Biological And Pre-Clinical Studies

 The Department of Biological and Pre-Clinical Studies is one of the three departments in the Institute of Traditional Medicine (ITM) involved in research, training and consultancy services. The Department has eight (8) academic members of staff including Associate Research Professors (2), Senior Research Fellows (1), Research Fellow (1), Assistant Lecturer (3) and Tutorial Assistant (1). In addition, the Department has two technical staff including Laboratory Scientist and Laboratory Assistant.

Major Functions

(i) Screening of medicinal plants collected from traditional healers to establish the presence of pharmacological activity.

(ii) To carry out toxicological studies on medicinal plant extracts to generate knowledge which will form the basis for:

• Assessment of the safety of different traditional medicines used in the country.
• Recommendation to the public on the safety of traditional medicines prepared by Traditional health Practitioners.
• Regulatory approval of newly developed herbal formulations or drugs

(iii) To search for reliable, simple and reproducible bioassays for preliminary screening of medicinal plant extracts.

(iv) To identify the mechanism of action of traditional medicines used by Traditional health Practitioners and suggest possible lines of development of products from isolated active compounds.

(v) To collaborate with the Department of Natural Products and Formulation To carry out standardization of indigenous and exotic medicinal plant products.

(vi) To collaborate with the Department of Natural Products and Formulation in the Bio-assay guided fractionation and isolation of active compounds from plant extracts.

In future, the Institute of Traditional Medicine intends to establish a related Department that will be responsible for Clinical Evaluation of traditional medicines. The new Department will have the following functions:

(i) To plan and conduct clinical trials to establish the safety and efficacy of traditional medicines within ethical and scientific requirements.

(ii) To document the relevant practices of Traditional health Practitioners as a means to identify effective therapies which can be taken up for drug development.

(iii) To monitor short term and long term toxicities due to traditional medicines.

(iv) To generate clinical data to support regulatory approval of traditional medicines.

2. Research

HIV/AIDS Projects:

Researchers and students from this Department collaborated with other researchers within ITM and from outside Tanzania in HIV research works. There were studies on various plants including of the genus Combretum, Terminalia, Garcinia and Carissa. These species have been earmarked as potential sources of bioactive anti-HIV-1 compounds. Screening of the crude extracts, fractions and isolated compounds for HIV-1 PR and RT inhibition and HIV-1 neutralization activities were reported.

In-vivo and in-vitro antimalarial testing:

Both, in-vivo and in vitro testing for antimalaria activity has been established. In vivo testing using Plasmodium berghei malaria model in mice has been strengthened by involving undergraduate and postgraduate (MSc & PhD) students. Two academicians in the department were trained on malaria parasite culture and in vitro testing for anti-plasmodial activity. In addition, Plasmodium falciparum malaria parasites and basic equipment for in-vitro testing have been procured and a laboratory dedicated for cell culture work has been established.

Pest and vector control for health and crop protection.

Studies geared into isolation of active compounds for pest and vector control for health and crop protection have been initiated. Facilities to test for mosquitocidal activities have been established whereby there are three on-going projects. One of the projects is seeking to isolate compounds and formulate mosquito larvicidal agents. The other two projects are searching for botanicals for crop protection in collaboration with Sokoine University of Agriculture.

Antimicrobial testing:

This program mainly involves in vitro evaluation of plant extracts, fractions and isolated compounds against bacteria and fungi using disc diffusion and microdilution assays. Many projects were carried out which led to the isolation of several active compounds against bacteria and fungi.

Cytotoxicity testing:

The brine shrimp lethality assay is a well-established in the Department as a preliminary test for toxicity, as a screening tool for possible anticancer activity and other non-specific biological activities. Recently, the Department has established Cell and Tissue Culture Laboratory with important equipment to evaluate cytotoxic and anticancer activity on mammalian cells.

Anti convulsant testing:

Testing for anticonvulsant activity using the chemical-induced convulsions model is well established in the Department. The convulsions in animals (mice) are induced using picrotoxin, isoniazid and pentylenetetrazol convulsant agents. This is one of the areas which generated publications and further studies are ongoing.

Anti-TB Natural Products research:

Search for anti-TB compounds from Tanzanian medicinal plants is an on-going process. Two anti-TB assays have been established: Whole cell inhibition assay (using Mtb marker organisms), and the enzyme assay which inhibits Mycothione reductase redox cycle. Furthermore, various analytical instruments for the assays have been procured.

Anti-ulcers research

Currently several models of anti-ulcer studies have been in use. The Ethanol/Hydrochloric acid, aspirin and indomethacin models have been used to induce gastric ulcers in rats. Using these models, several plant species were tested for their protective effect and some were found to be gastro-protective. The Department is intending to develop other peptic ulcer models to facilitate understanding the mechanisms of antiulcer activity of plant extracts. Helicobacter pylori is implicated in peptic ulcer disease and therefore testing herbal extracts against this bacterium can provide an additional information regarding the use of medicinal plants in the treatment of peptic ulcers. The Department is now in the process of getting the standard strains of this bacterium so as to be used as a screening tool.

Anti-diabetes research

Oral glucose Tolerance Test (OGTT) and streptozotocin-induced (STZ) diabetes are two diabetes models established in the department for screening of medicinal plants with hypoglycaemic potential. A number of publications have been obtained through the research works in this area.

3. Training programme

The department participates in training of postgraduate students; by teaching three modules namely TM 604-1 Basic Biochemistry and Molecular Biology Techniques, TM 604-2 General Principles of the Quantitative and Qualitative aspects of Drug Action, and TM 604-3 Pre-Clinical Safety Testing and Good Laboratory Practice to MSc Traditional Medicine Development Programme and PhD students. The members of staff in the department are also involved in teaching courses offered in other Departments at MUHAS and short courses on Traditional Medicine Development to Traditional Health Practitioners every year. The senior academicians are also involved in supervision of MSc Dissertations and PhD Theses.

4. Consultancy

Some of the consultancies which have been done include evaluation of medicinal plants for anti-ulcer activity and evaluation of a dental formula. Other areas of consultancy include training of Traditional Health Practitioners and conducting different bioassays that are available in the department.