Ethnobotanical plants used in the management of symptoms of tuberculosis in rural Uganda

Investigation of the antimycobacterial activity of African medicinal plants combined with chemometric analysis to identify potential leads

The emergence of drug-resistant Mycobacterium tuberculosis strains is a threat to global health necessitating the discovery of novel chemotherapeutic agents. Natural products drug discovery, which previously led to the discovery of rifamycins, is a valuable approach in this endeavor. Against this backdrop, we set out to investigate the in vitro antimycobacterial properties of medicinal plants from Ghana and South Africa, evaluating 36 extracts and their 252 corresponding solid phase extraction (SPE) generated fractions primarily against the non-pathogenic Mycobacterium smegmatis and Mycobacterium aurum species. The most potent fraction was further evaluated in vitro against infectious M. tuberculosis strain. Crinum asiaticum (bulb) (Amaryllidaceae) emerged as the most potent plant species with specific fractions showing exceptional, near equipotent activity against the non-pathogenic Mycobacterium species (0.39 µg/ml ≤ MIC ≤ 25 µg/ml) with one fraction being moderately active (MIC = 32.6 µg/ml) against M. tuberculosis. Metabolomic analysis led to the identification of eight compounds predicted to be active against M. smegmatis and M. aurum. In conclusion, from our comprehensive study, we generated data which provided an insight into the antimycobacterial properties of Ghanaian and South African plants. Future work will be focused on the isolation and evaluation of the compounds predicted to be active.

Medicinal plants used by traditional medicine practitioners in treatment of alcohol-related disorders in Bushenyi District, southwestern Uganda

Background

Alcohol-related disorders rank seventh among risk factors for morbidity and mortality globally, posing a significant public health burden. In Africa, including Uganda, there is limited availability and utilization of pharmacotherapies to treat alcohol-related disorders. This study documented medicinal plant species, plant parts used, and the methods of preparation and administration utilized by Traditional Medicine Practitioners (TMPs) in treating alcohol-related disorders in southwestern Uganda.

Methods

A descriptive cross-sectional ethnopharmacological survey was conducted among TMPs within Bushenyi District, southwestern Uganda. Data was collected with key informant interviews using semi-structured questionnaires. The TMPs identified medicinal plants by local names. Plant specimens were collected and deposited at the Department of Biology, Faculty of Science, Mbarara University for identification and voucher numbers allocated. The plant scientific names and species were identified based on the International Plant Names Index. Plant species, family, life form, number of mentions, method of collection, preparation and administration were analyzed using descriptive statistics in Microsoft Excel. The survey data were utilized to compute Frequency of Citation, Relative Frequency of Citation, and Informant Consensus Factor.

Results

We enrolled 50 traditional medicine practitioners aged between 34 and 98 years, with a mean age of 67. Approximately two-thirds were female (66%, 33/50), and mean experience in traditional healing was 31 years. The total number of plants identified were 25 belonging to 20 families. The most prevalent plant life form was herbs (36%) while grasses (4%), were the least. Leaves (48%) were the most utilized plant parts with the least utilized being the barks. The most prevalent method, adopted by approximately one-third of the TMPs, involved drying the plant material in the sun. The Informant Consensus Factor was 0.67.

Conclusion

The study shows that the traditional medicine practitioners in Bushenyi district use a wide diversity of plants species to treat alcohol related disorders. The relatively high Informant Consensus Factor suggests a significant level of agreement among TMPs regarding the use of the identified plants. We recommend further investigations into phytochemistry, safety, efficacy, and mechanisms of action of the identified plants.

Ethnobotanical study of nutraceutical plants used to manage opportunistic infections associated with HIV/AIDS in Acholi sub-region, Northern Uganda

BACKGROUND

Nutraceutical plants play a potential role as supportive treatment with antiretroviral drugs in the management of opportunistic infections associated with HIV/AIDS. There is limited documentation of nutraceutical plants in Northern Uganda and limited literature addressing processes to be adopted for quality assurance of herbal formulations in Uganda. This study aimed to document plant species with nutritional and medicinal properties used for managing opportunistic infections associated with HIV/AIDS by traditional medicine practitioners (TMPs), who included professional herbalists, herbal farmers and herbal sellers in Acholi sub region, Northern Uganda.

METHODS

An ethnobotanical study was carried out in Amuru, Gulu and Pader districts, Northern Uganda. Cross-sectional data were collected using purposive and snowball sampling techniques. A total of four hundred (378 women and 22 men) informants were selected. Data were collected using semistructured interviews, focus group discussions and direct observation. Data were analysed using descriptive statistics, familiarity index (FI), fidelity level (FL) and informant consensus factor (ICF).

RESULTS

This study recorded a total of 84 nutraceutical plant species, which are used to manage opportunistic infections associated with HIV/AIDS. Most abundant families were Leguminoceae, Asteraceae and Solanaceae. Six nutraceutical plants that had higher fidelity level and familiarity index values included Momordica foetida Schumach, Erigeron floribundus (Kunth) Sch. Bip, Mangifera indica L, Cajanus cajan L. Millsp, Eucalyptus globulus Labill and Cucurbita pepo L. Respondents' knowledge on nutraceutical plants had a positive significant correlation with age (R2 = 0.0524, p ≤ 0.01). The popular mode of preparation are decoctions/boiling in water (70%), while the most used route of administration is oral (76%). TMPs tried to ensure that during collection and processing, plant materials were free from contamination. TMPs reported limited knowledge on preservation techniques.

CONCLUSIONS

This study demonstrates the availability and diversity of nutraceutical plants in Uganda and reports methods of processing and administration used by TMPs. Both men and women used nutraceutical plants to manage opportunistic infections associated with HIV/AIDS and showed great extent of their traditional knowledge. Most of the nutraceutical plants in study area are wild and abundant; however, high percentage use of plant roots and bark threatens the sustainable use from the wild.

Herbal remedies used by traditional healers to treat haemorrhoids in Tabora region, Tanzania

CONTEXT

Haemorrhoids are one of the most common gastrointestinal disorders in humans. In Tanzania, particularly in the Tabora region, medicinal plants (MPs) are used by traditional healers (THs) to treat haemorrhoids, but no study has explicitly attempted to compile these treatments.

OBJECTIVE

This study documents MPs used by THs of the Tabora region in Tanzania to treat haemorrhoids.

MATERIALS AND METHODS

A semi-structured questionnaire was used to gather ethnobotanical data from 44 THs on MPs used to treat haemorrhoids, parts used, preparation methods and administration routes. The collected ethnobotanical data were analysed by computing percentage frequencies and relative frequency citations.

RESULTS

Twenty-six MPs belonging to 19 families and 25 genera, used to manage haemorrhoids, were documented. Fabaceae was the dominant family (four species), whereas shrubs constituted a high proportion (38.46%) of the MPs, and the root was the most (30.3%) utilized plant part. Decoction (38.5%) and topical application (53.8%) were the most preferred preparation and administration techniques. Most MP materials (76.9%) were sourced from the wild. Aloe vera (L.) Burm.f. (Asphodelaceae) (68%), followed by Allium sativum L. (Alliaceae) (66%) and Psidium guajava L. (Myrtaceae) (66%) were the most utilized MPs. Among the recorded MPs, 12 are reported for the first time for the treatment of haemorrhoids. The recorded MPs are believed to possess anti-inflammatory properties that aid in managing inflammation associated with bowel diseases, including haemorrhoids.

CONCLUSIONS

This study has documented valuable MPs used to manage haemorrhoids and provides a basis for further studies to discover efficient and affordable anti-haemorrhoid drugs.

Medicinal plant use, conservation, and the associated traditional knowledge in rural communities in Eastern Uganda

Background

The global consumption of herbal medicine is increasing steadily, posing an extinction risk to medicinal plants. Uganda is among the top ten countries with a high threat of herbal medicine extinction, and Traditional Medicinal Knowledge (TMK) erosion. This might be attributed to the inadequate documentation, plus many more unclear hindrances. In this study, plant species used to treat human diseases in Butaleja district in Eastern Uganda and their associated TMK were documented. The conservation methods for medicinal plants were also evaluated. The rationale was to support the preservation of ethnopharmacological knowledge.

Methods

Data were collected from 80 herbalists using semi-structured questionnaires, from July 2020 to March 2021. Additionally, guided field walks and observations were conducted. Quantitative indices such as, use categories and informant consensus factor (ICF) were evaluated to elucidate the importance of the medicinal plants. Data were analyzed using STATA version-15.0 software.

Results

In total, 133 species, belonging to 34 families and 125 genera were identified. Fabaceae (65%), and Solanaceae (29%) were the dominant families. Leaves (80%), and roots (15%), were the commonest parts used in medicinal preparations; mostly administered orally as decoctions (34.6%) and infusions (16%). The commonest illnesses treated were cough (7.74%), gastric ulcers (7.42%), and malaria (4.52%). The informant consensus factor was high for all disease categories (≥ 0.8), indicating homogeneity of knowledge about remedies used. Only 73% of the respondents made efforts to conserve medicinal plants. The commonest conservation strategy was preservation of forests with spiritually valued species (100%), while compliance with government regulations was the rarest (4.5%). Overall, efforts to stop the extinction of medicinal plants and TMK were inadequate.

Conclusion and recommendations

There was enormous dependency on a rich diversity of medicinal plant species and TMK for healthcare and income generation. The potential for medicinal plant biodiversity loss was evident due to habitat destruction. Inclusion of traditional cultural norms in conservation strategies, and laboratory-based efficacy tests for the species identified are necessary, to promote the conservative and utilization of validated herbal medicines and TMK in rural settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41182-022-00428-1.

Phytochemical screening, antimycobacterial activity and acute toxicity of crude extracts of selected medicinal plant species used locally in the treatment of tuberculosis in Uganda

Background

Tuberculosis (TB) is one of the leading causes of death globally, and the rise in drug-resistant forms of TB has become a significant threat. Subsequently, it is crucial to explore new, effective and safe anti-TB agents. This study aimed at conducting phytochemical screening, antimycobacterial activity, and acute toxicity of the selected plant species’ crude extracts to assess their toxicological potentials and efficacies against TB.

Methods

The aqueous and methanol/dichloromethane (DCM) (1:1) extracts of each selected plant species were subjected to phytochemical screening and antimycobacterial activity using microplate alamar blue assay. For acute toxicity, a single dose (2000 mg/kg) of the aqueous extracts was orally administered to each animal following the Organization for Economic Cooperation and Development (OECD) guidelines No. 425 and then observed for 14 days. The animals were closely observed on the general behavior and clinical signs of toxicity, and body weights were recorded. After the termination of the experiment, hematological, biochemical, and histopathological analyses were performed.

Results

The extracts contained alkaloids, flavonoids, tannins, saponins, steroids, terpenoids, resins, cardiac glycosides, phenolic compounds, and coumarins. Aqueous extracts showed moderate to weak activity against the susceptible (H₃₇Rv) M. tuberculosis strain and weak activity against the MDR-TB strain with Minimum Inhibitory Concentrations (MIC μg/mL) ranging from 293.0–2344.0 and 1172.0–4688.0, respectively. Methanol/DCM extracts showed significant to moderate activity against the susceptible TB strain and moderate to weak activity against the MDR-TB strain with MIC (μg/mL) ranging from 98.0–586.0 and 293.0–781.0, respectively. One mortality was recorded from the A. coriaria treated group following the acute toxicity tests, but the LD₅₀ of all the extracts was estimated to be above 2000 mg/kg. Histopathological analyses did not show any significant lesions in the examined organs except those from the A. coriaria treated group.

Conclusion

Phytochemical screening of the extracts revealed the presence of alkaloids, tannins, saponins, flavonoids, steroids, terpenoids, resins, cardiac glycosides, phenolic compounds, and coumarins. All the methanol/DCM extracts of the plant species studied have promising antimycobacterial activity. The selected plant extracts studied exhibited low acute toxicity levels except for A. coriaria and could be safe for formulations into herbal products.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41182-022-00406-7.