EFFECTS OF GESTATIONAL EXPOSURE TO 2, 4-DICHLOROPHENOYACETIC ACID ON EMBRYOTOXICITY AND FETOTOXICITY IN FEMALE WISTAR RATS

Neila Marouani, Donia Cherif, Olfa Tebourbi, Mohsen Sakly, Moncef Benkhalif and Khémais Ben
Rhouma*

ABSTRACT

2,4- dichlorophenoxyacetic acid (2,4-D), a plant growth regulator, has been used worldwide as an herbicide. It has been shown to produce a wide range of adverse effects from embryotoxicity and teratogenicity to neurotoxicity on animal and human health. In the present study we investigated the effect of 2,4- D on embryo- and fetal development in female rats. Female Wistar rats received orally by intra-gastric gavage (i.g.) 100 and 200 mg of 2,4-D/kg body weight (bw) during organogenesis (days 6 to 15 of gestation). Then the reproductive parameters were determined in animals, fetuses were examined for external and skeletal malformations. Placenta was examined histologically. Reduced fetal weight, retarded fetal development, number of fetuses per mother and high incidences of dead fetuses and resorptions in treated mothers were observed. Gross morphological abnormalities, such as displayed form of oedema, lack of tail, hypotrophy, severs subdermal haemorrhage patches and hypotrophy of placenta were observed in fetuses after 2,4-D-treated mothers. A skeletal development of fetuses presented an incomplete ossification in nasal, cranium, abdominal or caudal bones in rats treated with 100 mg/kg of 2,4-D, whereas rats treated with 200 mg/kg showed absence of ossification of the sacral vertebrae compared with the control. Placental histological observations revealed a pronounced morphological alteration, with atrophy of decidual cells, a degenerated of chorionic villi and hypertrophy of blood lacuna. The present study suggests a risk to the developing embryo when the mother is exposed to a high concentration of 2,4-D during organogenesis.

Keywords: Embryotoxicity, 2,4-Dichlorophenoxyacetic acid, Malformations, Skeletal, Placenta.