For investigations, methanolic plant extracts were prepared by soaking 50 mg of dry powder plant material from each plant species in methanol (10 ml of methanol /mg of plant material) with stirring for 48 h and then filtered through double layers of muslin, centrifuged at 9000 rpm/min for 10 min and finally filtered again through Whatman filter paper No. (41) to remove leaf debris and obtain a clear filtrate. The filtrates were evaporated and dried under reduced pressure and temperature below 40°C. The yield of the dry residues in relation to the starting plant material was calculated.