Effect of maternal oral gavage of <i>Equisetum ramosissimum</i> extract on neural tube development in Sprague-Dawley rats: Morphological evaluations and a light microscopic study

Consumption of Equisetum ramosissimum extract during pregnancy is common. However, very little information is available regarding its effect on fetal brain development, even though it is known that Equisetum ramosissimum has thiaminase activity, which can induce thiamine deficiency. The aim of this study was to determine the effects of Equisetum ramosissimum extract on fetal neural tube development in pregnant Sprague-Dawley rats. Females were mated and the coupling time was recorded at gestation day 0 / E0. Four experimental groups I, II, III, and IV, received daily gavage doses of 0 mg, 500 mg, 250 mg, and 125 mg/kg, respectively, of Equisetum ramosissimum extract. On E20, the animals were sacrificed and fetuses removed and fixed in 10% saline formalin for 10 days. Subsequently, cervical, thoracic, lumbar, and sacral segments of the spinal cord from randomly selected fetuses were embedded in paraffin, sectioned, stained, and investigated for neural tube closure. Morphological evaluations detected differences between the control group and those treated with Equisetum ramosissimum extract, promoting further studies to clarify the mechanism by which the extract can alter normal neural tube development.