Date palm (Phoenix dacfyiifear L.) tip shoot was extracted with ethanol 80% (Et) and ethylacetate before hydrolysis with HCI (EA-1) and after hydrolysis (EA-2) to obtain flavonoids. The yield and flavonoids content of every extract were determined.
Polyphenols and flavonoids were fractionated from ethanolic extract by HPLC, eighteen compounds were identified and the major constituents were myricetin 14.48%, couman‘n 13.66 and pyrogallic acid 8.21%.
Free radical and superoxide radical scavenging activity of different extracts (Et, EA—1, EA—2) were determined using 2,2-diphenyl-1-picrylhydryzyl (DPPH') and nitro blue tetrazolium (NBT) reduction method. The obtained results revealed that ethanolic extract Et has high effect in free radical scavenging (92.12%) compared with rutin 94.75%) and superoxide radical scavenging (91.15% compared with rutin 96.54%).
The hypocholesterolemic effect of ethanolic extract was investigated on - hypercholesterolemic rats by using three concentrations from ethanolic extract (50, 75 and 100mgi'kg body weight for 30 days).
The results indicated that high flavonoids content in the extract caused significant increase in body weight gain and feed efficiency. Also, significant decrease in serum total cholesterol, total lipids. triglycerides and LDL-cholesterol and significant increase in HDL—cholesterol compared with hypercholesterolemic rats. On the other hand, high flavonoids content improvement from liver and kidney functions.