2.3. Plant extracts
Fresh and mature leaves of four different plant species (Acacia
albida, Argemone mexicana, Dovalis abyssinicaandProsopis juliflora)
were collected from Haramaya, eastern Ethiopia. Samples of each of
the plant specimens to be tested were air dried under shade and
ground into powder using a laboratory mill (model F3100). Fifty
grams of the pulverized plant specimen was extracted with 250 mL
water (1:5 w/v) by stirring at room temperature with a magnetic
stirrer for 2 h. The extracts were then immediately filtered by
passing through a double layer of cheese cloth and divided into two
halves. One half of each of the extracts was diluted 1:1 in distilled
water