@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} } @article {1506, title = {Antihyperglycemic Activity and Standardization of the Bioactive Extract of Cleome droserifolia Growing in Egypt}, journal = {Pharmacognosy Journal}, volume = {6}, year = {2014}, month = {2nd July 2014}, pages = {15-21}, type = {Original Article}, abstract = {

Background:Cleome droserifolia herb is well known in the Egyptian folk medicine for the treatment of diabetes. However, a standardized active extract of the herb was never prepared for incorporation into a pharmaceutical dosage form. Materials and Methods: Comparative high performance liquid chromatography (HPLC) chromatographic profi les were established in order to study the ethnopharmacological use of the antihyperglycemic herb using a validated reversed phase- HPLC method which was developed for standardization of the active aqueous extract. A biologically guided fractionation of the antihyperglycemic aqueous extract was carried out in vivo using alloxan induced diabetic rats. Results: The aqueous extract contained the highest percent of the total active fl avonol glycosides (78.20\%) compared to the 70\% and 50\% ethanolic extracts (51.17 and 42.66\%, respectively). The aqueous extract and its ethyl acetate fraction possessed the highest antihyperglycemic activities. A standard calibration curve, established for the major bioactive methoxylated fl avonol glycoside (kaempferol-4\’-methoxy-3,7-dirhamnoside) at a concentration range of 44-174 \μg/ml, showed good linearity with a correlation coeffi cient (R2) of 0.998. The recovery of the method was 100.5\%. A high degree of precision (relative standard deviation values \<5\%) was achieved. The limits of detection and quantifi cation were 0.01 and 0.02 \μg/ml, respectively, indicating the sensitivity of the method. Conclusion: The aqueous extract contained the highest percent of the total active fl avonol glycosides. The extract, standardized to contain not \<1.5 \± 0.06\% of kaempferol-4\’-methoxy- 3,7-dirhamnoside, was tested at three different dose levels showing a 63.3\% activity of that of metformin at100 mg/kg body weight. Furthermore, it raised the blood insulin level by 146.26\% at this dose level.

Key words: Antihyperglycemic, Cleome droserifolia, high performance liquid chromatography standardization, kaempferol-4\’-methoxy-3,7-dirhamnoside, validation.

}, keywords = {7-dirhamnoside, Antihyperglycemic, Cleome droserifolia, high performance liquid chromatography standardization, kaempferol-4{\textquoteright}-methoxy-3, Validation}, author = {Amira Abdel Motaal and Shahira M. Ezzat and Hesham El-Askary} }