IN VITRO ANTIOXIDANT ACTIVITY OF AQEOUS LEAF EXTRACT OF Delonix regia

Abstract

Free radicals are reactive particles engaged with numerous physiological processes and have been related with numerous illnesses. Therefore, there is need to investigate substances with free radical scavenging ability. The present investigation was intended to assess the free radical scavenging action of aqueous extract of leaf of Delonix regia utilizing different in vitro models. The extract was subjected to qualitative and quantitative (total phenol, total flavonoid and total antioxidant capacity) phytochemical screening. Ascorbic acid was the reference in the investigation. 1,1-Diphenyl-2-picryl hydroxyl (DPPH) and nitric oxide scavenging assays, as well as reducing power assay were carried out in this analysis. The capacity of the extracts to restrain lipid
peroxidation was estimated by the in vitro lipid peroxidation assay. The extracts were at 20, 40, 60, 80 and 100 μg/mL concentrations and radical scavenging activity was determined in terms of inhibition percentage. The IC50 (concentration required for 50 % inhibition) was likewise ascertained for every radical. Qualitative phytochemical screening uncovered the presence of alkaloid, flavonoid, tannin, saponin, diterpenes, phenol, amino acids. The study additionally uncovered that the aqueous extract of Delonix regia leaf has a high radical scavenging action in the different radical systems. The total phenolic content and, flavonoid contents were 34.31 ± 0.169 mg Gallic acid equivalent (GAE)/g extract and 55.765±0.898 mg Quercetin/g extract respectively while the total antioxidant capacity was 52.33±1.443 mg ascorbic acid equivalent. The antioxidant activity of Delonix regia aqueous leaf extract could be related to high flavonoid and phenol content of the plant.