Essay On Olive Leaves

MATERIALS AND METHODS

Plant material

Olive leaves were randomly obtained from the olive trees (Nabali Baladi variety) from a local farm in the northern part of Jordan. 25 years old trees, rain-fed only and lived in an organic way in the last 10 years. The collection of leaves on a reasonable height around the entire circumference of each tree. The collected leaves were kept in special plastic bags. Then the leaves were washed to remove dirties such as dust then drying in the dark at 20 °C and then crushed (Moulinex Miller, France) (20 mesh).

Extraction of olive leaves

The ground leaves were extracted in deionized water, 80 % acetone, 80 % ethanol, and 80 % methanol at a concentration of 20 % (w/v). The mixtures were mixed at room temperature

The emulsion of linoleic acid was prepared by mixing 0.28 g of linoleic acid (Labchem, USA), 0.28 g of Tween-20 (Labchem, USA) emulsifier and 50 ml of phosphate buffer (0.2 M, pH 7.0). The mixture is then run through the homogenizer (Ultra-Turax T25, IKA-Labortechnik, Germany). One hundred microliters of 100, 400, 800, 1600, 2000 and 2400 µg.ml-1 of OLE in methanol was mixed with linoleic acid emulsion (2.5 ml, 0.2 M, at pH 7.0) and phosphate buffer (2 ml, 0.2 M, pH 7.0). To accelerate the peroxidation reaction the mixture was left in the dark at 37

Bovine serum albumin (BSA) (Sigma-Aldrich, USA) was oxidized by a Fenton-type reaction (Kızıl, et al., 2011). 1.2 ml of the reaction mixture, containing 80 % ethanol OLE sample (50-2400 µg crude extract. ml-1), potassium phosphate buffer (20 mM, pH 7.4), BSA (4 mg. ml-1), ferric chloride (50 µM) (Labchem, USA), H2O2 (1 mM) and ascorbic acid (100 µM), was incubated at a temperature of 37 for a period of 30 minutes (Kızıl, et al., 2011). The results were expressed as the percentage of inhibition, calculated from a control test without the OLE sample. The following formula was used to calculate percentage of inhibition (Kızıl, et al.,