Medicinal Bark Research Articles

Online appendix 1:Is the present Brackenridgea Nature Reserve large enough to ensure the survival of <i>Brackenridgea zanguebarica</i> Oliv.?

The Brackenridgea Nature Reserve is a 110 ha protected area established by the provincial Limpopo Department of Economic Development, Environment and Tourism as a way of protecting the population of Brackenridgea zanguebarica, a species classified as critically endangered in South Africa. In the whole of South Africa, the species is found in only one small area around Thengwe–Mafukani in Venda. It is threatened with extirpation due to high demand for its medicinal bark. This study investigated the adequacy of the reserve to conserve the species using a method established in 2001 by Burgman et al. This method involves 12 steps to quantify the risk of the decline or possible extinction of the species and takes current human activities, disturbances and the viability of the population into consideration for setting a conservation target. From the results, it was clear that more area is needed for the current population to survive beyond 50 years. Assuming the status quo, it will require 410 ha to maintain the population, whereas a 50% reduction in human-related activities, such as cultivation, harvesting and livestock grazing, will lower the required potential habitat to 203 ha and a conservation option, which allows for bark harvesting, will require 179 ha. Conservation implications: The results of this study will have conservation implication on management of viable species population within a nature reserve. It will require managers to take into consideration the reserve size in relation to potential habitats for the development of species under their management.

Is the present Brackenridgea Nature Reserve large enough to ensure the survival of <i>Brackenridgea zanguebarica</i> Oliv.?

The Brackenridgea Nature Reserve is a 110 ha protected area established by the provincial Limpopo Department of Economic Development, Environment and Tourism as a way of protecting the population of Brackenridgea zanguebarica, a species classified as critically endangered in South Africa. In the whole of South Africa, the species is found in only one small area around Thengwe–Mafukani in Venda. It is threatened with extirpation due to high demand for its medicinal bark. This study investigated the adequacy of the reserve to conserve the species using a method established in 2001 by Burgman et al. This method involves 12 steps to quantify the risk of the decline or possible extinction of the species and takes current human activities, disturbances and the viability of the population into consideration for setting a conservation target. From the results, it was clear that more area is needed for the current population to survive beyond 50 years. Assuming the status quo, it will require 410 ha to maintain the population, whereas a 50% reduction in human-related activities, such as cultivation, harvesting and livestock grazing, will lower the required potential habitat to 203 ha and a conservation option, which allows for bark harvesting, will require 179 ha. Conservation implications: The results of this study will have conservation implication on management of viable species population within a nature reserve. It will require managers to take into consideration the reserve size in relation to potential habitats for the development of species under their management.

Evaluation of some medicinal properties of Ceiba aesculifolia subsp. parvifolia

The bark of Ceiba aesculifolia subsp. parvifolia is used for the treatment of diabetes, kidneys maladies, tumors, gastritis, and wounds by the people of San Rafael, Coxcatlan, Puebla. The aim of this work was to investigate antimicrobial activity, general toxicity, and antioxidant activity of the bark of this species. The methanol extract was obtained by maceration. After obtaining the methanol extract (MeOH1), methanol (MeOH2) and hexane (H) fractions were obtained. The antibacterial and antifungal activities were evaluated through the disc-diffusion method. The general toxicity test was carried out by using brine shrimp Artemia salina. The quenching of free radicals was evaluated by the decolouration of a methanol solution of diphenyl picryl hydrazyl (DPPH). Total phenolics were determined by Folin Ciocalteu reagent. Gram-positive and Gram-negative bacteria were sensitive to MeOH1 and MeOH2; MeOH2 had a bactericidal effect on Staphylococcus epidermidis(minimum inhibitory concentration (MIC) = 0.75 mg/ml) and Vibrio cholera Tor (MIC = 0.50 mg/ml). MeOH2 showed inhibition of DPPH radical (SC50 = 6.15 μg/ml), 28% of total phenolics and was toxic against A. salina (LC50 = 2.82 μg/ml). The methanol extract showed a variety of different compounds such as terpens, isoflavones and a coumarin. The antimicrobial, antioxidant, and toxicity activities and a qualitative chemical characterization of C. aesculifolia subsp. parvifolia are reported here for the first time. Key words: Ceiba aesculifolia, Bombacaceae, medicinal bark, antibacterial activity, antioxidant activity.

Population biology of Brackenridgea zanguebarica in the presence of harvesting

Population biology studies play a major role in understanding the ecology of our highly utilized natural resources. Intense and frequent harvesting of bark from species with a high market demand often result in ring-barking of trees. The trees subsequently die, and the species becomes rare over time. Brackenridgea zanguebarica Oliv. is a species in demand not only because of its medicinal value but also because it is highly regarded for its magical value. The species has a limited distribution and is found only at Thengwe in the whole of South Africa. The population structure of the species was investigated and the response of the species to harvesting pressure evaluated in order to gain an understanding of its survival strategies. In spite of the high demand for the species it seems to be surviving the harvesting pressure. B. zanguebarica showed a healthy population structure with lots of seedlings. The adult individuals showed a very high degree of bark regeneration as a response to bark removal from medicine men. The inverse J-shaped curve showed that the population is healthy although sharp decreases between stem diameter size classes were observed. Fewer older individuals have healthy crown covers since crown health status tends to decrease with increase in stem diameter. It is therefore important to monitor the diameter size classes that are being impacted negatively by medicinal bark harvesting for the population to remain viable at all times. Key words: Bark harvesting, magical value, population structure, regeneration, South Africa.

Ghana's herbal market

Ethnopharmacological relevanceMedicinal plant markets not only provide a snapshot of a country's medicinal flora, they also reflect local health concerns and the importance of traditional medicine among its inhabitants. This study aimed to describe and quantify the Ghanaian market in herbal medicine, and the diversity of the species traded, in order to evaluate their economic value. Materials and methodsInitial visual surveys on the markets were followed by a detailed quantitative survey of 27 stalls in August 2010. Market samples were processed into herbarium vouchers and when possible matched with fertile vouchers from the field. ResultsWe encountered 244 medicinal plant products, representing 186–209 species. Fourteen species were sold at more than 25% of the market stalls. Seeds and fruits that doubled as spice and medicine (Xylopia aethiopica, Monodora myristica, Aframomum melegueta) were in highest demand, followed by the medicinal barks of Khaya senegalensis and Pteleopsis suberosa. Plants sold at the market were mostly used for women's health, in rituals, as aphrodisiacs and against sexually transmitted diseases. An estimated 951tons of crude herbal medicine were sold at Ghana's herbal markets in 2010, with a total value of around US$ 7.8 million. Between 20 and 30% of the Ghanaian medicinal flora was encountered during this survey. Roots were less dominant at the market than in dryer parts of Africa. Tons of Griffonia simplicifolia and Voacanga africana seeds and Fadogia agrestis bark are exported annually, but data on revenues are scanty. None of these species were sold on the domestic market. ConclusionOur quantitative market survey reveals that the trade in Ghanaian herbal medicine is of considerable economic importance. Regarding the specific demand, it seems that medicinal plants are used to complement or substitute Western medicine. Further research is needed on the ecological impact of medicinal plant extraction.

Response of Ocotea bullata, Curtisia dentata and Rapanea melanophloeos to medicinal bark stripping in the southern Cape, South Africa: implications for sustainable use

Tree bark is commonly used for traditional medicine in southern Africa and further afield. Increasing demand and commercialisation have resulted in the overexploitation of many species, posing a major challenge to forest managers to develop mechanisms for sustainable resource use. An experimental bark harvesting research project was initiated in the southern Cape, South Africa, to inform best practices for bark harvesting based on tree response to bark stripping. The species selected for the study, Ocotea bullata, Curtisia dentata and Rapanea melanophloeos, are much sought after and well represented in southern Cape forests. The treatment entailed removing vertical strips of bark, 1 m in length and of different strip widths, covering the full range of tree size classes ≥10 cm DBH. The treatments were applied during two seasons, winter and summer. Evaluations were done every six months to assess tree response to bark stripping in terms of bark regrowth through phellogen edge and sheet development, and susceptibility to insect and fungal damage. The results show a differential response of tree species in terms of phellogen edge and sheet growth, as well as susceptibility to fungal and insect attack. Rapanea melanophloeos was the most vulnerable to fungal and insect damage and displayed little bark regrowth following wounding. Curtisia dentata showed best bark regrowth through sheet development. Only O. bullata, though, showed adequate bark regrowth (through edge development) to allow for sustainable strip harvesting. Bark regrowth is influenced by season of stripping, although this is difficult to define considering the wide range of environmental and other factors affecting tree response to bark removal. Smaller trees are more vulnerable to bark stripping, especially with a wide strip, with poorer bark regrowth than bigger trees.

From conflict of use to multiple use: Forest management innovations by small holders in Amazonian logging frontiers

The Brazilian Amazon is a significant source of timber as well as a rich source of non-timber forest products (NTFPs) such as medicinal barks, oils and fruits. Lack of quantity, quality, uniformity and price as well as a lack understanding of NTFPs socioeconomic, cultural or spiritual value and function in societies relegates them to a marginal economic status eclipsed by timber. The data vacuum for most NTFPs is contrasted by the large amount of timber-specific data available for many logged species. Such data sources can offer insights into the extraction level and locations of a subset of species that are valued for both timber and NTFPs. These are referred to as ‘conflict-of-use’ species. In this article we examine three such species, focusing on the Amazonian state of Pará. Pará is situated in the Brazilian “arc of deforestation” and the state accounts for 47% of all timber produced in the Legal Amazon. We describe three highly-utilized Amazonian NTFPs currently logged commercially: (1) Cumuru, Dipteryx odorata, which bears a seed yielding an essential oil employed in the perfume industry and providing income and medicine to rural families; (2) Amapá amargoso, Parahancornia fasciculata, which produces a powerful exudate used as a treatment of respiratory diseases; and (3) Uxi, Endopleura uchi, which produces a nutritious fruit consumed by humans and wildlife. We analyze data from the timber industry indicating the rate of extraction of these species, as well as data regarding their use and value as NTFPs. Results indicate that extraction of these species in logging frontiers contributes to declining access. However, in communities with links to markets, undocumented management systems supply the increasing demand for NTFPs in urban areas. While there are no formal management plans for these species and few scientific attempts made to manage them, small holders have developed local knowledge and innovative techniques to improve productivity, increase density and create multiple-use systems in the face of growing land use pressures.

Antimicrobial and antioxidative effects of Ugandan medicinal barks

Despite a rich tradition of medicinal plants use by local communities in Uganda their direct antimicrobial effectives together with potential to protect human health against diseases induced by oxidative stress are still poorly documented. The aim of this study is to investigate the in vitro antimicrobial and total antioxidative activities of barks from five tree species selected using information on their traditional use by Karamojong healers in Uganda. The antimicrobial activity of crude ethanol extracts of Fagaropsis angolensis (Engl.) H. M. Gardener (Rutaceae), Trichilia prieuriana A. Juss. (Meliaceae), Turraea floribunda Hochs t. (Meliaceae), Warburgia salutaris Sprague (Canellaeceae) and Zanthoxylum chalybeum Engl. (Rutaceae) were tested against four bacteria and one yeast species using the broth microdilution method. The total antioxidative activity was determined by 2,2-diphenyl-1- picrylhydrazil free radical scavenging assay. It was found that the extract of F. angolensis possess the strongest antimicrobial activity inhibiting growth of Staphylococcus aureus and Candida albicans with minimum inhibitory concentrations of 64 and 32 μg/ml, respectively. Among all plants tested, W. salutaris showed the most promising antioxidative properties (IC 50 = 6.59 μg/ml). As a result of this study, F. angolensis and W. salutaris possessed significant antimicrobial and antioxidative effects which indicates prospective pharmacological properties of both species. Key words : Antimicrobial activity, total antioxidative activity, crude extracts, medicinal plants, Uganda.

A “reasoned proposal” against “vain science”: Creole negotiations of an Atlantic medicament in the Audiencia of Quito (1776–92)

This essay discusses the 1779 report on quina by Miguel García de Cáceres, a customs official in Guayaquil, for the Visitador General to the Audiencia of Quito. Quina, a medicinal tree bark, was an important export commodity in the region which had been recognized since the mid seventeenth century by medical practitioners throughout the Atlantic world as an effective treatment for periodic fevers, one of the most prevalent ailments in the early modern world. In 1751, the Crown had established a royal monopoly of quina – a mechanism for asserting an exclusive claim to annual shipments of quina from Loja, the province reputed to produce the best bark. The remainder of quina was open to private harvesting and trading. In the late 1770s, the Crown wanted to know if it would be useful and profitable to expand its monopoly of quina. Cáceres was in favor of the proposed expansion, but his final report provided much more than a simple policy recommendation. In fact, the majority of his report was a critique of what he called the “vain science” employed primarily, but not solely, by European scientific and medical practitioners in the study of quina. He argued that this “science” produced “verisimilitude” rather than true knowledge, and that this false knowledge had a negative impact on the quina trade and threatened the very survival of the cinchona trees from which quina was harvested. More than a case of Creole patriotic epistemology, this essay argues that Cáceres’ report demonstrates how local debates among Creoles shaped the production of knowledge about quina – an object that moved within overlapping transatlantic networks of trade, empire, and science. Such entanglements of knowledge, politics, and economics at the local level characterized many of the knowledge-making enterprises in the early modern Atlantic world.

Antimicrobial activity of some medicinal barks used in Peruvian Amazon

The aim of this study was to evaluate the antimicrobial activity of six barks traditionally used in Callería District (Ucayali Department, Peru) for treating conditions likely to be associated with microorganisms. Ethanol extracts of stem barks of Abuta grandifolia (Menispermaceae), Dipteryx micrantha (Leguminosae), Cordia alliodora (Boraginaceae), Naucleopsis glabra (Moraceae), Pterocarpus rohrii (Leguminosae), and root bark of Maytenus macrocarpa (Celastraceae) were tested against nine bacteria and one yeast using the broth microdilution method. All plants possessed significant antimicrobial effect, however, the extract of Naucleopsis glabra exhibited the strongest activity against Gram-positive bacteria (MICs ranging from 62.5 to 125 μg/ml), while the broadest spectrum of action was shown by the extract of Maytenus macrocarpa, which inhibited all the strains tested with MICs ranging from 125 to 250 μg/ml.

Bark medicines used in traditional healthcare in KwaZulu-Natal, South Africa: An inventory

Bark is an important source of medicine in South African traditional healthcare but is poorly documented. From thorough surveys of the popular ethnobotanical literature, and other less widely available sources, 174 species (spanning 108 genera and 50 families) used for their bark in KwaZulu-Natal, were inventoried. Vernacular names, morphological and phytochemical properties, usage and conservation data were captured in a database that aimed to synthesise published information of such species. Data specificity was found to be the major limiting factor in the study and resulted in uneven distribution of information in the database. Overlapping vernacular names recorded in the literature indicated that it may be unreliable in local plant identifications. Most (43%) bark medicines were documented for the treatment of internal ailments. Sixteen percent of species were classed in threatened conservation categories, but conservation and management data were limited or absent from a further 62%. There is a need for research and specialist publications to address the gaps in existing knowledge of medicinal bark species and their management to conserve the South African flora.

The suitability of Thin Layer Chromatography for authenticating bark medicines used in South African traditional healthcare

Thin Layer Chromatography (TLC) was investigated as a potential tool with which medicinal bark products used in South African traditional healthcare may be authenticated. Dried bark products are difficult to identify, and misidentification or adulteration increasingly affect their appropriate use and accurate documentation of their trade. A traditional medical practitioner pinpointed eight bark species used in KwaZulu-Natal, South Africa, that are difficult to identify. These were Ekebergia capensis (Meliaceae), Harpephyllum caffrum (Anacardiaceae), Rapanea melanophloeos (Myrsinaceae), Schotia brachypetala (Caesalpiniaceae), Croton sylvaticus (Euphorbiaceae), Albizia adianthifolia, Acacia sieberiana and Acacia xanthophloea (Mimosaceae). Three reference bark samples of each species were extracted in ethanol or hexane, separated on silica gel in petroleum spirit : ethyl acetate : chloroform : formic acid (8:7:5:1), and treated with anisaldehyde or vanillin reagents. TLC proved useful for showing similarities in the phytochemical fingerprints of a single species, but less so in distinguishing between the phytochemical fingerprints of different species. The technique assisted in confirming the identity of several medicinal bark products.

Fragoso, Monardes and pre-Chinchonian knowledge of Cinchona

The entry of Quina Bark into modern pharmacology has been clouded by unreliable sources, apocryphal ornament and botanical confusion. This paper examines two of the best reviews of the historiography of this saga, those by A.W. Haggis and F. Guerra, to show that there remain several unresolved issues. The references given by these authors, supplemented by other sources, have been used to compile a list of the early literature and to establish some critical dates in the diffusion of Quina Bark, emphasizing that the remedy was discovered in the seventeenth century. But almost a century earlier the Spanish physicians Juan Fragoso and Nicolas Monardes published accounts on a medicinal bark from a tree they chose not to name. However, they said that the tree was from the New World and described its use in terms suggestive of Quina Bark; in the first place, the mode of preparation and administration is similar to that recorded by the earliest bona fide Cinchona chroniclers; secondly, the tree's leaf shape and the bark's flavour and colour agree with Cinchona traits; thirdly, in these texts the salutary tree is clearly distinguished from other exotic plants with which Quina Bark was later confused; and, lastly, these authors' assertion that the tree bears no fruit is also found in Sebastiano Bado's classical account on the bark, honoured by Linnaeus when he assigned the name Cinchona to the plant. The purported lack of fruit was explained by the French savant La Condamine, the first botanically-trained observer to study the plant in the field. Fragoso and Monardes said that the Indians held the remedy in high esteem and that the Spaniards learned its use from them. If these physicians' mystery tree was indeed Cinchona, the view that Quina Bark was part of pre-Columbian indigenous medicinal lore and that it was sent to Spain soon after the first regular trans-Atlantic contacts may thus be strongly supported.

Impacts of Informal Settlements on South-Eastern Cape Coastal Vegetation (South Africa)

The distribution of informal settlements in the south-eastern Cape coastal region and the types of impacts on the vegetation were assessed Natural vegetation adjacent to some of these settlements was sampled by means of the Braun-Blanquet and pointcentred quarter methods. Informal settlements in the south-eastern Cape coastal region exist at Port Alfred, Kenton-on-Sea, Jeffreys Bay, Plettenberg Bay and Knysna. Population numbers of these settlements vary from 180 to 4796 people. Five vegetation types are being impacted. The collection of firewood was found to be the most important impact. Other impacts include footpaths, the collecting of medicinal bark or muti, solid waste pollution and soil erosion. It was also found that the extent of impact is a function of distance away from settlements.