Effects of phytoestrogens from Curcuma comosa Roxb. on rat aorta relaxation

Abstract

The present study aims to investigate the effect of Curcuma comosa Roxb., family Zingiberaceae, containing phytoestrogens on vascular relaxation. Isolated thoracic aorta from adult female rats were incubated with C. comosa hexane extract, and an isolated diarylheptanoid, [(3R)‐1,7‐diphenyl‐(4E,6E)‐4,6‐heptadien‐3‐ol] which is the major in the extract. Both the extract and diarylheptanoid compound enhanced the endothelium‐dependent relaxation response to acetylcholine. Co‐incubation of C. comosa with ICI182,780 (ER antagonist), L‐NAME (NOS‐inhibitor) or ODQ (guanylase cyclase inhibitor) abolished the enhancing effects. C. comosa extract and the compound also increased the phosphorylation levels of serine 1177‐eNOS and serine 473‐Akt. In addition to the acute exposure, the effects of long‐term treatment (12 weeks) of C. comosa to the ovariectomized rats (OVX) were also investigated. Both C. comosa and diarylheptanoid compound treatments resumed the impairment of endothelium functions, and increased mRNA levels of both ERα and eNOS. The results suggest that the enhancing endothelium‐dependent relaxation by phytoestrogens from C. comosa is both non‐genomic and genomic effects and mediates through ER‐dependent and NO‐pathways.Supported by TRF through RGJ Ph.D. Program (Grant PHD/0094/2547) and research grant from TRF (DBG 5180020)