The methanol extract of Euonymus laxiflorus, Rubia lanceolata and Gardenia jasminoides inhibits xanthine oxidase and reduce serum uric acid level in rats.[Pubmed: 24845958]

Chinese herbal medicinal plants, Euonymus laxiflorus (EL), Rubia lanceolata (RL) and Gardenia jasminoides (GJ), have been used wildly to treat arthritis and gout in Taiwan for decades. To understand the beneficial effects of these three plants, their xanthine oxidase (XO) inhibitory activity in vitro and hypouricaemic activity in vivo were investigated. Our results suggested that methanol extracts were better than water extracts for inhibition of XO activity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, except the water extract of GJ, which exhibited the strongest radical scavenging effect. In animal study, the serum urate level was significantly decreased after oral administration of higher dose (0.39g/kg) methanol extract of the mixture of three plants (ERG). In addition, methanol extract of ERG reduced the pain reaction time in the second phase of formalin induced pain. The results provide useful information on the pharmacological activities of these plants for the potential in treating hyperuricemia.

Laxifolone A suppresses LPS/IFN-gamma-induced NO synthesis by attenuating NF-kappaB translocation: role of NF-kappaB p105 level.[Pubmed: 15971121]

Laxifolone A is a triterpene isolated from Euonymus laxiflorus Champ. Exposure of RAW264.7 macrophages to laxifolone A concentration-dependently suppressed lipopolysaccharide/interferon-gamma (LPS/IFN-gamma)-induced nitrite production (IC50 = 0.37 +/- 0.05 microM), inducible NO synthase (iNOS) protein, and iNOS mRNA expression. Translocation of nuclear factor-kappaB (NF-kappaB) into the nucleus with subsequent activation of iNOS gene transcription is essential in NO signaling. Western blot analysis indicated that the cytosolic NF-kappaB/p65 was obviously decreased after LPS/IFN-gamma stimulation for 30 min and this phenomenon could be reversed by laxifolone A. Similarly, a time-related NF-kappaB/p65 nuclear translocation induced by LPS/IFN-gamma was diminished in the presence of laxifolone A. However, laxifolone A failed to interfere in LPS/IFN-gamma-evoked IkappaB degradation. Our results also showed that LPS/IFN-gamma-stimulation resulted in the degradation of NF-kappaB p105, the NF-kappaB precursor, and laxifolone A treatment significantly counteracted this effect. Furthermore, laxifolone A itself was able to enhance NF-kappaB p105 protein expression. In summary, these results suggest that inhibition of NF-kappaB p105 degradation in cytoplasm may participate in the abrogation of LPS/IFN-gamma-induced NF-kappaB translocation and subsequent NO synthesis by laxifolone A.

A novel NO-production-inhibiting triterpene and cytotoxicity of known alkaloids from Euonymus laxiflorus.[Pubmed: 12713415]

A new triterpene, laxifolone A (1), four known sesquiterpene alkaloids, ebenifoline E-II (2), carigorinine E (3), euojaponine C (4), and emarginatine E (5), and six triterpenoids, 3-hydroxyolean-12-en-22,29-gamma-lactone, 3,11-dioxo-beta-amyrene, 3beta,22alpha-dihydroxyolean-12-en-29-oic acid, 28,29-dihydroxyfriedelan-3-one, 29-hydroxy-3-oxo-D:A-friedooleanan-28-oic acid, and putranjivadione, were isolated from the stems and leaves of Euonymus laxiflorus. Structural elucidations of these compounds were established by spectral analysis. Compound 1 displayed significant nitric oxide (NO) inhibitory effect.