Systematic review on traditional medicinal plants used for the treatment of malaria in Ethiopia: trends and perspectives

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 medicinal plants used for traditional malaria treatment in Ethiopia. Data were collected from a total of 82 Ethiopian studies meeting specific inclusion criteria including published research articles and unpublished thesis reports.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 different plant species (from 71 families) used for traditional malaria treatment were identified in different parts of Ethiopia. Distribution and usage pattern of anti-malarial plants showed substantial variability across different geographic settings. A higher diversity of anti-malarial plants was reported from western and southwestern 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. Information on potential side effects of anti-malarial herbal preparations was patchy. However, some anti-malarial plants were reported to have potentially serious side effects using different local antidotes and some specific contra-indications.

Conclusion: The study highlighted a rich diversity of indigenous anti-malarial medicinal plants with equally divergent herbal remedy preparation and use pattern in Ethiopia. Baseline information gaps were observed in key geographic 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: Ethiopia; Malaria; Medicinal plants.

Fig. 1

The geographical distribution of anti-malarial plants based on malaria risk stratification map of Ethiopia (adopted from the Malaria NSP 2014–2020). Malaria risk stratification was revised in 2014 using annual parasite incidence per 1000 population (per WHO recommendation) plus altitude and expert opinions from different malaria stakeholders [4]. Malaria risk is thought to be one important factor affecting the abundance of anti-malarial plants. Hence, numbers indicated in the map represent the total amount of anti-malarial plants reported from each administrative region (e.g., 24 plants reported from Tigray region)

Fig. 2

Frequency of herbal preparation methods

Fig. 3

Frequency of the reported plant parts used for herbal preparations