Ethnobotanical Study of Medicinal Plants in Chilga District, Northwestern Ethiopia

Ipomoea reniformis Chaos is claimed in Indian traditional medical practice to be useful in the treatment of epilepsy and neurological disorders. In the present study, pretreatment effect of methanolic extract of Ipomoea reniformis on epilepsy and psychosis was evaluated in rodents using standard procedures. Besides evaluating epileptic and behavioral parameters, neurotransmitters such as Gamma-Amino Butyric Acid (GABA) in epilepsy and in psychosis dopamine, noradrenaline and serotonin contents in the rodent brain were estimated. The extract pretreatment reduced maximal electro shock; Isoniazid (INH) and Pentylenetetrazole (PTZ) induced seizures and also significantly inhibited the attenuation of brain GABA levels by INH and PTZ in mice. These results suggested that the observed beneficial effect in epilepsy may be by enhancing the GABAergic system. The test drug also inhibited the apomorphine induced climbing and stereotyped behavior and showed significantly reduced levels of brain dopamine, noradrenaline and serotonin which may be due to blocking of central dopaminergic, noradrenergic and serotonergic pathways or by enhancing the GABAergic system. The results obtained in present study suggest that the title plant possesses antiepileptic and antipsychotic activities in rodents.


Introduction
Ipomoea reniformis (IR) also called as merremia emarginata (Burm. f.) is a procumbent herb belonging to the family convolvulaceae. In India, it is commonly known as Undirkana and Mushakparni. The plant is widely distributed in India, Sri Lanka, Philippines, Malaysia, Tropical Africa and mainly grows in rainy and winter season. In India, it is found in Southern part mainly counting Chennai, and some places of Andhra Pradesh [1]. Traditionally, IR has been used to treat diverse clinical conditions ranging from pain; fever to neurological disorders [2]. IR has been claimed to be useful for inflammation, headache, fever, cough, neuralgia, rheumatism and also in liver and kidney diseases [3]. The powder of leaves is used as a snuff during epileptic seizures. Juice acts as purgative and the root is having diuretic, laxative actions and applied in the disease of the eyes and gums [4].
The plant contains various neuroprotective chemical constituents such as caffeic, p-coumaric, ferulic and sinapic acid esters. Petroleum ether extract contains fats and fixed oil while aqueous extract contains amino acids, tannins (condensed and pseudo tannins) and starch [5]. IR has been reported to possess various pharmacological actions, mainly antidiabetic [6], antiinflammatory [7], nephroprotective [8], antibacterial [9], antioxidant and antimicrobial activity [10]. Further, the principle constituents of IR such as sinapic and ferulic acids have exhibited behavioural and pharmacological

Introduction
Nearly 100,000 plant species have been regularly used for food, shelter and medicines in the world 25 . However, most of the plant is ignored 22,25 due to lack of documentation, scientific knowledge and dismination, although these medicinal plants are the pillars to the health care system and livelihood of rural community 4,23 .
Higher medicinal plant diversity is comprised in Ethiopia because of the presence of broad latitudinal ranges 4 . In Northwestern parts of Ethiopia, which is endowed with humid, sub-humid, dry, highland and lowland areas, plenty of medicinal plants are present. However, nowadays the extents of medicinal plant resources are highly degraded.
About 80 % of the population in Ethiopia is suffering from the lack of healthcare services 4,12 . Thus, in most cases, rural communities depend on medicinal plants to meet their healthcare needs 4 due to their easily accessibility and affordability 20 .
Identifying medicinal plants, documenting their uses and assessing the threats create a base for local decision making, applying appropriate management, conduct detail pharmacological analysis and select species for different land uses. However, there is scanty of information on their medicinal uses, ecological distribution and conservation.

Description of the Study Area
The study was conducted in Chilga district, North Gondar province of the Amhara Regional State. Chilga district is located 12°55" N and 37°06" E. The district had 41 rural Kebele administrative (KAs) and two town associations 7 . The altitude of the district ranges from 900 to 2267 meter above sea level (m.a.s.l). It had midland (1500-2267 m.a.s.l) and lowland (900-1500 m.a.s.l) agroecology. About 33% of the District is midland, while 67 % lowland agro-ecology. There are rivers and streams traversing the District and often serving as sources of water for the population 7 . The major soils of Chilga District are 45 % Cambisols, 40 % Vertisols, 15 %, and Nitosols 7 . The vegetation is predominantly composed of different woody and herbaceous species. The natural vegetation of Chilga is mainly composed of various lowland and midland species. The temperature ranges from 11 to 32ºC and mean annual rainfall is between 995 to 1175 mm. The District had a total population of 241,712 and a total area of 3181 km 2 . The local people are mainly dependent on subsistence mixed agriculture (crop-livestock production and rearing).

Selection of Study Sites and Respondents
The study was carried out in four KAs of Chilga District from October 8 to December 20 2012. District and Kebele experts and knowledgeable persons were first contacted to have general information. In addition, secondary archived materials were reviewed from district agricultural office to get further information. Based on preliminary information, the socio-demographic and biophysical characteristics of the two agro-ecologies (midland and lowland) are not the same, while Kebeles in same agroecology are fundamentally similar from one another. Thus, based on accessibility for data collection and availability of medicinal plants, two sample KAs from each agroecology and two sample villages from each KA were selected (Table 1). For this study, key informants (KI) and households were participated for data collection. KIs are defined as knowledgeable persons about medicinal plants as well as local conditions. A simple stratification of households (HHs) was conducted by age (≤ 40 and > 40) and wealth

Data Collection
Questionnaires and checklists were prepared, pre-tested and administered to HHs and KIs, respectively. Consent and a formal permission letter were obtained from district agricultural office. All interviewees were met on a 'one-to-one' basis and were asked the same standard (open-and closed-ended) questions using the local language (Amharic). Information regarding local names of medicinal plants, parts used and diseases treated and application methods were recorded. In addition, information on other uses and threats of medicinal plants were gathered.
Field observations were conducted in areas using transect walk where most of the medicinal plants are grown/cultivated. The purpose of the field observation was to obtain actual information of presence, growth habit, habitat characteristics and identification of medicinal plant species mentioned during the interviews.
A focused group discussion of KI was conducted at each study site to verify the data. All medicinal plants listed in the socio-economic survey were verified and idiosyncratic ideas were removed from the data. Idiosyncratic ideas are ideas/data which represent only the idea of respondent and was not accepted as correct by other key informants. Some ideas of two persons were assumed idiosyncratic and were rejected.
Direct matrix ranking method was exercised for commonly reported multipurpose medicinal plants to assess their relative importance to the local people and the extent of the existing threats related to their use values following the method of Martin 26 . Based on their relative uses, eight most knowledgeable KIs were selected out of the entire KIs and were asked to assign use values for seven medicinal plant species (5 = best, 4 = very good, 3 = good, 2 = less used, 1 = least used and 0 = not used) to each use category. Frequency of citation as multipurpose species was used in ranking medicinal plant species. Use categories used in the comparison include construction, medicine, fruit/food, fuel wood, shade, farm and household implements, and fence.
Preference ranking was also conducted for 6 commonly reported medicinal plants used to treat rabies in the district following the method of Martin 26 . Rabies was the common ailment for which the local communities do not sought help from primary health services in their locality. Eight KI (most knowledgeable) were selected among 24 KI and participated in the ranking process. The ranking of selected medicinal plants was carried out in pre-designed semi-structured interview items based on their personal preference of efficacy from highest score (supposed to be the most effective) to the lowest score (least effective). The major human and natural factors possibly threatening the survival of medicinal plants were identified through preliminary assessment. Thus, based on the relative importance of the threatening factors, priority ranking was conducted by 8 KIs using the method of Martin 26 . One to five scores were assigned where 1 was for the least and 5 were for the most destructive threat. Then, all ranks were summed up and total ranking was conducted to know the main threats.
All encountered plants were identified and recorded by their vernacular names. Later, converted to their botanical names using flora of Ethiopia and Eritrea [9][10][11][17][18][19] (Edwards 1989), and own experience. Plant specimens were collected and taken to National Herbarium of Addis Ababa University for plant identification.

Data Analysis
Descriptive quantitative and qualitative data analyses were employed after the necessary data collection. Statistical Package for Social Sciences (SPSS) Version16.0 was used for data analysis. The data from ranking methods was presented in the form of ranks. T test statistical analysis was employed for mean separation. Spearman's Rank Order Correlation was used to test the relation between ages and use knowledge.

Medicinal Plants Habit, Parts Used and Diversity of Uses
Overall, herbaceous species were the most widely used plants for the treatment of ailments (36 % of species) followed by shrubs (30%) (  (Table 4). About 89.8 % of remedies are prepared from roots and leafs. The remaining 10.2 % are prepared from other plant parts (Stem and root barks, apex, seed, tuber, fruits, sap, oil and fruit coats). In addition, some medicinal plants in the study area were used to treat more than one ailment ( Table 2).
Medicinal plants play an important role in provision of other uses such as fuel wood, construction, food, fencing and others in addition to medicinal uses (Table  5). About 68.48 % out of 83 and 76.3 % out of 84 medicinal plants in the lowland and midland agroecology provide additional uses respectively.

Preference and Utilization of Medicinal Plants
Informant consensus on most commonly utilized medicinal plants in the study sites is presented in Table  7. Over all in the study area, Zehneria scabra (mentioned by 31% informants) and Carisa spinarum (mentioned by 28 % informants) were popularly used medicinal plants. Site-specific preference based on percentage of informants also assured Zehneria scabra was frequently cited medicinal plant in Walideba, Quavier lomiye and Tenbera. Similarly, Carissa spinarum was the most cited plant in Chalia Debire Kebele. Rabies was the most common disease that the most people visit traditional healer in the study area. Through preference ranking, seven medicinal plants treating rabies were selected (Table 7). Of these, Dorstenia barnimiana and Euphorbia abyssinica were the first and the second ranked species in treating rabies, respectively. However, Cucumis ficifolius was the last ranked species.      Selection and direct matrix ranking of seven multipurpose medicinal plants was also conducted to know the relative importance of these plants to the local community (Table 8). Cordia africana and Syzygium guineense were the first and the second ranked multipurpose species. Of the seven-selected use categories, medicinal and fuel wood were ranked first and second.

Medicinal Plant Knowledge Distribution
The study proved presence of difference in medicinal plant citation among age classes in each study sites (Fig. 2a). Accordingly, elders know better than younger's do. The Spearman's Rank Order Correlation test also confirmed that there was a significant positive correlation between age and medicinal plant list (r = 0.587, P < 0.01). Majority of respondents (73%) from Midland agroecology and 50% of respondents from Lowland agroecology indicated that they acquire knowledge from their parent (Fig. 2b). Almost the same proportions of informants got knowledge on medicinal plants from traditional healer. Modern education was the least method of acquisition and transfer in both lowland and midland agroecologies. The free-list exercise of respondents also shows the presence medicinal plant citation between wealth categories in Quavier Lomiye Kebele (Table 9). Medicinal plant citation of wealthier people were significant (p <0.05) than poorest. Score criteria: 5 = best, 4 = very good, 3 = good, 2 = less used, 1 = least used and 0 = not used.

Threats of Medicinal Plants
Plant identification and preference ranking of major medicinal plant threats was conducted based on their destructive effect. Thus, illegal charcoal production (36 total score) and fuel wood collection (31 total score) were the first and second ranked threats (Table 10).

Floristic Composition, Diversity and Distribution of Medicinal Plants
The study area contains high floristic profile of medicinal plant families compared to other semi-arid areas of Ethiopia 28,33,35 . Fabaceae is the most widely used family for medicine purpose. Hailrmariam et al. 15 24 and Mesfin et al. 27 in the humid areas, and Adefa 1 , Zenebe et al. 35 , Yirga 33,34 in semi-arid areas of Ethiopia also documented an appreciable number of medicinal plants.

Utilization and Socioeconomic Implication
Herbaceous plants were the most widely used medicinal plants followed by shrubs and trees in the treatment of ailments in the study sites. The wide utilization of herbs is also reported in other areas of Ethiopia (   difference because of variation in culture 8 agroecologies and topographic features 4 and easily availability of the species in question 5 . More than half of plant remedies in the study area were prepared from roots and leaves. Flatie et al. 13 and Lulekal et al. 24 also found roots take the highest proportion due to the efficacy of roots in treating the ailments. Conversely, leaves were the most widely used parts of plants 1,2,28,32,35 . Utilization of a greater number of medicinal plants (101 species) in the study area indicated the strong dependency of the local community on plants to sustain their health care. It also revealed that the endowment and the depth of local people with the associated plant lore. The study conducted in other semi-arid areas of Some medicinal plants were most preferred and commonly used (e.g. Dorstenia barnimiana and Euphorbia abyssinica were used for treatment of rabies) due to their efficacious and low cost (affordable) for the community for specific ailments. Although some plants were available for rabies vaccine they were not popular by most community. Since, the use of the plants was acknowledged only by a few people. Like the present finding other plants e.g Flueggea virosa (Roxb. ex Willd.) Royle (Zenebe et al. 35 in other areas also used for treatment of rabies virus. Some ailments such as mental problem/ mental disorder (the abnormality of a person mentally or a person unable to do his day to day activities due to illness of the mind), evil spirit (illness of a person due to the force of the devil), Meftehe sery (illness of a person when he given mind distorting plant medicine by other person secretly), evil eye (the evil eye is a specific type of magical curse which is believed to cause harm, illness and even death) and impotency for men were also believed to be cured only by traditional healers using medicinal plants. Similarly, Flatie et al. 13 and Zenebe et al. 35 reported "mental problem" believed to cure only by traditional healers and traditional medicines. Medicinal plants were also used for protection and promotion of human physical, spiritual, social, mental and material wellbeing. For instance, traditional healers used medicinal plants to fix bone fracture in the study area. Similarly, Deribe et al. 8 report the use of medicinal plants for settlement of bone fracture.
Most medicinal plants (67.3 %) in Chilga district provide multiple uses in addition to their medicinal values (food, construction, fence, fuel wood, farm tools and household implements, fodder, timber or commercial purpose and toothbrush). Other researchers elsewhere in Ethiopia also reported multi-purpose roles of medicinal plants 1,21,32,34,35 . Some medicinal plants such as S. guenees and X. Americana were eaten to supplement the normal food diet. Medicinal plants were also the means of livelihood especially for traditional healers that they fetch income by preparing and selling traditional medicines. Medicinal plants are economically affordable and easily accessible to the rural community and poorest communities. This indicates the contribution of medicinal plants in the livelihood diversification of the local community.

Knowledge Distribution and Threats of Medicinal Plant
The distribution of knowledge varies between different social categories. There is a positive correlation between age and numbers of plants cited i.e. elders cited higher number of medicinal plants than younger people did. Medicinal plant knowledge increases as age increases due to accumulation of knowledge through  33 is in agreement with the present result that parents, traditional healers and friends are the major sources of knowledge. Mostly it is passed to generations orally and in some cases is secretly. Thus, traditional knowledge of medicinal plants might be lost over time.
Agricultural expansion, over grazing, fire and utilization related factors such as fuel wood and charcoal, construction, house and farm implements are the major threatening factors in both agroecologies. Different researchers have also accounted for these threats 4,15,24,27,33 . Furthermore, most of the plants are collected in the natural environments that are subjected to less management and anthropogenic factors 15 .

Conclusion and Recommendations
Good numbers of medicinal plants were recorded in lowland and midland agroecologies of the study area. These medicinal plants were claimed by KIs to treat 52 (human and livestock) ailments. Majority of medicinal plant used for treatment of ailments were herbs and shrubs. Most of the encountered medicinal plants provide other services including food, fuel wood and charcoal, construction, timber, farm and household implements, generating income from selling the products and their parts. Medicinal plants were suffering from the threats of agricultural expansion, fuel wood, and construction and over grazing in both agroecologies. Thus, conservation activities from local and national level are needed before the extinction of these plants.

Competing Interest
The authors declare that they have no competing interests.

Authors' Contributions
MT: conception and design, data collection and analysis, manuscript writing and final approval of the manuscript.
ZA: data analysis, critical revision and final approval of the manuscript. SZ: critical revision and final approval of the manuscript. All authors read and approved the final manuscript.

Acknowledgement
We thank to the Development Partnership in higher Education, Department for International development, (DeLPHE) for financial support of this research which otherwise would have faced financial constraints. We are also thankful to the traditional healers and local people of Chilga district who generously shared their knowledge on underutilized medicinal plants. Finally, our acknowledgement passed to the Environmental Protection and Agricultural offices of Chilga district that provide us various basic data and support.