The plant material were collected from Cymbopogon nardus Rendle; Cymbopogon citratus Stapf ; Ocimum basilicum L.Each plant material was extracted for plant extracts by stems and leafs and kept in closed bottle and placed in refrigerator befored being used. Standard stock solution were prepared at 5% and 10% by dissolving in ethyl alcohol, which was used for the bioassays.