In the history of Ethiopia, the use of traditional medicinal plants for treating different human ailments can be confirmed in all parts of the country. The plant remedies are still the most important and sometimes the only source of therapeutics for nearly 80% of the population in Ethiopia, especially rural populations (Lulekal et al., 2008). The collection and processing of medicinal plants provide employment and income opportunities for a large number of people in rural areas (Ngarivhume et al., 2015). The importance of traditional medicinal plants in conservation of biological diversity merits the attention it has gotten worldwide.     

Gastrointestinal parasitic infections caused by intestinal protozoa and helminths are among the most common human infections throughout the world especially high prevalence in poor and socio-economically deprived communities in the tropical and subtropical countries including Ethiopia. Parasitic infections due to protozoa and helminthes are responsible for substantial morbidity and mortality worldwide especially children in developing countries (Utzinger  et al., 1999; Norhayati et al., 2003; Stepek et al., 2006; Haque, 2007; Ukwubile, 2012; Speich et al., 2013; Traore et al., 2013; Abdullah et al., 2016).

The intestinal parasitic infections are transmitted mainly through fecal contamination of food or water. These are the most frequent in areas where sanitation and hygiene are poor. The most common gastrointestinal parasites that cause frequent diseases/infections on human are protozoa (amoebiasis, giardiasis) and helminthes. Ascariasis, taeniasis (tapeworms), hookworm infection trichuriasis and etc. are among the top ten most common infections in the world (Norhayati et al., 2003; Corrigan et al., 2011). These infections continue to be a global health challenge, particularly among children in poor communities in developing countries. Epidemiological assessments of these infections have traditionally focused on estimating the number of infections (prevalence), which occur worldwide. Unfortunately, rural populations have limited access to health services and anti-parasitic substances used for gastrointestinal parasites control, due to poverty and inaccessibility. On the other hand, most of the existing drugs produce side effects such as abdominal pain, loss of appetite, nausea, vomiting, head ache and diarrhea. Therefore, these people are closely associated with medicinal plants to treat the intestinal parasite infection.  

According to Lulekal et al. (2008) and Kefalew (2015), there is a considerable global interest in tapping the accumulated knowledge of traditional medicine and therefore, researches are being carried out in the district region with the aim of increasing the use of traditional medicine   to   the  welfare  of  the  human  population.  In addition, the increase in population growth rate would result in the intensification of agriculture in marginal areas which would lead to deforestation with decrease in number or loss of medicinal plants in the wild (Pankhurst, 2001). Therefore, the study was carried out to document ethnomedicinal plants used for the treatment of gastrointestinal parasitic diseases in human in Yeki district, southwest Ethiopia and for sustainable conservation of these species.

 

 

General information of informants

In this survey, a total of 34 persons (26 informants and 8 traditional healers) were involved for reliable data collection in Yeki district of four villages. Most of the informants found in the study area were males (88.24%) because the traditional knowledge of practicing medicinal plants as healers was transmitted from father to the elder son. Therefore, females could not be the healer or practitioners however; four of the elder female informants were selected for approving the practice in the locality. Most of the respondents were between the age of 55 and 75 years old (93.6%). The person in this age group is more experienced and knowledgeable as compare to the younger age. Orthodox religion and informant job account for higher percentage of the study participants.

Prevalence of gastrointestinal parasite diseases and signs

Among the common intestinal parasites affecting human wellbeing were protozoa (48.28%) followed by ascaris (20.69%) (Table 1). Therefore, the study revealed that the most prevalent parasitic diseases in the area were protozoal such as amobia and giardia followed by ascaris. This prevalence is seen because of lack of sanitation in the area.

 

 

Similarly, the case is described in some local communities of the world that are exposed to parasitic diseases (Speich et al., 2013; Saqur et al., 2017). The major clinical signs as identified by the traditional herbalists considered as being related to gastrointestinal parasites infections in humans are stomach ache, presence of tapeworm segments in the faeces as well as the presence of blood and mucous in the faeces and/or diarrhea for protozoa parasitic infections. In this case, most of the tradisional herbalists used different diagnosis to identify the type of protozoa and helminthes diseases. Based on this, amoebiasis differ from giardiasis infection due to mucus with faeces and the diarrhoea contains mucus and blood. These results are also in line with the findings of Stepek et al. (2006), Haque (2007) and Saqur et al. (2017) which was conducted in different parts of the world. The parasitic diseases are frequently observed in children compared to adult because children play with each other in the dirt without washing their hands except their parents instruct them to wash their hands. Similarly according to the study of Abdullah et al. (2016) and Saqur et al. (2017), children are mostly faced with intestinal parasitic infection.

The most common gastro-intestinal parasite infected age groups of human in the study area were identified by the traditional medical practitioners and key informants. Based    on    the     response,   gastrointestinal   parasite frequently affects children of ages of 3 to 10 (47.06%) followed by age group 11 to 20 (26.47%) and less than 2 years old (11.76%) (Figure 2).  Hence, these age groups are susceptible to develop the parasitic infection compared to other age groups. This finding was also in agreement with the finding of different researchers conducted across the world by which most of children were infected by intestinal parasitic infections (Norhayati et al., 2003; Stepek et al., 2006; Haque, 2007) (Figure 2).

 

 

The result showed that diseases that were frequent in the study area have higher informant consensus factor (ICF). Medicinal plants that are effective in treating certain disease and well known by community members also have higher ICF. Intestine worms had the highest ICF value (1) followed by tapeworms (0.75) whereas; protozoa had the lowest ICF value (0.5) (Table 1). Fidelity level (FL) as an estimation healing potential was determined for some medicinal plants.

Accordingly, Pycnostachys meyeri, Hagenia abyssinica, Ocimum lamifolium and Croton macrostachyus were the plants having the highest level values for their use to treat intestinal parasitic infections and diseases. As the medicinal plants prescribed by informants for the same health problem such as protozoa infections (amoeba), the informants showed preference of one over the other. Preference ranking of six medicinal plants that were reported for treating amoeba was conducted after selecting six key informants. The informants were asked to compare the given medicinal plants based on their efficacy and to give the highest number (1) for the medicinal plant which they thought most effective and the lowest number (6) for the least effective plant. Maytenus arbutifolia and Pycnostachys meyeri ranked first indicating that it is the most effective in treating protozoa infections (amoeba) followed by Prunus Africana and the least effective was Brucea antidysenterica (Table 2).   

 

 

Medicinal plants used

A total of 29 species of medicinal plants used for the treatment of gastrointestinal parasitic diseases was collected and documented from the study area. These identified species were represented with 20 families. From which, family Lamiaceae had the highest species contributing 4 species (13.79%) and closely followed by family Asteraceae with 3 species (10.34%), and Cucurbitaceae, Euphorbiaceae, Rosaceae and Rubiaceae represented each with 2 species (6.89%). The remaining 14 families represented each by 1 species (Figure 3). The numbers of medicinal plants used for treating human ailments and associated ethnomedicinal knowledge has been observed in different regional state of Ethiopia (Lulekal et al., 2008; Tolossa et al., 2013; Kefalew et al., 2015). The existence and utilization of such a large number of medicinal plants by people in the study area indicates that the majority of the people  used  indigenous medicinal practices to treat different health problems. The study shows that the traditional healers of the study area were found to play great roles in the primary healthcare systems of the local people as they were treating resource poor people who had little access and could not afford the cost of modern medications.

 

 

Habits of medicinal plants

The  assessment  on  the  growth  form  of  the  medicinal plants depicted that herbs constituted the highest number of 11 species (37.93%) collected, and closely followed by tress 7 (24.14%) and 6 species shrub (20.69%) (Figure 4). However, a single plant belongs to epiphytic medicinal plants. This finding show that the most represented life forms of medicinal plants for the treatment of gastrointestinal parasite in the study area was herbs followed by trees. This might show that there is abundance of herbs in the study area because the area is rich with rainfall for nine or more months. This makes the area conducive for the  growth  of  herbs.  Therefore,  the trend of using more of herbaceous plants could be advantageous as it is easier to cultivate them when they are in short supply and even naturally grown in natural environment. In similar fashion, the present study was in line with the report made by Mirutse et al. (2009) in Southwest Ethiopia, in cases where it is humid for most months of the year creating a favorable condition for the growth of herbs. Apparently, the herbs were the most harvested for the treatment of  diseases  of  humans  and the livestock, which agrees with the previous studies of Mirutse (2001), Mirutse et al. (2009) and Mohammed and Berhanu (2011) on ethnobotanical conducted in Ethiopia. Nonetheless, the findings of Debela et al. (2004), Haile and Delenasaw (2007) and Fisseha et al. (2009) conducted in various parts of the country, sees shrubs as the primary growth form of remedies. Furthermore, the study area remains moisture/humid for several months for  the  year  creating  conducive   environments  for  the growth and management of herbs. Thus, this is why local people of the study area mostly harvested leaves, fruits, seeds, rhizomes and bulbs of crops and herbs in every season.  

 

 

Habitat of medicinal plants

Based on the data collected from key informants of the study area, around 8 species (27.59%) medicinal plants were obtained from both homegarden and farmland closely followed by 7 species (24.14%) obtained from forest, and 5 species (17.24%) collected from forest and grassland area (Figure 5). The finding of the present study agreed with the study conducted in other part of Ethiopia by Yalew et al. (2012), which revealed that medicinal plant (47.37%) were collected from the wild in the nearby forest and grassland areas, and almost above half (51.5%) of the medicinal plants were collected from the natural habitat (Gidey et al., 2011). On the other hand, the finding was in line with that of Gidey (2010) who reported highest number of medicinal plants from home garden in Alamata Town, Northern Ethiopia. This difference might be related to the variation in medicinal plant distribution in different climatic zone. Moreover, Yeki district got rain throughout the year unlike northern part of the country which gets sufficient rain in only two seasons mainly summer and autumn.

 

 

Plant parts used

Cumulatively, twenty nine (29) medicinal plants were used in the 4 sites (villages) of the district for the treatment of gastrointestinal parasitic infection/diseases in human. Frequently cited plant by the traditional healers was Sonchus bipontini (Asteraceae). The data revealed that most of  the  medicinal  plants  are  used  separately. Different plant parts such as leaves, stem, barks, fruits, roots, seeds and flowers were used in preparing the remedies. The plants parts widely used by the traditional healers are the leaf (51.72%) followed by bark, seed, fruit and leaf and roots each with 6.89% (Figure 6). Grinding and mixing with water are the predominant modes of preparation of the medicine plants provided by local herbalists, and the oral route is used as the main administration way (96.55%). The dosage of a remedy depends on the age of the patient. In general, children have small quantities compared to adult. Almost all of the interviewed healers were men. Generally, they use their knowledge on medicinal plants to help the community by selling their products to the patients in the village and district. The major signs/symptoms diagnosis by healer to treat the parasite infection considered as being due to gastrointestinal parasites infections were stomach-ache, diarrhea, the presence of the worms and blood in the faeces. Five (20.83%) of the medicinal plants reported were approved, and commonly used in all of the four sites for the treatment of gastrointestinal parasitism.

 

 

 

 

 

 

 

 

 

 

 

 

 

This study underlined that  29 medicinal  plants were used to treat gastrointestinal parasites diseases in human, and the symptoms that might be related to gastrointestinal parasites identified by traditional healers. Therefore, there is a realistic potential that these plants would contain compounds with anti-parasitic potency. This study contributes to the enormous indigenous knowledge on medicinal plants and plant-based remedies practiced within ethnic groups. The finding needs the improvement and promotion of the local traditional practitioners using medicinal plants to treat gastrointestinal parasites. There is also the need to investigate the phytochemical, pharmacological and toxicological profile of the plants used in order to ensure their efficacy as well as their safety. Anti-parasitic tests should be carried out to assess the efficacy of the inventoried plants on gastrointestinal parasites. Every stakeholder must consider the status of these very valuable medicinal plants to propagate in homegarden and botanical garden for Ex situ conservation purposes.

 

The authors have not declared any conflict of interests.

 

We are thankful to the informants who gave us clear  information and shared their medicinal plant knowledge as well as the elders and the local administration for their support in facilitating the interview process.  We also thank the staff of Biology Department and Mizan-Tepi University for their support, and the National herbarium of Addis Ababa University for letting them make use of their Herbarium during plant identification