Effects of phenylpropanoid and iridoid glycosides on free radical-induced impairment of endothelium-dependent relaxation in rat aortic rings


Ismailoglu U., Saracoglu I., Harput U., Sahin-Erdemli I.

JOURNAL OF ETHNOPHARMACOLOGY, vol.79, no.2, pp.193-197, 2002 (Peer-Reviewed Journal) identifier

  • Publication Type: Article / Article
  • Volume: 79 Issue: 2
  • Publication Date: 2002
  • Doi Number: 10.1016/s0378-8741(01)00377-4
  • Journal Name: JOURNAL OF ETHNOPHARMACOLOGY
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.193-197
  • Keywords: phenylpropanoid glycosides, iridoids, Phlomis pungens var. pungens, rat aorta, endothelium dependent relaxation, electrolysis, free radical scavenger activity, PROTECTION

Abstract

The protective effect of phenylpropanoid glycosides, forsythoside B and alyssonoside, and the iridoid glycoside lamiide, isolated from the aerial parts of Phlomis pungens var. pungens, against free radical-induced impairment of endothelium-dependent relaxation in isolated rat aorta was investigated. Aortic rings were exposed to free radicals by the electrolysis of the physiological bathing solution. Free radical-induced inhibition of the endothelium-dependent relaxation in response to acetylcholine was countered by incubation of the aortic rings before electrolysis with the aqueous extract (100 mug/ml), phenylpropanoid fraction (100 mug/ml) and iridoid fraction (150 mug/ml) of P. pungens var. pungens. Major components of the phenylpropanoid fraction forsythoside B and alyssonoside also prevented the inhibition of the acetylcholine response, at 10(-4) M concentration. However, the major component of iridoid fraction lamiide was found ineffective at the same concentration. The protective activity of phenylpropanoid glycosides against the free radical-induced impairment of endothelium-dependent relaxation may be related to their free radical scavenging property. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.