Evaluation Of Anti-Hypertensive And Vasorelaxant Effects Of Phaleria Macrocarpa Extracts

Simple item page
dc.contributor.authorAltaf, Rabia
dc.date.accessioned2016-08-03T03:55:23Z
dc.date.available2016-08-03T03:55:23Z
dc.date.issued2015-04
dc.description.abstractThe present study investigated the anti-hypertensive effect of Phaleria macrocarpa extracts in spontaneously hypertensive rats (SHR), Wistar Kyoto (WKY) rats and the vasorelaxant effect of the extracts in isolated rat aorta of Sprague Dawley rats using bioactivity guided approach. The dried fruits were extracted sequentially in solvents with different polarity. The anti-hypertensive effect of the graded doses of crude extracts was evaluated in SHR by non-invasive blood pressure method. Petroleum ether (PE) and water extracts (WE) significantly reduced the blood pressure on 14th day of treatment (15.9 and 27.7% respectively, p<0.05) suggesting profound anti-hypertensive activity of these two extracts. WE reduced both the mean arterial pressure (MAP) and heart rate (HR) in WKY by 16.3 and 4.3% respectively (p<0.05). WE inhibited norepinephrine (NE) induced elevation of MAP and HR in WKY with less effects against the pressor responses to isoprenaline (p<0.05) suggesting its possible alpha-antagonistic and calcium channel blocking effect. WE significantly inhibited MAP, HR and pulse wave velocity (PWV) when compared with control group (p<0.05). An oral administration of WE to SHR for 14 days significantly inhibited the plasma level of angiotensin converting enzyme (p<0.05). Moreover, it elevated plasma nitric oxide (NO) level with respect to control group (p<0.05) supporting its effect on PWV as NO directly reduces the stiffness in arteries determined by the values of PWV. In the in vitro study, PE and WE inhibited NE induced contraction in rat aortic rings by 40 and 58% respectively (p<0.05). The active WE fraction WF-4 showed considerable vasorelaxant effect (42.8% relaxation, p<0.05). The sub-fraction SF-2 of WF-4 inhibited contraction in rat aorta up to 44.5% (p<0.05). SF-2 elicited vasorelaxation in aortic rings with both denuded as well intact endothelium. However, incubation of intact aortic rings with L-NAME and indomethacin significantly blocked the vasorelaxant effect of SF-2, suggesting the involvement of NO and prostacyclin pathway respectively. Moreover, SF-2 was found to exhibit its vasorelaxant effect in denuded aortic rings pre-contracted with NE by inhibiting calcium induced contraction in calcium free Kreb’s solution suggesting blockage of calcium influx through receptor operated calcium channels (ROCC) (p<0.05). When subjected to high performance liquid chromatography (HPLC) analysis, SF-2 was found to contain rutin, mangiferin and gallic acid (0.04%, 0.21% and 0.04% respectively) in SF-2. This study supports the potential of use of Phaleria macrocarpa extracts to treat hypertension in traditional medicine.en_US
dc.identifier.urihttp://hdl.handle.net/123456789/2370
dc.subjectPharmacyen_US
dc.titleEvaluation Of Anti-Hypertensive And Vasorelaxant Effects Of Phaleria Macrocarpa Extractsen_US
dc.typeThesisen_US
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Pusat Pengajian Sains Farmasi - Tesis