Research Specifications

One of the challenges in plant materials as a source of pesticide is their complex mode of action. In most of the botanicals the mode of action is unknown or plant extracts affects insects by more than one mode of actions. In this study, anti acetylcholinesterase (CHE) activity of different extracts of Falcaria vulgaris and Apium graveolens were studied. Potato tuber moths (Phthorimaea operculella) were reared in controlled condition on potato tubers. Forth larval instars whole body was homogenated and centrifuged at 10000 rpm for 10 min at 4 􁤪C, then, the supernatant were used as crude enzyme source. Hexane, ethylacetate and methanolic extract of plants prepared by maceration method. Enzyme activity and inhibitory were measured by a special diagnostic kit (Biorexfars-Iran). Butyrylthiocholin is the substrate of CHE which changes to Butyric acid and thiocholine in the present of Cholinesterase. Absorbance was recorded at 405 nm. For inhibitory activity assays, enzymes were pre incubated with plant extracts and imidacloprid (LC30 and LC50) as positive control. The results revealed that, the inhibitory activity of plant extracts was compatible with positive control (Imidacloprid). CHE inhibition increased with dose dependent manner and the most inhibition recorded at LC70 value of hexane extract of F. vulgaris and A. graveolens (71.4 and 64 %, respectively). LC70 values of ethylacetate extract of F. vulgaris and A. graveolens inhibited CHE activity by 62.6 and 57.2 %, respectively. Methanolic extracts inhibited CHE activity by 42.5 and 58 % in LC70 values. Ethylacetate, methanol and hexane extracts of F. vulgaris in LC30 values inhibited CHE activity by 3.2, 30.5 and 40.6 %, respectively. Ethylacetate, methanol and hexane extracts of A. graveolens inhibited CHE by 55.2, 54.5 and 39.5 %, respectively. It seems that acute toxicity of F. vulgaris and A. graveolens extracts against PTM larvae is related to the CHE inhibitory potential of these compounds.