17 research outputs found
Selection of active plant extracts against the coffee leaf miner Leucoptera coffeella (Lepidoptera: Lyonetiidae)
Traditional healer's knowledge and implications to the management and control of HIV/AIDS in Arusha, Tanzania
Due do limited coverage of conventional health care services in
Tanzania, a number of HIV/AIDS patients are consequently being cared
for and managed by traditional healers. Knowledge of 132 traditional
healers on HIV/AIDS was assessed through a questionnaire that sought
among other things the symptoms that these traditional healers
associate with HIV/AIDS. Seventy-seven (61%) healers claimed to be
treating HIV/AIDS patients. Twenty-five percent (33 healers) had poor,
52.3% (69 healers) had moderate, 22.7% (30 healers) had good knowledge
of HIV/AIDS. Sixty-nine (52%) among the traditional healers mentioned
six and thirty (23%) healers mentioned more than six symptoms
associated with HIV/AIDS as outlined by the WHO clinical HIV staging
system. Almost all the healers were aware that HIV/AIDS is spread
sexually and through body fluid contact and claimed that precautionary
measures are taken to avoid spread of the disease. Knowledge on
HIV/AIDS infection from mother to child during pregnancy, at delivery
and through breastfeeding was poor for most healers. It seems most
traditional healers meet HIV/AIDS patients in their terminal stages
when HIV/AIDS-related opportunistic infections are highly manifest, a
situation exemplified by the recorded symptoms that were not specific
or directly related to HIV/AIDS. There is a need to impart the
appropriate knowledge in the identified deficient areas to avoid
possibilities of further spread of the disease through the traditional
medicine delivery system
Evaluation of the potential of the marine sponges of the Zanzibar Island to yield antimalarial and antimicrobial active compounds
Emergence of new and re-emergence of old infections continue to elude
prospects of reducing morbidity and mortality caused by microbial
infections. Trends of resistance to currently in use antimicrobials and
antimalarials threaten to increase mortality caused by these
infections. This study explores the potential of marine invertebrates
as a source for new antimicrobials and antimalarials. The lactate
dehydrogenase method was used to assay marine sponges for activity
against Plasmodium falciparum, while the disc diffusion method was used
to assay the extracts for antibacterial and antifungal activity.
Extracts of some marine sponges from the Zanzibar Island exhibited both
antiplasmodial and antimicrobial activities. Among the 55 marine sponge
extracts that were tested 23 (41.8%) inhibited Plasmodium falciparum W2
strain by more than 50% at both 250 and 50 μg/ml concentrations.
Moderate polar extracts were more active against Plasmodium falciparum
W2 strain than polar and non-polar extracts. None of the 12 extracts
that were tested on Plasmodium falciparum strain D6 exhibited
inhibitory activity reaching 50%. Among 18 marine sponge extracts that
were tested for antimicrobial activity 12 (66.7%) showed activity
against one or more of the bacteria and fungi used ranging from weak to
strong on an arbitrary criterion. The ethyl acetate extracts of Agelas
mauritania and Oceanopia sp. exhibited high activity against the
fungi Candida albicans and Cryptococcus neoformans . The best
antibacterial profile was exhibited by ethyl acetate extracts of
Aplysinopsis sp., Halichondrida sp. 1 and Oceanopia sp. In
conclusion, these results support the need for intensified efforts to
search for active antimalarial and antimicrobial compounds from the
Zanzibar marine sponges
Research Project on the Feasibility Study on Essential Oil Distillation in Tanzania : final report
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Brine shrimp toxicity of some plants used as traditional medicines in Kagera Region, north western Tanzania
Dichloromethane and/or ethanol extracts of 30 plants used as
traditional medicines in Bukoba district, northwestern Tanzania were
evaluated for brine shrimp toxicity. Among the 50 extracts tested, 32
extracts (64%) showed very low toxicity with LC50 values above 100
μg/ml. Among these 12 (24%) which had LC50 >500 μg /ml can
be categorized as being practically non-toxic. Among the remaining
extracts 19 (38%) which showed LC50 >100 < 500 μg /ml are
also considered to be non-toxic. Extracts that showed LC50 results
between 30-100 μg/ml have been categorized as mildly toxic; these
include ethanol extracts of Lantana trifolia (LC50 32.3 μg/ml),
Vernonia bradycalyx (LC50 33.9 μg/ml), Antiaris toxicaria (LC50
38.2 μg /ml) and Rubus rigidus (LC50 41.7 μg /ml) and the
dichloromethane extracts of Gynura scandens (LC50 36.5 μg /ml) and
Bridelia micrantha (LC50 32.0 μg /ml). The dichloromethane
extracts of Picralima nitida (LC50 18.3 μg/ml) and Rubus rigidus
(LC50 19.8 μg /ml), were only moderately toxic. Picralima nitida
and Rubus rigidus extracts are only 1.1 and 1.2 less toxic than the
standard drug, cyclophosphamide (LC50 16.3 μg /ml). In conclusion,
the results indicate that among the 30 plants used as traditional
medicines, 28 are safe for short term use. Picralima nitida and Rubus
rigidus extracts are mildly toxic, but by comparison have a remote
possibility to yield active anticancer compounds
Antimicrobial and brine shrimp activity of Acanthus pubescens root extracts
The root dichloromethane and ethyl acetate extracts of Acanthus
pubescens (Oliv.) Engl (ACANTHACEAE) exhibited weak antibacterial
activity against Staphylococcus aureus, Bacillus subtilis, Bacillus
anthracis, Salmonella typhi, Streptococcus faecalis, Streptococcus
agalactiae and Pseudomonas aeruginosa, with MIC values ranging from
1.6-6.25 mg/ml. The two extracts also exhibited weak antifungal
activity against Candida albicans (MIC 6.25 mg/ml). Using the brine
shrimps lethality test ethanol, ethyl acetate and aqueous extracts were
virtually non-toxic to brine shrimp larvae, but the dichloromethane
extract (LC50 38.9 μg/ml) was mildly toxic. These results support
the use of the plant in traditional medicine to treat gonorrhea,
syphilis, gastroenteritis and pneumonia. Since the plant is used in
combination with other plants it is difficult to make any final
conclusions regarding safety and efficacy. Further work is needed to
evaluate the activity of an extract made from a combination of the six
plants
Medicinal Plants in Tissue Engineering and Regenerative Medicine in the African Continent
Antimicrobial and brine shrimp toxicity of some plants used in traditional medicine in Bukoba District, north-western Tanzania
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 15.35-374.0μg/ml.
However, ethanol extracts of Dissotis brazzae and Strombosia scheffleri
had LC50 values of >1000μg/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
Antifungal activity of some Tanzanian plants used traditionally for the treatment of fungal infections.
Contains fulltext :
50678.pdf (publisher's version ) (Closed access)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
Evaluation of cytotoxic, genotoxic and CYP450 enzymatic competition effects of Tanzanian plant extracts traditionally used for treatment of fungal infections.
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