Comparative Study of the Antioxidant Activity of Holarrhena Floribunda and Picralima Nitida

Picralima nitida (Stapf) T.Durand & H.Durand and Holarrhena floribunda (G.Don) T.Durand & Schinz are West and Central African plant species belonging to the Apocynaceae family. These two plants are used in traditional Ivorian medicine to treat hypertension, urinary tract infections, diarrhea, gonorrhea, malaria and diabetes. Phytochemical screening and evaluation of antioxidant activity of P. nitida fruit and H. floribunda leaf extracts of each of these two species have already been performed. In the present study, a comparative evaluation of the antioxidant activity of fruit (P. nitida) and leaf (H. floribunda) decoctions was carried out. The decoctions of P. nitida fruits and H. floribunda leaves were rich in secondary metabolites, especially polyphenols which have good antioxidant activity. Quantification of total phenols and flavonoids gave respective values of QP = 15235.632 ± 622 µg GAE / g dry matter and FP = 2.387 ± 0.387% for P. nitida and QH = 68597.701 ± 3171 µg GAE / g dry matter and FH = 17.581 ± 0.379% for H. floribunda. P. nitida showed antioxidant activity against DPPH radical (IC50 = 104.30 ± 3.17 μg / mL) and ferric ion Fe3 + (261.4 ± 36. 87 μmoL Eq Trolox / g extract). H. floribunda showed antioxidant activity against DPPH radical (IC50 = 41.73 ± 0.29 μg / mL) and ferric ion Fe3 + (365 ± 20.36 μmol Eq Trolox / g ExS).