02821nas a2200241 4500008004100000245013700041210006900178260001400247300001200261490000700273520208500280653002102365653000902386653000902395653001402404653002002418653001502438100002002453700002502473700002002498700002602518856003502544 2018 eng d00aRenin and Angiotensin Converting Enzyme Inhibition of Standardized Bioactive Fractions of Hyphaene thebaica L. Mart Growing in Egypt0 aRenin and Angiotensin Converting Enzyme Inhibition of Standardiz cJune 2018 a622-6270 v103 a

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.

10aAntihypertensive10aDoum10aHPLC10aPhenolics10astandardization10aValidation1 aKhalil, Noha, A1 aMotaal, Amira, Abdel1 aMeselhy, Khaled1 akhalek, Soad, M Abdel uhttp://fulltxt.org/article/640