Effects of Mentha Piperita Extracts on Activities of Several Enzymes of Tetranychus Cinnabarinus

摘要

The specific acaricidal mechanisms of Mentha piperita extracts were studied. The acaricidal and relative enzyme activity in Tetranychus cinnabarinus after treatment with Mentha piperita extracts at the concentration of 2mg-ml- 1 was studied by using the slide dip technique and colorimetric method, respectively. The effects of Mentha piperita extracts on the poisonous symptom and ultrastructure of the treated mites were also observed. Our results showed that fraction V from Mentha piperita extracts had stronger toxicity than others. The mites had experienced four phases namely quiescence, excitement, spasm and death after treatment, indicating that the Mentha piperita extracts were able to cause the poisonous symptom of the treated mites. Enzyme activity assay showed that the activities of glutathione-S-transferase (GSTs) and monoamine oxidase (MAO) were strongly induced whereas the activities of acetylcholine esterase (AChE) and protease were restrained after treatment. The changes of these enzymes led to the death of mites due to the destruction in the nervous transmission and digestive system. The transmission electron microscopic observations revealed that the treated mites suffered from the rupture of ultrastructure such as endoplasmic reticulum, mitochondria and nuclear membrane. These data provided useful information for the use of Mentha piperita as a novel resource of botanical acaricide.