Teratogenic Effect of Crude Ethanolic Root Bark and Leaf Extracts of Rauwolfia vomitoria (Apocynaceae) on Nissl Substances of Albino Wistar Rat Fetuses

Rauwolfia vomitoria is a plant used for the treatment of insanity. The possible adverse effects of crude ethanolic root bark and leaf extract of the plant on Nissl substances of albino Wistar rat fetuses were studied using 25 mature female Wistar rats. The animals were divided equally into 5 groups, labeled A, B, C, D, and E. Group A was the control, while groups B, C, D, and E were the experimental. The female rats were mated with the males overnight, and the sperm positive day was designated as day zero of pregnancy. Oral doses of 150？mg/kg and 250？mg/kg body weight of the root bark extract were administered to groups B and C animals, respectively, while groups D and E animals received 150？mg/kg and 250？mg/kg body weight of the leaf extract, respectively, from day 7 to 11 of gestation. On day 20 of gestation, the rats were sacrificed, the fetuses brains extracted, and the cerebral cortices excised and routinely processed for Nissl substances using Cresyl fast violet staining method. Results showed reduced staining intensity of Nissl substances in the treated groups, especially those that received the root extract. Thus, the herbs may have adverse effects on protein synthesis within the cerebral cortex. 1. Introduction Herbal medicine is the oldest form of health care known to humanity and has been used in all cultures throughout history. Primitive people learned by trial and error to distinguish useful plants with beneficial effects from those that were toxic or nonactive. Even in cultures, tribal people methodically collected information on herbs and developed well-defined herbal pharmacopeias. Traditional medicine evolved over centuries depending on local flora, culture, and religion [1–3]. Rauwolfia vomitoria, the herb of study is mostly found in the rain forest of Southern Nigeria. The plant has many common names like serpent wood, serpent snake root, and swizzle stick. In Nigeria, it is known as asofeyeje in Yoruba, ira in Hausa, akata in Bini, and mmoneba and utoenyin in Efik languages, respectively [4]. Extensive studies carried out on its chemical properties showed that the plant contained more than 50 active indole alkaloids, each possessing remarkable pharmacological activities [5, 6]. Nigeria is one of the countries where traditional medicine practitioners prescribe and administer decoctions of the leaves and root bark to patients without regard to its possible adverse effects. This leads to the present investigation which was to assess the neurohistological effects of the crude ethanolic root bark and leaf extracts of Rauwolfia vomitoria