Abstract Mallotus repandus (MR) is contained in Thai traditional medicine recipes for antiinflammation and adaptive homeostasis. Bergenin is the bioactive constituent of MR stem. This study evaluated the in vitro antioxidant activity of bergenin and methanol, ethanol, and water extracts of MR stem prepared by maceration and soxhlet extraction by assaying 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS + ), hydroxyl ( OH), superoxide ( O 2), and nitric oxide (NO ) radical scavenging activity and ferric reducing antioxidant power. Bergenin had the highest ferric reducing power and all MR extracts showed concentration-dependent ferric reducing power. Methanol and water extracts showed superior radical scavenging activity compared to ethanol extract. The water and methanol soxhlet extracts demonstrated the highest ABTS + and OH radical scavenging activity, respectively and the macerated water extract had the lowest O 2 and NO IC50 values. Therefore, MR stem and bergenin are promising natural candidates to develop as antioxidant supplements.
… 2.1 Chemicals Bergenin (Cat. No. BP0258, purity > 98%) was a product of Biopurify Phytochemicals (Chengdu, China). …
