Effects Of Extracts From Paederia Scandens On Experimental Hyperuricemia

Hyperuricemia is a metabolic disorder associated with abnormal amounts of uric acid in the body caused by overproduction or low excretion,resulting in gouty arthritis and uric acid nephrolithiasis.Extracts from Paederia Scandens(EPS) was extracted from Paederia scandens(Lour.) Merrill.The essential components of EPS are asperuloside, paederoside,scandoside,γ-sitosterol,essential oil et al.Paederia scandens was described to use as analgesic,anti-inflammatory,and to treat bruise and rheumatism through eliminating heat and excreting dampness in terms of traditional Chinese medicine.It has not been reported about the hypouricemic effect of EPS.This study is intended to investigate the hypouricemic effect of EPS.The main results are as follow:1 Effects of EPS on normal miceEPS(6.30,3.15,1.57 g/kg,ig,qd×14d) had no significant effects on serum uric acid level,the XO activity and the body weight of normal mice.2 Effects of EPS on hyperurieemie mouse induced by yeastThe experimental animal model of hyperuricemia induced by i.g.of yeast(30 g/kg,ig, qd×14d) was adopted.The results showed that,EPS(6.30,3.15,1.57 g/kg,ig,qd×14d) could reduce serum uric acid level to the normal,and decrease in the xanthine oxidase activity in the mouse liver was significantly.These findings indicate that EPS could effectively inhibit the xanthine oxidase activity and show hypouricemic effect. 3 Effects of EPS on hyperuricemic mouse induced by yeast and potassium oxonateThe experimental animal model of hyperuricemia induced by i.g.of yeast(30 g/kg,ig, qd×14d) and i.p.of potassium oxonate(300 mg/kg,ip,14^th,qd) was adopted.The results showed that,EPS(6.30,3.15,1.57 g/kg,ig,qd×14d) could reduce serum uric acid level,and decrease in the xanthine oxidase activity in the mouse liver was obvioustly.EPS(6.30,3.15,1.57 g/kg,qd×14d) had no effct on body weight,serum Cre and BUN.EPS(6.30 g/kg,qd×14d) could reduce the ADA activity.These findings indicate that the hypouricemic effect of EPS may be caused by inhibition of XO and ADA activity.And EPS can be used safely.4 Effects of EPS on hyperuricemic rat induced by potassium oxonateThe experimental animal model of hyperuricemia induced by i.p.of potassium oxonate (200 mg/kg,ip,14^th,qd) was adopted.The results showed that,EPS(4.50,2.25,1.125 g/kg,ig,qd×14d) could reduce serum uric acid level,and decrease in the xanthine oxidase activity in the mouse liver was significantly.EPS(4.50,2.25,1.125 g/kg,ig,qd×14d) had no effct on serum and liver ADA activity.EPS(4.50,2.25 g/kg,ig,qd×14d) could obviously increase the fractional excretion of urate in the hyperuricemic rats. These results suggest that the hypouricemic effect is partly due to inhibition of XO activity in rat liver and enhancement urate clearance.5 Inhibitory activities of EPS on xanthine oxidase in vitroThe results showed that,EPS(1.60,0.80,0.40 g/L) could decrease the activity of XO. Lineweaver-burk analysis of the enzyme kinetics data showed that the inhibition of xanthine oxidase by EPS was of a mixed type.These results suggest EPS can inhibit the activity of xanthine oxidase in a concentration-dependent manner,with an IC₅₀ value of 1.00 g/L.Conclusion:EPS exhibited hyporuicemic effect on hyperuricemia model animals,and its mechanisms might be associated with inhibition of XO activity and enhancement of urate clearance.