10 The multi-purpose tree:

GENERAL INFORMATION

Implementing institution Institute of Pathobiology, Addis Ababa University

Head Dr.Yalemtsehay Mekonnen (director)

Details of institution Address: Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia Tel.: (+251) 1 763091 Fax: (+251) 1 755296 E-mail: [email protected]

Implementation period The time frame of the project was from 1996 up to June 2002. However, the project is still ongoing.

Costs The project was supported by: the Research and Publication Office, Addis Ababa University (US$1,400); the International Foundation for Science (US$11,450); and the Third World Academy of Sciences (US$7,500). In addition, the Alexander von Humboldt Foundation of the Government of Germany financed research work at Martin Luther University, Halle, Germany, for nine months. 111 112 VOLUME 10: EXAMPLES OF THE DEVELOPMENT OF PHARMACEUTICAL PRODUCTS FROM MEDICINAL

S UMMARY tard-like taste, contain , and other trace minerals, and are eaten as a In 1996, a pilot project to document the supplement to the major staple foods. uses of in the areas of Worldwide, some 14 species of the Ethiopia where it grows widely was car- Moringa tree (family Moringaceae) have ried out. The survey showed that the tree been described. Among these, the best is used for a variety of purposes. In most studied with regard to potential medici- households, for example, the fresh leaves nal uses and the identification of com- are cooked and eaten. Communities also pounds of potential therapeutic impor- use the roots for treating and tance, is M. oleifera, which is native to the other internal health problems. Indian subcontinent. Laboratory experiments conducted on the basis of the information obtained Based on a review of the literature from the survey indicated that the anti- concerning M. oleifera, a project was devel- trypanosomal, anti-fertility and, in partic- oped to investigate the traditional uses of ular, the antimicrobial properties of the M. stenopetala, a species that grows widely seeds could be exploited in the produc- in southern parts of Ethiopia (fig. 1). tion of phytopharmaceuticals. The sur- As well as being eaten, M. stenopetala, vey also led to the establishment of an ad also known as aleko or shiferaw among local hoc national committee that intends to communities, has a variety of uses, many promote and popularize Moringa trees in of them medicinal. Thus, as with M. Ethiopia. It is hoped that the efforts of oleifera, there is good potential to exploit the research team and other interested the both as a nutritious food supple- groups will be instrumental in developing ment and to isolate and characterize lead methods to promote the sustainable compounds for pharmaceutical product exploitation of M. stenopetala as both a development. food source and a medicinal plant.

B ACKGROUND AND JUSTIFICATION

Among the main staple crops of Ethiopia are maize, , teff (a native grain somewhat similar to millet) and wheat. People also exploit other indigenous plants, including wild banana (Ensete ventri- cosum), eating the starch-containing pith Figure 1 of the stems, and Moringa trees, the leaves The Moringa stenopetala tree grows widely of which have a distinctive strong, mus- in southern Ethiopia. The multi-purpose Moringa tree: Ethiopia 113

D ESCRIPTION maize and sorghum). In contrast, the people of Konso use the tree not only for The project can be divided into three food but also as a medicine and they cul- main phases. tivate it in large areas around their vil- lages (fig. 3). There are claims that the leaves, boiled in water, can cure malaria, P HASE 1: DOCUMENTATION hypertension and stomach pain, whereas OF THE USES MADE OF the roots, chopped and mixed with water, M. STENOPETALA are also used for treating severe cases of Between March and September 1996, a malaria. M. stenopetala is used as a herbal survey to document the uses to which medicine in areas where visceral leishma- local communities put M. stenopetala was niasis or kala-azar (caused by the carried out in southern Ethiopia. In the Leishmania parasite) prevails. surveyed regions, particularly in the Arba In addition, there are reported cases Minch and Wollayta areas, the local peo- of M. stenopetala leaves being used to expel ple cook the leaves of the M. stenopetala the retained placenta in women who tree (fig. 2) and eat them with their tradi- have just given birth, and the seeds are tional kurkufa (a cereal dish made with used to clear muddy water.

Figure 2 Leaves of the Moringa stenopetala tree are used as both food and medicine.

Figure 3 Villages around Konso in southern Ethiopia cultivate the multi-purpose M. stenopetala trees in plantations. 114 VOLUME 10: EXAMPLES OF THE DEVELOPMENT OF PHARMACEUTICAL PRODUCTS FROM MEDICINAL PLANTS

P HASE 2: LABORATORY which compounds in M. stenopetala exert EXPERIMENTS the reported effects. A series of laboratory experiments were performed to evaluate the claims that M. P HASE 3: ISOLATION AND stenopetala leaves could be used to treat IDENTIFICATION OF BIOLOGICALLY malaria and other parasitic diseases. ACTIVE COMPOUNDS Crude ethanol extracts of the leaves Both leaves and seeds, which are rich in and the roots were tested on promastig- oils, were subjected to bioassay-guided otes of Leishmania donovani (the infective fractionation to develop extraction meth- stage of the disease inoculated into the ods for bioactive molecules and as an ini- blood by the bite of the sandfly vector). tial step in determining their identity. For After incubating for 48 hours, the para- example, powdered seeds (without their site had undergone morphological seed coat) were incubated with an changes, indicating an adverse reaction enzyme (myrosinase) for 6 hours in 1.5 to the M. stenopetala extract. litres of water before the mixture was fil- tered and reduced to a volume of 20 mil- Leaf and root extracts of M. stenopetala lilitres by evaporation. This viscous liquid were also tested against the infective was then suspended in a mixture of chlo- stages of Trypanosoma brucei (a parasite that roform and methanol (in a 9:1 ratio), fil- causes a sleeping-sickness-like disease of tered and dried. One gramme of this horses, cattle and sheep that is common product was added to a silica gel column in tropical ), T. cruzi (the causal and washed through 200 millilitres of agent of Chagas’ disease in South each of four different eluents: a 1:1 mix- America) and amastigotes (the stage that ture of chloroform and hexane, a 3:1 mix- lives inside the host cells) of L. donovani. ture of chloroform and hexane, followed Of particular note, an ethanol extract of by two washes of chloroform. fresh root wood and an acetone extract of dried leaves both showed activity against After evaporation, these fractions T. brucei. were used in agar diffusion bioassays against Staphylococcus aureus, Salmonella Further studies using ethanol extracts typhi (the causal organism of typhoid), of M. stenopetala leaves demonstrated that, Shigella (the causal organism of dysentery) in mice, fertility was reduced by some 75 and Candida albicans (a fungus that causes per cent. The leaf ethanol extract also candidiasis or thrush). Using a known showed some oxytocic activity (or a antibiotic (penicillin) as a control, it was speeding up of labour) in experiments possible to determine whether the puri- using guinea pig and mouse uteri. On the fied fractions had any antibiotic activity. other hand, higher concentrations of the In fact, the fourth fraction, obtained extract abolished spontaneous contrac- using the second chloroform wash, had tions in the mouse uterus. It is not known the greatest antibiotic activity (fig. 4). The multi-purpose Moringa tree: Ethiopia 115

Analytical techniques, including elec- before these compounds can be declared tro-spray ionization mass spectrometry lead compounds for development into (ESI-MS), high performance liquid chro- potential phytopharmaceutical products. matography (HPLC), thin layer chro- matography (TLC) and nuclear magnetic resonance (NMR) imaging, were used to PARTNERSHIPS further characterize and identify purified samples of M. stenopetala secondary The research team investigating the metabolites. Of particular interest were Moringa tree plays the primary role in pro- the glucosinolates — a group of chemi- moting the many uses of the tree. cals commonly found in plants of the However, the recently established ad hoc Brassicaceae family, including national committee made up of a local and mustard — which have been shown non-governmental organization, a com- to have useful antioxidant and anti-can- mercial company (Teppo Agricultural and cer properties. Two main compounds Trade plc), researchers from national and were identified from M. stenopetala seeds, international institutions and other inter- glucoconringiin and O- (rhamnopyra- ested individuals will combine their nosyloxy) benzyl glucosinolate, which expertise to promote the dissemination were present at three per cent and 19 per and use of M. stenopetala. Together, this cent of the dry mass of the seeds, respec- forum will introduce the benefits and use- tively. However, although these com- fulness of the Moringa tree to a range of pounds have potential therapeutic value, individuals, including farmers, researchers, degradation products of glucosinolates agricultural experts and policy-makers. have also been shown to interfere with some metabolic pathways, including the Recently, German researchers have synthesis of thyroid hormone. Further shown interest in developing a joint proj- tests and analyses are required, therefore, ect to examine the use of M. stenopetala seeds to clarify dirty water.

Figure 4 Agar diffusion test of bacterial inhibition by M. stenopetala seed extract fractions. Bacteria are grown across the whole plate. The two central discs are the positive con- trol, penicillin, and have a clear ring around them, representing the region in which the antibiotic activity is killing off the bacteria. Likewise, the second chloroform fraction from M. stenopetala seeds (see text) also shows some antibiotic activity. 116 VOLUME 10: EXAMPLES OF THE DEVELOPMENT OF PHARMACEUTICAL PRODUCTS FROM MEDICINAL PLANTS

R EPLICABILITY Moringa tree must be raised by a series of promotional campaigns. The trees must The survey and laboratory procedures be introduced into areas where they are followed by the Institute of Pathobiology not currently grown and people encour- could easily be replicated in similar agro- aged to eat the leaves along with their ecological and social situations to analyse staple foods. Eventually, with the aid of the medicinal properties of other tradi- public information campaigns, people tional herbal remedies. In addition, given will also become aware of the trees’ that there are reports of Moringa seeds medicinal uses. being used to clarify dirty water in and that the leaves and pods are eaten in I MPACT parts of , it is likely that people in these areas would also accept that the tree can be used medicinally. Therefore, The implementation of the innovative the project has a direct relevance not experience — i.e., the dissemination of only to Ethiopia but also to other African Moringa trees throughout Ethiopia — is countries. still in its early stages. Thus, a more com- plete assessment of the impact of the proj- ect requires some time. The continuing P OLICY IMPLICATIONS effort of the research team provides a good opportunity to introduce the benefits of There are plans to attempt to influence the Moringa tree to the wider population. government policy and/or legislation, for example with regard to the proper con- F UTURE PLANS servation and planting of M. stenopetala, by lobbying Ethiopia’s agricultural research institutions and the Science and Future work will focus on the following Technology Commission that have man- areas: dates for such initiatives. • Strengthening the research component. Further work on M. stenopetala is required to identify the active L ESSONS LEARNED ingredients in the extracts and to test preparations for their efficacy The promotion of pharmaceutical prod- under different experimental ucts derived from medicinal plants is a regimes. One such project that the new experience in Ethiopia. Traditionally, Institute has already begun is to however, making the public accept new test the anti-malarial and anti- medicines is not easy. In this regard, pub- leishmanial effects of the extracts. lic awareness of the benefits of the In the long term, the Institute The multi-purpose Moringa tree: Ethiopia 117

envisages developing formulations P UBLICATIONS of purified active compounds, preclinical trials and clinical trials The project resulted in the publication with eventual pre-commercial of the following peer-reviewed scientific papers: product development. • Networking. National and interna- Mekonnen, Y. (1999). Effects of ethanol tional organizations that are extract of Moringa stenopetala leaves on interested in similar programmes guinea pig and mouse smooth muscle. will be contacted. In particular, Phytotherapy Research, 13:442-444. contacts should be made with the neighbouring countries, Kenya Mekonnen, Y. and Dräger, B. (2003). and Sudan. These will be useful Glucosinolates in Moringa stenopetala. Planta Medica for sharing experiences and , 69:380-382. developing a wider programme. Mekonnen, Y. and Gessesse, A. (1998). There is also a need to popularize Documentation on the uses of Moringa the multi-purpose uses of the tree stenopetala and its possible antileishmanial and to invite local pharmaceutical and antifertility effects. SINET: Ethiopian companies, many of which have Journal of Science, 21:287-295. been created in the past few years, to exploit the plant for drug Mekonnen, Y., Yardley, V., Rock, P. development. and Croft, S. (1999). In vitro anti- trypanosomal activity of M. stenopetala • Community outreach. Interested leaves and roots. Phytotherapy Research, researchers and the ad hoc national 13:538-539. committee that was recently established will be instrumental in promoting the use of the plant as both a food and a medicine. This Case study prepared by: could be facilitated by organizing Yalemtsehay Mekonnen workshops and visits to villages Institute of Pathobiology, Addis Ababa and local community centres. University, P.O. Box 1176, Addis Ababa, Ethiopia • Need for finance. Research and other Tel: (+251) 1 763091 related activities, such as promoting Fax: (+251) 1 755296 the use of the tree, require finan- E-mail: [email protected], cial resources. Grant proposals [email protected] will be developed and potential contributors invited to join this innovative exercise. 118 VOLUME 10: EXAMPLES OF THE DEVELOPMENT OF PHARMACEUTICAL PRODUCTS FROM MEDICINAL PLANTS

Project participants: Amare Gessesse: Documentation of the use of M. stenopetala in southern Ethiopia.

Ermias Dagne: Advisory role during the initial phase of the project.

Wendimagegn Mamo: Nuclear magnetic resonance (NMR) imaging to identify M. stenopetala seed extract fractions.

Birgit Draeger: Research collaborator, identification and characterization of the glucosinolates from M. stenopetala.