Figure 5.

Oxidation of Fe²⁺ by aqueous (A) and ethanolic (B) extracts from the leaves of R. echinus (1–60 μg/mL). The extracts (30–120 μg/mL) were incubated with FeSO₄ (110 μM) for 10 min. Then, ortho-phenanthroline was added and the absorbance of the reaction mixture was measured at 0, 10 and 20 min following its addition. After the last reading (at 20 min), 5 mM ascorbic acid (AA) was added to the reaction mixture, and the absorbance was read again after 5 min (at 25 min), 10 min (at 30 min) and 20 min (at 40 min) (see Table 1 for details). Values represent the mean ± SEM of three independent experiments performed in duplicate. AERE, aqueous extract of R. echinus; EERE, ethanolic extract of R. echinus.