Globally, an estimated 25-50% of drugs prescribed are derived from plants (1) of which 80% have their uses related to their original ethnopharmacological purposes (2). Traditional knowledge of plant uses provides a criterion for the pharmaceutical industry to develop the plants (materials) into products (3, 4). Unfortunately, there is poor documentation of the traditional medicinal uses of most of these plants as it is often secretly verbally passed on from one generation to another (5, 6). This leads to high risk of loss of knowledge about plants with medicinal values.
Corchorus olitorius L (also commonly known as Jute mallow and locally referred to as Otigo nino by the Langi people of Northern Uganda), is one of the green leafy vegetables used as traditional medicinal plant in different parts of the world. It belongs to the genus Corchorus, the family of tiliceae. The genus Corchorus comprises an uncertain number of species, with estimates ranging from 40–100. The genus Corchorus probably originated from Africa, with a secondary center of diversity in the Indo-Burmese region. Corchorus olitorius L (C. olitorius) is widespread over tropical Africa and is also found in Nepal, Pakistan, India and Northern Australia. In Africa it occurs from Senegal in the west, east to Somalia and south to South Africa (7). C. olitorius seems closest to Corchorus aestuans, but this particular species has winged fruits (7). C. olitorius has alternate, simple, lanceolate, ﬁnely serrated leaves and small (2–3 cm diameter) yellow ﬂowers with ﬁve petals plus a multi-seeded fruit capsule (7). It can be easily identified by the 3 small horns at the top of the slender capsules, which split at maturity with 3 valves. C. olitorius is propagated by seed (8), although it is occasionally tolerated as a wild vegetable in crop fields with selective weeding, or grown in home gardens. It grows rapidly in the rainy season with flowering occurring continuously about 6 weeks after germination and seeds maturing at 90–110 days from the time of sowing and can be found throughout the year (8). C. olitorius is normally found in savanna, woodland and scrub vegetation, and often grows as a weed. It can be found up to 1700 meter altitude, but is generally grown below 700 meters. In the lowland African tropics, the plant is collected throughout the year. Although it thrives best during the rainy season, it is a drought resistant plant. It can 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 well-drained, 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 (10-14). 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.