Could humic acid relieve the biochemical toxicities and DNA damage caused by nickel and deltamethrin in earthworms (Eisenia foetida)?
The aim of the study was to determine whether humic acid (HA) prevented gene and biochemical toxic effects in earthworms (Eisenia foetida) exposed to nickel and deltamethrin (at 100 and 1 mg kg(-1), respectively) in soil. Cellular- and molecular-level toxic effects of nickel and deltamethrin in earthworms were evaluated by measuring damage to lipid membranes and DNA and the production of protein carbonyls over 42 days of exposure. Nickel and deltamethrin induced significant levels of oxidative stress in earthworms, increasing the production of peroxidation products (malondialdehyde and protein carbonyls) and increasing the comet assay tail DNA% (determined by single-cell gel electrophoresis). DNA damage was the most sensitive of the three indices because it gave a higher sample/control ratio than did the other indices. The presence of HA alleviated (in decreasing order of effectiveness) damage to DNA, proteins, and lipid membranes caused by nickel and deltamethrin. A low HA dose (0.5-1% HA in soil) prevented a great deal of lipid membrane damage, but the highest HA dose (3% HA in soil) prevented still more DNA damage. However, the malondialdehyde concentrations in earthworms were higher at the highest HA dose than at the lower HA doses. The amounts of protein carbonyls produced at different HA doses were not significantly different. The toxic effects to earthworms caused by increased oxidizable nickel concentrations could be relieved by adding HA.
Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China. shentujl@mail.zjgsu.edu.cn.
Chen-Chao
CC
Shen
Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China. shentujl@mail.zjgsu.edu.cn.
Dong-Sheng
DS
Shen
Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China. shentujl@mail.zjgsu.edu.cn.
Jia-Li
JL
Shentu
Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China. shentujl@mail.zjgsu.edu.cn.
Mei-Zhen
MZ
Wang
Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China. shentujl@mail.zjgsu.edu.cn.
Ming-Yang
MY
Wan
D000818:Animals; D020552:Comet Assay; D004249:DNA Damage; D006812:Humic Substances; D008315:Malondialdehyde / Q000378:metabolism; D009532:Nickel / Q000737:chemistry / Q000633:toxicity*; D009570:Nitriles / Q000737:chemistry / Q000633:toxicity*; D009835:Oligochaeta; D018384:Oxidative Stress; D011722:Pyrethrins / Q000737:chemistry / Q000633:toxicity*; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity*
D006812:Humic Substances; D009570:Nitriles; D011722:Pyrethrins; D012989:Soil Pollutants; C017180:decamethrin; D008315:Malondialdehyde; D009532:Nickel