The Dual Actions of Paederia scandens Extract as a Hypouricemic Agent: Xanthine Oxidase Inhibitory Activity and Uricosuric Effect

The structures presented in Fig. 1 have to be corrected as shown here. These compounds were isolated and identified as reported before [1], [2], [3], [4], [5].

In the present paper it was concluded that oral administration of a P. scandens extract possessed hypouricemic effects. Nevertheless, considering the experimental set up, this wording could be misleading since the treatment already started before the disease was included. Most species used for pharmacological experiments have rather low blood levels of uric acid. Experimental hyperuricamia can be induced by inhibition of the enzyme uricase. In most species uricase metabolizes uric acid to allantoin which easily can be excreted.

Potassium oxonate blocks uricase and increases endogenously synthesized uric acid. This increase is blocked by compounds like allopurinol. Here animals were pretreated over a 14 days period with various doses of an extract prepared from the arial parts of P. scandens. On day 14 the animals received a single dose injection of the uricase inhibitor potassium oxonate. The results clearly showed that pretreatment of mice with a P. scandens extract could prevent an increase in uric acid levels. Thus, the extract seems to have beneficial effects in the prevention of gout attacks.

References

¹ Inouye H, Inouye S, Shimokawa N, Okigawa M. Studies on monoterpene glucosides. VII. Iridoid glucosides of Paederia scandens. Chem Pharm Bull 1969; 17: 1942 – 8

² Inouye H, Inouye S, Shimokawa N, Okigawa M. The iridoidglucosides from Paederia scandens (Lour.) Merrill var. Mairei (Léveillé) Hara. Tetrahedron Lett 1968; 6: 683 – 8

³ Inouye H, Kuobe K, Huial M. Studies on monoterpene glucosides and related natural products. XXXI. Gas chromatography and gas chromatography-mass spectrometry of iridoid and secoiridoid glucosides. J. Chromatogr 1976; 118: 201 – 16

⁴ Yangmin M, Yuan M. Study progress on chemical constituents of Paederia scandens. Shaanxi Forest Science and Technology. 2002; 2: 73 – 6

⁵ Zou X, Peng S, Liu X, Bai B, Ding L. Sulfur-containing iridoid glucosides from Paederia scandens. Fitoterapia 2006; 77: 374 – 7

Fig. 1 Chemical structure of asperuliside (1), paederoside (2) and scandoside (3)