RESUMO
Excoecaria agallocha L. [Family: Euphorbiaceae] is a Bangladeshi medicinal plant found predominantly in the tidal forests and swamps of the Sundarbans and other coastal areas in Bangladesh. As part of our on-going phytochemical and bioactivity studies on medicinal plants from Bangladeshi flora, the in vitro antioxidant property on the bark of this plant was evaluated. The hydroalcohol extract of the dried and ground bark of E. agallocha was assessed for antioxidant activity using a series of well-established assays including the 2, 2-diphenyl-1-picrylhydrazyl [DPPH], the lipid peroxidation by thiobarbituric acid [TBA], the reducing power, the nitric oxide [NO.] and the hydrogen peroxide [H[2] O[2]] scavenging assays. In the DPPH, the NO and the H[2]O[2] scavenging assays, the extract of E. agallocha displayed significant antioxidant activities with the IC[50] values of 179.16, 120.24 and 134.29 microg/ml, respectively. The reducing power of the extract increased dose-dependently, and the extract reduced the most Fe[3+] ions to the extent less than butylated hydroxy toluene [BHT]. In the lipid peroxidation assay, the extract showed significant inhibition of peroxidation effect at all concentrations, with an IC[50] value of 189.27 microg/ml. Since reactive oxygen species are important contributors to serious ailments such as atherosclerosis, alcoholic liver cirrhosis and cancer, the antioxidant property of the extract of E. agallocha as observed in the present study might be useful for the development of newer and more potent antioxidants