Alebie et al. Malar J (2017) 16:307 DOI 10.1186/s12936-017-1953-2 Malaria Journal REVIEW Open Access Systematic review on traditional medicinal plants used for the treatment of malaria in Ethiopia: trends and perspectives Getachew Alebie1*, Befkadu Urga2 and Amha Worku1 Abstract Background: Ethiopia is endowed with abundant medicinal plant resources and traditional medicinal practices. However, available research evidence on indigenous anti-malarial plants is highly fragmented in the country. The present systematic review attempted to explore, synthesize and compile ethno-medicinal research evidence on anti- malarial medicinal plants in Ethiopia. Methods: A systematic web search analysis and review was conducted on research literature pertaining to medici- nal plants used for traditional malaria treatment in Ethiopia. Data were collected from a total of 82 Ethiopian studies meeting specifc inclusion criteria including published research articles and unpublished thesis reports. SPSS Version 16 was used to summarize relevant ethno-botanical/medicinal information using descriptive statistics, frequency, percentage, tables, and bar graphs. Results: A total of 200 diferent plant species (from 71 families) used for traditional malaria treatment were identi- fed in diferent parts of Ethiopia. Distribution and usage pattern of anti-malarial plants showed substantial variability across diferent geographic settings. A higher diversity of anti-malarial plants was reported from western and south- western parts of the country. Analysis of ethno-medicinal recipes indicated that mainly fresh leaves were used for preparation of remedies. Decoction, concoction and eating/chewing were found to be the most frequently employed herbal remedy preparation methods. Notably, anti-malarial herbal remedies were administered by oral route. Informa- tion on potential side efects of anti-malarial herbal preparations was patchy. However, some anti-malarial plants were reported to have potentially serious side efects using diferent local antidotes and some specifc contra-indications. Conclusion: The study highlighted a rich diversity of indigenous anti-malarial medicinal plants with equally diver- gent herbal remedy preparation and use pattern in Ethiopia. Baseline information gaps were observed in key geo- graphic settings. Likewise, herbal remedy toxicity risks and countermeasures generally entailed more exhaustive investigation. Experimental research and advanced chemical analysis are also required to validate the therapeutic potential of anti-malarial compounds from promising plant species. Keywords: Medicinal plants, Malaria, Ethiopia Background were estimated to have occurred in the sub-Saharan Malaria remains one of the world’s leading health prob- Africa region. Children were particularly afected by the lems, causing about 429,000 deaths in 2015, the vast disease with 70% of malaria-caused deaths occurring majority of deaths (99%) were due to Plasmodium falci- among the under fve-year age group [1, 2]. In Ethiopia, parum malaria [1]. In that year, most (92%) of the deaths the majority (around 68%) of populations live in areas deemed malarious or potentially malarious [3]. Despite recent improvements in malaria control strategies, the *Correspondence: [email protected] disease remains a major public health problem and a 1 Department of Biology, Jigjiga University, P.O. Box‑1020, Jijiga, Ethiopia Full list of author information is available at the end of the article © The Author(s) 2017. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Alebie et al. Malar J (2017) 16:307 Page 2 of 13 leading cause of outpatient consultations, admissions and Search strategy death in the country [4, 5]. A web-based systematic research literature search strat- In recent years, emergence of drug-resistant Plasmo- egy was employed. Ethno-botanical/ethno-medicinal dium species has exacerbated the health and economic studies reporting on medicinal plants used for traditional impact of malaria. In particular, P. falciparum (the malaria treatment in Ethiopia were gathered by two dif- most pathogenic human parasite) has developed resist- ferent search approaches, including: ance to virtually all currently available anti-malarial drugs [6]. Consequently, research for alternative anti- • Search for unpublished MSc/PhD thesis research malarial drugs has accelerated over the last two dec- reports using Google search engine and local univer- ades [7]. Historically, medicinal plants have been the sity websites; focus of many researches aimed at discovering alterna- • Search for published journal articles using interna- tive anti-malarial drugs in different parts of the world tional scientifc databases including PubMed, Science [8]. This has led to the discovery of numerous anti- direct, Web of Science, Google scholar, AJOL, etc. malarial compounds with significant structural varie- ties, including quinines, triterpenes, sesquiterpenoids, Literature search was performed using the following quassinoids, limnoids, alkaloids, lignans, and cou- key terms: Ethiopia/Ethiopian plants/Ethiopian medici- marins [9]. nal plants/Ethiopian anti-malarial plants, Malaria/Anti- Around 80% of Ethiopian populations (particularly malarial/Anti-malarial plants, Traditional/Traditional rural societies) still rely on traditional medicinal plants knowledge/Traditional Medicine/Traditional medicinal to fght a number of diseases. Tis was attributed to plants, Medicinal Plants/Medicinal herbs, Indigenous/ high cost of modern drugs, paucity and inaccessibility of Indigenous knowledge, Plants/Herbal/Medicine/Rem- modern health services, and cultural acceptability of tra- edies, Folk Medicine/Folk remedies/Home remedies/ ditional medicine [10, 11]. Communities inhabiting dif- Herbal remedies, Ethnobotany/Ethnobotanical, Ethnop- ferent localities in the country have developed their own harmacology/Ethnopharmacological, Ethnomedicine/ medical plant arsenals and knowledge on their utiliza- Ethnomedicinal, Ethnopharmaceutical, Medico-cultural. tion, management and conservation [12]. A large variety of medicinal plants are used as traditional malaria rem- Screening and criteria edy in diferent parts of Ethiopia [13–17]. Screening of search outputs was performed in two stages. Proper documentation of traditional medicine and First, the title and abstract of identifed journal articles/ plants used in the prophylaxis and treatment of malaria theses was overviewed. Tereafter, suitable articles/the- constitutes an important task not only in preserving ses were downloaded and critically inspected for inclu- precious indigenous knowledge and biodiversity but sion in the review. Literature screening was based on the also in enhancing community access to and stakes in following inclusion and exclusion criteria. improvement of malaria control interventions. It is also crucial for stimulating future research on safety and Inclusion criteria efcacy of medicinal plants and identifcation of chemi- Published and unpublished ethno-botanical and ethno- cal entities that could be developed into new standard- medicinal surveys reporting on anti-malarial plant/s, ized phytomedicines. In contrast, ethno-botanical and conducted at any time period in Ethiopia ethno-pharmacological research on indigenous anti- malarial plants is still at a rudimentary stage in Ethiopia Exclusion criteria [18]. Moreover, available research evidence on indig- Te following types of research data were excluded from enous anti-malarial plants is highly fragmented, which analysis: underscores serious need for systematic compilation and synthesis. • Data from review articles, historical documents or Te present systematic review attempted to explore, experimental studies; synthesize and compile ethno-medicinal research fnd- • Data from published and unpublished ethno-botani- ings on anti-malarial plants in Ethiopia. cal and ethno-medicinal surveys lacking information on anyone of the following: study areas/localities, Methods informant’s involvement, scientifc plant names, and A systematic analysis and review of research literature not reporting information about anti-malarial medic- related to medicinal plants used for traditional malaria inal plants; treatment in Ethiopia was conducted between April and • Data from non-open access journal articles or par- October 2016. tially accessed (abstract only) articles. Alebie et al. Malar J (2017) 16:307 Page 3 of 13 Data retrieval Anti‑malarial medicinal plants in Ethiopia Relevant information pertaining to Ethiopian anti-malar- In aggregate, 82 studies identifed a total 200 difer- ial medicinal plants was retrieved using a structured Excel ent plant species used in traditional malaria treatments format by directly quoting reported values. In order to throughout Ethiopia. Additional fle 1 summarizes the provide uniform information on preparation methods of distribution of the reported plants according to adminis- the remedy, the following terms were established, and they trative regions and foristic