Free radical scavenging activity of ornamental and edible cultivars of Canna found in Eastern India

Canna, the only genus of family Cannaceae, found in eastern India have gained economic importance for their starchy rhizomes and attractive flowers. The rhizome of some edible cultivars are consumed as food and herbal medicines in rural areas. The presence of total phenols, flavonoids and DPPH scavenging activity of both cold and hot extracts and their correlations have been studied for eleven cultivars of Canna spp. Antioxidants, quercetin and gallic acid equivalence of phenolic compounds were determined spectrophotometrically. It has been found that total phenol, flavonoids and DPPH free radical scavenging activity were higher in hot extracts than in cold. Further studies gave an idea about the correlation between phenol and flavonoid contents of both cold and hot extracts, but both the above said parameters were not correlated with DPPH scavenging activity. Finally it can be concluded that higher DPPH scavenging activities in all these Canna cultivars may not be due to the presence of endogenous phenols and flavonoids but these may be due to any other phytochemicals.