The Hypouricemic Effect of Balanophora laxiflora Extracts and Derived Phytochemicals in Hyperuricemic Mice.
The objective of this study is to evaluate the lowering of uric acid using Balanophora laxiflora extracts and derived phytochemicals on potassium-oxonate-(PO-) induced hyperuricemia in mice. The results revealed that ethyl acetate (EtOAc) fraction of B. laxiflora extracts exhibited strong xanthine-oxidase-(XOD-) inhibitory activity. In addition, among the 10 subfractions (EA1-10) derived from EtOAc fraction, subfraction 8 (EA8) exhibited the best XOD-inhibitory activity. Four specific phytochemicals, 1-O-(E)-caffeoyl-β-D-glucopyranose (1), 1-O-(E)-p-coumaroyl-β-D-glucopyranose (2), 1,3-di-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-β-D-glucopyranose (3), and 1-O-(E)-caffeoyl-4,6-(S)-hexahydroxydiphenoyl-β-D-glucopyranose (4), were further isolated and identified from this subfraction. Compounds 3 and 4 exhibited the strongest XOD-inhibitory activity compared with other compounds, and both hydrolyzable tannins were determined to be noncompetitive inhibitors according to the Lineweaver-Burk plot. On the other hand, the in vivo hypouricemic effect in hyperuricemic mice was consistent with XOD-inhibitory activity, indicating that B. laxiflora extracts and derived phytochemicals could be potential candidates as new hypouricemic agents.
Department of Forestry, National Chung Hsing University, Taichung 402, Taiwan.
Shang-Tse
ST
Ho
Yu-Tang
YT
Tung
Chi-Chang
CC
Huang
Chao-Lin
CL
Kuo
Chi-Chen
CC
Lin
Suh-Ching
SC
Yang
Jyh-Horng
JH
Wu