Pterocarpus Angolensis DC Research Articles

Phytochemicals from Pterocarpus angolensis DC and Their Cytotoxic Activities against Breast Cancer Cells.

Pterocarpus anglonesis DC is an indigenous medicinal plant belonging to the Pterocarpus genus of the Fabaceae family. It is used to treat stomach problems, headaches, mouth ulcers, malaria, blackwater fever, gonorrhea, ringworm, diarrhea, heavy menstruation, and breast milk stimulation. Column chromatography of the stem bark extracts resulted in the isolation of eight compounds, which included friedelan-3-one (1), 3α-hydroxyfriedel-2-one (2), 3-hydroxyfriedel-3-en-2-one (3), lup-20(29)-en-3-ol (4), Stigmasta-5-22-dien-3-ol (5), 4-O-methylangolensis (6), (3β)-3-acetoxyolean-12-en-28-oic acid (7), and tetradecyl (E)-ferulate (8). The structures were established based on NMR, IR, and MS spectroscopic analyses. Triple-negative breast cancer (HCC70), hormone receptor-positive breast cancer (MCF-7), and non-cancerous mammary epithelial cell lines (MCF-12A) were used to test the compounds' cytotoxicity. Overall, the compounds showed either no toxicity or very low toxicity to all three cell lines tested, except for the moderate toxicity displayed by lupeol (4) towards the non-cancerous MCF-12A cells, with an IC50 value of 36.60 μM. Compound (3β)-3-acetoxyolean-12-en-28-oic acid (7) was more toxic towards hormone-responsive (MCF-7) breast cancer cells than either triple-negative breast cancer (HCC70) or non-cancerous breast epithelial (MCF-12A) cells (IC50 values of 83.06 vs. 146.80 and 143.00 μM, respectively).

A Review of Ethnoveterinary Knowledge, Biological Activities and Secondary Metabolites of Medicinal Woody Plants Used for Managing Animal Health in South Africa.

Globally, the use of ethnoveterinary medicine as remedies for animal health among different ethnic groups justify the need for a systematic exploration to enhance their potential. In addition, the increasing popularity and utilisation of woody plants remain common in traditional medicine, which may be attributed to their inherent benefits. The current review was aimed at analysing ethnoveterinary surveys, biological activities, and secondary metabolites/phytochemical profiles of the woody plants of South Africa. Eligible literature (period: 2000 to 2020) were retrieved from different databases such as Google Scholar, PubMed, Sabinet, and Science Direct. Based on the inclusion and exclusion criteria, 20 ethnoveterinary surveys were eligible and were subjected to further analysis. We identified 104 woody plant species from 44 plant families that are used in the treatment of different diseases in animals, particularly cattle (70%) and goats (20%). The most mentioned (with six citations) woody plants were Terminalia sericea Burch. ex DC and Ziziphus mucronata Willd., which were followed by plants with five (Cussonia spicata Thunb., Pterocarpus angolensis DC and Vachellia karroo (Hayne) Banfi & Galasso) or four (Acokanthera oppositifolia (Lam.) Codd, Cassia abbreviata Oliv., and Strychnos henningsii Gilg) individual mentions. The most dominant families were Fabaceae (19%), Apocynaceae (5.8%), Rubiaceae (5.8%), Anacardiaceae (4.8%), Combretaceae (4.8%), Euphorbiaceae (4.8%), Malvaceae (4.8%), Rhamnaceae (4.8%), and Celastraceae (3.8%). Bark (33%), leaves (29%), and roots (19%) were the plant parts dominantly used to prepare remedies for ethnoveterinary medicine. An estimated 20% of woody plants have been screened for antimicrobial, anthelmintic, antioxidant, and cytotoxicity effects. Phytochemical profiles established a rich pool of valuable secondary metabolites (phenolic, flavonoids and condensed tannins) that may be responsible for the exerted biological activities. Overall, the significant portion of woody plants lacking empirical evidence on their biological effects indicates a major knowledge gap that requires more research efforts.

CROWN MORPHOMETRY FOR TWO VALUABLE TIMBER SPECIES FROM MIOMBO WOODLAND IN MOZAMBIQUE

Pterocarpus angolensis DC and Bobgunnia madagascariensis (Desv.) J. H. Kirkbr. & Wiersema are two hardwood species found in Miombo woodland. Crown size, being closely related to the photosynthetic capacity of a tree, is an important parameter in studies of the growth of individual trees. In this sense, the present study aimed to study the morphometric relationships of P. angolensis and B. madagascariensis as a resource to describe the morphometric features of these species. Data were sampled in 60 rectangular plots of 20 x 50 m, systematically distributed within the forest. In each plot, the diameter at breast height (DBH), height (h), crown insertion point (cih) and four crown radii of all trees with DBH ≥ 10 cm were measured. Results indicated that crown diameter and crown length of P. angolensis grow as DBH and height increase, the larger the crown, the greater the trees dimensions; as for B. madagascariensis, crown features have shown low correlation when considering DBH. It was concluded that crown features influence on tree growth and are important measures of description and planning of silvicultural activities to be performed in natural forests. The results are of interest to forest managers since they make decisions about silvicultural operations. Keywords: crown dimensions; prediction models; umbila; pau-ferro; forest management.

IN VITRO EFFICACY OF EXTRACTS FROM PLANTS USED BY SMALL-HOLDER FARMERS IN THE TREATMENT OF DERMATOPHILOSIS IN CATTLE.

Background:Bovine dermatophilosis, an important skin disease of cattle caused by Dermatophilus congolensis, negatively impacts the livelihoods of small-holder farmers in Zimbabwe. This impact is through, morbidity, loss of draught animal power, costs incurred to manage the disease, losses associated with devalued damaged hides and the resultant culling of some of the affected cattle. Due to the inaccessibility of conventional drugs to manage bovine dermatophilosis, farmers have been reported to use local medicinal plants to manage the disease. The aim of the study was to evaluate the in vitro antimicrobial activities of three plants that small-holder farmers in Zimbabwe used to manage bovine dermatophilosis.Methods:Dried plant materials were ground into powder and extracted individually using, water, 80 % acetone and 80 % methanol. The antimicrobial properties of the plants were evaluated against two Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and one Gram-positive (Staphylococcus aureus) reference bacterial strains. They were further evaluated against a field isolate of Dermatophilus congolensis. The assays used were the disc diffusion, minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC).Results:Acetone and methanol extracts had superior inhibitory activities than did those of water. Pterocarpus angolensis DC extracts had better inhibitory properties with absolute MIC values of 0.156 – 5 mg/ml, Cissus Quadrangularis L had MIC values in the range 0.156 – 5 mg/ml while that of Catunaregam spinosa Thunb, Terveng was 0.156 – 10 mg/ml. Dermatophilus congolensis was more sensitive to Pterocarpus angolensis DC average MIC = 0.63 mg/ml than to Cissus quadrangularis L average MIC = 1.25 mg/ml and Catunaregam. spinosa Thunb, Terveng average MIC = 2.08 mg/ml.Conclusion:These results suggest the potential antibacterial activities of extracts of the three plants and hence farmers are, in a way, justified in using the plants. Better results (lower MIC) could be obtained by extracting and evaluating pure active compounds of the plants.

Log sawing positioning optimization and log bucking of tropical hardwood species to increase the volume yield

ABSTRACTThe sawmill industry is a very important link in the Mozambique forest products value chain, but the industry is characterized by undeveloped processing technology and high-volume export of almost unrefined logs. The low volume yield of sawn timber has been identified as a critical gap in the technological development of the industry. To improve the profitability of the industry, there is thus a need to develop methods and techniques that improve the yield. In this paper, different positioning of logs prior to sawing and the possibility of increasing the volume yield of crooked logs by bucking the logs before sawing have been studied. A computer simulation was used to study the cant-sawing and through-and-through sawing of the logs to determine the volume yield of sawn timber from the jambirre (Millettia stuhlmannii Taub.) and umbila (Pterocarpus angolensis DC.) species. The optimal position, i.e. the position of the log before sawing that gives the highest volume yield of sawn timber for a given sawing pattern when the positioning parameters, offset, skew and rotation, are considered gave a considerable higher volume yield than the horns-down position. By bucking very crooked logs and using the horns-down positioning before sawing, the volume yield can be of the same magnitude as that obtained by optimal positioning on full-length (un-bucked) logs. The bucking reduces the crook of the logs and hence increases the volume yield of sawn timber.

The Effect of Log Position Accuracy on the Volume Yield in Sawmilling of Tropical Hardwood

This study investigated the effect of the positioning of the log before sawing on the volume yield of sawn timber from tropical hardwood species. Three positioning parameters were studied, the offset, skew, and rotation, combined with two sawing patterns of cant-sawing and through-and-through sawing. A database consisting of two tropical hardwood species with very different outer shapes, jambirre (Millettia stuhllmannii Taub.) and umbila (Pterocarpus angolensis DC.), was used to simulate the sawing process. The result of the simulation revealed that, according to the combined effect of offset, skew, and rotation positioning, the positioning of the log before sawing is extremely important to achieve a high volume yield of sawn timber. The positioning parameter that has the highest effect on the volume yield is the rotation, and the variation in the volume yield associated with a deviation in the positioning can reduce the volume yield of sawn timber by between 7.7% and 12.5%.

Annual diameter growth of Pterocarpus angolensis (Kiaat) and other woodland species in Namibia

Pterocarpus angolensis DC. (Kiaat) is one of the most preferred timber species that occurs in most southern African countries, including Namibia. In Namibia, the species mainly occurs across the five regions in the north-eastern part of the country where commercial timber harvesting has taken place since the 1940s. Information about the growth rates of the species is currently lacking, yet this information is required to determine a sustainable harvesting regime in Namibia. Therefore, more data about diameter increment is needed. This study aims to (1) determine annual diameter increment of P. angolensis in order to assist in planning for sustainable harvesting levels in the northern regions of Namibia, (2) compare growth of P. angolensis with other woodland species (Burkea africana, Baikiaea plurijuga, Terminalia sericea and Schinziophyton rautanenii) and (3) compare P. angolensis growth rates found in northern Namibia with those found in other countries within its distribution range. A total of 111 increment cores and 73 stem discs were collected for tree-ring analysis. The results showed that the average diameter increment of P. angolensis was higher in the Kavango regions (0.71–0.80cmyr−1) than in neighbouring regions (0.35–0.41cmyr−1). The northern Namibian growth rate is estimated as 0.50cmyr−1 and lies within the growth range reported for southern Africa. Growth rates of P. angolensis were more than 0.10cmyr−1 lower than rates of T. sericea and S. rautanenii, but 0.10cmyr−1 higher than B. africana and B. plurijuga. Age–diameter relationships of P. angolensis may be a good indicator of tree age if a sufficient number of samples are obtained. Our results revealed a rotation cycle of 95–100years to reach the minimum harvesting diameter of 45cm in the Kavango regions. This rotation cycle should be a good guideline for sustainable management of this species. This study suggests that simple ring counting on increment cores and stem discs with additional diameter data can provide valuable information on growth rates and rotation cycles. Additional data and work on older trees (>100years) is required to complete the age–diameter framework.

The Characterization of Wood Species from Mozambique as a Fuel

The efficient utilization of fuelwood as a source of energy is strongly dependent on the properties of the biomass. This study characterizes common hardwood species from Mozambique and evaluates their quality as a fuel. Disc samples, taken at breast height, from Afzelia quanzensis Welwn, Millettia stuhlmannii Taub, Pterocarpus angolensis DC, Sterculia appendiculata K. Schum, Pericopsis angolensis Meeuwen, Acacia nigrescens Oliv., Pseudolachostylis maprounaefolia Pax, and Icuria dunensis Wieringa, were collected from three provinces in Mozambique. Chemical and physical properties were analyzed. The raking of the species as fuel was performed using fuelwood value index. The higher heating value varied between 19.38 and 21.50 MJ/kg dry weight. The concentration of lignin ranged from 21.96 up to 36.69% weight dry basis (wt% d.b.), and ash free. All studied species showed very low concentrations of Si, S, and Cl. Ash content varied between 0.76–3.71 wt% (d.b.), while the basic density ranged from 536 to 1,111 k gm−3. Heavy metals were also determined and their concentrations were below the values reported in the literature. The species Acacia nigrescens had the highest fuelwood value index and it was closely followed by Icuria dunensis and Millettia stuhlmannii. The worst ranked was Sterculia appendiculata.

Potential, realised, future distribution and environmental suitability for Pterocarpus angolensis DC in southern Africa

The deciduous tree species Pterocarpus angolensis occurs in the dry woodlands of southern Africa and grows under a broad range of environmental conditions. It is threatened by overharvesting due to its valuable timber (Blood wood, Kiaat) and by land use changes. Information on the most suitable environmental conditions for the species is often old and anecdotal, while available data on its occurrence refer to range extent and not to distribution. Species distribution models (SDM) could provide more accurate information on distribution and environmental requirements and thereby assist sustainable management of this tree species.Maxent models were developed to estimate the potential, realised and future distribution of P. angolensis and to identify detailed environmental requirements. Occurrences data of the species were sourced from herbaria and other published sources; environmental data from global GIS databases. Relevant environmental predictors were selected through a jack-knife test of the first model runs. The addition of information on competing species, fires and deforestation was tested to determine realised distribution. Model quality was evaluated with an independent presence-absence dataset. The model was projected with two different climate change scenarios to study their effect on the distribution by 2080.Results show that a potential distribution map can be obtained with good discrimination of the presence of the species (AUC 0.83) and fairly good calibration (correlation coefficient 0.61). Range extent and environmental requirements are more detailed than those described in literature. The distribution of the species is mainly influenced by the amount of summer rainfall, by the minimum temperature in winter and by temperature seasonality. Potential and realised distributions are very similar, with Madagascar as major exception where the species can grow but does not occur. Adding the fire history of the last 13years or the distribution maps of potentially competing species as predictor variables did not improve the distribution model. It did illustrate that P. angolensis is mainly found in areas with annual fire frequency below 45% and that only a few of the tested species show signs of competition. Using a forest cover map improved the realised distribution slightly (Kappa coefficient 0.64). Climate change can decrease the species range considerably, especially in the west, threatening species existence in Namibia and Botswana. On the other hand, the species’ occurrence is predicted to increase in Zambia.

Chemical composition of traditionally and lesser used wood species from Mozambique

The main objective of this study was to determine the chemical composition of some lesser used Mozambican native wood species, such as Acacia nigrescens Oliv., Icuria dunensis Wieringa, Pseudolachnostylis maprounaefolia Pax and Sterculia appendiculata K. Schum. Another aim was to compare these species with traditionally used species, namely, Afzelia quanzensis Welwn, Milletia stuhlmannii Taub, Pericopsis angolensis Meeuwen and Pterocarpus angolensis DC. Wood samples for analysis were taken from sapwood, outer and inner heartwood. All chemical analyses were performed according to standard methods. The contents of carbohydrates, extractives and ash were in ranges considered normal for tropical species. The contents of lignin and minerals were unexpectedly high in Pseudolachnostylis (ntholo), reaching 37.51% and 2.2% (wt% extractive-free) on a dry basis, respectively. Based on the determined chemical features, it was concluded that Acacia and Pseudolachnostylis were similar to well-known species, whereas Icuria and Sterculia differed from the known species.

Climatic signals in tree rings of Burkea africana and Pterocarpus angolensis from semiarid forests in Namibia

Tree-ring studies contribute worldwide to the understanding of climate and its relation to tree growth. Long tree-ring chronologies serve as climate proxies for the reconstruction of past, pre-instrument climate and its recent change. In tropical regions, the availability of exactly dated tree-ring chronologies is limited. The dendroclimatic potential of two dominant species from dry forests in northern Namibia was examined in the study presented in this paper. Both species (Burkea africana Hook and Pterocarpus angolensis DC) were sampled at two sites (ca. 900 km apart), and the response to several climatic variables, including ENSO indices, is studied. All specimens showed distinct growth rings and cross-dating between radii was successful for all trees. Species-specific mean curves were built for both sites. The mean curves of different species of the same site synchronised significantly, allowing the construction of a site-specific chronology. Synchronisation between sites was not possible, but spectral analysis of the chronologies implied that both show similar long-term (6.7 year) oscillation patterns. B. africana is more sensitive to rainfall variation than P. angolensis at both sites. Growth response to rainfall was positive, but a time-lag in the reaction occurred between the sites, corresponding to the time-lag of the beginning of the rainy season. Air temperature showed a negative correlation with stem increment at both sites. The response at the westernmost site to two ENSO indices indicates a tree growth decrease during El Nino years, which are generally dry in southern Africa.

Effect of selective logging on tree and understory regeneration in miombo woodland in western Tanzania

AbstractTree regeneration and understory response to selective cutting of Pterocarpus angolensis DC, and Sterculia quinqueloba Sim, was measured outside Katavi National Park, Tanzania. Contrary to expectations, a selective harvest had no effect on tree recruitment for either species in this miombo woodland. In unlogged plots along transects taken at increasing distance from a main road, the stand densities of young trees declined away from the road. Since anthropogenic activity along the road results in a high fire frequency but low native ungulate densities, the increased rate of tree regeneration near the road may result from either reduced grazing and browsing pressure by native ungulates, or reduced fire intensity and severity along roads. These effects appear to mask any possible effect of selective harvest on tree recruitment. Currently, there is no evidence of compensatory recruitment of trees of any species into the canopy to replace logged trees and this will lead to a gradual thinning in overstory stand density.

PERCEPTIONS ABOUT MALARIA TRANSMISSION AND CONTROL USING ANTI-MALARIA PLANTS IN MOLA, KARIBA, ZIMBABWE

An ethnobotanical survey was conducted in Mola, Kariba district, in order to collect information on some common herbal remedies used by traditional healers and rural folk in the treatment and prevention of malaria. Structured questionnaires were administered to 220 respondents in Mola, Kariba. Two hundred and twenty questionnaires were administered to respondents who were between the ages of 14 andd 80 years. There were 88 (40%) males and 132 (60%) females with mean ages of 41.0682+17.4572 and 41.5000 + 18.7028 for males and females respectively. A total of 192 (87.3%) of the respondents mentioned mosquitoes as transmitting malaria, one (0.3%) mentioned dirty water and 27 (12.4%) did not know. Fifty-four (24.5%) respondents did not know signs and symptoms of malaria. High body temperature, headache and shivering (23.2%) were major signs used in diagnosing malaria. A total of 155 (70.5%) respondents would go to the clinic if they suspect that they have malaria and 36 (16.4%) will visit a Traditional Healer. The following plants were mentioned as being used as anti—malarials: Carica papaya L. (Caricaceae), Zea mays L. (Sapindaceae), Amblygonocarpus andongenis (Olvi.) Exell and Torre (Leguminosae), Zanha africana (Radlk.) Exell (Sapindaceae), Solanum incanum L. (Solananceae), Solanum indicum L. (Solanaceae), Solanum panduriforme E. May (Solanaceae), Diplorhynchus condylocarpon (Muell. Arg.) Pick. (Apocynaceae), Harungana madagascariensis Poir (Guittiferae), Pterocarpus angolensis DC (Leguminosae), Euclea divinorum Hiern (Ebenaceae), Sclerocarya caffra Sond (Anacardiaceae), Terminalia sericea DC (Combretaceae), Aloe chabaudii Schonl. (Liliaceae), Aloe excelsa Berg. (Liliaceae), Aloe greatheardii Schoni (Liliaceae), Colophospermum mopane (Benth.) J. Leonard (Leguminosae) and Garcinia huillensis Oliv. (Guttiferae). In clonclusion, several plants used as anti-malarials were identified and their acivity will be determined. Key Words: Malaria, Zimbabwe, Antimalarial plants Nig. J. Nat Prod. And Med. Vol.5 2001: 4-7

Germination of Pterocarpus angolensis DC. and evaluation of the possible antimicrobial action of the phloem sap

The Transvaal teak (Pterocarpus angolensis) is being over utilised in its natural habitat, although it is a protected tree in South Africa, Swaziland and Namibia. The phloem sap of this species has several traditional, medicinal uses and the wood is used primarily for furniture and fuelwood. The aim of this study was firstly, to determine which seed pre-treatments would ensure optimal germination and secondly, to evaluate the potential antimicrobial activity of the phloem sap. The initial germination trial was conducted by using unsterilised seeds in the dark, which resulted in low germination rates (7.78%) and high percentages of fungal infections (45.56%), primarily Aspergillus niger and a Fusarium sp. In the second experiment the seeds were sterilised with a mixture of 60 g Thiram and 70 g Captan and germinated in an alternating light/dark environment. In both experiments the seeds were subjected to either a hormonal, heat or control pre-treatment and were allowed to germinate at three different temperature regimes. Different sap concentrations were tested for antimicrobial activity against both gram positive (Staphylococcus aureus) and gram negative (Escherichia coli; Pseudomonas aeruginosa) procaryotes as well as two eucaryotes (Candida albicans; Aspergillus niger), with negative results. The phloem sap was analysed by means of GC-MS and a few compounds, which have been identified, are reported.

The population dynamics and life-history attributes of a Pterocarpus angolensis DC. population in the Northern Province, South Africa

This article examines the population dynamics and life-history attributes of a single P. angolensis population in the Northern Province, South Africa. An introduction to the use of matrix models in population biology is presented. A frequency distribution of diameters reveals a bimodal distribution of stems. Yearly diameter growth increases with age. It is, therefore, concluded that this bimodal size distribution is indicative of discrete recruitment events of permanent stems and not of an unstable population. Established trees and seedlings (suffrutices) can persist in the landscape by means of coppicing. A matrix model, combined with an elasticity analysis of the derived transition matrix is used to isolate key life-history stages. Life-history stages lying along the diagonal of the matrix have the highest elasticity values, emphasizing the importance of stem survivorship, as opposed to growth or fecundity, in the survival of this tree. Long-term survival greater than the life-span of a stem depends on seedling recruitment events. The model is also used to predict the outcome of two harvesting strategies on the future of the population. Some suggestions for management and priorities for future research are presented.

The Doctrine of Signatures or Similitudes: A Comparison of the Efficacy of Praziquantel and Traditional Herbal Remedies Used for the Treatment of Urinary Schistosomiasis in Zimbabwe

AbstractThe Doctrine of Signatures or Similitudes simply states that “like cures like” and each medicinal product from nature indicates by an obvious and well-marked character the disease for which it is a remedy or the object for which it can be employed. The Doctrine exerted influence in Europe until late in the 17th century and still does so in most parts of Africa including Zimbabwe. Medicinal plants found, from interviewing traditional healers, to be commonly used for the treatment of Schistosoma haematobium, most of which produce either red seeds, red sap or red extract, were collected and investigated for their anti-schistosoma activities. The plant materials were prepared according to the guidelines of the traditional healers and their efficacy was determined by administering the crude extracts to laboratory animals infected with S. haematobium. The results suggested that plant extracts from Abrus precatorius L., Pterocarpus angolensis DC. and Ozoroa insignis Del. complied with the apparent signat...

A New Vascular Wilt Disease and its Relationship to Widespread Decline of Pterocarpus angolensis in Zambia

Abstract A serious decline of mukwa (Pterocarpus angolensis DC.), a timber tree of considerable economic importance, has caused concern in parts of southern Africa for many years. Dieback and deaths have variously been investigated in the past and attributed to a succession of drought years. A new and discrete vascular wilt disease, characterised by a combination of distinctive crown symptoms with streaks of vascular discolouration in the youngest sapwood, is described from Zambia. Fusarium oxysporum Schlect is provisionally regarded as the causal organism. The widespread decline phenomenon is interpreted in the light of this disease which is named mukwa wilt and now dominates the pathology of mukwa, and is the most important disease of an indigenous tree species in Zambia.