Chronic Effects of Endosulfan on Acetylcholinesterase and Cellulase Enzyme Activity of Earthworm Eisenia Foetida

Abstract

Pesticides produces considerable effects on biochemical parameters of organisms and since enzymes allow specific reactions to proceed and collectively constitute the metabolism, studies on metabolic enzymes and proteins of earthworms may be useful biomarkers for ecotoxicological aspects. Endosulfan, belonging to the organochlorine group of pesticides on growth, reproduction and avoidance behavior of earthworm E. foetida and found that the pesticide significantly affected the parameters. Due to its used against a broad spectrum of insects and mites in agriculture and allied sectors, it is one of the most extensively used pesticides in the agricultural fields of MP, Central India. The present study has been undertaken to reveal its chronic effects on two important enzymes, i.e. Acetylcholinesterase and Cellulase of earthworm E. foetida. Both the enzymes have their own significance in earthworm physiology. The inhibition of AchE activity was found to be concentration dependent. During the exposure period of 28 days the percent of AchE activity was found as 43%, 51% and 68% at doses of 0.5, 1 and 2mg/kg endosulfan whereas, during the exposure period of 30 to 90 days same doses caused inhibition of AchE activity up to 25%, 39% and 63% after first 30 days of exposure and no significant changes or recovery of enzyme activity was observed after 90 days of exposure. Therefore, from the present findings it can be concluded that long term exposure to organochlorine pesticides could lead to severe and irreparable effects on biochemical mechanisms of earthworms. Citation Extraction of EnzymesFollowing the method of Mishra et al. [9] with slight modifications earthworms taken for enzyme estimation were kept in moist filter paper for 24hrs to void their gut contents and then homogenized (10%w/v) in 0.1M,pH 7.5 phosphate buffer. For Cellulase estimation the homogenates were centrifuged at 2,500rpm for 10 min, the supernatant fluid was removed into another centrifuge tube and were centrifuged at 3000 rpm for 5 min, the supernatant fluid was collected and used to test enzyme activity. For Acetyl Cholinesterase activity, the homogenates cooled up to 4°C were centrifuged at 10,000rpm for 10 min and the resultant supernatant was recentrifuged at 10,000rpm for 10 min (name of the centrifuge model) and supernatant was stored in ice for AchE activity [10]. Determination of cellulase activityCellulase activity was determined by following the method of Mishra et al. [9] with little modifications. Incubate 1 ml of cellulose solution, 1ml of Cellulase extract and 1 ml of phosphate buffer (pH 6.4) in a test tube for 24hrs. The enzyme activity was measured using the DNS method when 1ml of working DNS reagent was added to each test tube covered with a marble and kept in boiling water bath for 5 min, cool it and absorbance was measured against a suitable blank. The activity of cellulase was measured in terms of mgs of glucose/ hr/per mg body proteins by plotting the linear regression curve with glucose standards. Determination of acet...

Responses of Earthworms to Acetamiprid

“…In two separate investigations, Earthworm (Eisenia fetida) showed avoidance responses to exposed Dimethoate and Dichlorvos pesticides. [44,45] The results of the present study showed that the pituitary thyroid axis was impacted, as re ected by the decrease in thyroid hormones (T3 and T4) and an increase of TSH after 14 d exposure of earthworm to acetamiprid. The decrease of T3 and T4 could be due to a reduction in their synthesis and release of these hormones and their storage in the colloids due to hypothyroidism.…”