Study of antioxidant activity and free radical scavenging power of Rheum Ribes flower extract

In recent years, the use of synthetic antioxidants and the degradation products derived from them is limited, because they are toxic and carcinogenic. So, studying on the use of natural antioxidants to replace the synthetic antioxidants is very important. Natural antioxidants are healthier and have more benefits and fewer harmful side effects. In this study, first, the Rheum Ribes of flower was extracted by maceration method with methanol. The extract’s phenolic compounds and inhibitory activity of free radicals were evaluated in different concentrations (100, 150, 200, 250 and 300 ppm) by Folin-Ciocalteu method and DPPH test, respectively and then, compared with the synthetic antioxidant of BHT at the constant concentration of 200 ppm. The results showed that the highest antioxidant properties of the extract was related to the concentration of 300 ppm and also the concentration of 250 ppm of the extract of Rheum Ribes of flower was equivalent to a concentration of 200 ppm of BHT in terms of free radical scavenging properties.Keywords: Rheum Ribes flower, Free radical scavenging power, Natural antioxidants, Phenolic compound