Biological effects of pyrimethinal on aquatic worms (Tubifex tubifex) under laboratory conditions.

Laboratory studies were conducted to determine the effects of different concentrations of pyrimethinal on protein contents, and some oxidative stress in Tubifex tubifex after an exposure of 2, 4, and 7 days. Residues of the fungicide were followed in water and in the worms. In water, pyrimethinal concentration decreased slowly (maximum -6.4 % ± 0.8 % after 2 days for 25 mg L(-1)). In the worms, it increased after 4 days and decreased thereafter. LC50 values were between 49.2 ± 0.58 and 39.5 ± 0.95 mg L(-1) depending on exposure time. The activity of catalase increased in response to the fungicide after 2 days of exposure to 25 mg L(-1) of pyrimethinal (+90 %). The highest decrease of glutathione-S-transferase activity (-29.7 %) was found after 7 days in the presence of 25 mg L(-1).

Assessing the toxicity of herbicide isoproturon on Aporrectodea caliginosa (Oligochaeta) and its fate in soil ecosystem.

This study was conducted to determine the residues of isoproturon and its metabolites, 1-(4-isopropylphenyl)-3-methylurea, 1-(4-isopropylphenyl) urea, and 4-isopropylanilin in soil and mature earthworms under laboratory conditions. Mature earthworms (Aporrectodea caliginosa) were exposed for various durations (7, 15, 30, and 60 days) to soils contaminated with isoproturon concentrations (2, 4, 6, 8, and 10 mg kg(-1) soil). The decrease in isoproturon concentration in the soil was inversely correlated to it's initial concentration. The highest concentration detected for isoproturon in earthworms was observed during the first 15 days and decreased thereafter. Acute toxicity of isoproturon was investigated; total soluble protein content and glycogen of the worms were evaluated. Levels of these parameters were related to isoproturon concentration in soil and earthworms. No lethal effect of isoproturon was observed even at the concentration of 1200 mg kg(-1) soil after 60 days of exposure. A reduction of total soluble protein was observed in all treated worms (maximum 59.54%). This study suggests the use of the total soluble protein content and glycogen of earthworms as biomarkers of exposure to isoproturon.

Quercetin and omega 3 ameliorate oxidative stress induced by aluminium chloride in the brain.

Exposure to high levels of aluminum (Al) leads to neurodegeneration, which may be mediated through over-generation of free radicals. So, in the present study, we investigated the ability of both quercetin and omega 3 to ameliorate adverse effects of Al on brain antioxidants by monitoring the main brain antioxidant enzymes on molecular and cellular levels. The obtained results indicated that Al induced oxidative stress through induction of free radical production and inhibition of activity and expression of the antioxidant enzymes catalase (CAT), glutathione reductase (GR), and glutathione peroxidase (GPx); and at the same time induced superoxide dismutase (SOD) activity and gene expression. Both quercetin (QE) and omega 3 have the ability to overcome Al-induced oxidative stress, manifested by the significant reduction in free radical concentration and induction of the activity and gene expression of the brain antioxidant enzymes.