@article {609, title = {Renin and Angiotensin Converting Enzyme Inhibition of Standardized Bioactive Fractions of Hyphaene thebaica L. Mart Growing in Egypt}, journal = {Pharmacognosy Journal}, volume = {10}, year = {2018}, month = {June 2018}, pages = {622-627}, type = {Original Article}, chapter = {622}, abstract = {

Introduction: Hyphaene thebaica L. fruit is known in Egypt for its antihypertensive activity. However a standardized herbal extract/fraction was never prepared. Methods: A biologically guided fractionation was carried out in-vitro for the 50\% and 70\% ethanol extracts of Hyphaene thebaica L. fruit using the angiotensin converting enzyme (ACE) inhibition and renin inhibition assays. A validated reversed phase HPLC method was developed for the standardization of the active fractions. Results: The ethyl acetate fraction of the 70\% extract contained higher percentages of the three bioactive markers chlorogenic acid, quercetin and apigenin (1.940 \± 0.140\%, 2.994 \± 0.349\% and 0.612 \± 0.0354\%, respectively) relative to the ethyl acetate fraction of the 50\% extract (1.384 \± 0.157\%, 0.342 \± 0.0834\% and 0.070 \± 0.00225\%, respectively). The butanol fraction of the 70\% extract was found to possess the highest antihypertensive activity (93.69 \± 5.695 \% renin inhibition activity at 0.5 mg/mL and IC50 of 0.001436 +0.00044 mg/mL for ACE inhibition activity). A standard calibration curve for the three compounds was established at a concentration range of 0.1-50 \μg/Ml, they showed good linearity with a correlation coefficient (R2) of (1.00, 1.00 and 0.999; respectively). A high degree of precision (relative standard deviation values \<5\%) was achieved. The limits of detection for the three compounds were 0.428, 0.368 and 0.849; respectively, while the limits of quantitation were 1.29, 1.11 and 2.57, respectively. Conclusions: Current results showed that the butanol fraction of the 70\% extract revealed the highest antihypertensive activity through ACE and renin inhibition mechanisms. In addition, recorded observations concerning linearity of the used bioactive markers offer a support for the possible utility of the tested fractions as potent standardized antihypertensive drugs.

}, keywords = {Antihypertensive, Doum, HPLC, Phenolics, standardization, Validation}, doi = {10.5530/pj.2018.4.102}, url = {http://fulltxt.org/article/640}, author = {Noha A Khalil and Amira Abdel Motaal and Khaled Meselhy and Soad M Abdel khalek} }