Folkloric use of root-bark extract of Alstonia boonei in the treatment and management of many disease conditions may be associated with free radical scavenging as part of its mechanisms of action. We therefore evaluated the ability of different solvent fractions of the methanol extract, crude precipitate from the extract, and isolated compound from the crude precipitate for scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Phytochemical analysis revealed the presence of useful phytocompounds. Ethyl acetate fraction showed better antioxidant activity with IC50 of 54.25？μg/mL while acetone and methanol fractions have 121.79 and 141.67？μg/mL, respectively. The crude precipitate and isolated compound showed IC50 values of 364.39 and 354.94？μg/mL, respectively. The crude precipitate, fractions, and compound 1 showed antioxidant activity against DPPH radical although lower than that of ascorbic acid. 1. Introduction Antioxidants are gaining special attention owing to their confirmed roles in prevention and management of chronic and degenerative diseases such as arthritis, cancer, cataract, and cardiovascular diseases [1]. Alstonia boonei is a large deciduous tree. It is widely distributed in Africa: Egypt, Cameroon, Central African Republic, Ghana, Code D’Ivoire, and Nigeria [2]. The various ethnomedicinal, chemical, pharmacological, and toxicological properties of Alstonia boonei were recently reviewed and the profile revealed that it is useful in the treatment and management of several illnesses [2]. The root bark is commonly used in West and Central Africa along with other herbs in the management of arthritis [3, 4]. The anti-inflammatory and antiarthritic properties of the root barks have been demonstrated [5, 6]. Furthermore, the antioxidant property of the stem bark has been documented [7]. Based on the diverse medicinal values of A. boonei, it is likely that inhibition of oxidative stress and free radicals might contribute to their medicinal effects. In this work, we hypothesize that the usefulness of the root extract in the management of chronic and degenerative diseases will likely have to be connected with the presence of some antioxidant property. Hence we set out to screen different solvent fractions of root-bark of Alstonia boonei for antioxidant effect since there is no literature report of antioxidant property in the root extract. 2. Materials and Methods 2.1. Plant Material The root bark of Alstonia boonei was collected from Oba Nsukka Enugu State and authenticated by Mr. Alfred Ozioko of the Bio-resources Development and Conservation
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