Indian Journal of Traditional Knowledge Vol. 17 (1), January 2018, pp. 71-77 Ethnomedicinal uses of exotic plant species in South-central Zimbabwe Alfred Maroyi Medicinal plants and Economic Development Research (MPED) Center, Department of Botany, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa E-mail: [email protected] Received 3 April 2017, revised 21 August 2017 Herbal medicines are important for primary healthcare needs of both rural and urban communities in Zimbabwe, and among these therapies are those made from exotic plants. The aim of this study was to document ethnomedicinal uses of exotic plants in Shurugwi district, South-central Zimbabwe. Semi-structured interviews, personal observations and guided field walks were conducted between December 2014 and January 2015 with 128 participants comprising of community members (93.0 %, n = 119) and traditional healers (7.1 %, n = 9) from seven villages to obtain ethnobotanical data on medicinal uses of these plants. Data collected included local and scientific names of plants used, parts used, methods of herbal preparation and administration. A total of 26 exotic plants belonging to 15 families and 23 genera, mostly from Euphorbiaceae and Solanaceae (15.4 % each), Asteraceae (11.5 %), Apocynaceae and Myrtaceae (7.7 % each) were used to traditionally manage 21 human and four animal diseases. Majority of the plant species used (69.2 %) had one or two therapeutic uses while Bidens pilosa, Citrus lemon, Datura stramonium, Eucalyptus camaldulensis, Nicotiana tabacum, Psidium guajava and Schkuhria pinnata had at least three therapeutic uses each. This study revealed that exotic plants play an important role in provision of primary healthcare to local communities in South-central Zimbabwe. Keywords: Exotic plant species, Herbal medicine, Primary health, South-central Zimbabwe IPC Int. Cl.8: A61K 36/00 Exotic or non-native plants with medicinal properties a local community, residents usually experiment with are receiving more attention worldwide1-9. Exotic the traditional pharmacopoeias resulting in the addition plant species are employed as medicines throughout of exotic plants as sources of herbal medicines. In the world and are now recognized as an important Zimbabwe, the indigenous knowledge on medicinal component of indigenous pharmacopoeia in several uses of native plant species is well documented10-14, but countries1-9. Bennett & Prance1 showed that exotic very little is known about the medicinal uses of exotic plants cultivated as ornamentals or food plants in species. Therefore, the current study was aimed at South America were incorporated into traditional documenting indigenous knowledge associated with pharmacopoeias as herbal medicines mainly due to ethnomedicinal uses of exotic plants in Shurugwi their use-versatility applications. Such findings were district, South-central Zimbabwe. supported by Palmer4 who demonstrated that the number of native plants used as herbal medicines in Materials and methods Hawaii was decreasing with time while exotic plants Study area, environment and geocultural situation used as herbal medicines were increasing with time. This study was conducted in Shurugwi district Similar results were also obtained by Alencar et al.5 (Fig. 1A&B), a semi-intensive agricultural region in who addressed the intercultural exchange of traditional the Midlands province, South-central Zimbabwe. The herbal medicines due to incorporation of new study area lies between 19°57´S to 20°30´S latitude knowledge, traditions and customs. Alencar et al.5 and 30°00´E to 30°58´E longitude. The average argued that local communities incorporate exotic annual rainfall ranges from 650-800 mm and mean medicinal plants into their medical repertoire in order temperatures range from 9 ºC to 31 ºC12. Soils are to diversify the local traditional medicine stock. In sandy loam largely derived from granitic-gneissic another study, Alencar et al.6 argued that the rocks characterised by low agricultural potential due composition of medicinal plants in any local to low fertility, water-holding capacity, low pH, and community is influenced by cultural and environmental deficiencies in nitrogen, phosphorus, and sulphur12. factors. These authors argued that during the history of The dominant vegetation type is miombo woodland 72 INDIAN J TRADIT KNOWLE, VOL. 17, NO. 1, JANUARY 2018 Fig. 1 Geographical location of the study area in relation to other major towns in Zimbabwe (A) and detailed map showing villages in which the study was undertaken (B) characterized by Brachystegia spiciformis Benth. used for finding, selecting and inviting participants Julbernardia globiflora (Benth.) Troupin, Hyparrhenia who were knowledgeable about medicinal plants. A spp., Eragrostis spp., Heteropogon spp. and Digitaria total of 128 participants took part in this study, with spp. grasses15. Research by Maroyi12,15 revealed that 17 community members (lay people) and at least one residents of the study area are dependent on the traditional healer per village. Structured and semi- natural environment for plant resources such as structured interviews were carried out in Shona, a construction timber, firewood and fencing materials, language spoken by all participants. Through as well as non-timber forest products (NTFPs) such as interviews with participants, information was insects, mushrooms, wild fruits, leafy vegetables and collected on the local and scientific names of exotic medicines. Their agricultural practices are essentially plants used for the treatment of human and livestock subsistence in nature, with land and livestock being ailments, vernacular names of diseases treated, plant the primary household assets. The main cultivated part(s) used, as well as methods of herbal preparation crop in the study area is maize (Zea mays L.), with and administration. During field excursions and field other grains such as sorghum [Sorghum bicolor (L.) walks with participants, voucher specimens were Moench] and millet [Pennisetum glaucum (L.) R. Br.] collected for later identification by plant taxonomists. planted by most households as insurance against poor All voucher specimens have been deposited in the rains, which in some years are inadequate to produce National Herbarium, Harare (SRGH). a good maize crop12,15. Data analysis Data collection Triangulation involving more than one source of A collection of photographs of 115 exotic plants research data was the principal method used in this that are known to be used as food, medicines and study16. Ethnomedicinal data from previous surveys other uses in Zimbabwe were used to guide undertaken by the author7,12,13,15,17 were used in discussions on exotic plants used as herbal medicines planning the current study which focused on exotic in Shurugwi district. Literature review was also plant species used as herbal medicines in Shurugwi undertaken aimed at documenting pharmacological district. Over the years, the author created a database properties of exotic plants used as herbal medicines in of 115 exotic plant species that are widely used as the study area. food, medicinal, construction material and ornamental purposes in Zimbabwe18. The current study Results and discussion undertaken in Chikato, Donga, Gamwa, Gundura, Medicinal plant diversity Hanke, Tongogara and Zvamatenga villages in This study recorded a total of 26 exotic plant Shurugwi district (Fig. 1B) was conducted between species used to traditionally manage various human December 2014 and January 2015. A snowball and livestock diseases in Shurugwi district, Zimbabwe research technique as described by Heckathorn19 was (Table 1). Of these, 22 species (84.6 %) have escaped MAROYI: ETHNOMEDICINAL USES OF EXOTIC PLANT SPECIES IN SOUTH-CENTRAL ZIMBABWE 73 Table 1 Therapeutic applications of exotic species used in traditional medicine in Shurugwi district, Zimbabwe. Veterinary ailments are marked with an asterisk (*). Species that have escaped from cultivation and regarded as weeds are marked with a hatch (#). Family, species name Vernacular name Habit Parts Ailment(s) treated in English and Shona, Reported biological or and voucher number (Shona) used herbal preparation and administration pharmacological activities Agavaceae Agave sisalana Perrine #; Mukonje Shrub Leaves General body pain (marwadzoemuviri), Saponins & sterols29 MA 1314 extract taken by mouth. Anacardiaceae Mangifera indica L. #; Mumango Tree Bark Diarrhoea (manyoka), extract taken by Antibacterial activity30 MA 1321 mouth. Apocynaceae Catharanthus roseus (L.) Chirindamatongo Herb Roots Diarrhoea (manyoka), extract taken by Catharanthine, leurosine and G. Don #; MA 1322 mouth. vindoline responsible for hypoglycaemic effect23 Nerium oleander L.; Oleander Shrub Leaves Sexually transmitted infections (STIs) Anti-inflammatory and MA 1348 (siki), infusion taken by mouth. antibacterial activities31 Asteraceae Bidens pilosa L. #; Tsine Herb Roots Hypertension (BP), oral thrush Antibacterial and MA 1349 (marondaemumuromo) and stomach pains antimicrobial activities26 (mudumbu), infusion taken by mouth. Schkuhria pinnata (Lam.) Ruhwahwa Herb Whole STI (siki), stomach pains (mudumbu), to Anti-diarrheal, anti-emetic Kuntze ex Thell. #; plant cause abortion (kubvisanhumbu), infusion and antiseptic activities23 MA 1360 taken by mouth. Tagetes minuta L. #; Mbanje Herb Leaves Wounds (maronda), wounds washed with Antimicrobial activity32 MA 1317 infusion. Cucurbitaceae Cucumis anguria L. var. Muchacha Herb Fruits Snake repellent (kudzinganyoka),