Ethno-pharmacological survey of herbal remedies used in the treatment of paediatric diseases in Buhunga parish, Rukungiri District, Uganda

Buhunga Parish is located in Buhunga Sub-County, Rukungiri District in the Kigezi Sub-Region of Western Uganda. It is located between latitudes 0^o45^’18.7^″S and longitudes 29^o59^’0.9.6^″E. It is densely populated with a density of 328.8 people per square kilometre. The majority of the people are females. The parish consists of six villages namely Mutanoga, Kitookye, Rutooma, Kishaka, Nyamuyaga and Oruhita. The area is characterized by a hilly fertile landscape with occasional valleys that are dominated by livestock farms and banana plantations. There are two rainy seasons, one occurring from March to May and the other from September to November. The dominant tribes are the Banyakole and Bakiga.

The participants were mainly women (60%) above 18 years old. They had low education levels whereby 50% had not attained any formal education, 40% had attained at least primary education with the balance having attained secondary education level. A majority of participants were women because they are usually involved in caring for children. Most of the women were either single parents or widowed and thus with a heavy burden of providing for their children and had not attained any formal education compared to men who had at least attained primary and secondary levels of education. The low levels of education of participants imply limited employment opportunities and hence limited income. With the limited income, they have no option except the use of herbal medicine to provide healthcare for their children.

The survey revealed a total of 50 medicinal plant species from 26 families were used to treat paediatric diseases. Scientific names, local names, family, growth form, disease treated, plant part(s) and mode of preparation and administration are presented in Table 1. Asteraceae was the most dominant family and contributed eight species followed by Lamiaceae (7), Fabaceae (5), Solanaceae (4) and Myrtaceae (3). The other families had one to two species each.

Herbs formed the highest proportion of medicinal plant species (36%) closely followed by shrubs (32%), trees (22%), climbers (6%) and grasses (4%). The various plants parts used in herbal remedy preparation included fruits, leaves, roots, seeds, stems and the bark. In some cases whole plants were used. Leaves were the most frequently used part (58%), followed by roots (16%). The use of other plant parts was less common and in the range of 2–5%. However, there were instances where more than one plant parts of the same plant were used. For instance the leaves and roots of Vernonia amygdalina were used to treat malaria and worm infestation; leaves and stem bark of Spathodea companulata were used against allergy, dysentery, diarrhoea and asthma; seeds, leaves and roots of Dracaena fragrans were used to treat stomachaches while leaves and roots of Mimosa pudica were used against sores and abscesses.

For herbs, the whole plant was uprooted, leaves were plucked off from shrubs and for trees debarking was the main method of harvesting. Other methods of harvesting included digging out the roots, cutting young branches and picking seeds. Participants revealed that in instances where the species were rare, uprooting whole plants and digging out roots were avoided. They also reported controlled harvesting of plant parts in the range of 0.5–5.0 kg once or twice a week depending on the availability of the plant, severity of the ailment and age of the child.

Some plant parts were extracted from more than one habitat (Table 2). Farmlands were the most common sources of medicinal plant species with frequency of 47% followed by bushes 26%. Only two plant species Datura innoxia and Centella asiatica were extracted from swamps.

A total of 29 diseases were managed using medicinal plant species. The diseases were grouped into 10 categories of which digestive disorders, malaria and respiratory tract infections featured predominantly (Table 3). Species that treated the highest number of health conditions were; Bidens pilosa, Mormodica foetida, Leonotis nepetifolia and Azadirachta indica (Table 1). Some diseases were treated using a single plant species and in other cases a mixture of plant parts from different species were used. Monotherapy preparations were dominant compared to herbal concoctions. For instance jaundice was treated either using the roots of Vernonia lasiopas or leaves of Erlangea tomentosa; asthma using the whole plant of Euphorbia hirta, anal rectal prolapse using leaves of Chenopodium murale, constipation using leaves of Vernonia amygdalina, allergy using leaves of Erlangea cordifolia, epilepsy using leaves of Sesbania sesban and the root tuber of Euphorbia tirucalli as an antidote.

Ailments that were managed using a combination of parts from different plants were; fever using a mixture of leaves of Vernonia amygdalina and V. lasiopas or leaves of V. amygdalina and roots of Iboza riparia. Cough was treated using a mixture of leaves of Eucalyptus grandis, Mangifera indica and Callistemon citrinus. A mixture of leaves of V. amygdalina and Erlangea cordifolia were used to treat headache. Dysentery was treated using leaves of Chenopodium murale and V. amygdalina, toothache using leaves of V. lasiopas and Bidens pilosa.

The major methods of preparation of plant extracts were decoction, infusion, maceration and chewing (Fig. 1). Water was the main solvent used in preparation of herbal therapies. Concoctions involved mixing water with an assortment of different plant parts. Decoctions were commonly used (80%) and were prepared by boiling plant materials in a specific quantity of water for 15–20 min and the mixture allowed to cool before administration. Decoctions were followed by infusions (38%) that involved pouring hot/warm water onto the plant material and allowing the mixture to cool. Maceration was used in 22% of the plant species. It involved crushing plant materials of a single species or a combination of more than one plant parts from different species to extract a liquid which was applied either topically or orally. Minor methods of preparation like pounding and roasting were used with low frequencies in the range of 2–6% of the medicinal plant species.

Some remedies were prepared by pounding the plant material and applying the paste topically on the affected part. In other instances the paste was mixed with water and the resulting mixture drunk. For children below three years of age, the leaves were chewed by the mother of the child who spat the resulting mixture into the child’s mouth. Children above three years of age chewed the leaves on their own. Some plant materials were roasted before applying them topically on the affected body parts. These were mainly used as poultices against abscesses, wounds and snake bites.

The modes of administration of herbal remedies included; leaking dry powdered plant materials especially leaves, drinking decoctions, infusions or concoctions, bathing the child with cold or warm extracts, applying crushed plant materials on the affected body parts, rubbing macerated plant materials on the affected part and mixing herbal preparations with food. Most respondents agreed that oral administration of herbal remedies was the most convenient for children.

There were similarities and variations in the use of plant species in the different villages in the study area. Some plant species were used in all the villages to treat the same ailments. For instance Mangifera indica and Psidium guajava for cough, Vernonia amygdalina against malaria, Dracaena fragrans and Ocimum sauve against stomach pains and Albizia adianthifolia against fever. In contrast, some plant species were used to treat different diseases in different villages. For instance Spathodea campanulata was used to manage asthma in Rutooma and Kishaka villages but used against dysentery in Mutanoga village. Aspilia africana was used to treat epilepsy in Oruhita village but used for diarrhoea in Kitookye and stomachache in Kishaka and Nyamuyaga villages.