Previous studies have reported in vitro antioxidant and inhibitory activity on xanthine oxidase of Jasminum subtriplinerve Blume, Oleaceae, which suggested the potential prevention of gout and supplementary treatment. This study evaluated analgesic, anti-inflammatory, and hypouricemic effects of the 50% ethanolic extract of J. subtriplinerve (EEJS) at the oral doses of 800 and 1200 mg/kg in mice. For acute oral toxicity, after oral administration of single doses of EEJS; mortality and toxic signs in male and female mice were noticed within 72 hours and 14 days. The analgesic effect was observed in acid acetic induced writhing in mouse model within 40 minutes. The anti-inflammatory effect was determined in mice-induced edema by 1% carrageenan. The hypouricemic effect was evaluated in mice with the peritoneal injection of potassium oxonate inducing acute and chronic hyperuricemia. The results showed that there was not any toxic sign in mice given orally at the maximum dose (Dmax) of 20 g EEJS/kg. At the dose of 800 and 1200 mg/kg, EEJS did exhibit analgesic effect until 40th minute. EEJS 1200 mg/kg expressed acute anti-inflammatory effect. EEJS had no acute hypouricemic effect at the oral doses of 800 and 1200 mg/kg. When given to mice with chronic hyperuricemia, 800 mg/kg EEJS reduced 30-44% blood uric acid concentration compared to pathological group. In conclusion, EEJS did not cause any toxic sign in mice at the Dmax of 20 g/kg. This extract had analgesic and chronic hypouricemic effects at the oral dose of 800 mg/kg in mice. 

The flowers of Hylocereus undatus (Haw.) Britton & Rose have been reported in vitro antioxidant and tyrosinase inhibitory activities. This study screened preliminarily the triterpenoid constituents and evaluated in vitro tyrosinase inhibitory activity of H. undatus flowers. H. undatus flowers were harvested from Binh Thuan Province, Vietnam at four different flowering stages, and their five separated parts (stamen, pistil, petals, ovary, and sepals) were extracted with ethanol. Triterpenoids were identified in the extracts by thin-layer chromatography and Liebermann - Burchard reaction. Tyrosinase inhibitory activity was evaluated using the dopachrome method with L-tyrosine substrate and kojic acid as the positive control. Results showed that at the different flowering periods, there was the formation of different parts of the flowers. The triterpenoid compounds are the main constituents in the H. undatus flower extracts. The 70% ethanol extract from H. undatus flower at the stage of 2 - 3 days before blooming exhibited the strongest tyrosinase inhibitory activity with IC50 value of 266.4 μg/mL compared to that of 7.60 μg/mL of kojic acid. In the case of separation of flower parts, 70% ethanol extracts of each part inhibited weakly the tyrosinase enzyme. In conclusion, the present study provided information about the morphological characteristics of H. undatus flower collected from Binh Thuan Province, Vietnam. Triterpenoid was found as the main constituents of the ethanolic extracts of H. undatus flower. The 70% ethanol extract from whole H. undatus flower at the stage of 2 - 3 days before blooming exhibited strong tyrosinase inhibitory activity.