Ethnobotanical study of medicinal plants used by agro pastoralist Somali people for the management of human ailments in Jeldesa Cluster, Dire Dawa Administration, Eastern Ethiopia

Ethnobotanical study of medicinal plants in selected kebeles of Jeldesa cluster, Dire Dawa Administration, eastern Ethiopia was carried out with the aim of assessing and documenting the indigenous knowledge of medicinal plants used in the communities and preserves it to be used by the next generations. Ethnobotanical data collection was carried out from September 2015 to March 2016. Three study sites (kebeles) were selected purposefully based on the preliminary survey and recommendations of elders in the study area. Ethno-botanical data were collected using semistructured interviews, field observations and group discussion. About 24 informants (21 male and 3 female) were involved in this study. A total of 52 medicinal plant species belonging to 43 genera and 30 families were documented for the management of 48 human ailments; with details on their local name, family, habit, habitat, and their mode of preparation and mode of administration. Fabaceae had a relatively high number of species 7(13.5%), followed by Lamiaceae 4 (7.7%). Shrubs constituted 23 species (44%) followed by herbs 19 species (37%). Oral route contributed (57.7%) of the total species, followed by dermal (27.1%). Most of these species (83%) were wild and harvested mainly for their leaves (34%). Most herbal remedies are prepared using fresh plant materials (48%) in the form of crushing (31%). Ailment categories with high ICF value were swollen body parts (Gofla), wounds, and poisonous animal bites that had ICF values of 0.68, 0.66 and 0.64, respectively. Fidelity level index of Euphorbia somalinsis, Xanthium spinosum and Tribulus terrestris for kidney problem, Crotalaria laburnifolia for constipation, Eulophia petersii for swollen body part/GOFLA and Barleria orbicularis, Solanum sepiculum and Echidnopsis dammanniana for snake poison showed a fidelity level of 100% this indicated their outstanding preference for treating the corresponding ailments. The results of the present study also showed that deforestation and human encroachment were ranked 1st and 2nd as threats to conservation of medicinal plants. The present paper represents significant ethnobotanical information on medical plants which provides baseline data for future pharmacological and phytochemical studies.


INTRODUCTION
Ethiopia has a long history of traditional medicine and has developed ways to combat disease through it.It is gifted with a huge potential of medicinal plants and their uses that provide a wide contribution to the treatment of human ailments (Asfaw, 2001;Giday, 2003).About 80% of Ethiopian people rely on traditional medicine to meet their health care needs (Bekele, 2007).The wide spread use of traditional medicine could be attributed to cultural acceptability, perceived efficacy against certain types of diseases, physical accessibility and affordability as compared to modern medicine (Bekele, 2007;Hunde et al., 2006).Nevertheless, little effort has so far been made to properly document the associated knowledge base and conserve medicinal plants in the country (Gidey et al., 2009).Even though encouraging initiatives have emerged in recent years, studies conducted hitherto are far from complete owing to the multiethnic cultural diversity and the diverse flora of Ethiopia (Bekele, 2007;Yineger et al., 2008).Medicinal plants and the associated knowledge are being threatened by ongoing deforestation, environmental degradation and 'modernization' (Balemie et al., 2004;Bekele, 2007).All this necessitates the need to investigate the status of medicinal plant resources and knowledge base associated with it for successful resource conservation and development.
Similar to elsewhere in Ethiopia, Somali people living in Dire Dawa Administration have traditional practices which have passed from generation to generation in order to treat both humans and livestock ailments.A large proportion of the people living in the region depend on direct herbal medicine to treat a wide range of human ailments (Abduljawad et al., 2011).Most of the studies on medicinal plants in Ethiopia have so far concentrated in the south, south west, central, north and north-western parts of the country (Belayneh and Bussa, 2014).Therefore, this study area is selected; because there is no ethnobotanical collection, identification and documentation carried out on medicinal plant species of the area.In addition, most of the natural vegetation of the study area is lost due to natural and human impacts (Abduljawad et al., 2011).Therefore, the current study was conducted to assess and document the indigenous knowledge of medicinal plants and identify the major threats of medicinal plants in the study area.The information generated enhances the ethnobotanical knowledge of the region and provides recommendations that would help to combat problems in the conservation and sustainable use of medicinal plants and serve as baseline information for future pharmacological and phytochemical studies.

Description of study area
Jeldesa Cluster is consisted of nine rural kebeles (Jeldesa, Ciremiti, Gerba aneno, Mudi aneno, Ayale gumgum Legedini, Debeley, Melkakero and Kulayu) it is located at about 45 km North East of Dire Dawa city.Jeldesa cluster has a population of 30,564 male comprise 51% (15,588) and female comprise 49% (14,976) of the total population (CSA, 2007).The cluster is totally resided by agro pastoralist communities.Metro logically, the region is characterized by an arid climate with low and erratic rainfall and a mean annual temperature which lies between 29 and 32°C.The rainfall pattern is bimodal characterized by small rains in autumn (February to April), big rains in summer (July to September).The mean annual rainfall is 660 mm.However, recently, rainfall pattern has become much more unpredictable with receiving extremely minimum and maximum rainfall per year.The selected study kebeles were Jeldesa, Gerba aneno and Chire miti.These kebeles are relatively wider and have higher number of traditional healers resided in them.Kebele is the smallest administrative unit in Ethiopia.According to Dire Dawa Health Bureau the healthcare coverage of the cluster is 51.52% and the major disease categories recorded by the Health Bureau (2015/2016) gastrointestinal disorders and upper respiratory tract infection.

Traditional healer selection and collection of ethnobotanical data
A total of 24 traditional healers (21 males and 3females) from the age of 28 to 75 years were sampled based on recommendations of local elders and kebele administrators.Ethnobotanical study was conducted between September 2015 to March 2016 in three kebeles of the cluster.Prior to data collection discussion was made with the traditional healers to get their verbal informed consent.Semi-structured interview (was conducted in local language (s), Somali) with the help of interpreter, group discussion (average members of 8 per group), and field observation were employed to collect basic information on the local name (s), diseases treated, parts used, method of preparations and routes of administration.Furthermore, guided field walks with traditional healers were employed to collect specimens of each medicinal plant species.Identification of specimens were made using the published volumes of the Flora of Ethiopia and Eritrea while for unknown plant specimens identification was made by comparing their voucher specimen with authentic specimens deposited in the National Herbarium, Addis Ababa University and by getting assistance from taxonomic personnel.

Data analyses
Ethnobotanical data were analyzed using simple descriptive statistics using Microsoft Excel 2013.The MS Excel Spreadsheet was also utilized for drawing bar graphs.Preference ranking was computed according to Martin (1995).Informant consensus factor (ICF) values were determined following Heinrich et al. ( 1998).To evaluate the consensus among traditional healers or to evaluate the reliability of the information provided by the informants.
Where, Nur: Number of use-reports for a particular use category; Nt: Number of taxa used for a particular use category by all informants.
The Pearson Correlation Test was calculated using SPSS 17.0.1 software package and employed to evaluate whether there was significant (p < 0.05) correlation between i) the age of the traditional healers' and the number of medicinal plant species reported, and ii) the educational level of traditional healers' and the number of medicinal plant species reported.The informants who cannot read and write were considered as illiterate while, those respondents attended formal education were considered educated.
The Fidelity Level (FL) index was calculated based on the formula recommended by Friedman et al. (1986), which is used to quantify the importance of a given species for a particular purpose in a given cultural group or to determine the most preferred plants for a treatment of a particular disease and calculated as: Where, Np : Number of use-reports cited for a given species for a particular ailment N : Total number of use-reports cited for any given species

Ranking of threats to medicinal plants
Ranking of threats to medicinal plants that were reported by most of the informants in the study area was conducted using six selected key respondents as described by Martin (1995) and Alexiades (1996).The informants were asked to give seven for the most threatening factor and one for the least threatening factor in the study area.As mentioned by most of the informants' six threats were selected and the informants were asked to give seven for the most threatening factor and one for the least threatening factor in the study area.This information is used to determine the highest threats to traditional medicinal plants in the study area and helps to suggest the necessary appropriate conservation measures.

Ranking of threatened medicinal plants
The ranking of medicinal plants based on the degree of threats was conducted using the method applied by Martin (1995) and Alexiades (1996), five medicinal plants that were reported by the informants as threatened in the study area were ranked with six key informants (knowledgeable traditional healers) by giving 5 for the most threatened and 1 for the least threatened plant species.

Characteristics of respondents
A total of 24 traditional healers (21 males and 3 females) Ayalew et al. 173 from the age of 28 to 75 years were sampled.The respondents were with an average age of 48 years.Males were dominant representing (87.5%) of the respondents.Generally, (66.6%) of the respondents were above 50 years (Figure 1).The majority (50%) of them attended non-formal education (quran) and those who attended formal education constituted (4%) while (46%) were illiterate.Generally, the informants were grouped into three age groups, young (20-35), adult (36-50) and elderly (above 50) to see how the knowledge varies with age as described in Belayneh et al. ( 2012).There was a significant positive correlation (Pearson correlation coefficient, r =0.27, at α = 0.05, p = 0.04) between the age of informants and the number of species reported by the informants.Differences in medicinal plants knowledge among age groups was also reported in other studies (Gebrezgabiher et al., 2013;Tamiru et al., 2013;Yigezu et al., 2014;Chekole et al., 2015;Tugume et al., 2016).This might be attributed to the current expansion of education and health centers to kebele level which has resulted in the young generation focusing on modern medicines (Belayneh and Bussa, 2014) and advancement in science and technology has changed the social values and therefore, transformed the younger generation at a faster rate into the new tradition (Awas, 2007;Murad et al., 2013).

Habitat of medicinal plants
Forty-one (79%) species of the medicinal plants were obtained from the wild vegetation followed by 7 (13%) of medicinal species from Home garden (Figure 3).This result is similar with other studies (Yineger and Yewhalaw, 2007;Lulekal et al., 2008;Yineger et al., 2008;Megersa et al., 2013, Getaneh and Girma, 2014and Alemayehu et al., 2015) conducted in Ethiopia as well as in other countries such as Pakistan (Ugulu et al., 2009), Uganda (Mugisha and Uriga, 2007;Tugume et al., 2016) and Peru (Bussmann and Sharon,2006), where the majority of the medicinal plants were collected from the wild.This implies that the majority of plants of medical importance were not yet cultivated by traditional healers (Yineger and Yehwalaw, 2007).

Habit of the medicinal plant
Of the total 52 medicinal plants collected from the study area, 23 species (44%) were shrubs followed by 19 species (37%) herbs and 10 species (19%) trees (Figure 4).The highest proportion of growth habit was covered by shrubs and herbs both constitute 81% of the total traditional medicinal plants.This can be related to the floristic composition of vegetation, which is dominated by woodland, bush land and scrubland vegetation types in the study area.Similar patterns were reported by some ethinobotanical studies (Teklehymanot et al., 2007;   Mesfin et al., 2009;Belayneh and Bussa, 2014) where shrubs and herbs are the largest plant growth habits.

Plant parts used for medicine
According to the ethnobotanical data result, leaves are the most commonly used plant parts accounting for 34% of the total, followed by root (33%), seed (9%), all part and fruit constituted (5%) each.Use of other plant parts is as indicated in Figure 5. Latest findings in agreement with this study conducted in Ethiopia indicated that leaf used more than other parts (Megersa et al., 2013;Getaneh and Girma, 2014;Maryo et al., 2015), as well as in other countries such as Pakistan (Murad et al., 2013) and Uganda (Tugume et al., 2016), reported similar findings.Utilization of leaves for drug preparation may not cause detrimental effect on the plants compared to the root or whole plant collections (Megersa et al., 2013;Regassa, 2013;Abera, 2014;Maryo et al., 2015).preparation of plant material for medicinal use including by crushing, squeezing, concoction, smoking, infusion, decoction, pounding, and chewing.Out of the total preparations (31%) are prepared in the form of crushing, followed by pounding (18%), concoction (12%), squeezing constituted (10%), decoction and infusion constituted (8%) each implantation and chewing constituted (4%) each of the total mode of preparations (Figure 6).This agrees with the results of studies carried out by Abdurhman (2010), Regassa (2013) and Megersa et al. (2013) who found that the main mode of preparation is crushing, accounting for 26.2, 29 and 28.2%, respectively.

Route of administration
Different routes were used in administration of herbal preparations.The major routes of administration in the study area are oral, dermal, nasal and optical.Oral route contributed (57.7%) of the total species, followed by dermal (27.1%), nasal and oral and dermal (3.5%) each, optical (2.8%) and smoke bath (2.1%), surgically implanted (1.4%).The least used route of herbal administration were auricular and nasal and auricular which were (0.7%) each (Figure 7).According to Abera (2014), Alemayehu et al. (2015) and Birhanu et al. (2015), oral administration was the dominant route of remedy administration, which constituted 63, 54.21 and 57.1% in their respective study areas (Figure 8).In a similar study by Tugume et al. (2016) on medicinal plants used by Mabira communities in Uganda, it was reported that oral route of administration was commonly used route constituting 53% of the route of administrations used by the local people in the study area.In the present study, lack of agreement among the informant on doses of remedies was the major drawback in the application of traditional medicinal plants in the study area.In a similar study, Belayneh and Busa (2014) reported lack of precision and standardization in the prescription of herbal remedies in the study area and also confirmed that overdose of remedies bring adverse effects like, diarrhea, vomiting, abdominal pain, unconsciousness, and fainting of the patient.

Informant consensus factor (ICF)
ICF for different ailment categories was calculated to test for homogeneity or consistency of informants' knowledge about a particular remedy for an ailment category.ICF indicated which plants are widely used and thus merit further pharmacological and phytochemical studies.In this study ailments with a relatively high ICF value were swollen body parts (Boil, Gofla), wound healing (Korokor, sore, wounds), Poisonous animal bites (snake, scorpion and spider bite), and Organ problems (kidney, liver, heart, eye, nose, ear problems) and that had ICF values of 0.68, 0.66, 0.64, and 0.57, respectively (Table 1).Three ailment categories had ICF of zero (0) since each respondent reported a different species used for the same ailment (Table 2).

Fidelity level (FL) of medicinal plants
The fidelity level of medicinal plants on frequently reported diseases was calculated and summarized in Table 3. Results revealed 100% fidelity level for the following plants; Euphorbia somalinsis, Xanthium spinosum and Tribulus terrestris for kidney problem, Crotalaria laburnifolia for constipation, Eulophia petersii for swollen body part/GOFLA and Barleria orbicularis Hochst, Solanum sepiculum and Echidnopsis dammanniana for snake poison.A fidelity level of 100% for these species indicated their outstanding preference for treating the corresponding aliments.This will also attract pharmacologists for further pharmacological investigation of the traditional plant species.

Threats to medicinal plants in the study area
As mentioned by most of the informants six threats were selected in the study area.This information is used to determine the highest threats to medicinal plants in the study area and helps to suggest the necessary appropriate conservation measures.The results of the present study showed that deforestation and human encroachment were ranked 1st and 2nd, respectively and these were followed by drought and charcoal making in the 3rd and 4th places, respectively as the major threats to the medicinal plants (Table 4).Similar to the current study, Lulekal et al. (2008) confirmed that the main threats to the survival of medicinal plants in the Mana Angetu district were agricultural expansion and    medicinal plant survival in the study area.
In addition, improper use of resources such as harvesting the root of a medicinal plant could be a significant threat to medicinal plants as; our result showed that roots were the second major plant parts where 33% of the medicinal plant species were harvested to treat ailments.Root and whole plant harvesting are destructive practice which may result in species extinction.Root as the most commonly used plant part in remedy preparation was reported (Giday et al., 2007(Giday et al., , 2009;;Lulekal et al., 2013;Maryo et al., 2015).

Threatened medicinal plants
The results (Table 5) indicated that Balanites aegyptiaca, is the most threatened followed by Cadaba farinosa and Tamarindus indica and the least threatened one is Solanum somalensis.

Medicinal plant conservation efforts of the local people
About 33.62% of the informants reported that they had awareness of the importance of conserving medicinal plant species and were practicing some conservation activities like cultivation in home gardens.The rest of the informants were not practicing any conservation effort.They simply went to the wild to collect medicinal plants as their need arose and did not bother about the long term survival of these plants.It was found that only 13% of the medicinal plants were obtained from home garden about 8% from both wild and home garden this shows that most of the herbalists are not interested to grow medicinal plants in their home garden in order to keep the secrecy of their medicinal value.According to Etana (2010), about 38%, of the medicinal plants collected were reported as found cultivated at home gardens.Some traditional practitioners have started to conserve medicinal plants by cultivating at home garden, such as Jatropha curcas L., Withania somnifera (L.) Dunal and Punica granatum L. The people's culture and spiritual beliefs somehow has helped in the conservation of medicinal plants.For instance, the claim of the traditional healers that medicinal plants are effective only if cut or collected and administered by traditional healers helped in conservation of medicinal plants.Similar cultural and spiritual believes were reported in the study of medicinal plants in Wenago Woreda, SNNPR, Ethiopia (Mesfin et al., 2009).

Conclusions
In the present study, fifty two plant species of medicinal importance were recorded and documented.The majority of the reported medicinal plant species were wild.Many medicinal plant species were also reported to be rare.These demand an urgent attention to conserve such vital resources so as to optimize their use in the primary healthcare system.A rich heritage of indigenous medicinal plant use and knowledge was also recognized.However, awareness creation should be made among the healers so as to avoid erosion of the indigenous knowledge and to ensure its sustainable use and conservation as some healers were not transferring it all.Further phytochemical and biological activity studies should also be conducted on the preferred medicinal plant species so as to utilize them in drug development.

R Alati
The bark of fresh root is crushed and mixed with coffee pulp and boiled and consumed after addition of sugar or goat milk.

Oral Fever
The bark of fresh root is crushed and mixed with coffee ashara and boiled and consumed after addition of sugar or goat milk.The site of the bite will be tied cut with blade and fresh leaf pounded and tied on the cut body part and also the pounded leaf is mixed with water and consumed

Dermal and oral
Repel snake Burning the leaf on fire Smoking

Figure 3 .
Figure 3. Family distribution of medicinal plants.

Figure 4 .
Figure 4. Percentage of medicinal plants on the basis of their habitats.

Figure 5 .
Figure 5. Habit distribution of the reported medicinal plants.

Figure 6 .
Figure 6.Types of plant parts used in remedial preparation and percentage of preparations per plant part.

Figure 7 .
Figure 7. Percentage of method of preparation of traditional medicinal plant remedies.

Figure 8 .
Figure 8. Percentage of administration route of medicinal plants.

Table 1 .
Medicinal plant used for the treatment of human diseases; scientific name, local name, Habit, part (s) used, method of preparation, administration route and diseases treated.

Table 3 .
Fidelity value of medicinal plants for the most frequently reported diseases.

Table 4 .
Ranking of threats to medicinal plants.

Table 5 .
Ranking of threatened medicinal plants in the study area.