Pharmacognosy Research logo
Submit
Pharmacognosy ResearchACADEMIC PUBLISHING
Article

Vasorelaxant effect of diterpenoid lactones from Andrographis paniculata chloroform extract on rat aortic rings

1★, 2, 2, 3, 2★ Corresponding author

  1. 1Department of Pharmacology, School of Pharmaceutical Sciences, Universiti Sains, Malaysia, 3Island College of Technology, Department of Pharmacy, Sungai rusa, Balik pulau, Pulau Pinang, Malaysia
  2. 2Department of Pharmacology, School of Pharmaceutical Sciences, Universiti Sains, Malaysia
  3. 3Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Universiti Sains Malaysia

CORRESPONDENCE

R. N. Sriramaneni

Department of Pharmacology, School of Pharmaceutical Sciences, Universiti Sains, Malaysia

sraghavanaidu@yahoo.com

Received: 15-05-2010; Accepted: 07-09-2010.

Volume 2, Issue 4 · pp. 242-246 · 2010 · DOI: 10.4103/0974-8490.69125

ABSTRACT

The aim of the present study is to evaluate the possible mechanism of the vasorelaxant effect of the Andrographis paniculata chloroform extract (APCE) and diterpenoids, such as, 14-deoxyandrographolide (DA) and 14-deoxy-11, 12-didehydroandrographolide (DDA), on rat aortic rings. DA and DDA (10 μM to 40 μM) induce relaxation in the aortic rings pre-contracted with KCl (80 mM). The IC50 values are 40.47 ± 1.44 and 37.43 ± 1.41%, respectively, and this inhibition is antagonized by increasing the Ca2+ concentration in the Kreb’s medium. The results indicate that APCE, DA, and DDA may have a calcium anatgonist property. APCE, DA, and DDA also relax norepinephrene (NE)-induced sustained contractions with IC50 values 41.63 ± 1.19, 49.22 ± 2.76, and 37.46 ± 1.41% and this relaxant effect is unaffected by the removal of the endothelium or by the presence of indomethacin and Nω-nitroL-arginine (L-NAME). Moreover, DA and DDA inhibit the phasic and tonic contractions induced by NE in a concentration-dependent manner and show the most potent inhibition on phasic contraction (P < 0.01). This study shows that APCE, DA, and DDA pre-treatment presents a more potent inhibition compared to post-treatment, after the tension has reached a steady state. These results suggest that the vasorelaxation of APCE, DA, and DDA direct the inhibition of the calcium influx. The vasorelaxant effect is more active in the calcium independent pathway and more sensitive in the intial stage of contraction.

KEYWORDS

Open in new tab

REFERENCES

As published

Showing references and in-text citations exactly as published.

    Cite this article

    SELECT FORMAT

    Sriramaneni, R. N., Omar, A. Z., Ibrahim, S. M., Amirin, S., & Zaini, A. M. (2010). Vasorelaxant effect of diterpenoid lactones from Andrographis paniculata chloroform extract on rat aortic rings. Pharmacognosy Research, 2(4), 242-246. https://doi.org/10.4103/0974-8490.69125

    Copyright and licence

    © 2010 Author(s)

    This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms. CC BY-NC-SA 4.0