative ability of antioxidants to scavenge the ABTS generated in aqueous phase, as compared with a Trolox (water soluble vitamin E analogue) standard. The ABTS is generated by reacting with a strong oxidizing agent (eg, potassium permanganate or potassium persulfate) with the ABTS salt.

How do you test for antioxidant properties?

Antioxidant activity can be monitored by a variety of assays with different mechanisms, including hydrogen atom transfer (HAT), single electron transfer (ET), reducing power, and metal chelation, among others.

How is antioxidant activity measured in plants?

Among the SET methods, the most used are 2,2-di-phenyl-1-picrylhydrazyl (DPPH radical scavenging capacity assay), ferric reducing (FRAP) assay, Trolox equivalent antioxidant capacity (TEAC or ABTS) assay, copper reduction (CUPRAC) assay and reducing power assay (RP).

What is the full form of DPPH?

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.

How is DPPH calculated?

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. As DPPH was soluble in methanol, it was taken up as organic phase.

How is ABT assay calculated?

Percent inhibition of absorbance at 734 nm was calculated using the formula, ABTS·+ scavenging effect (%) = ((AB–AA)/ AB)×100 (2), where, AB is absorbance of ABTS radical + methanol; AA is absorbance of ABTS radical + sample extract/standard. Trolox was used as standard substance.

What is reducing power assay?

Reducing power assay method is based on the principle that substances, which have reduction potential, react with potassium ferricyanide (Fe3+) to form potassium ferrocyanide (Fe2+), which then reacts with ferric chloride to form ferric–ferrous complex that has an absorption maximum at 700 nm.

How do you calculate total antioxidant capacity?

Total antioxidant capacity (Ta) was calculated with the equation Ta = 100/(OD1 + 2 * OD2 + 2 * OD3 + 2 * OD4 + OD5), and average activity (A) was calculated as A = Ta/M. Results. The potassium permanganate method generated similar results to the iodimetric method.

How do you calculate antioxidant activity?

The capability to scavenge the DPPH radical was calculated using the following equation [4]. DPPH Scavenged (%)= ((AB–AA)/AB)×100….. (1), where, AB is absorbance of blank at t= 0 min; AA is absorbance of the antioxidant at t= 30 min.

What does DPPH stand for?

What is the principle of DPPH assay? 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 ABTS assay? The ABTS…