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Methylene blue attenuates acute liver injury induced by paraquat in rats
Jun-Liang Chen1, Li Dai2, Peng Zhang1
1Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu 214122, China.
Abstract:
Paraquat (PQ) poisoning often leads to severe oxidative liver injury. Recent studies have reported that methylene blue (MB) can prevent oxidative stress-induced diseases. This study tested the hypothesis that MB treatment reduced acute liver injury induced by PQ in rats. Adult male Sprague-Dawley (SD) rats were randomly divided into four groups: (1) normal group, (2) MB group (2mg/kg i.p.), (3) PQ group (35 mg/kg i.p.) and (4) PQ+MB group (MB 2mg/kg i.p. administrated 2h after PQ). We evaluated the changes of liver histopathology, serum liver enzymatic activities, oxidative stress, heme oxygenase-1 expression, and mitochondrial permeability transition. The rats were injected with PQ produced liver injury, evidenced by histological changes and elevated serum alkaline phosphatase and alanine transaminase levels; PQ also led to oxidative stress, an increase of malondialdehyde content and mitochondrial permeability transition pore opening. Pathological damage and all of the above mentioned markers were reversed in the animals treated with MB than in those who received PQ alone. Meanwhile, MB significantly increased the contents of superoxide dismutase, adenosine triphosphate and the expression of heme oxygenase-1. In conclusion, MB had a protective effect against PQ-induced hepatic damage in rats. The mechanisms of the protection seem to be the inhibition of mitochondrial permeability transition opening and the increase of heme oxygenase-1 expression.
Insights
Methylene blue (MB) protects against paraquat (PQ)-induced liver injury in rats. MB treatment reversed PQ-induced damage by reducing oxidative stress and improving liver function markers.
Area of Science:
- Toxicology
- Hepatology
- Pharmacology
Background:
- Paraquat (PQ) poisoning is a significant cause of acute liver injury, characterized by severe oxidative stress.
- Methylene blue (MB) has demonstrated potential in mitigating diseases associated with oxidative stress.
Purpose of the Study:
- To investigate the protective effects of methylene blue (MB) against paraquat (PQ)-induced acute liver injury in a rat model.
- To elucidate the underlying mechanisms of MB's protective action, focusing on oxidative stress and mitochondrial function.
Main Methods:
- Adult male Sprague-Dawley rats were assigned to four groups: control, MB alone, PQ alone, and PQ+MB.
- Evaluations included liver histopathology, serum liver enzymes (ALT, ALP), oxidative stress markers (MDA, SOD), ATP levels, heme oxygenase-1 (HO-1) expression, and mitochondrial permeability transition (MPT).
Main Results:
- PQ administration induced significant liver damage, evidenced by histological alterations and elevated liver enzymes.
- PQ exposure increased oxidative stress markers and MPT pore opening, while decreasing ATP levels.
- MB treatment significantly attenuated PQ-induced liver injury, reversed biochemical markers, reduced oxidative stress, and increased HO-1 expression and ATP levels.
Conclusions:
- Methylene blue exhibits a significant protective effect against paraquat-induced hepatic damage in rats.
- MB's protective mechanisms involve the inhibition of mitochondrial permeability transition pore opening and the upregulation of heme oxygenase-1 expression.
