Effect of Rhaza stricta on the developing rat fetus

Rhazya stricta is a medicinal plant traditionally used in the treatment of diabetes mellitus, inflammation, and helminthiasis. Our objective was to determine if the plant extract has any effect on fetal development in the rat. A lyophilized extract of the plant was administered daily on three consecutive gestation days (GD) covering the period of preimplantation and organogenesis. The fetuses were examined on GD 20. Higher doses (5.0 or 8.0 g/kg) of R. stricta generally caused a reduction in maternal weight gain, compared to controls, whereas the lower doses (0.5 to 2.0 g/kg) did not. Treatment on GD 1, 2, 3, or 7, 8, 9 had no effect on the fetal weight. Treatment on later days GD 8, 9, 10, or 10, 11, 12, or 13, 14, 15 reduced both the number of live fetuses and their weight. Pronounced intrauterine growth retardation (IUGR) was observed in groups treated at later stages, particularly in the high dose groups. Extreme resorption characterized R. stricta treatment on GD 10, 11, and 12. Examination of the conceptus 24 h after R. stricta treatment indicated retarded placental development associated with hypovascularity, which possibly contributed to the IUGR and fetal death. The incidence of malformations such as micromelia, adactyly, maxillary-mundibular hypoplasia, protruding tongue, and edema, did not reach statistical significance. Except perhaps for a generalized growth retardation, no skeletal malformations were obvious. These observations are suggestive of potential fetal toxicity of R. stricta if taken during pregnancy.