Monocrotaline

Crotalaria juncea Da220020

Biosynthesis route of retronecine

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Biosynthesis of MC

Biotransformation of monocrotaline in rats 3

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Monocrotaline mechanism of action in organism

Monocrotaline is a toxic pyrrolizidine alkaloid found in the plant species of the genus Crotalaria. Crotalaria is a large genus of plants known commonly as rattlepods or rattlebox, which belongs to the Fabaceae family, also known as the legume, pea, or bean family. Monocrotaline is of significant interest in the fields of toxicology, pharmacology, and medicine due to its potent toxic effects, particularly on the liver and lungs.

Chemical Structure and Properties

Monocrotaline is a secondary metabolite with a complex chemical structure characterized by a necine base structure typical of pyrrolizidine alkaloids. Its molecular formula is C_16H_23NO_6, indicating it contains 16 carbon atoms, 23 hydrogen atoms, one nitrogen atom, and six oxygen atoms. This compound is highly toxic, especially when metabolized in the liver to its active pyrrolic metabolites, which can bind to cellular macromolecules such as DNA, leading to cell damage and death.

Toxicity and Health Effects

The primary concern with monocrotaline is its hepatotoxicity (liver toxicity) and pneumotoxicity (lung toxicity). In the liver, its metabolites can cause veno-occlusive disease, a condition where small veins in the liver are obstructed, leading to liver damage and, in severe cases, liver failure. In the lungs, monocrotaline can induce pulmonary hypertension, a serious condition characterized by high blood pressure in the pulmonary arteries, leading to heart failure and death if untreated.

Mechanism of Action

The toxic effects of monocrotaline are primarily due to its metabolism by cytochrome P450 enzymes in the liver, producing reactive metabolites that form adducts with DNA and proteins. This leads to cellular damage, oxidative stress, and the activation of signaling pathways that result in inflammation, fibrosis, and vascular remodeling in the lungs.

Uses in Research

Despite its toxicity, monocrotaline has been used in scientific research as a tool to study the mechanisms of pulmonary hypertension and liver disease. Animal models treated with monocrotaline can mimic the clinical features of these diseases, providing valuable insights into their pathophysiology and potential therapeutic targets.

Prevention and Treatment

Exposure to monocrotaline is primarily through ingestion of contaminated grains or herbal remedies containing Crotalaria species. Prevention involves controlling the spread of these plants in fields and ensuring that food and herbal products are free from contamination. There is no specific antidote for monocrotaline poisoning, and treatment is supportive, focusing on managing symptoms and preventing further damage.

Conclusion

Monocrotaline is a potent toxin with significant health implications for humans and animals. Its study has contributed to our understanding of liver and lung diseases, highlighting the importance of natural toxins in medical research and public health.

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