Inhibition of thyroid peroxidase by Myrcia uniflora flavonoids.
Chem Res Toxicol
; 19(3): 351-5, 2006 Mar.
Article
em En
| MEDLINE
| ID: mdl-16544938
ABSTRACT
Thyroid peroxidase (TPO), the key enzyme in thyroid hormone biosynthesis, is inhibited by dietary flavonoids; thus, a high consumption of plants containing inhibitory flavonoids may affect thyroid function and lead to hypothyroidism. In this work, TPO inhibition by the aqueous partition of Myrcia uniflora and its isolated compounds has been evaluated. The aqueous partition of the methanolic extract of M. uniflora is able to inhibit TPO activity in vitro. Two known flavonoids were isolated and characterized by mass spectrometry and (1)H NMR from plant extracts mearnsitrin and myricitrin. The degree of TPO inhibition produced by the aqueous solution of the flavonoids was very high, with a 50% inhibition of the original TPO activity (IC(50)) obtained at 1.97 microM mearnsitrin and at 2.88 microM myricitrin. These results suggest that the indiscriminated consumption of M. uniflora pharmaceutical products allied to the nutritional deficiency of iodine might contribute to the development of hypothyroidism and goiter.
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Base de dados:
MEDLINE
Assunto principal:
Plantas
/
Flavonoides
/
Inibidores Enzimáticos
/
Iodeto Peroxidase
Idioma:
En
Revista:
Chem Res Toxicol
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Brasil