Embryo and Fetal Toxic Effects of the Hydroethanol Extract of Urtica simensis Hochst. Ex. A. Rich Leaves in Pregnant Rats.

Introduction: Urtica simensis has been used to treat various diseases such as malaria, hypertension, diabetes, gonorrhea, gastritis, body swelling, and wound infections. However, the safety of consuming U. simensis leaves during pregnancy has not been evaluated yet. Therefore, this experimental study was conducted to evaluate the toxic effects of U. simensis leaf extract on the prenatal development of embryos and fetuses in pregnant rats. Methods: Fifty pregnant Wistar albino rats were randomly assigned to five groups of 10 gravid rats for each experiment. Groups I-III were given 70% ethanol leaf extract of U. simensis at doses of 250, 500, and 1000 mg/kg daily from 6^th to 12^th days of gestation. Groups IV-V were kept as pair-fed and ad libitum controls. The developing embryos and fetuses were retrieved on 12 days and 20 days of gestation, respectively. Embryos were evaluated for growth and developmental delays. Fetuses were also assessed for growth retardation and external and visceral anomalies. Results: In the embryonic experiment, somite numbers (p=0.001) and morphological scores (p=0.029) were significantly decreased in pregnant rats given 1000 mg/kg of U. simensis leaf extract. Embryonic developments of the caudal neural tube (CNT) (p=0.001), otic system (p=0.025), olfactory system (p=0.013), and limb buds (p=0.026) were significantly delayed in pregnant rats given 1000 mg/kg of extract. Oral administration of 500 mg/kg of U. simensis leaf extract also caused significant developmental delays in the CNT (p=0.021) and olfactory system (p=0.032). In the fetal experiment, fetal resorption (p=0.015) was significantly increased whereas crown rump length (p=0.012) and fetal weight (p=0.019) were significantly decreased in pregnant rats given 1000 mg/kg of U. simensis leaf extract. Conclusions: The embryotoxic effects of U. simensis leaf extract were evidenced by significant developmental delays. The fetal toxic effects of U. simensis leaf extract were also shown by significant decreases in fetal growth indices. Therefore, pregnant women should be well informed of the possible toxic effects of consuming U. simensis leaf during pregnancy.