Pharmacognosy Research

ORIGINAL ARTICLE
Year
: 2010  |  Volume : 2  |  Issue : 4  |  Page : 242--246

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


RN Sriramaneni1, Ameer Z Omar3, Salman M Ibrahim3, Sadikun Amirin2, Asmawi Mohd Zaini4 
1 Department of Pharmacology, School of Pharmaceutical Sciences, Universiti Sains, Malaysia; Island College of Technology, Department of Pharmacy, Sungai rusa, Balik pulau, Pulau Pinang, Malaysia
2 Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Universiti Sains, Malaysia

Correspondence Address:
R N Sriramaneni
1003, Arlene Ct, Apt#9, Bloomington, 61701, Illinois, USA

Background: 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. Methods: DA and DDA (10 μM to 40 μM) induce relaxation in the aortic rings pre-contracted with KCl (80 mM). Results: The IC 50 values are 40.47 ± 1.44 and 37.43 ± 1.41%, respectively, and this inhibition is antagonized by increasing the Ca 2+ concentration in the Kreb«SQ»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 IC 50 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-nitro-L-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). Conclusion: 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.


How to cite this article:
Sriramaneni R N, Omar AZ, Ibrahim SM, Amirin S, Mohd Zaini A. Vasorelaxant effect of diterpenoid lactones from Andrographis paniculata chloroform extract on rat aortic rings.Phcog Res 2010;2:242-246


How to cite this URL:
Sriramaneni R N, Omar AZ, Ibrahim SM, Amirin S, Mohd Zaini A. Vasorelaxant effect of diterpenoid lactones from Andrographis paniculata chloroform extract on rat aortic rings. Phcog Res [serial online] 2010 [cited 2020 Nov 26 ];2:242-246
Available from: http://www.phcogres.com/article.asp?issn=0974-8490;year=2010;volume=2;issue=4;spage=242;epage=246;aulast=Sriramaneni;type=0