The metabolic process and toxicology of nitrofuran metabolites in the body

7.
1.
2.
1 Metabolism in the body

NFs are rapidly decomposed in the animal body, and the stability of the original drug is only a few hours
.

The metabolic mechanism of NFs in animals is relatively complicated, and eventually they can form stable metabolites that are tightly combined with proteins.

Figure 7-1 Structure diagram of NFs and their metabolites

Taking furazolidone as an example, after entering the animal's body, it is metabolized very rapidly
.

The content of furazolidone and AOZ in tilapia muscle reached the highest 6 hours after drug withdrawal and "zero hour", respectively.
After 24 hours, the furazolidone content was lower than the detection limit, while the content of AOZ in muscle did not fall below the detection limit after 528h.

At the same time, studies have also shown that the metabolite AOZ is slowly eliminated in animals
.

After feeding pigs for 7 days and 4 weeks after drug withdrawal, AOZ can still be detected in the liver, muscle and kidney; feeding chickens for 14 days and 21 days after drug withdrawal can still detect AOZ

7.
1.
2.
2 Toxicology

NFs are toxic to livestock and poultry.
Large doses of animals or long-term continuous application can easily cause toxic reactions
.

In particular, the toxic reaction of nitrofurazone is the strongest, followed by nitrofurantoin, and the toxicity of furazolidone is one-tenth of that of nitrofurazone

At the same time, NFs are also a class of substances that can cause cancer and induce mutations in organisms
.

Toxicity studies in mice and rats have shown that furazolidone can induce breast and bronchial cancer, and there is a dose-response relationship

In recent years, studies have shown that the metabolites of NFs also have considerable toxicity and side effects.
They can induce genetic mutations in organisms, have teratogenic induction effects, and can induce cancer, so they are highly valued by people
.

The protein-bound furazolidone residue, under the weakly acidic conditions of the human stomach, the side chain can be dissociated from the protein-bound parent molecule, and AOZ is metabolized into β-hydroxyethyl hydrazine, which is mutagenic and carcinogenic The role of