Search

Background: The Kagera region of north western Tanzania has a rich culture of traditional medicine use and practice. Traditional medicines are the mainstay of healthcare in this region and are known to support the management of many illnesses such as malaria, bacterial infections, epilepsy, gynecological problems and others. However, most of the plants being used have either not been documented or evaluated for safety and efficacy or both. This study, the sixth of an ongoing series, reports on the medicinal plants that are used at Kikuku village, Muleba District., Methodology: A semi-structured questionnaire was used to collect information on the common/local names of the plants, parts of the plants used, diseases treated, methods of preparing the herbal remedies, dosage of the remedies administered, frequency and duration of treatment and toxicity of the medicines. A literature review was carried out for information on the ethnomedical uses of the reported plants., Results: A total of 49 plant species belonging to 47 genera and 24 plant families were documented. The family Euphorbiaceae and Asteraceae had the highest representation. The plants are used for the treatment of skin conditions (10 plants; 20%), bacterial infections and wounds (14 plants; 28.6%), malaria (14 plants; 28.6%), gastrointestinal disorders (11 plants; 22.4%), gynecological problems including infertility (8 plants; 16.3%), hypertension (5 plants; 10.2%), viral infections (7 plants; 14.3%), chest problems (5 plants; 10.2%), diabetes (3 plants; 6.1%), cancer (2 plants; 4.1%), inflammatory conditions (arthritis, rheumatism), HIV and AIDS, and hernia each treated by 1 plant (3 plants in total; 6.1%). Information obtained from the literature indicate that 25 (51.0%) of the therapeutic claims are supported by laboratory results or have similar claims of ethnomedical use from other countries., Conclusion: Herbal remedies comprise an important and effective component of the healthcare system in Kikuku village with plants in the families Euphorbiaceae and Asteraceae comprising an important part of plants used in the indigenous healthcare management in the village. Malaria and bacterial infections dominate the list of diseases that are managed using traditional medicines.

Background: The Kagera region of north western Tanzania has a rich culture of traditional medicine use and practices. The dynamic inter-ethnic interactions of different people from the surrounding countries constitute a rich reservoir of herbal based healing practices. This study, the second in an ongoing series, reports on the medicinal plant species used in Katoro ward, Bukoba District, and tries to use the literature to establish proof of the therapeutic claims., Methodology: Ethnomedical information was collected using semi-structured interviews in Kyamlaile and Kashaba villages of Katoro, and in roadside bushes on the way from Katoro to Bukoba through Kyaka. Data collected included the common/local names of the plants, parts used, the diseases treated, methods of preparation, dosage, frequency and duration of treatments. Information on toxicity and antidote were also collected. Literature was consulted to get corroborative information on similar ethnomedical claims and proven biological activities of the plants., Results: Thirty three (33) plant species for treatment of 13 different disease categories were documented. The most frequently treated diseases were those categorized as specific diseases/conditions (23.8% of all remedies) while eye diseases were the least treated using medicinal plants (1.5% of all remedies). Literature reports support 47% of the claims including proven anti-malarial, anti-microbial and anti-inflammatory activity or similar ethnomedical uses. Leaves were the most frequently used plant part (20 species) followed by roots (13 species) while making of decoctions, pounding, squeezing, making infusions, burning and grinding to powder were the most common methods used to prepare a majority of the therapies., Conclusion: Therapeutic claims made on plants used in traditional medicine in Katoro ward of Bukoba district are well supported by literature, with 47% of the claims having already been reported. This study further enhances the validity of plants used in traditional medicine in this region as resources that can be relied on to provide effective, accessible and affordable basic healthcare to the local communities. The plants documented also have the potential of being used in drug development and on farm domestication initiatives.

Background: The Kagera region, in north western Tanzania, is endowed with a strong culture of traditional medicine that is well supported by a rich diversity of medicinal plants. However, most of the plants in this region have not been documented nor evaluated for safety and efficacy. As an initiative in that direction, this study documented the knowledge on medicinal plant use by traditional healers of Bugabo Ward in Bukoba District., Methods: Key informants were selected with the help of local government officials and information on their knowledge and use of plants for therapeutic purposes was gathered using a semi-structured interview format., Results: In this study 94 plant species representing 84 genera and 43 families were found to be commonly used in the treatment of a variety of human ailments. The family Asteraceae had the highest number of species being used as traditional medicines. The study revealed that Malaria is treated using the highest number of different medicinal species (30), followed by skin conditions (19), maternal illnesses and sexually transmitted diseases (14), respiratory diseases (11) and yellow fever, Herpes simplex and peptic ulcers (10). Majority of the species are used to treat less than five different diseases/conditions each and leaves were the most commonly used part, comprising 40% of all the reports on use of plant parts. Trees comprised the most dominant growth form among all plants used for medicinal purposes in the study area., Conclusion: Bugabo Ward has a rich repository of medicinal plants and this reinforces the need for an extensive and comprehensive documentation of medicinal plants in the area and a concomitant evaluation of their biological activity as a basis for developing future medicines.

Herbal medicines constitute a potentially important resource for new and safe drugs for the management of microbial infections and other diseases. In this study, dichloromethane, ethylacetate and ethanol extracts of Canarium schweinfurthii Engl., Dissotis brazzae Cong., Iboza urticifolia (Bak) E.A.Bruce, Isoglosa lacteal Lindau, Strombosia Scheffleri Engl., and Whitfieldia elongate T. Anders were tested for antimicrobial activity and brine shrimp toxicity. The objective was to validate claims that they are used to treat bacterial infections, diarrhoea and heal wounds among the Haya tribe of north-western Tanzania. At least one extract of each plant showed antibacterial activity. Dichloromethane extracts were the most active while ethanol extracts were the least active. Extracts of Whitfieldia elongate and Isoglossa lacteal were the most and least active with MICs in the range 0.08-0.62 mg/ml and 15.6-62.5 mg/ml, respectively. The dichloromethane extract of Whitfieldia elongate exhibited strong antifungal activity against Cryptococcus neoformans. Against brine shrimp larvae, the extracts from the six plants exhibited a low to very low toxicity with LC50 values ranging from 15.35-374.0 microg/ml. However, ethanol extracts of Dissotis brazzae and Strombosia scheffleri had LC50 values of >1000 microg/ml. The seemingly innocuous nature and relatively good antibacterial activity against skin infections and gastrointestinal pathogenic bacteria support the traditional uses of the plants and deserve more detailed studies.

HIV-infected patients in sub-Saharan countries highly depend on traditional medicines for the treatment of opportunistic oral infections as candidiasis. Previous investigations on antifungal activity of medicinal plant extracts utilized by traditional healers in Tanzania have revealed 12 extracts with potent antifungal activity. Although the plants may be good candidates for new treatment opportunities, they can be toxic or genotoxic and could cause pharmacokinetic interactions when used concomitantly with antiretroviral agents. Therefore, we investigated the cytotoxicity, genotoxicity and cytochrome P450 interaction potential of these medicinal plants. Cytotoxicity was tested by Hoechst 33342, Alamar Blue, calcein-AM, glutathione depletion and O(2)-consumption assays and genotoxicity by a Vitotox assay. Competition of the 12 extracts on substrate metabolism by CYP3A4, 2C9, 2C19 and 2D6 was tested with high-throughput CYP inhibition screening. Pregnane X receptor (PXR) activation was tested using Chinese hamster ovary cell lines expressing human PXR. Herbal extracts inducing high human PXR activation were tested for enhanced CYP3A4 mRNA levels with quantitative polymerase chain reaction. Genotoxicity was found for Jatropha multifida, Sterculia africana and Spirostachys africana. All plant extracts showed high cytotoxic effects in almost all tests. Potent competition with CYP3A4, 2D6, 2C9 and 2C19 was found for 75% of the herbal extracts. Spirostachys africana did not affect CYP2D6 and for S. africana and Turraea holstii no effect on CYP2D6 and CYP3A4 (DBF) was found. Nine plant extracts showed significant activation of human PXR, but only Agaura salicifolia, Turraea holstii and S. africana significantly induced CYP3A4 mRNA levels. These results indicate the possibility of potential medicinal plant-antiretroviral interactions.

Collaboration between traditional healers and biomedical practitioners is now being accepted by many African countries south of the Sahara because of the increasing problem of HIV/AIDS. The key problem, however, is how to initiate collaboration between two health systems which differ in theory of disease causation and management. This paper presents findings on experience learned by initiation of collaboration between traditional healers and the Institute of Traditional Medicine in Arusha and Dar-es-Salaam Municipalities, Tanzania where 132 and 60 traditional healers respectively were interviewed. Of these 110 traditional healers claimed to be treating HIV/AIDS. The objective of the study was to initiate sustainable collaboration with traditional healers in managing HIV/AIDS. Consultative meetings with leaders of traditional healers' associations and government officials were held, followed by surveys at respective traditional healers' "vilinge" (traditional clinics). The findings were analysed using both qualitative and quantitative methods. The findings showed that influential people and leaders of traditional healers' association appeared to be gatekeepers to access potential good healers in the two study areas. After consultative meetings these leaders showed to be willing to collaborate; and opened doors to other traditional healers, who too were willing to collaborate with the Institute of Traditional Medicine in managing HIV/AIDS patients. Seventy five percent of traditional healers who claimed to be treating HIV/AIDS knew some HIV/AIDS symptoms; and some traditional healers attempted to manage these symptoms. Even though, they were willing to collaborate with the Institute of Traditional Medicine there were nevertheless some reservations based on questions surrounding sharing from collaboration. The reality of past experiences of mistreatment of traditional healers in the colonial period informed these reservations. General findings suggest that initiating collaboration is not as easy as it appears to be from the literature, if it is to be meaningful; and thus we are calling for appropriate strategies to access potential healers targeted for any study designed with sustainability in mind.

Using the ethnobotanical approach, some Tanzanian plants reported to be used by traditional healers for the treatment of oral candidiasis and fungal infections of the skin were collected and screened for their antifungal activity against Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, Candida krusei and Cryptococcus neoformans. A total of 65 crude methanol extracts belonging to 56 plant species and 38 families were screened using the broth microdilution method, according to the guidelines of the Clinical and Laboratory Standard Institute (CLSI) (formerly, National Committee for Clinical and Laboratory Standards) [National Committee for Clinical Laboratory Standards, 2002. Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts. Approved Standard-2nd Edition M27-A2, National Committee for Clinical Laboratory Standards, Wayne, PA, USA]. Among the tested plant species, 45% (25 species) showed antifungal activity against one or more of the test fungi. The most susceptible yeasts were Cryptococcus neoformans, followed by Candida krusei, Candida tropicalis, and Candida parapsilosis. The least susceptible were Candida albicans and Candida glabrata. Strong antifungal activity was exhibited by extracts of Clausena anisata Oliv., Sclerocariya birrea Sond, Turraea holstii Gurk, Sterculia africana (Lour) Fiori, Acacia robusta subsp. Usambarensis (Taub) Brenan, Cyphosterma hildebrandti (Gilg), Desc, Elaeodendron buchannanii (Lows), Acacia nilotica (L.) Wild ex Del, Jatropha multifida L., and Pteridium aquilinum (L.) Kuhn.

An ethnomedical survey in Coast, Dar es Salaam, Morogoro and Tanga regions of Tanzania has resulted in the identification of 36 plant species belonging to 21 plant families that are used traditionally for the treatment of Candida infections. Twenty-one plants constituting 58.3% of all collected plants are used to treat of oral candidiasis (Utando) one of the important signs of HIV/AIDS. The knowledge of traditional healers for the treatment of Candida infections has been highly supported by the literature in that 13 (36.1%) out of the 36 plants identified have been proven to be active against Candida albicans and/or other species of Candida. Also, some of the plants were reported to be active against other species of fungi including Cryptococcus neoformans, one of the important pathogenic fungi in HIV/AIDS. It can be seen that ethnomedical information from traditional healers provides a solid lead towards development of new drugs than random screening. The task that remains is to screen extracts prepared from these plants and perform a bioassay-guided fractionation of the active extracts so as to isolate the active compounds from these plants.

A cross-sectional study performed in Temeke District (Dar es Salaam, Tanzania) showed that 5.5% of the traditional healers have knowledge for the treatment of epilepsy. Of the 100 healers interviewed, 30 (30%) believed that epilepsy was caused by witchcraft, while 19 (19%) thought epilepsy has a genetic origin which can be inherited. Other healers thought epilepsy can be caused by head injury or malaria (24%), and the remaining 27% did not know the cause. Most of the healers (92%) could present an accurate account on the symptoms of the disease, including dizziness, loss of consciousness, abrupt falling down, frothing from the mouth, loss of memory, biting of the tongue, confusion, and restlessness. They showed competence in the treatment of the disease, whereby 60 plants that are commonly used were mentioned. Abrus precatorius L. (Leguminosae), Clausena anisata (Willd.) Oliv. (Rutaceae) and Hoslundia opposita Vahl (Lamiaceae), which are among the plants mentioned, have proven anticonvulsant activity, while a few other species on their list have been reported to be useful in the treatment of epilepsy. Biological testing of these plants, using different models of convulsions is, suggested.