Medicinal plants used by Tanzanian traditional healers in the management of Candida infections.

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.

Quality of antiretroviral drugs, stavudine and indinavir capsules available in the Tanzanian market

Background: The number of antiretroviral drugs (ARVs) available to HIV/AIDS patients in Tanzania is increasing due to a number of intervention programs such as PEPFAR and the Clinton Foundation. These ARVs are imported from a number of countries. However; currently there are no reports on the quality of these medicines imported into Tanzania.The sale of substandard and counterfeit drugs has been well documented particularly in developing countries. The marketing of counterfeit and substandard antiretroviral drugs has also been widely reported in Africa. It is therefore important to closely monitor the quality of ARVs marketed in Tanzania to ensure that substandard or fake products are uncovered before great harm is done to public health.Objective: To assess the quality of ARVs marketed in Tanzania.Methodology: A total of five samples of two generic drugs (stavudine and indinavir) from different manufacturers were randomly collected from various retail pharmacies.Assessment of package inserts and labels was carried out using the Tanzania Food and Drugs Authority (TFDA) specifications. The capsules were analyzed for the content of the active components using validated in-house methodsResults: All samples of Indinavir and Stavudine investigated conformed to the packaging and labeling specifications. However; all Indinavir samples were found to contain excess amount of active ingredient (112.6- 118) compared to the official limit of 95 - 105. One sample of stavudine capsules failed the dissolution test; releasing only 56instead of the specified 80of the active ingredient. Conclusion: The results of this study emphasize the need for careful monitoring of the quality of drugs to ensure their safety and efficacy

Antimicrobial activity of tanzanian chewing sticks against oral pathogenic microbes.

Methanol extracts from the bark and wood of ten plants used as chewing sticks in Morogoro region, in Tanzania, were tested for their ability to inhibit the growth of cariogenic bacteria, Streptococcus mutans , Actinomyces viscosus and a yeast Candida albicans . Screening for antimicrobial activity was done by the agar-hole diffusion method, and minimum inhibitory concentrations (MICs) were determined by the agar dilution method. Extracts from seven out of the ten plants showed varying degrees of growth inhibitory effect on the microorganisms, with Acacia senegal var. senegal stem bark being the most active, followed by the stem bark of Eriosema psoraleoides . Their MICs ranged from 0.63 mg/ml to 5 mg/ml. Three plants Ocimum suave , Opilia celtidifolia and Xerophyta suaveolens did not exhibit any antimicrobial effect. Actinomyces viscosus was relatively more sensitive to the extracts than S. mutans and C. albicans . This study has also demonstrated that most bark extracts possessed antimicrobial activity, while many wood extracts were inactive. It is, therefore, advisable to use, for toothbrushing, unpeeled, rather than peeled chewing sticks, in order to exploit fully their antimicrobial effect. However, additional studies are needed to determine their antiplaque, anticaries and antimycotic effects.

Lupane derivatives from Lophopetalum wallichii with farnesyl protein transferase inhibitory activity.

Chloroform-soluble extracts of the stems and of the mixed stems and stem bark of Lophopetalum wallichii were found to be inhibitory in a farnesyl protein transferase (FPTase) bioassay system. During the course of activity-guided fractionation, the known lupane-type triterpenes, ochraceolide A (1), ochraceolide B (2), betulin, and lupeol and the new lupane lactone, dihydro ochraceolide A (4), were isolated. The stereochemistry of the epoxide group of ochraceolide B (2) was determined by preparation of both epoxide isomers [2, and the new semisynthetic derivative, 20-epi-ochraceolide B (3)] from 1. The structure of 4 was established by reduction of 1 with sodium borohydride. Compounds 1 and 2 exhibited significant inhibitory activity in the FPTase assay (IC50 values of 1.0 and 0.7 microgram/mL, respectively). Lupeol was found to be weakly active (IC50 65.0 micrograms/mL) in this test system, whereas no significant inhibition was detected for betulin or compounds 3 or 4. When evaluated against a panel of human cancer cells in culture, compounds 1 and 4 were modestly cytotoxic. Compounds 2 and 3 were not active in the panel.

Quinone-methide triterpenes and salaspermic acid from Kokoona ochracea.

Tingenone[1],20-hydroxy-20-epi-tingenone[2],celastrol[ 3], and salaspermic acid [4] have been isolated from Kokoona ochracea stem bark. The quinone-methide triterpenes 1-3 exhibited strong but non-specific in vitro cytotoxicity against P-388 murine lymphocytic leukemia cells and a panel of human cancer cell lines. Salaspermic acid [4] was not active in all the cancer cell lines used in this investigation. 13C-nmr spectra assignments for salaspermic acid have been accomplished through the application of 1D and 2D nmr spectral techniques, and 13C-nmr assignments for celastrol [3] have been revised.

Isolation of echinocystic acid-3-O-sulfate, a new triterpene, from Tetrapleura tetraptera, and evaluation of the mutagenic potential of molluscicidal extracts and isolates.

A known triterpene glycoside, 3-O-[beta-D-glucopyranosyl-(1"-6')-2'-acetamido-2'-deoxy-beta-D-gluco pyranosyl]olean-12-en-28-oic acid [3], and new sulfated triterpene, echinocystic acid-3-O-sodium sulfate [4], have been isolated from the stem bark of Tetrapleura tetraptera. Compound 3 was 100% lethal to Biomphalaria glabrata at 20 ppm, while 4 was not molluscicidal at the same concentration. In a forward mutation assay utilizing Salmonella typhimurium strain TM677, T. tetraptera stem bark extracts were found to be mutagenic in the absence of a metabolic activating system (S-9). An MeOH extract of the fruit exhibited weak mutagenic activity only in the presence of S-9. The stem bark isolates, which included aridanin [1], 3-O-(2'-acetamido-2'-deoxy-beta-D-glucopyranosyl)echinocystic acid [2], and compounds 3 and 4, were not mutagenic either with or without metabolic activation.

Further lupane lactones from Kokoona ochracea.

Additional new lupane lactones were isolated from the stem bark of Kokoona ochracea (Celastraceae). Their structures have been elucidated, through the application of 1D and 2D nmr spectroscopic methods, as 20,29-dihydroxy-3-oxolupan-30,21 alpha-olide (ochraceolide D) [1] and 28-hydroxy-3-oxolup-20(29)-en-30,21 alpha-olide (ochraceolide E) [2]. These compounds and the mono- and di-acetates of ochraceolide D (4 and 5, respectively) were evaluated for in vitro cytotoxic activity against P-388 murine lymphocytic leukemia cells and a panel of human cancer cell systems. Ochraceolide D [1] was significantly cytotoxic (ED50, 3.9 micrograms/ml) against human glioblastoma (U373) cells. Other compounds (4, 5, and 2) exhibited only a weak cytotoxic response in certain cancer cell lines.

New cytotoxic lupane lactones from Kokoona ochracea.

Three new compounds, ochraceolides A, B, and C, were isolated from nonpolar extracts derived from Kokoona ochracea stem bark. Based on spectroscopic data, their structures were determined to be the closely related lupane lactones: 3-oxolup-20(29)-en-30,21 alpha-olide, 20,29-epoxy-3-oxolupan-30,21 alpha-olide, and 3,6-dioxolup-20(29)-en-30,21 alpha-olide. Compounds 1 and 3 exhibited significant cytotoxic activity with cultured P-388 cells (ED50 values of 0.26 and 0.53 microgram/ml, respectively) but were at least tenfold less active with a variety of human tumor cell lines. Compound 2 was weakly active with cultured P-388 and KB-3 cells (ED50 values of 7.8 and 5.2 micrograms/ml, respectively), but no significant activity was observed with other human cancer cell types (ED50 values of more than 20 micrograms/ml).