ABSTRACT
The antioxidant activity of different extracts of Thuja orientalis was evaluated by employing three in vitro experiments namely (1, 1-Diphenyl-2-picrylhydrazyl) (DPPH), reducing power and chelating power assays. The stem powder of the plant was extracted with different solvents by maceration method in order of decreasing polarity and then partitioned (Flow Chart 1). The differential activities of the different extracts could be correlated with their respective phenolic and flavanoid contents and compared with standards L-ascorbic acid and butylated hydroxytoluene (BHT). All the extracts exhibit a remarkable concentration dependant scavenging activity. Moreover, among the different extract, methanol extract exhibited good scavenging response of 74.3%, 59.51% and 0.997% in DPPH, chelating power and reducing power assay in decreasing order of solvent polarity at maximum concentration, respectively. Studies are in progress to isolate and identify the active principle components responsible for this activity.