Hi Devina,

I did not understand your question. Actually, IC50 itself means that, amount of sample required for 50% inhibition of DPPH solution used in the study right? You need % of what??

Thanks Mahesha.

Actually I was confused between IC50 and % DPPH scavenging effect

Hi Devina,

The free-radical scavenging activity of sample towards DPPH radical can be calculated using Equation:

Antioxidant activity (%inhibition) = (1-(Abs sample/Abs blank))*100

IC50 itself is 50% inhibition. I think you can report only IC50 values also. No need of percentage calculation in that case. For antioxidant activity measurement, the formula given by Dr. Zielinski is perfect. 

Regards 

Hi, Agree with the answer given by Acaco and Alok...