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Detection of borderline dosage of malathion intoxication in a rat's brain
S Varol1, S K Başarslan, U Fırat
1Department of Neurology, Faculty of Medicine, Dicle University, Diyarbakır, Turkey. kaganbasarslan@hotmail.com.
Objective:
Humans and other animals are liable to expose to low doses of malathion (MAL). However, experimental studies on its toxic threshold dose and toxic low-dose effects have not been conducted. The aims of this study were to detect the initiation of the toxic effects of sub-acute low doses (2.5, 5, and 10 mg/kg) of MAL by immunohistochemical and biochemical parameters in rat brain.
Materials And Methods:
Twenty-eight rats were randomly assigned into four groups (n=7) including control and three different amounts of MAL-exposed groups (2.5, 5, and 10 mg/kg).
Results:
On immunohistochemical examination, the number of caspase-3-positive cells in all MAL-exposed groups was significantly higher than in the control group. Consistent with this, the total antioxidant capacity, total oxidant status, and the levels of superoxide dismutase, malondialdehyde, and paraoxanase activity were significantly different in the 5 and 10 mg/kg MAL-exposed groups compared with the control group. Additionally, the total oxidant status and malondialdehyde levels were significantly higher in the 5 and 10 mg/kg MAL-exposed groups compared with those in the 2.5 mg/kg MAL-exposed group.
Conclusions:
Our results indicate that over 5 mg/kg MAL exposure may result in dose-dependent oxidative stress, increased caspase-3 activity, and launching to the toxic effects in rat brain.
Insights
Low-dose malathion (MAL) exposure in rats shows dose-dependent toxicity. Doses over 5 mg/kg MAL significantly increase oxidative stress and caspase-3 activity in the brain, indicating potential neurotoxic effects.
Area of Science:
- Neuroscience
- Toxicology
- Biochemistry
Background:
- Malathion (MAL) is an organophosphate insecticide widely used globally.
- Low-dose exposure to MAL is common in humans and animals.
- Limited data exists on the toxic threshold and low-dose effects of MAL.
Purpose of the Study:
- To investigate the toxic effects of sub-acute low doses of malathion (MAL) in the rat brain.
- To determine the dose-dependent neurotoxic threshold of MAL using immunohistochemical and biochemical markers.
Main Methods:
- Twenty-eight rats were divided into four groups: control and MAL-exposed (2.5, 5, 10 mg/kg).
- Immunohistochemical analysis was performed to detect caspase-3 positive cells.
- Biochemical assays measured antioxidant capacity, oxidant status, superoxide dismutase, malondialdehyde, and paraoxanase activity.
Main Results:
- All MAL-exposed groups showed significantly increased caspase-3 positive cells compared to controls.
- Significant alterations in oxidative stress markers (total antioxidant capacity, total oxidant status, superoxide dismutase, malondialdehyde, paraoxanase activity) were observed in the 5 and 10 mg/kg MAL groups.
- Higher doses (5 and 10 mg/kg) of MAL resulted in significantly elevated total oxidant status and malondialdehyde levels compared to the 2.5 mg/kg group.
Conclusions:
- Malathion exposure above 5 mg/kg induces dose-dependent oxidative stress in the rat brain.
- Increased caspase-3 activity suggests MAL initiates apoptotic pathways at these doses.
- These findings highlight potential neurotoxic risks associated with low-dose malathion exposure.
