Ethnobotanical study of antimalarial plants in Shinile District, Somali Region, Ethiopia, and in vivo evaluation of selected ones against Plasmodium berghei

Ethnopharmacological relevance: The study documented medicinal plants that are traditionally used for treatment of malaria in Shinile District, eastern Ethiopia, and evaluated selected medicinal plants for their antiplasmodial activities against Plasmodium berghei. Materials and methods: The study was conducted in four kebeles of Shinile District, Somali Region, Ethiopia. A total of 15 traditional healers were sampled based on recommendations of local elders and administrators. Specimens of the reported antimalarial plants were collected and stored at the Mini Herbarium of the Aklilu Lemma Institute of Pathobiology, Addis Ababa University, following identification. Crude aqueous and ethanol extracts of Aloe sp., Azadirachta indica and Tamarindus indica were tested in vivo against Plasmodium berghei. The three plants were selected based on the frequency antimalarial use report by healers. Results: The study revealed 27 antimalarial plants, the majority of which were harvested from the wild. Root was the most frequently sought plant part. Most of the remedies were used in decoction form. Aloe sp., Azadirachta indica and Tamarindus indica were the most commonly reported plants for their antimalarial use. For the in vivo test, all the plant extracts were given to mice orally. Ethanol and aqueous leaf extracts of Aloe sp. caused 73.94% and 58.10% parasitaemia suppression, respectively at dose of 650 mg/kg. Ethanol extract of Azadirachta indica leaves induced 54.79% parasitaemia suppression at the dose of 650 mg/kg and its water extract induced 21.47% parasite suppression at a similar dose. Water extract of the fruits of Tamarindus indica showed the highest parasitaemia suppression (81.09%) at the dose of 650 mg/kg. Most Plasmodium berghei infected mice treated with high dose of plant extracts survived relatively longer compared to their respective controls although the difference was not significant. Conclusions: The result of this study may support the traditional use of Aloe sp., Azadirachta indica and Tamarindus indica in the study area against malaria. Results of this study can be used as a basis for further phytochemical and pharmacological investigations in the effort for search of new and locally affordable antimalarial agents. (C) 2011 Elsevier Ireland Ltd. All rights reserved.