Potential of antioxidants and cytotoxicity of prenylated xanthone from the twigs of Garcinia xanthochymus

Abstract

Garcinia xanthochymus Hook. F. ex T. Anderson (Clusiaceae) is a traditional herbalist remedy. Xanthones are the main phenolic compounds in Garcinia and exhibit diverse biological activities, including antioxidant and anticancer properties. These compounds can act as powerful free radical scavengers and mutant pathways of oxidative stress, as validated in earlier studies. In addition to their antioxidant activity, several xanthones have been shown to exhibit cytotoxicity in various cancer cell lines. This study was to determine the antioxidant and cytotoxic activities of xanthones isolated from G. xanthochymus twigs against cervical cancer (HeLa) cells. Two known xanthones, 1,4,6-trihydroxy-5-methoxy-7-isoprenylxanthone (1) and 1,4,5,6-tetrahydroxy-7,8-diisoprenyl-xanthone (2), were successfully isolated from G. xanthochymus twigs. The structures of these xanthones were elucidated by NMR spectroscopy (1D and 2D), and UV spectrophotometry. The cytotoxic compound 1 showed strong activity (IC50 = 2.00 μg/mL), while compound 2 was very weak. In the DPPH assay, compound 1 also showed a slightly greater antioxidant capacity (IC50 = 8.29 μg/mL) than compound 2 (IC50 = 9.09 μg/mL), indicating superior overall bioactivity.