Medicinal Plants Used for Treating Human and Livestock Ailments in Tiyo District, Arsi Zone of Oromia, Ethiopia


 Background Systematic documentation and promotion of indigenous knowledge associated with medicinal plants are limited. The aim of this study was to undertake ethnobotanical investigation on medicinal plants used for the treatment of human and livestock ailments and document indigenous knowledge of local communities on the preparation and administration of herbal remedies in the study area. Methods The study involved 153 informants from nine kebeles, comprising traditional healers, knowledgeable elders and local user communities. Various ethnobotanical techniques were used to collect and analyze data: semi- structured interview, guided field walk, group discussion, preference ranking, and fidelity level index. Data was analyzed using descriptive statistical analysis. Results Local communities had rich and diverse indigenous knowledge on medicinal plants, types of ailments, methods of remedy preparations and routes of applications. There were differences in this indigenous knowledge across age and sex. A total of 83 medicinal plants were documented during this study. Fifty two (62.65%) plants were used for treating human ailments, 20 species (24.10%) for treating health problems of livestock and the remaining 11 (13.25%) for treating both human and livestock ailments. The highest informant consensus was documented for the plants Allium sativum , Asparagus africanus and Azadirachta indica. Leaves were the most commonly used parts of medicinal plants accounting for 51.81% of the total followed by roots (20.48%) and barks (2.41%). Oral administration of the herbal medicine was the dominant route 66.3%, followed by dermal (22.7%) which included washing, holding on, rubbing and brushing. Smoking (8.5%) was also important. It was documented that 27 species (32.5%) were used in fresh, 13 species (15.7%) dried and 43 species (51.8%) either in dry or fresh state. Conclusion Owing to their access, curing ability, manageable charges, existence of deep indigenous knowledge and other associated cultural values, medicinal plants continued to play a significant role in meeting healthcare needs of the community in the study area. Conservation and sustainable use of the diverse medicinal plants need to be promoted. Systemic documentation and protection of the rich knowledge of local communities and further research on selected potential species was recommended as a result of this study.

3 as a result of this study.

Background
Ethnobotany is a broad and complex term referring to the study of direct interactions and interrelations between humans and plants [1,2]. Local communities especially in rural developing countries are dependent on herbal medicines. This indispensable dependency of human communities upon plants for their livelihood was primarily started by domestication and dates back to 10,000 years [1].
Globally, the estimate of medicinal plants ranges from 35,000-50,000 species and out of this about 4000-6000 species have entered the world market of medicinal plants [3]. However, only about 100 species have been used as a source of modern drugs. Ethiopia has rich floristic composition and is among few megadiverse countries in the world. Out of the estimated 6000 vascular plant species in Ethiopia, about 10% are estimated to be edible [4] and over 10% (about 600 to 1,000 species) have medicinal values [5]. The country is also home to many languages, cultures and beliefs which have in turn contributed to the high diversity of traditional knowledge and practices [6]. Following the concentration of biological and cultural diversity, the greater concentration of medicinal plants is found in the south and south western parts of Ethiopia [7].
Medicinal plants and traditional medicine play an important role in the healthcare system of most developing countries. Traditional medicinal plants have been used in Ethiopia as a source of medicine since antiquity to treat various health problems. It is estimated that about 80% of the rural people in Ethiopia and about 90% of the livestock population rely on traditional medicine to meet their primary healthcare needs [5,8,9]. The wide spread use of traditional medicine in Ethiopia could be due to cultural acceptability, efficacy against certain types of diseases, physical accessibility and economic affordability as compared to modern medicine [5,9,10].
Indigenous knowledge on plants appeared when humans started and learned how to use plants [11].
Over centuries, indigenous people have developed their own locality specific knowledge on plant use, management and conservation [12]. The complex knowledge, beliefs and practices generally known as indigenous knowledge (IK) or traditional knowledge develops and changes with time and space, 4 with change of resources and culture.
In Ethiopia, traditional medicine has been facing challenges of sustainability and continuity mainly due to the loss of taxa of medicinal plants [13]; as well as habitats and cultures [14]. Other studies also showed that the diversity of plants in Ethiopia is on the process of being eroded mainly due to human induced pressures [15]. Habitat destruction and deforestation for commercial timber, encroachment by agriculture and other land uses have resulted in the loss of some thousand hectares of forest that harbour useful medicinal plants, annually over the past several decades. With the present ecological and socio-economic changes, the medicinal plants together with ethnobotanical knowledge, may disappear and thus may be lost from humanity forever [16].
Traditional medicine continues to be widely used in Ethiopia

Methods Geographic Location and Description of the Study Area
The study was conducted in Tiyo District of East Arsi Administrative Zone, Oromia National Regional State of Ethiopia (Fig. 1

Climate
According to the records of the National Meteorological Agency (NAMA) of Ethiopia, the mean annual rainfall of the District is 1100 mm. Distribution of the rainfall is bimodal, which occurs in the major rainy season (Kiremt) and the short rainy season is (belg). The major rainy season occurs from June to 6 October and the short rainy season occurs in March, April and May. The dry season extends from November to February. The mean annual maximum temperature was 23.

Sampling Study Sites And Informants
Study sites were selected purposively through feasibility study based on the agro-ecological zones of the district (lowland, middle and highland) because such stratification can represent the whole district. This helps for the effective evaluation of the distribution of medicinal plants and the variability of traditional knowledge in different agro-climatic zone. The Kebeles selected are shown in Representative informants were selected through systematic random sampling by flipping a coin for household and/or for individuals to be selected based on the age, sex and educational background.
When the coin comes up a head, the informant was selected, if tail comes up the informant was not selected following the method recommended by Martin [1]. This helps to provide equal statistical chance to all members of population with the age ranges between 18 and 75, different sex and level of educational back ground, etc. Knowledgeable informants were selected by using purposive sampling methods based on recommendation obtained from elders and local authorities (Development Agents and kebele administration leaders). The total sample size was decided by using the following simplified formula following Yamane Taro [18]:

Semi-structured Interview
Semi-structured interview was conducted using prepared questions in Afaan Oromo, which is the local language of the informants following the accepted practice [1,12]. During interview, issues regarding 9 name, age, sex, level of education, occupation, religion and ethnicity of the informants were included.

Focus Group Discussion
Discussion with knowledgeable informants over all kebeles were also designed and performed so as to gather further information on medicinal plants and in general to prove reliability of information gathered during semi-structured interview.

Guided Field Walk
Two to three field walks were made as necessary with knowledgeable informants and this provided an opportunity for more discussion with the herbalists' and the practical identification of traditionally used medicinal plants in their natural environment. It also helps to obtain firsthand impression on the abundance, habit and habitat characteristics of the plant species mentioned during interviews. During this observation medicinal plant species were identified, specimens collected and photographs were taken.

Free Listing
In this exercise the informants were asked to list all medicinal plants which are used for a particular purpose. The medicinal plants which are more significant were more likely to be mentioned by several informants.

Informant Consensus
In order to evaluate the reliability of information recorded during the interview, informants were visited more than one times for the same ideas and the validity of the information was proved and recorded. Consequently, if the idea of an informant deviates from the original information, it was rejected since it was considered irrelevant information. Only the relevant ones were taken into account and statistically analysed by the methods adopted from Alexiades [19].

Paired Comparison
A paired comparison was conducted for five medicinal plants that were used for treating wart. Nine key informants participated in the paired comparison. Accordingly, Euphorbia dumalis was first followed by Lepidium sativum as shown in Table 12. This result indicated that Euphorbia dumalis was much favored over other plant species cited for treating wart in the area. Moreover, the result could be a testimony for the efficacy of these two plant species to treat wart at least in the study area.

Fidelity Level Index
Many plant species were used in the same use category that necessitated to determine the most preferred species used in treatment of a particular ailment, which can be done with the fidelity level [22]. The fidelity level (FL), is the percentage of informants claiming the use of a certain plant species for the same major purpose. It was calculated for the most frequently reported diseases as: Where Np is the number of informants that claim the use of a plant species to treat a particular disease, and N is the number of informants that use the plant species as a medicine to treat any given disease [19].

Review Of Secondary Sources
Data of secondary sources were reviewed from public and livestock health centers to evaluate their view of traditional medication system, to obtain the list of the most frequent health problems in the District, Agricultural and Rural Development office of the district to gather information about the socio-economic, demographic, location, climatic (ten years climatic data), edaphic and vegetation characteristics of the study area. In addition, information on the working cooperation between modern health practitioners and traditional herbalists were gathered.

Voucher Specimen Collection And Identification
All interviews, discussions as well as field surveys were accompanied with voucher specimen collection that was carried out with the help of traditional healers and local field assistants. The specimens were air-dried, numbered, labelled, pressed, heater-dried, deep-frozen, identified and deposited at the National Herbarium (ETH) in Addis Ababa University. Identification of specimens were performed both in the field and later at ETH using taxonomic keys and the relevant volumes of the Flora of Ethiopia and Eritrea [23][24][25][26][27][28][29].

Ethical Consideration
All participants in this ethnobotanical survey were informed about the detailed objectives of the research before starting any data collection and information sharing. Informants were clearly informed that the results will be used for academic purposes only not for commercial purpose. The procedure involved asking permission of the local administration and each informant.

Data analysis
Ethnobotanical data analysis Descriptive statistical methods (both qualitative and quantitative analytical tools) were used for data analysis following Martin [1] and Cotton [12]. Data on informants' background, medicinal plants used and associated traditional knowledge were entered in Excel spread sheet software and organized for statistical data analysis. Traditional knowledge dynamics on use of medicinal plants by men and 13 women, young to middle aged and elder; literate (completed at least primary education) and illiterate, knowledgeable (key) and local (encountered randomly) informants were compared by using SPSS and Excel software.
Descriptive statistical methods were also applied to analyze medicinal value, methods of preparation, application techniques, route of administration, disease treated, plant parts used and habit of medicinal plants. In addition, six categories of plant use-reports, frequency and relative frequency of tree species were employed to analyze data statistically.

Results
Indigenous knowledge about health in the study area songs that were recorded during discussion with elders. They gave high value for their health, as they believed that their health is their life and security. To cite few of these: "Fayyan faayaa eeggadhu" meaning health is very precious take care of it.
"Dhibbi abbaan hin beekne fayyaadha" meaning health is a great wealth and gift not well recognized by oneself.
From these local proverbs, it is clear that health is considered as a great asset, and a life engine for any aspect of life activities in the area.
One hundred fifty two (96.2%) informants were supportive of traditional medication system provided by indigenous herbalists. They also believed that diseases were not created without medicine.
According to the perception of these participants, all plant materials on the earth are created to cure diseases unless it is beyond the scope of human knowledge. They were also classifying health problems into those that can be treated and those that cannot be treated. For instance, 96.2% informants pointed out that locally acceptable spiritual diseases (dhibee ayyanaa) were non-curable either traditionally or by modern treatment but evil eye; evil spirit and jaundice can be cured by traditional means than the modern treatment. The rest six informants did not support the traditional medication system and did not believe in the efficacy of herbal medicine. They reported that they 14 were not using herbal medicine against human and livestock diseases.

Indigenous knowledge on treatment of ailments in the study area
The results obtained from the community of the study area showed that treatment strategies could be classified as home remedy, indigenous medicine and modern medicine. Despite their distinct features and procedures of treatment, these healthcare strategies often overlap, as patients appear to utilize one strategy after another without taking time to see the effect of each medication. As gathered from group discussion and interviews made during field observation, the local people always exploit their shared wisdom in order to manage health problems at home before looking for other options regardless of the type of health problem and its intensity. Accordingly, the sick person is given either traditional medicine (prepared from plant and/or animal sources) or treated spiritually through prayer according to their religion. In most cases, all these were employed in combination for the treatment of specific health problems. Seeking modern health service often comes after the above were exhausted or rarely simultaneously. According to their reports, they first look for traditional medication system because of several reasons including:

Easy access
Unlike modern healthcare station, local healers are found within accessible distance at their neighbours. This was found to be helpful in emergency cases (dhibee tasaa) to provide first aid and/or full treatment.

Efficacy on treatment
They also reported that traditional medication system was very effective to cure locally acceptable diseases caused by devil (seeyxaana) or, evil eye (budaa), manmade poisoning (falfala), hookworm (maagaa), urine of bat (simbira), infectious eczema (sarariitii) and rabies (waan saree). They perceived that these diseases could easily be treated at local level by traditional healers. On the other hand, gastritis, cardiovascular, mental and gastrointestinal problems are often taken to modern health centers.
Cost of treatment: The problems related to getting fast health service with affordable cost was among major factors that determine healthcare choice of individuals or communities. According to most informants (96.20%), local healers provide healthcare with relatively manageable and negotiable charges. In the study area, there was traditional rule among healers and their clients which says " pay once and be treated many times", i.e. once the payment is made for the treatment of a particular health problem, no more payment is asked for repeated medications that runs up to curing. If the client is not in a position to pay any amount of cash at all, he/she may then give the healer a few blades of fresh grass called (irressaa). This is simply made for moral satisfaction of both the healer and his client. According to information obtained from elders, this irressa has dual purposes: Thanks/respect to the healer and maintenance of curative power to the drugs. According to their cultural belief, it was also generally accepted that the herbal drug given free or without any irressa will lose its curative power.

Medicinal Plants Used For The Treatment Of Human Ailments
This study documented a total of 52 (62.65% of total) medicinal plants used for treating human ailments (Table 3).   (Table 5). The informants revealed that in most cases they treat their livestock by traditional medication system and rarely look for modern medication. preparations were involved. Rabies ranked first as it was treated by seven plant species and followed by diarrhoea and blackleg treated with three plant species each (Table 6). Table 6 Common livestock ailments and number of plant species claimed to treat them in Tiyo District, Arsi Zone, Oromia, Ethiopia.

Administration Of Herbal Preparations/formulations
The routes of administration of the prepared medicine were mainly internal applications 75 (70.75%), out of which oral application was the major one (Table 8). On the other hand, the external application was about 31 (29.25%).    (Table 10). Furthermore, data collected from field observation and interviews revealed that informants in the first and second age group were not conversant enough in providing some ethnobotanical information clearly on the method of medicine preparation from plants, mode of application and plant parts used. Large numbers of key informants were found in the third and fourth age groups. The results showed that the knowledge of medicinal plant increased as the age of the informant 24 increased. The young generation particularly those in the age category less than 45 years have no or a little concept about herbal medicine when compared to population with age category above 45 years.

Preference Of Medicinal Plants
Preference ranking and paired comparison exercise based on key informant responses gave quantified ideas about the relative importance of some medicinal plants in Tiyo District.

Preferences of nine key informants on the medicinal plants used in treating rabies indicated that
Phytolacca dodecandra stood first among twelve medicinal plant species followed by Datura stramonium and the entire data are as shown in Table 11.  Table 14. Table 13 Average scores of direct matrix ranking for eight medicinal plants with their use diversity in Tiyo District, Arsi Zone, Oromia, Ethiopia.
The medicine becomes cheap and the charges for service provision will be low if the medicine is known by many people.

2.
The medicine will lose its curative power if it is shown to patients confidentially. According to the report of informants, although some people knew the medicinal plants and the methods to prepare the medicine, they did not exercise the knowledge. This was because they did not receive blessings from a well-known elder or he/she might not from a blessed family.

Indigenous Knowledge Across Age And Sex
Ethnomedicinal knowledge involves traditional diagnosis, collection of plant materials and preparation of plant remedies in many countries including Ethiopia and is transferred from one generation to the other generation verbally with great secrecy. In the study area, it was noted that herbal medicine was not shown to others because; it was considered a professional secret, also essential for maintenance of the curative power of the medicine. This had great impact on the distribution of medicinal plants and associated traditional knowledge of the community. Previous study has reported similar practices describing the fact that such secret and verbal transfer make the indigenous knowledge or ethnomedicinal knowledge vulnerable to distortion and in most cases some of the lore may be lost at each point of transfer [8]. This has called for the high need for systematic documentation of such useful knowledge [8,38].
The community in the study area had their own set of orally transmitted knowledge on health and medicinal use of many plant species. It was noted that the local communities had rich indigenous knowledge that was still beneficial to their livelihoods including health and food. Informants' consensus values obtained from this study were found to be high indicating the deep-rooted indigenous knowledge maintained among local people in practicing and utilizing traditional medicine.
However, some differences in this indigenous knowledge were noted across age and sex. Informants from the elder age group (greater than 45 years) were more knowledgeable than the youngsters.

Plant Parts Used, Medicine Preparation And Application
The result of this study revealed that leaves were the most commonly used plant parts accounting for 51.81% of the total, followed by roots (20.48%). Previous study reports from different parts of Ethiopia [6,46,47,48,33] also documented that leaves followed by roots were the most common plant parts used to treat various health problems. On the other hand, in some studies roots were as the most widely used plant parts [10,49,37].
Community of the study area prepared most of the remedies from single plants which accounts for 63 (75.90%) and preparation from combined plant species accounting for 20 (24.01%) of the remedies.
The result was in agreement with the findings [50,10] in which the single plant preparations were reported to be high. However, this report disagreed with the other reports [6,34] in which the combined plant materials were reported to have high proportion in herbal preparation. Among various popular methods of the herbal medicine preparation practiced by herbalists of the study area, crushing, pounding and homogenizing in water was the most common method accounting for about 24.62% preparations, followed by chewing 9.47% and tie on or hold on 8.33%. This result was different from the finding that reported 32 (36.4%) preparations were made in the form of powder, 29 (32.9%) crushed and pounded materials, and 12 (11.3%) in the form of chewing of plant parts for treatment of human health problems [49].
The most commonly used route of administration of herbal medicine in the study area was oral (62.3%) followed by dermal (20.7). Many studies agree with this finding of oral application as major route of application [51,6,32,33]. For example, the most common (67.19%) route of administration of traditional remedies in Bule Hora District, Oromia, Ethiopia was oral [32]. Summary of studies in Ethiopia showed that the leading route of application of all the reported herbal remedies was oral accounting for about 42% [52].

Other Services Obtained From Home Garden Medicinal Plants
Local people obtain various services from the plants growing in their home gardens. According to this study 3 plant species in the home garden provided food and medicine, 4 were used as live fence, wind break and medicine and 2 used for medicine and construction purposes. This finding agrees with many previous studies [32].
Many of the home garden medicinal plants identified during this study were cultivated for other purposes but they were used as medicine when sudden sickness occurred. This observation was in agreement with previous study that reported only 6% of the plants maintained in home gardens in Ethiopia were primarily cultivated for their medicinal value even though many other plants grown for non-medicinal purposes turn out to be important medicines when some health problems are encountered [53].
According to the home garden owners, cultivation of home garden plants is their long-life practice.
Even, some of them reported that they inherited their gardens from their parents. They also added that home garden has been very important source of their livelihood all the time particularly during the off set of rainy season. Practices of home garden were reported to be as old as agriculture in Ethiopia [54].

Conclusions
The      Methods of medicine preparation from plants in Tiyo District, Arsi, Oromia, Ethiopia.
52 Figure 5 Methods of medicine preparation from plants in Tiyo District, Arsi, Oromia, Ethiopia.