Development of pregnancy in rats treated with Hypericum perforatum.

St John's wort (Hypericum perforatum) is a medicinal plant used in the treatment of depression and other psychiatric disorders. In the present paper, the toxicity of H. perforatum administered to female rats during the period of organogenesis (day 9-15 of pregnancy) was evaluated. Thirty inseminated Wistar rats were randomly distributed into control and treated groups, which received, by gavage, 0.5 mL of saline and 36 mg/kg body weight of Jarsin dried extract diluted into 0.5 mL of saline, respectively. Maternal toxicity was evaluated through: water and food intake, body weight gain, piloerection, locomotor activity, diarrhea and death occurrence. Animals were killed on day 21 of pregnancy, when fetuses and placentas were removed and weighed. The indices of implantation and resorption were calculated. Clinical signs of maternal toxicity were not observed and none of the variables analysed showed statistically significant differences. In the dose administered in the experimental model used, H. perforatum does not seem to be toxic to the mother nor to interfere with the progress of gestation during organogenesis. Copyright (c) 2005 John Wiley & Sons, Ltd.