Abstract
BACKGROUND: Iron overload and inflammation are severe conditions that can lead to various chronic diseases. However, the current iron chelator drugs have their limitations. The phytochemical compounds from herbals, such as brazilin, the major active compound in Caesalpinia sappan Linn., have significant therapeutic potential in various chronic diseases. Our study was designed to examine the effect of brazilin on iron chelating properties, antioxidant activity in hepatocytes, and anti-inflammatory potential in macrophages. METHODS: This study focused on the isolation, purification, and evaluation of brazilin, the principal bioactive constituent found in C. sappan wood. Brazilin was extracted via methanol maceration followed by column chromatography purification. The purified compound was characterized using high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS). The antioxidant potential of brazilin was assessed by in vitro assays, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzthiazolin-6-sulfonic acid (ABTS), and ferric-reducing antioxidant power (FRAP). Furthermore, its cellular antioxidant activity was evaluated using hydrogen peroxide-induced oxidative stress in the hepatocellular carcinoma cell line (Huh-7). The iron-chelating capacity of brazilin was determined spectrophotometrically, and Job's plot method was used to elucidated the stoichiometry of the iron-brazilin complex formation. The anti-inflammatory properties of brazilin were investigated in lipopolysaccharide (LPS)-stimulated macrophages (RAW 264.7). Nitric oxide (NO) inhibition was quantified using the Griess reagent, while the expression levels of pro-inflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), were evaluated by RT-qPCR. RESULTS: The results demonstrated that brazilin exhibited potent antioxidant activity in vitro and hepatocytes in a concentration-dependent manner. It also showed anti-inflammatory activity, in which NO production was significantly reduced and IL-6 and TNF-α expression in LPS-induced macrophages were repressed. Furthermore, it can bind ferric and ferrous ions. Brazilin acts as a bidentate iron chelator that forms a complex with iron in a 2:1 ratio, and two water molecules are used as additional chelators in this complex. CONCLUSIONS: Our findings have significant implications. Brazilin can potentially alleviate the harmful effects of iron-induced oxidative stress and inflammatory disorders.