Conservation priorities for Prunus africana defined with the aid of spatial analysis of genetic data and climatic variables

Conservation priorities for Prunus africana, a tree species found across Afromontane regions, which is of great commercial interest internationally and of local value for rural communities, were defined with the aid of spatial analyses applied to a set of georeferenced molecular marker data (chloroplast and nuclear microsatellites) from 32 populations in 9 African countries. Two approaches for the selection of priority populations for conservation were used differing in the way they optimize representation of intra-specific diversity of P. africana across a minimum number of populations. The first method (Si) was aimed at maximizing genetic diversity of the conservation units and their distinctiveness with regard to climatic conditions, the second method (S2) at optimizing representativeness of the genetic diversity found throughout the species' range. Populations in East African countries (especially Kenya and Tanzania) were found to be of great conservation value, as suggested by previous findings. These populations are complemented by those in Madagascar and Cameroon. The combination of the two methods for prioritization led to the identification of a set of 6 priority populations. The potential distribution of P. africana was then modeled based on a dataset of 1,500 georeferenced observations. This enabled an assessment of whether the priority populations identified are exposed to threats from agricultural expansion and climate change, and whether they are located within the boundaries of protected areas. The range of the species has been affected by past climate change and the modeled distribution of P. africana indicates that the species is likely to be negatively affected in future, with an expected decrease in distribution by 2050. Based on these insights, further research at the regional and national scale is recommended, in order to strengthen P. africana conservation efforts

Multiple Events of Allopolyploidy in the Evolution of the Racemose Lineages in Prunus (Rosaceae) Based on Integrated Evidence from Nuclear and Plastid Data.

Prunus is an economically important genus well-known for cherries, plums, almonds, and peaches. The genus can be divided into three major groups based on inflorescence structure and ploidy levels: (1) the diploid solitary-flower group (subg. Prunus, Amygdalus and Emplectocladus); (2) the diploid corymbose group (subg. Cerasus); and (3) the polyploid racemose group (subg. Padus, subg. Laurocerasus, and the Maddenia group). The plastid phylogeny suggests three major clades within Prunus: Prunus-Amygdalus-Emplectocladus, Cerasus, and Laurocerasus-Padus-Maddenia, while nuclear ITS trees resolve Laurocerasus-Padus-Maddenia as a paraphyletic group. In this study, we employed sequences of the nuclear loci At103, ITS and s6pdh to explore the origins and evolution of the racemose group. Two copies of the At103 gene were identified in Prunus. One copy is found in Prunus species with solitary and corymbose inflorescences as well as those with racemose inflorescences, while the second copy (II) is present only in taxa with racemose inflorescences. The copy I sequences suggest that all racemose species form a paraphyletic group composed of four clades, each of which is definable by morphology and geography. The tree from the combined At103 and ITS sequences and the tree based on the single gene s6pdh had similar general topologies to the tree based on the copy I sequences of At103, with the combined At103-ITS tree showing stronger support in most clades. The nuclear At103, ITS and s6pdh data in conjunction with the plastid data are consistent with the hypothesis that multiple independent allopolyploidy events contributed to the origins of the racemose group. A widespread species or lineage may have served as the maternal parent for multiple hybridizations involving several paternal lineages. This hypothesis of the complex evolutionary history of the racemose group in Prunus reflects a major step forward in our understanding of diversification of the genus and has important implications for the interpretation of its phylogeny, evolution, and classification

Perspectives for sustainable Prunus africana production and trade

This brief documents current knowledge about pygeum (Prunus africana). It aims to inform decision makers in governments in producing and consumer countries, international and civil society organisations and researchers, about sustainable (international) trade and governance of the species

Ensuring the future of the pygeum tree (Prunus africana)

This report is aimed at trainers and support organisations for farmers and tree owners, as well as commercial tree nursery operators, government extension agencies and NGOs, among others, who are interested in cultivating the pygeum tree

Indigenous Knowledge, Uses and Conservation of Prunus africana (Hook. F.) Kalkman in Nandi Forests

Prunus africana is a multipurpose medicinal tree of worldwide fame in treatment of benign prostate cancer. However, the wild collection is no-longer sustainable due to overharvesting. In order to conserve the species, there is need to determine the status of the local community knowledge on uses and conservation measures to develop protocols for sustainable utilization and avert extinction of the species. Stratified random sampling was used to interview and administer questionnaires to 188 households and herbalists within a buffer zone of 1 km in South Nandi Forest. The study found that 99% of the locals were aware of the P. africana tree. Majority (82%) agreed that P. africana population was decreasing both in the forests and farmlands. Almost all parts of the P. africana were utilized for different purposes. Majority of the locals (66%) acquire P. africana products from the forest. Closer proximity to the forest and uncontrolled harvesting provides easier accessibility to P. africana for households use. The study concluded that P. africana is an important multipurpose medicinal tree to the local community and recommends enhanced planting and protection within and outside the forests to ensure posterity. Keywords: Multipurpose, medicinal, sustainable, local community, use

Mass of Prunus africana stem barks on Tchabal mbabo and Tchabal Gang Daba Mountain Forests, Cameroon

Prunus africana is a species of the Rosaceae family, known under its common name as pygeum or African cherry. The bark is the major source of an extract used to treat benign prostatic hyperplasia, an increasingly common health problem in older men in the western world. A study which aimed to produce a formula for establishing the mass of the bark of Prunus africana specimens was carried out in May 2011 on Tchabal Mbabo and Tchabal Gang Daba mountain forests, in the Adamaoua region of Cameroon. The diameter at breast height (DBH), the height of the tree and the thickness of the stem bark of each pygeum tree were recorded in order to establish the cubic volume of each specimen. This data was used to calculate the relationship between the diameter and the volume of the bark. Samples of bark were collected in order to establish the relationship between the volume of the bark and its mass (measure mass per cubic metre). A total of 105 pygeum trees were sampled, including 50 trees in Gang Daba considered as an un-exploited production site and 55 trees in Mbabo referred to an exploited production site. The best equation which links the volume (Vb) of fresh barks to the diameter (D) of each pygeum tree is Vb=a/(1+b*exp(-cD)) with a = 1.79588278896E-001, b =  5.29124992540E+002, c = 1.45488065368E-001. The average thickness of the bark is 13.01 ± 4.8 mm. This value is comprised between that of unexploited (16.99 ± 3.7 mm) and exploited (9.40 ± 2.07 mm) pygeum trees. Considering that for all trees above 30 cm DBH, only two quarters of the bark are taken from the main stem up to the first branch, the average sustainable mass of pygeum tree in Adamaoua region will be about 69.3 kg of fresh bark per tree. This value is comprised between that of unexploited (80 kg) and exploited (60 kg) pygeum trees in Ganga Daba and Mbabo respectively.Key words: Threatened species, Prunus africana, pygeum, Tchabal  mountain forests, Bitterlich’s Relascope, cubic tariff, CITES

Evaluation of the Therapeutic Potential of Warburgia ugandensis, Prunus africana, and Piliostigma thonningii against Leishmania donovani in vitro and in Balb/c Mice

Leishmaniasis is a zoonotic disease caused by protozoan parasites of the genus Leishmania. Conventional chemotherapy remains to be the most preferred measure against leishmaniasis despite being associated with high toxicity and relapse rates. They are also expensive and require hospitalization. Plant-based compounds provide a better treatment alternative because they are effective, cheap, and less associated with toxicity and resistance. This study examined the therapeutic potential of Warburgia ugandensis, Prunus africana, and Piliostigma thonningii against Leishmania donovani infection in BALB/c mice. Anti-promastigote and toxicity studies were evaluated by incubating the test compound with promastigotes and Vero cells, respectively. Serum was obtained from the mice for total immunoglobulin gamma (IgG) quantification. For in vivo studies, the mice were infected with virulent Leishmania donovani then treated with methanolic extracts of Warburgia ugandensis, Prunus africana, and Piliostigma thonningii and control drug, pentostam (sodium stibogluconate). Treatment with the plant extracts and standard drug resulted to significant reduction in parasite burden. Outcomes in the mice treated with plant extracts were comparable to those treated with pentostam (P≥0.05). In the promastigote assay, all the test compounds killed more than half of the promastigotes at the highest concentration (500 µg/mL). Warburgia ugandensis, P. thonningii, and P. africana reduced the number of promastigotes from 2.0 × 106 to 7.7 × 103 , 72.0 × 103 , and 5.0 × 103 , respectively. Pentostam had the lowest IC50 (210 µg/mL), followed by Warburgia ugandensis (IC50 of 270 µg/mL). Piliostigma thonningii and P. africana were less toxic with IC50 of 720 µg/mL and 500 µg/mL, respectively. There was low production of IgG antibodies following treatment with the plant extracts and high levels in the untreated control