Journal of Ethnopharmacology 203 (2017) 288–303 Contents lists available at ScienceDirect Journal of Ethnopharmacology journal homepage: www.elsevier.com/locate/jep Review An overview on Leucosidea sericea Eckl. & Zeyh.: A multi-purpose tree MARK with potential as a phytomedicine ⁎ Tshepiso C. Mafolea, Adeyemi O. Aremua, , Thandekile Mthethwab, Mack Moyoc a School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, Private Bag X01, Scottsville 3209, South Africa b Biocatalysis and Technical Biology Research Group, Institute of Biomedical and Microbial Technology, Cape Peninsula University of Technology, Symphony Way, P.O. Box 1906, Bellville 7535, Cape Town, South Africa c Department of Horticultural Sciences, Faculty of Applied Sciences, Cape Peninsula University of Technology, Symphony Way, P.O. Box 1906, Bellville 7535, Cape Town, South Africa ARTICLE INFO ABSTRACT Keywords: Ethnopharmacological relevance: Leucosidea sericea (the sole species in this genus) is a tree species found in Antimicrobial southern Africa and possesses several therapeutical effects against infectious diseases in humans and livestock. Antioxidants This review aims to document and summarize the botany, phytochemical and biological properties of fl Anti-in ammatory Leucosidea sericea. Essential oil Materials and methods: Using the term ‘Leucosidea sericea’, we systematically searched literature including Natural product library catalogues, academic dissertations and databases such as PubMed, SciFinder, Web of Science, Google Rosaceae ‘ ’ Toxicology Scholar and Wanfang. Taxonomy of the species was validated using The Plant List (www.theplantlist.org). Results: Leucosidea sericea remains a widely used species among the different ethnic groups in southern Africa. The species is a rich source of approximately 50 essential oils and different classes of phytochemicals (phenolics, phloroglucinols, cholestane triterpenoids, alkaloids and saponins) which may account for their diverse biological properties. Documented biological activities which were mainly observed under in vitro systems included antimicrobial, anti-parasitic, antioxidant, acetylcholinesterase (AChE) inhibition and anti- inflammatory properties. Preliminary safety tests on Leucosidea sericea extracts suggest moderate cytotoxic effects based on a few cell lines that were investigated. Conclusions: Leucosidea sericea possesses diverse medicinal potential with the antimicrobial, anti-parasitic, antioxidant and anti-inflammatory activities being the most prominent. The relative abundance and tendency of Leucosidea sericea to evade in nature suggest an abundant reservoir of raw materials for potential commercialization (upon validation of its pharmacological potential). However, more stringent investigations on the extracts (and isolated bioactive compounds) focusing on the mode of actions, which will inevitably unravel their pharmacokinetics, pharmacodynamics and clinical relevance remain pertinent. 1. Introduction round. Based on their availability, woody plants possibly play a greater role in African traditional medicine when compared to herbs. Available In Africa, woody species are vital plant forms serving as a source evidence suggests a steady increasing research interest on woody and reservoir of traditional medicine (Van Wyk et al., 2008). For species as sources of indigenous medicinal remedies (Adamu et al., instance, woody plants including shrubs and trees make-up more than 2014; Eldeen et al., 2005; Furukawa et al., 2016; Komane et al., 2011; 65% of the documented top 51 medicinal plants in Africa (Brendler Mongalo et al., 2016; Netshiluvhi and Eloff, 2016; Yaoitcha et al., et al., 2010; Moyo et al., 2015). Unlike other plant forms (e.g. herbs), 2015). Many woody species found in Africa have demonstrated many plant parts of woody species are often readily available year- pharmacological potential including antimicrobial, antioxidant, anthel- Abbreviations: 2-AA, 2-aminoathracene; 4-NQO, 4-nitroquinoline-1-oxide; ABTS, 2, 2′-azino-di-(3-ethylbenzthiazoline sulfonic acid); AChE, acetylcholinesterase; BHT, butylated hydroxytoluene; COX, cyclooxygenase; DCM, dichloromethane; DPPH, 1, 2-diphenyl-1- picrylhydrazyl; EA, ethyl acetate; EtOH, ethanol; HAT, hydrogen atom transfer; IL 8, interleukin 8; LOX, lipoxygenase; MeOH, methanol; MIC, minimum inhibitory concentration; MLC, minimum lethal concentration; MTT, 3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazolium bromide; NTDs, neglected tropical diseases; PBS, phosphate buffer saline; PE, petroleum ether; SET, single electron transfer; TEAC, trolox equivalent antioxidant assay; TNF α, tumor necrosis factor; XTT, sodium 3′-[1-[(phenylamino)-carbony]-3, 4-tetrazolium]-bis (4-methoxy-6- nitro) benzene-sulfonic acid hydrate ⁎ Corresponding author. E-mail addresses: [email protected], [email protected] (A.O. Aremu). http://dx.doi.org/10.1016/j.jep.2017.03.044 Received 15 December 2016; Received in revised form 22 March 2017; Accepted 23 March 2017 Available online 28 March 2017 0378-8741/ © 2017 Elsevier B.V. All rights reserved. T.C. Mafole et al. Journal of Ethnopharmacology 203 (2017) 288–303 mintic and anti-inflammatory activities (Adamu et al., 2014; Eldeen et al., 2002). Due to the palatability of the flowers and young shoots, et al., 2005; Eldeen and Van Staden, 2008; Mongalo et al., 2016; the species is widely browsed by livestock during Spring (Pooley, Netshiluvhi and Eloff, 2016). In terms of economic value, woody 1993). species also constitute a sizeable number of indigenous South African Due to the texture and strength of the wood of Leucosidea sericea, plant species with potential importance in the formulation of commer- it is used for making durable fence posts in wet conditions and their cial herbal medicines and natural products (Makunga et al., 2008). In occurrence near streams (in mountainous areas) provide a cue on their fact, woody species such as Prunus africana and Sclerocarya birrea suitability for being stocked with trout (Sieben et al., 2010). Another are partly or fully commercialised (Van Wyk, 2011). important feature of Leucosidea sericea is the tendency of the wood to Leucosidea sericea Eckl. & Zeyh. (Family Rosaceae) is one of the burn slowly and produce heavy smoke which is typical of old, dry and 1700 different native trees in Southern Africa (http://www.plantzafri- decaying wood. This possibly explains the preference of Leucosidea ca.com/plants/treesae.htm). In South Africa, the species is catalogued sericea as the most favoured species for firewood in Lesotho (Letšela as No. 145 and occurs in majority of the Provinces (7 of the 9 et al., 2003). Provinces). In addition to its socio-economic and ecological impor- tance, the medicinal value of Leucosidea sericea among different ethnic 4. Occurrence and distribution groups in southern Africa is well-documented (Hutchings et al., 1996; Moteetee and Van Wyk, 2011; Mugomeri et al., 2016; Seleteng Kose Leucosidea sericea has a narrow global distribution and mainly et al., 2015; Watt and Breyer Brandwijk, 1962). On the basis of the found in southern Africa (Fig. 2), where it occurs abundantly in South investigation by several researchers (Adamu et al., 2012; Aremu et al., Africa and Lesotho and to a lesser extent in Swaziland and Zimbabwe. 2011; Pitso and Ashafa, 2015; Samie et al., 2012; Sharma et al., 2014), Although the species occurs naturally and is well-adapted to the the pharmacological properties of Leucosidea sericea have brought southern hemisphere conditions, evidence of its introduction and about the interest to extensively collate information on its medicinal cultivation in locations such as Seattle and Washington (USA) in the potential that could assist in making the available knowledge to become northern hemisphere have been documented (http://www.arthurleej.- of practical and economic value. In this review, a critical appraisal of com/p-o-m-June08.html). the ethnobotany, phytochemistry and pharmacology as well as the In South Africa, Leucosidea sericea occurs in seven Provinces safety evaluation of Leucosidea sericea was conducted. namely Eastern Cape, North West, KwaZulu-Natal, Free State, Gauteng, Mpumalanga and Limpopo (Daemane et al., 2010; Pond 2. Methodology et al., 2002; Pooley, 1993; Sieben et al., 2010; Van Wyk et al., 2008; Wirminghaus, 1990). Currently, Leucosidea sericea is categorized as a Literature using the search term ‘Leucosidea sericea’ was obtained species of least concern due to its abundant occurrence in South Africa from different databases including Google scholar (435), Sciencedirect (Raimondo et al., 2009). As a result of the wide distribution of (30), Web of Science (18), Scopus (19), SpringerLink (39), PubMed (5), Leucosidea sericea in Lesotho, it remains a major plant resource for PubMed Central (12), PubChem Substance (15), PubChem Compound subsistence in many households in di fferent regions of the country (1), Taxonomy (1), Nucleotide (10), Protein (4), PopSet (5), NLM (Goebel et al., 1990; Letšela et al., 2003). Catalog (3) and MeSH (7). No time limit was set for the online resources. Additional information was sourced from dissertations and 5. Ethnobotanical uses, trades and economic value theses as well as literature covering indigenous medicine from the University of KwaZulu-Natal library, Pietermaritzburg, South Africa. Most of the plant organs of Leucosidea sericea are useful in These materials were screened and included in this study based on indigenous medicine (Table 1). For instance, the leaves of Leucosidea