Traditional uses of Corchorus olitorius L in Oyam District, Northern Uganda: A cross-sectional ethnobotanical survey

Background: Corchorus olitorius L is a naturally growing green leafy vegetable used for various medicinal purposes worldwide. Several studies conducted elsewhere indicate that the plant is used for treating cardiac insufficiency, infertility, wounds, malaria, typhoid fever, female and ulcers. However, in Uganda most studies that define medicinal plants do not reveal Corchorus olitorius L as being one of them. As a result, there is dearth of documented information regarding its medicinal benefits in the country. In order to bridge this gap, we conducted a study to establish the traditional medicinal uses of Corchorus olitorius L in Oyam District, Northern Uganda. Methods: We employed an ethnobotanical survey using quantitative approach of data collection and analysis. We randomly sampled 246 participants from 40 villages and four sub counties from Oyam district. Data was collected using an interviewer-administered semi-structured questionnaire and analyzed for descriptive statistics using SPSS v20 software. Results : We collected a total of 239 valid questionnaires giving a response rate of 97 %. The study found out that 231 (96.7%) of the participants ate Corchorus olitorius L whereas 185 (77.4%) used it for medicinal purposes. Interestingly, they used it mainly for treatment of joint difficulties (58.12%) and gastrointestinal disturbances (31.19%). Conclusion: Corchorus olitorius L is predominantly used as a medicinal plant for the treatment of joint and gastrointestinal complications.

persist up to a month without rainfall, but irrigation improves its growth rate and yields. It also tolerates a high level of rainfall but is very sensitive to excessive water when young. Favorable temperatures range from 22-35°C and diurnal variations within this bracket encourage leaf development. C. olitorius can be grown in a range of soil types but welldrained, alluvial or sandy loams are preferable. A soil pH of 6.5-7 is favorable, but it tolerates a pH range of 5.5-8.5 (7,8). About 40 days after sowing, when the plants have made adequate foliage, harvesting is done every fortnight by topping the leafy shoots.
Topping encourages branching and hence gives a higher yield. As flowering occurs concurrently with new leaf formation, flowers of leafy shoots are removed. Fruits become brown when mature and are harvested before shattering the seeds; they are threshed and winnowed to obtain seeds for sowing (7,8). C. olitorius is used as a traditional medicine among various communities (7) for the treatment of: malaria, typhoid fever, female fertility, heart failure, ulcers (7), cold and tumours (9). The plant is also reported to be a demulcent, deobstruent, diuretic, lactagogue, purgative, and tonic (9).
A number of ethnobotanical studies have been conducted in Uganda to define medicinal plants but they do not reveal C. olitorius (10)(11)(12)(13)(14). Examples include: a study conducted in 2007 by Okello and Ssegawa in Ngai and Apac (15) and another by Kamatenesi conducted in 2011 in Oyam district, (16) both of which were carried out in Northern Uganda. These studies focused on plants with medicinal uses but C. olitorius was never mentioned. The only study during which C. olitorius was mentioned as a medicinal plant for treating muscle spasms was conducted by Tabuti and others in Bulamogi (Eastern Uganda) (17).
However, this study did not specifically focus on C. olitorius. Due to the fact that most of the ethnobotanical studies conducted in the region and Uganda remain silent on C.
olitorius as a medicinal plant, there is limited documentation of its traditional medicinal uses in the country.
We therefore conducted an ethnobotanical survey to investigate the traditional medicinal uses of C. olitorius among selected community members of Oyam district, Northern Uganda. Specifically, the study set out to establish: the medicinal use (s), the plant part (s) used, the mode of preparation, the route of administration and the dosage.

Methods
In this study, we set out to describe the traditional medicinal uses of C. olitorius by communities of Oyam district in Northern Uganda. Findings from the study reveal that the plant is a highly consumed vegetable as well as a medicine. The main traditional medicinal uses of C. Olitorius we identified were related to the musculoskeletal disorders (63.78%) and gastrointestinal abnormalities (34.05%). These medicinal uses included: joints pain and stiffness; bone pain and weakness; muscular rigidity; gastric ulcers, obstruction and constipation ( Table 1). The study participants reported using leaves for medicinal uses. They boiled and ate the leaves as food on a regular basis.
The use of C. olitorius for joint and bone pains could probably be attributed to the fact that the plant is rich in calcium which favors bone mineralization thus strength. This in turn prevents fractures coupled to enhancing fracture healing (24). C. olitorius use in the treatment of joint pains could as well be explained by its antioxidant activity. Antioxidants are recognized for their ability to activate differentiation of osteoblasts, enhance bone mineralization and reduce osteoclast activity (25,26). The relief of joint and bone pains as well as menstrual pains could be attributed to the anti-inflammatory effects of C. olitorius.
Owoyele and others in their study described the anti-inflammatory effects of C. olitorius to be due to its phytochemical constituents that have the potential to reduce the level of inflammatory mediators (27). According to a study conducted in Zimbabwe, C. olitorius is used for backaches (28). This is in agreement with the findings of the current study as the study participants reported using the plant for body aches and muscular rigidity. It is also supported by the findings of Tabuti and others who reported that C. olitorius is used for treating muscle spasms (17). This too could be attributed to the anti-inflammatory properties of C. olitorius (27). Interestingly, the uses of C. olitorius in the current study (treating joint pain and stiffness) were partly contrary to its uses in other places for example Benin where the plant is mostly used for cardiovascular and gastrointestinal ailments as well as fever, malaria and female infertility (29). Perhaps Ugandan natives have not been keen enough to observe the effect of C. olitorius in these conditions. A study in Bangladesh reported C. olitorius to be rich in beta carotene, iron, calcium and vitamins A, C and E (9). This discovery supports the findings of the current study where the participants reported that they used C. olitorius for improving vision, appetite and managing anemia. The plant is also rich in fiber (30) which makes it useful as a laxative, purgative and for improving digestion as reported in the present study. The plant has also been reported to be gastro-protective (31) which supports its use for managing gastrointestinal (GI) disturbances such as constipation, peptic ulcers, and 'heart burn'.
The plant was also reported to aid in parturition. This was in accordance with the findings of a study conducted by Attah in Nigeria (32). The plant appears to stimulate smooth muscle contraction as can be noted in its ability to treat constipation, cause purgation and aid in parturition.
In Uganda (Bunyoro-kitara region), the vegetable is used to treat fresh wounds and cuts (33). However, only one person reported using C. olitorius L for wound treatment in the current study. This is possibly due to lack of awareness of its values in wound healing.
Most of the study participants reported using the leaves whereas a few use fruits and seeds of the plant for the different medicinal applications. This is in line with other findings in Bangladesh (9) and in Benin (29). In this study, the leaves were often boiled and eaten as part of their daily food. The leaves and fruits may be dried as a mode of preservation for further use whereas the seeds are crushed to form a powder which is used as a herbal tea. This too agrees with the findings in Benin and Bangladesh (9,29).

Results
A total of 239 out of 246 participants responded fully to the questionnaires giving a response rate of 97.15%. Most of the respondents (165 [69%]) were females, majority (76.7%) being in the age group 45-54 years, while 77 (32.2%) had no formal education and 218 (91%) were subsistence farmers.

Traditional medicinal uses of Olitorius in Oyam district
C. olitorius is a widely consumed green leafy vegetable that also has a variety of medicinal uses. We conducted a cross-sectional ethnobotanical survey among the community members of Oyam district to delineate the traditional medicinal uses of C.
olitorius. From the data that was analyzed, most of the respondents (96.7%) stated that they use C. olitorius for consumption purposes. More than three quarters of the respondents (185, 77.4%) reported that they used C. olitorius for medicinal purposes. Out of those (77.4%), about two thirds (118, 63.78%) used it for the treatment of diseases related to musculoskeletal systems such as joint pain and stiffness, joint lubrication and strength, prevention and treatment of bone fractures as well as weak muscles. On the other hand, almost a third of the respondents (63, 34.05%) mentioned that they used plant for treating gastrointestinal system disorders such as constipation, ulcers, 'heart burn', hemorrhoids and poor appetite (Table 1).

Parts of olitorius used for medicinal purposes in Oyam district
The study also set out to find out which parts of C. olitorius were used by the study participants for the medicinal purposes. Findings from the data analyzed indicated that most of the study participants (88%) used the leaves of C. olitorius. (Table 2).

Mode of preparation, route of administration & dosage of olitorius in Oyam district
Another objective of the study was to find out the mode of preparation of the plant, routes  The use of C. olitorius for joint and bone pains could probably be attributed to the fact that the plant is rich in calcium which favors bone mineralization thus strength. This in turn prevents fractures coupled to enhancing fracture healing (24). C. olitorius use in the treatment of joint pains could as well be explained by its antioxidant activity. Antioxidants are recognized for their ability to activate differentiation of osteoblasts, enhance bone mineralization and reduce osteoclast activity (25,26). The relief of joint and bone pains as well as menstrual pains could be attributed to the anti-inflammatory effects of C. olitorius.
Owoyele and others in their study described the anti-inflammatory effects of C. olitorius to be due to its phytochemical constituents that have the potential to reduce the level of inflammatory mediators (27). According to a study conducted in Zimbabwe, C. olitorius is used for backaches (28). This is in agreement with the findings of the current study as the study participants reported using the plant for body aches and muscular rigidity. It is also supported by the findings of Tabuti and others who reported that C. olitorius is used for treating muscle spasms (17). This too could be attributed to the anti-inflammatory properties of C. olitorius (27). Interestingly, the uses of C. olitorius in the current study (treating joint pain and stiffness) were partly contrary to its uses in other places for example Benin where the plant is mostly used for cardiovascular and gastrointestinal ailments as well as fever, malaria and female infertility (29). Perhaps Ugandan natives have not been keen enough to observe the effect of C. olitorius in these conditions. A study in Bangladesh reported C. olitorius to be rich in beta carotene, iron, calcium and vitamins A, C and E (9). This discovery supports the findings of the current study where the participants reported that they used C. olitorius for improving vision, appetite and managing anemia. The plant is also rich in fiber (30) which makes it useful as a laxative, purgative and for improving digestion as reported in the present study. The plant has also been reported to be gastro-protective (31) which supports its use for managing gastrointestinal (GI) disturbances such as constipation, peptic ulcers, and 'heart burn'.
The plant was also reported to aid in parturition. This was in accordance with the findings of a study conducted by Attah in Nigeria (32). The plant appears to stimulate smooth muscle contraction as can be noted in its ability to treat constipation, cause purgation and aid in parturition.
In Uganda (Bunyoro-kitara region), the vegetable is used to treat fresh wounds and cuts (33). However, only one person reported using C. olitorius L for wound treatment in the current study. This is possibly due to lack of awareness of its values in wound healing.
Most of the study participants reported using the leaves whereas a few use fruits and seeds of the plant for the different medicinal applications. This is in line with other findings in Bangladesh (9) and in Benin (29). In this study, the leaves were often boiled and eaten as part of their daily food. The leaves and fruits may be dried as a mode of preservation for further use whereas the seeds are crushed to form a powder which is used as a herbal tea. This too agrees with the findings in Benin and Bangladesh (9,29).

Conclusions
In All authors read and approved the final manuscript.
The datasets generated and/or analyzed during the current study are not publicly available due to the fact that study is just a portion of a bigger academic study which is still ongoing. Data will be deposited in the Lira university repository upon completion of the study. However, the data can be provided by the corresponding author upon reasonable request.

Corresponding Author
Correspondence to Rebecca Nakaziba

Ethics approval and consent to participate
The study was approved by the REC of Mbarara University of Science and Technology and the National council for Science and Technology. Permission to conduct the study was sought from the area local leaders before accessing the community. In addition, the study aims were thoroughly explained to the participants and their consent obtained by signing a consent form before interviews were conducted.

Consent for publication
Not applicable Map of Oyam district (19)