Chemical Composition and Antimicrobial Activity of Geniosporum rotundifolium Briq and Haumaniastrum villosum (Bene) AJ Paton (Lamiaceae) Essential Oils from Tanzania

Purpose: To determine the chemical composition and antimicrobial potential of essential oils from two aromatic plants of Tanzania, Geniosporum rotundifolium Briq. and Haumaniastrum villosum (Benè) A.J. Paton (Lamiaceae).Method: Essential oils from the aerial parts of the plants were extracted by hydro-distillation for 3 h using a Clevenger type of apparatus. The constituents were analyzed by gas chromatography – mass spectrometry (GC/MS).The minimum inhibitory concentrations of the essential oils were determined for eight bacterial strains and three pathogenic fungi using agar dilution method.Results: The constituents of G. rotundifolium oil were mainly oxygenated derivatives of mono- and sesquiterpenes; spathulenol (12.46 %), α-terpineol (4.65 %) and germacrene-D (3.71 %) were the most abundant. Those of H. villosum oil were predominantly sesquiterpenes (72.61 %) with caryophyllene oxide (19.01 %), humulene epoxide II (11.95 %), β-bourbonene (5.7 %), α-humulene (5.63 %) and β- caryophyllene (5.39 %) being more abundant. The oil of G. rotundifolium exhibited weak to moderate activity against the bacterial species but showed no activity against the test fungi. However, H. villosum oil showed very promising activity against all the test microorganisms (MIC 0.08 – 10.34 mg/mL).Conclusion: The major components of G. rotundifolium essential oil were oxygenated derivatives of mono- and sesquiterpenes whereas those of H. villosum were sesquiterpenes. All tested microorganisms were susceptible to H. villosum oil.Keywords: Geniosporum rotundifolium, Haumaniastrum villosum, Essential oils, Chemical composition, Antimicrobial activit

Screening of Tanzanian medicinal plants for anti-Candida activity

BACKGROUND: Candida albicans has become resistant to the already limited, toxic and expensive anti-Candida agents available in the market. These factors necessitate the search for new anti-fungal agents. METHODS: Sixty-three plant extracts, from 56 Tanzanian plant species obtained through the literature and interviews with traditional healers, were evaluated for anti-Candida activity. Aqueous methanolic extracts were screened for anti-Candida activity by bioautography agar overlay method, using a standard strain of Candida albicans (ATCC 90028). RESULTS: Twenty- seven (48%) out of the 56 plants were found to be active. Extracts of the root barks of Albizia anthelmintica and Balanites aegyptiaca, and roots of Plectranthus barbatus showed strong activity. CONCLUSION: The extracts that showed strong anti-Candida activity are worth of further investigation in order to isolate and identify the active compounds

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-30,21alpha-olide (ochraceolide D) [1] and 28-hydroxy-3-oxolup-20(29)-en-30,21alpha-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 mug/ml) against human glioblastoma (U373) cells. Other compounds (4, 5, and 2) exhibited only a weak cytotoxic response in certain cancer cell lines

Isolation of a new cytotoxic compound, 3-((Z)-heptadec-14-enyl) benzene-1-ol from Rhus natalensis root extract

Background: R. natalensis.Bernh ex C.Krauss (Anacardiaceae) is used by Traditional Health Practitioners (THPs) in Same district, north eastern Tanzania, for treatment of cancer and other diseases. The current study was done to determine its cytotoxic activity. Methodology: Dried root powder was extracted by cold maceration with a 1:1 mixture of methanol and dichloromethane. Sequential VLC fractions (Petroleum ether, ethyl acetate, and methanol) of the extract were made and tested for toxicity against brine shrimp (Artemia salina) larvae. The ethyl acetate fraction, which exhibited the highest toxicity against brine shrimp larvae, was used for bioassay-guided isolation and to test for cytotoxic activity against HeLa cervical cancer cells and antioxidant activity. Results: The ethyl acetate extract was the most toxic against the brine shrimp larvae with LC50 7.2 mu g/mL at (95 % CI of 4.993/10.033), while the methanol fraction gave an LC50 346.8 mu g/mL. The ethyl acetate extracts exhibited antioxidant activity in both the DPPH and FRAP with EC50 = 83.05 +/- 0.06 mu g/mL and (58.75 +/- 0.091 mu mol Fe2+ /g dry weight respectively. It also revealed cytotoxic activity against HeLa cervical cancer cells with IC50 of 17.2 +/- 3.4 mu g/mL. A new compound, 3-((Z)-heptadec-14-enyl) benzene -1-ol, isolated from the ethyl acetate extract exhibited a weak cytotoxic activity of 35.24 +/- 3.5 mu g/mL on HeLa cells. Cell cycle analysis showed that the ethyl acetate extract inhibited mitosis and induced apoptosis as evidenced by activation of caspase 3 and membrane phosphatidylserine translocation. Conclusion: The present results provide initial evidence that the root extract of R.natalensis contains compounds with both cytotoxic and antioxidant activity. Further studies are needed to determine activity on other cancer cell lines and to further elucidate the mechanism of cytotoxic activity

Curricular transformation of health professions education in Tanzania: The process at Muhimbili University of Health and Allied Sciences (2008–2011)

Tanzania requires more health professionals equipped to tackle its serious health challenges. When it became an independent university in 2007, Muhimbili University of Health and Allied Sciences (MUHAS) decided to transform its educational offerings to ensure its students practice competently and contribute to improving population health. In 2008, in collaboration with the University of California San Francisco (UCSF), all MUHAS's schools (dentistry, medicine, nursing, pharmacy, and public health and social sciences) and institutes (traditional medicine and allied health sciences) began a university-wide process to revise curricula. Adopting university-wide committee structures, procedures, and a common schedule, MUHAS faculty set out to: (i) identify specific competencies for students to achieve by graduation (in eight domains, six that are interprofessional, hence consistent across schools); (ii) engage stakeholders to understand adequacies and inadequacies of current curricula; and (iii) restructure and revise curricula introducing competencies. The Tanzania Commission for Universities accredited the curricula in September 2011, and faculty started implementation with first-year students in October 2011. We learned that curricular revision of this magnitude requires: a compelling directive for change, designated leadership, resource mobilization inclusion of all stakeholders, clear guiding principles, an iterative plan linking flexible timetables to phases for curriculum development, engagement in skills training for the cultivation of future leaders, and extensive communication.</p