Lonicera hypoglauca inhibits xanthine oxidase and reduces serum uric acid in mice.
Xanthine oxidase (XOD) catalyzes the oxidation of hypoxanthine to xanthine and then to uric acid, and is a key enzyme in the pathogenesis of hyperuricemia. The ability of extracts of Lonicera hypoglauca (Caprifoliaceae) to inhibit XOD was investigated in this study. An ethanol extract (LH-crude) of the leaves of L. hypoglauca and its derived EtOAc soluble sub-fractions (LH-EA) significantly inhibited XOD activity, with IC50 values for LH-crude and LH-EA of 48.8 and 35.2 microg/mL. Moreover, LH-EA reduced serum urate levels IN VIVO in a potassium oxonate-induced hyperuricemic mouse model, by 70.1% and 93.7% of the hyperuricemic untreated group at doses of 300 and 500 mg/kg of LH-EA, respectively. Finally, we used bioactivity-guided fractionation to isolate a new bisflavonoid, loniceraflavone, which showed significant inhibition of XOD (IC50=0.85 microg/mL). These results suggest that L. hypoglauca and its extracts may have a considerable potential for development as an anti-hyperuricemia agent for clinical application.
Chien
Shih-Chang
SC
School of Chinese Medicine Resources, China Medical University, Taichung, Taiwan.
Yang
Chen-Wei
CW
Tseng
Yen-Hsueh
YH
Tsay
Hsin-Sheng
HS
Kuo
Yueh-Hsiung
YH
Wang
Sheng-Yang
SY
D000818:Animals; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology; D033461:Hyperuricemia / Q000097:blood / Q000139:chemically induced* / Q000188:drug therapy; D031239:Lonicera / Q000737:chemistry*; D008297:Male; D008516:Medicine, Chinese Traditional; D051379:Mice; D008813:Mice, Inbred ICR; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D014527:Uric Acid / Q000097:blood*; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*
D005419:Flavonoids; D010936:Plant Extracts; C540621:loniceraflavone; D014527:Uric Acid; D014969:Xanthine Oxidase