Assessment of Cholinesterase inhibition activity of birds inhabiting pesticide exposed croplands and protected area in hot semi-arid region of Pakistan.

M Umar,S K Maloney,M Hussain

doi:10.1590/1519-6984.248842

Abstract

Acetylcholinesterase (AChE) activity levels can be used as an indicator for AChE inhibition due to pesticide poisoning in bird species. We assessed the comparative brain cholinesterase (AChE) activity level of five bird species inhabiting pesticide exposed croplands and Protected Area i.e. Deva Vatala National Park (DVNP), Bhimber by using a spectrophotometric method. AChE activity levels ranged from 56.3 to 85.9 µmol/min/g of brain tissue of birds representing DVNP. However, AChE activity levels ranged from 27.6 to 79.9 µmol/min/g of brain tissue of birds representing croplands. AChE activity levels observed in Jungle babbler, Common babbler, and Red-vented bulbul showed significant differences (P < 0.05) at two sites. However, White wagtail and Black drongo demonstrated non-significant differences (P > 0.05). Maximum inhibition was recorded in Jungle babbler (53%) followed by Common babbler (35%), Red-vented bulbul (18%), White wagtail (15%), and Black drongo (7%). The brain cholinesterase inhibition levels under-protected ecosystems (DVNP, Bhimber) and agricultural landscape suggest insecticidal contamination and its impact on avifauna diversity. The study also emphasizes on the importance of pesticide-free zones to protect the biodiversity of birds.

Highlights

Whereas a different order of AChE activity levels was observed in the bird species captured from Deva Vatala National Park (DVNP) i.e. White wagtail, Jungle babbler, Red-vented bulbul, Common babbler, and Black drongo (Table 1)
Bird species captured from the croplands of Gujrat showed a lower level of brain AChE activity than the samples collected from the Deva Vatala National Park (DVNP)
Significant differences were noted in AChE activity levels of bird species between Gujrat croplands and protected area (DVNP)

Summary

Introduction

Insecticides are an integral part of crop protection strategies, their extensive use and toxicity results in biodiversity loss, reduce the population of beneficial organisms, and destabilize ecological resilience (Krebs et al, 1999; Oliver et al, 2015; Bashir et al, 2018; Huang et al, 2018; Wyckhuys et al, 2019; Khan et al, 2020).Insects constitute the diet of about eighty percent of species of birds (Morse, 1975) and have great nutritional value (Klasing, 2000). The decrease in the insectivorous bird species has been reported from different agroecosystems (Hussain, 2005) associated with the decline in the population of insect fauna (Hallmann et al, 2014) and. Organophosphates (OPs) and carbamate compounds produce toxic effects by inhibition of the activity of AChE resulting in the accumulation of acetylcholine (Dhalla and Sharma, 2013). The poison works by inhibiting the activity of the AChE, the enzyme that breaks down acetylcholine, resulting in higher levels of acetylcholine (Hallmann et al, 2014)

Methods

Results

Discussion

Conclusion